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Ira A. Fulton College of Engineering
Electrical and Computer Engineering
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Karl Warnick Picture

Karl Warnick

Professor
Curriculum Vitae
Faculty
Website: http://ras.groups.et.byu.net
Email: warnick@byu.edu

Office: 450H EB
Provo, Utah 84602

Phone: 422-1732

Karl F. Warnick received the B.S. degree in Electrical Engineering and Mathematics and the Ph.D. degree in Electrical Engineering from Brigham Young University (BYU), Provo, UT, in 1994 and 1997, respectively. From 1998 to 2000, he was a Postdoctoral Research Associate and Visiting Assistant Professor in the Center for Computational Electromagnetics at the University of Illinois at Urbana-Champaign. Since 2000, he has been a faculty member in the Department of Electrical and Computer Engineering at BYU, where he is currently a Professor. He is a Fellow of the IEEE and a recipient of a National Science Foundation Graduate Research Fellowship, Outstanding Faculty Member Award for Electrical and Computer Engineering, the BYU Young Scholar Award, the Ira A. Fulton College of Engineering and Technology Excellence in Scholarship Award, and the BYU Karl G. Maeser Research and Creative Arts Award. Dr. Warnick has published many books, scientific articles and conference papers on electromagnetic theory, numerical methods, antenna applications, and high sensitivity phased arrays for satellite communications and radio astronomy. For more information on Dr. Warnick's research please visit his smart antenna system and radio astronomy systems pages.

Publications

  • K. T. Selvan and K. F. Warnick, “Engineering program accreditation: where have we been and where should we go?”, TechRxiv preprint, https://doi.org/10.36227/techrxiv.19219857.v1, 2022.
  • K. F. Warnick, M. Burnett, and D. Buck, “Experimental measurement of noise figure and radiation efficiency with the antenna Y factor method at X band,” IEEE Transactions on Antennas and Propagation, in review, 2022
  • K. F. Warnick, “Noise figure of an active antenna array and receiver system” IEEE Antennas and Wireless Propagation Letters, in press, DOI: 10.1109/LAWP.2022.3175146, 2022.
  • J. Kunzler* and K. F. Warnick, “Wideband radio frequency interference cancellation for high-sensitivity phased array receivers with true time delays and truncated Hadamard projection,” IEEE Transactions on Antennas and Propagation, in press, pp. 1-8, 2022.
  • A. Vishwas, D. Campbell, B. D. Jeffs, K. F. Warnick, et al., “ALPACA: a fully cryogenic L-band phased array feed for radio astronomy,” SPIE, in review, 2022.
  • M. Burnett, N. Ashcraft, S. Ammermon, B. Jeffs, K. F. Warnick, “Low noise L-band RF-over-fiber signal transport for ALPACA on the GBT,” URSI National Radio Science Meeting, Boulder, CO, Jan. 4-8, 2022.
  • J. Kunzler, K. F. Warnick, J. Bartschi, S. Ammermon, M. Burnett, “Bench testing a system on chip adaptive beamformer for GPS,” URSI National Radio Science Meeting, Boulder, CO, Jan. 4-8, 2022.
  • M. Ruzindana, M. Burnett, J. Kunzler, D. Marsh, K. Lyman, K. Evans, A. Whipple, K. F. Warnick, B. Jeffs, “Real-time signal processing with FPGAs and GPUs for wideband interference-resilient communications,” IEEE International Symposium on Antennas and Propagation and URSI Radio Science Meeting, Singapore, Dec. 4-10, 2021.
  • J. Kunzler, K. F. Warnick, M. Chahardori, D. Heo, “Wideband RFI cancellation using true time delays and a Hadamard projection operator,” IEEE International Symposium on Antennas and Propagation and URSI Radio Science Meeting, Singapore, Dec. 4-10, 2021.
  • K. F. Warnick, M. Burnett, J. Kunzler, A. Vishwas, D. Campbell, B. D. Jeffs, “Performance of the ALPACA L band Phased Array Feed on the Green Bank Telescope”, IEEE International Symposium on Antennas and Propagation and URSI Radio Science Meeting, Singapore, Dec. 4-10, 2021.
  • A. Sheldon, L. Belostotski, H. Mani, Hamdi, C. Groppi, and K. F. Warnick, “Automated noise-parameter measurements of cryogenic LNAs,” 2021 97th ARFTG Microwave Measurement Conference.
  • E. Nygaard, N. Ashcraft, M. Burnett, B. D. Jeffs and K. F. Warnick, “Signal transport and digital signal processing for the ALPACA L band array feed,” European Conference on Antennas and Propagation (EuCAP), 2021, doi: 10.23919/EuCAP51087.2021.9411112.
  • K. F. Warnick, D. B. Davidson, and D. Buck*, “Embedded element pattern loading condition transformations for phased array modeling,” IEEE Transactions on Antennas and Propagation, DOI: 10.1109/TAP.2020.3027593, Vol. 69, No. 3, pp. 1769-1774, Mar. 2021.
  • A. Sheldon, L. Belostotski, H. Mani, C. Groppi, and K. F. Warnick, “Cryogenic noise-parameter measurements: recent research and a fully automated measurement application,” IEEE Microwave Magazine, Vol. 22, No. 8, pp. 52-64, Aug. 2021.
  • M. Eyler, C. Peterson, T. McLain, and K. F. Warnick, “Decentralized UAV tracking with networked radar systems,” AIAA SciTech Forum, DOI: 10.2514/6.2021-1160, Jan. 2021.
  • N. M. Pingel, D. J. Pisano, M. Ruzindana*, M. Burnett*, K. M. Rajwade, R. Black*, B. Jeffs, K. F. Warnick, D. R. Lorimer, A. Roshi, R. Prestage, M. A. McLaughlin, D. Agarwal, T. Chamberlin, L.
  • Hawkins, L. Jensen, P. Marganian, J. D. Nelson, W. Shillue, E. Smith, B. Simon, V. van Tonder, and S. White, “The commissioning of the HI observing mode of the beamformer for the cryogenically cooled focal L-band array for the GBT (FLAG),” Astronomical Journal, Vol. 161, No. 4, 24 pages, 2021.
  • K. T. Selvan and K. F. Warnick, Teaching Electromagnetics: Innovative Approaches and Pedagogical Strategies, CRC Press, 258 pages, 2021.
  • K. F. Warnick, “Mutual Coupling and Multiple Input Multiple Output (MIMO) Communications,” in T. S. Bird, ed., Mutual Coupling Between Antennas, Wiley, 2021.
  • K. F. Warnick, “Network theory of antenna arrays,” Encyclopedia of Electrical and Electronics Engineering, Wiley, 2021.
  • K. F. Warnick, Numerical Methods for Engineering with MATLAB and Computational Electromagnetics Examples Second Edition, IET Press, 2020.
  • J. Kunzler and K. F. Warnick, “Progress towards airborne GPS spatial filtering powered by recent advances in FPGA technology,” Intermountain Engineering, Technology, and Computing Conference (i-ETC), Orem, Utah, Sep. 2-3, 2020.
  • K. F. Warnick and D. Davidson, “Fast modeling, loading transformations, and impedances from embedded element patterns for mutually coupled antenna arrays,” IEEE International Symposium on Antennas and Propagation, Montreal, Canada, Jul. 5-10, 2020.
  • C. Burnett, J. Kunzler, E. Nygaard, B. D. Jeffs, K. F. Warnick, D. Campbell, G. Cortes-Medellin, S. Parshley, A. Vishwas, P. Perrilat, and D. A. Roshi, “Design and development of a wide-field fully cryogenic phased array feed for Arecibo,” URSI General Assembly, Rome, Italy, 29 Aug. – 5 Sep. 2020.
  • K. F. Warnick and K. T. Selvan, “Teaching and learning electromagnetics in 2020: issues, trends, opportunities, and ideas for developing courses,” IEEE Antennas and Propagation Magazine, Vol. 62, No. 2, pp. 24-30, Feb. 2020.
  • J. Kunzler*, J. Bartschi*, and K. F. Warnick, “Compact structure with high Tx-Rx isolation for frequency domain duplexing on printed circuit boards,” Journal of Electromagnetic Waves and Applications, DOI: 10.1080/09205071.2020.1715267, Vol. 34, No. 3, Jan. 2020.
  • K. Chen and K. F. Warnick, “Optimizing the design of phased array speeds for survey speed,” Electronics Letters, Vol. 56, No. 1, Jan. 2020.
  • L. Liu*, J. Diao, and K. F. Warnick, “Array antenna gain enhancement with the Poynting streamline method,” IEEE Antennas and Wireless Propagation Letters, Vo. 19, No. 1, pp. 143-147, 2020.
  • B. Anderson, J. Ellingson, M. Eyler, D. Buck, C. Peterson, T. McLain, K. F. Warnick, and R. Beard, “Networked radar systems for cooperative tracking of UAVs,” ICUAS, 2019, in review.
  • J. Ellingson, E. Pitts, C. K. Peterson, K. F. Warnick, and T. McLain, “Uncertainty velocity obstacle avoidance for sUAS trajectory planning in a 2D plane,” IEEE Aerospace Conference, Big Sky, Montana, Mar. 7014, 2020.
  • D. B. Davidson and K. F. Warnick, “Convergence and physics-based checks of thin-wire MoM formulations for phased array analysis,” International Conference on Electromagnetics in Advanced Applications (ICEAA), Granada, Spain, Sep. 9-13, 2019.

  • K. F. Warnick, J. Kunzler, and G. Cortes, “Geometry optimization of a phased array feed on the Arecibo telescope for maximum survey efficiency,” IEEE International Symposium on Antennas and Propagation, Atlanta, GA, July 7-12, 2019.

  • P. Walton*, J. Cannon*, B. Damitz*, T. Downs*, D. Glick*, J. Holtom*, N. Kohls*, A. Laraway*, I. Matheson*, J. Redding*, C. Robinson*, J. Ryan*, N. Stoddard*, J. Willis*, K. F. Warnick, M. Wirthlin, D. Wilde, B. Iverson, and D. Long, “Passive CubeSats for remote inspection of space vehicles,” Journal of Applied Remote Sensing, Vol. 13, No. 3, 2019.
  • K. M. Rajwade, D. Agarwal, D. R. Lorimer, N. M. Pingel, D. J. Pisano, M. Ruzindana, B. D. Jeffs, K. F. Warnick, A. Roshi, and M. McLaughlin, “A 21 cm survey for pulsars and transients using the Focal L-band Array for the Green Bank Telescope,” Monthly Notices of the Royal Astronomical Society, Vol. 489, pp. 1709-1718, Aug. 2019.
  • J. Diao, L. Liu, and K. F. Warnick, “An intuitive way to understand mutual coupling effects in antenna arrays using the Poynting streamline method,” IEEE Transactions on Antennas and Propagation, Vol. 67, No. 2, pp. 884-891, Feb. 2019.

  • R.A. Black*, B.D. Jeffs, and K. F. Warnick, “Deep, broad null formation for canceling moving RFI in radio astronomical arrays,” Journal of Astronomical Instrumentation, DOI: 10.1142/S2251171719400038, Vol. 8, No. 1, Mar. 2019

  • Warnick, Karl F., Maaskant, Rob, Ivashina, Marianna V., Davidson, David B., & Jeffs, Brian D. (July (3rd Quarter/Summer) 2018). Phased Arrays for Radio Astronomy, Remote Sensing, and Satellite Communications. Book, Scholarly. Cambridge University Press, Cambridge, Great Britain. , 413 pages.
  • Anish Roshi, D., Shillue, W., Simon, B., Warnick, Karl Foster, Jeffs, Brian D, Jeffs, Brian D, Pisano, D. J., Prestage, R., White, S., Fisher, J. R., Morgan, M., Black, R., Burnett, M., Diao, J., Ruzindana, M., van Tonder, V., Hawkins, L., Marganian, P., Chamberlin, T., Ray, J., Pingel, N. M., Rajwade, K., Lorimer, D. R., Rane, A., Castro, J., Groves, W., Jensen, L., Nelson, J. D., Boyd, T., & Beasley, A. J.. (No date available). Performance of a Highly Sensitive, 19-element, Dual-polarization, Cryogenic L-band Phased Array Feed on the Green Bank Telescope. Journal Article, Academic Journal. Astrophysical Journal, American Astronomical Society, Washington DC.
  • Burnett, Mitchell C., Jeffs, Brian D, Black, Richard A., & Warnick, Karl Foster. (12 March 2018). Subarray Processing for Projection-based RFI Mitigation in Radio Astronomical Interferometers. Journal Article, Academic Journal. Astronomical Journal, American Astronomical Society, Washington DC, USA. 155 (4) doi:10.3847/1538-3881/aaae6f
  • Austin, Daniel E, Higgs, J, Warnick, Karl Foster, & , . (February 2018). Field optimization of toroidal ion trap mass analyzers using toroidal multipoles. Journal Article, Academic Journal. International Journal of Mass Spectrometry, . 425 , 10-15. doi:doi.org/10.1016/j.ijms.2017.12.003
  • Sahawneh, Laith R., Wikle, Jared K., Roberts, Adam K., Spencer, Jonathan C., McLain, Timothy Wayne, Beard, Randal Winston, & Warnick, Karl Foster. (No date available). A ground-based sense-and-avoid system for small unmanned aircraft. Journal Article, Academic Journal. Journal of Aerospace Information Systems, American Institute of Aeronautics and Astronautics.
  • Diao, Junming, Kunzler, Jakob, & Warnick, Karl Foster. (December 2017). Sidelobe level and aperture efficiency optimization for tiled aperiodic array antennas. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 65 (12) , 7083-7090.
  • Diao, Junming, & Warnick, Karl Foster. (November 2017). Antenna loss and receiving efficiency for mutually coupled arrays. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 65 (11) , 5871-5877.
  • Jeffs, Brian D, Warnick, Karl Foster, Black, Richard A., Ruzindanna, Mark, Burnett, Mitchell, Pisano, D. J., Lorimer, D. R., Pingel, N., Rajwade, K., Prestae, R. M., White, S., Simon, B., Hawkins, L., Shillue, W., & Roshi, A.. (14 November 2017). Beamformer and Calibration Performance for the Focal-plane L-band Array feed for the Green Bank Telescope (FLAG). Conference Proceedings. PAF Workshop 2017, Phased Array Feed Workshop, CSIRO Astronomy and Space Science (CASS), Sydney, New South Wales, Australia. , 1 page. isbn:978 0 646 98052 2
  • Semic, D, Yang, Zhenchao, & Warnick, Karl Foster. (August 2017). Antenna efficiency measurement uncertainty in a reverberation chamber at millimeter-wave frequencies. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 65 (8) , 4209-4219.
  • Anish Roshi, D., Shillue, W., Fisher, J. R., Morgan, M., Castro, J., Groves, W., Boyd, T., Simon, B., Hawkins, L., van Tonder, V., Nelson, J. D., Ray, J., Chamberlain, T., White, S., Black, R., Warnick, Karl F., Jeffs, Brian D, & Prestage, R.. (19 August 2017). A highly-sensitive cryogenic phased array feed for the Green Bank Telescope. Conference Proceedings. General Assembly and Scientific Symposium of the International Union of Radio Science (URSI GASS), 2017 XXXIInd, IEEE, Montreal, Canada. doi:10.23919/URSIGASS.2017.8105219
  • Warnick, Karl Foster, & Diao, Junming. (14 July (3rd Quarter/Summer) 2017). Analysis of the degree of practically achievable superdirectivity using Poynting streamline method. Conference Proceedings. 2017 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, , San Diego, CA.
  • Warnick, Karl Foster. (14 July (3rd Quarter/Summer) 2017). Antenna terms and measurement techniques for active receiving arrays. Conference Proceedings. 2017 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, , San Diego, CA.
  • Warnick, Karl Foster, & Diao, Junming. (14 July (3rd Quarter/Summer) 2017). Beam scan angle dependence of array antenna loss and receiving efficiency. Conference Proceedings. 2017 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, , San Diego, CA.
  • Warnick, Karl Foster, Diao, Junming, & Kunzler, Jakob. (14 July (3rd Quarter/Summer) 2017). Optimization of rotated tiled aperiodic array antennas. Conference Proceedings. 2017 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting, , San Diego, CA.
  • Warnick, Karl Foster, & Hollenbeck, M.. (9 June 2017). Selective laser melting aluminum waveguide attenuation at K-band. Conference Proceedings. International Microwave Symposium, , Honolulu, HI.
  • Seng, Frederick, Yang, Zhenchao, King, Rex, Shumway, LeGrand, Stan, Nikola, Hammond, Alec, Warnick, Karl Foster, & Schultz, Stephen Marshall. (5 June 2017). Optical electric field sensor sensitivity direction rerouting and enhancement using a passive integrated dipole antenna. Journal Article, Academic Journal. Applied Optics, Optical Society of America. 56 (17) , 4911-4916. doi:10.1364/AO.56.004911
  • Diao, Junming, & Warnick, Karl Foster. (February 2017). Poynting streamlines, effective area shape, and the design of superdirective antennas. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 65 (2) , 861-866.
  • Khoshniat, A., Yekan, T., Baktur, R., & Warnick, Karl Foster. (January (1st Quarter/Winter) 2017). Active integrated antenna supporting linear and circular polarizations. Journal Article, Academic Journal. IEEE Transactions on Components, Packaging and Manufacturing Technology, . 7 (2) , 238-245.
  • Shillue, W., Roshi, D. A., Fisher, J. R., Morgan, M. A., Castro, J., Groves, W., Boyd, T., Prestage, R., White, S., Simon, R., van Tonder, V., Nelson, J. D., Ray, J., Chamberlain, T., Warnick, Karl Foster, & Jeffs, Brian D. (January (1st Quarter/Winter) 2017). An L-band cryogenic phased array for the Green Bank Telescope: Instrumentation upgrades and expanded field-of-view. Conference Proceedings. USNC - URSI National Radio Science Meeting, Boulder, The National Academies of Sciences, Engineering, Medicine, Boulder, Colorado.
  • Diao, Junming, Kunzler, Jakob, & Warnick, Karl Foster. (January (1st Quarter/Winter) 2017). Compromise between peak sidelobe level and element number and density for electrically scanned rotational aperiodic subarrays. Creative Contribution. URSI National Radio Science Meeting, .
  • Warnick, Karl Foster, & Diao, junming. (January (1st Quarter/Winter) 2017). Experimental demonstration of a superdirective horn antenna designed by Poynting streamline method. Conference Proceedings. URSI National Radio Science Meeting, .
  • Jeffs, Brian D, Black, R. A., & Warnick, Karl Foster. (January (1st Quarter/Winter) 2017). Array Processing Methods for Radio Astronomical RFI Mitigation: A Case Study for the ngVLA. Conference Proceedings. USNC-URSI National Radio Science Meeting, The National Academies of Sciences, Engineering, Medicine, Boulder, Colorado.
  • Warnick, Karl Foster, McClelland, H., Woolsey, C., & Roberts, A.. (11 January (1st Quarter/Winter) 2017). Small aircraft flight encounters database for UAS sense and avoid. Conference Proceedings. AIAA Science and Technology Forum and Exposition, .
  • Yang, Zhenchao, & Warnick, Karl Foster. (2016). Analysis and Design of Intrinsically Dual Circular Polarized Microstrip Antennas Using an Equivalent Circuit Model and Jones Matrix Formulation. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 64 (9) , 3858–3868.
  • Diao, J, & Warnick, Karl Foster. (2016). Definition of effective area shape and guide for superdirective antenna design using Poynting streamlines analysis. Conference Proceedings. IEEE International Symposium on Antennas and Propagation and CNC/USNC-URSI Meeting, .
  • Diao, J., Black, R., Warnick, Karl Foster, Jeffs, Brian D, Erickson, N., & Narayanan, G.. (2016). Experimental tests of a mm-wave array feed for the Green Bank Telescope. Conference Proceedings. 2016 IEEE International Symposium on Antennas and Propagation and CNC/USNC-URSI Meeting, .
  • Yang, Zhenchao, Browning, Kyle C, & Warnick, Karl Foster. (2016). High-Efficiency Stacked Shorted Annular Patch Antenna Feed for Ku-Band Satellite Communications. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 64 (6) , 2568–2572.
  • Diao, Junming, & Warnick, Karl Foster. (2016). On the Bandwidth Gap Between the Array-Feed and Cluster-Feed Regimes for Broadband Multifeed Systems. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 64 (6) , 2207–2216.
  • Diao, J., Black, R. A., Warnick, Karl Foster, Jeffs, Brian D, & Erickson, N.. (2016). Performance analysis of a mm-wave phased array feed for the Green Bank Telescope. Conference Proceedings. URSI National Radio Science Meeting, . , 1.
  • Black, R. A., Brady, J. M., Jeffs, Brian D, Diao, J., & Warnick, Karl Foster. (2016). Phased-array 64-element 20-MHz receiver for data capture and real-time beamforming. Conference Proceedings. URSI National Radio Science Meeting, . , 1.
  • Warnick, Karl Foster, Maaskant, Rob, Ivashina, Marianna V., Davidson, David B., & Jeffs, Brian D. (2016). High sensitivity phased array receivers for radio astronomy. Journal Article, Academic Journal. Proceedings of the IEEE, IEEE, USA. doi:10.1109/JPROC.2015.2491886
  • Jeffs, Brian D, Black, R. A., & Warnick, Karl Foster. (October (4th Quarter/Autumn) 2016). Array Processing Methods for Radio Astronomical RFI Mitigation: Assessment of the State of the Art. Conference Proceedings. RFI 2016, Coexisting with Radio Frequency Interference, NRAO, Socorro, New Mexico.
  • Jeffs, Brian D, Black, R., Diao, J., Ruzindana, M., Warnick, Karl Foster, Prestage, R., Ford, J., White, S., Simon, R., Roshi, A., van Tonder, V., Pingel, N., Rajwade, K., Pisano, D. J., & Lorimer, D.. (August 2016). Early commissioning results from the Focal L-band array for the Green Bank Telescope (FLAG). Conference Proceedings. PAF2016 Phased Array Feed Workshop, .
  • Roshi, D., Shillue, W., Fisher, J. R., Morgan, M., Castro, J., Groves, W., Camberline, T., Prestage, R., Ray, J., Simon, R., van Tonder, V., White, S., Warnick, Karl Foster, & Jeffs, Brian D. (24 August 2016). Focal L-band array for the GBT (FLAG): instrumentation upgrades and initial commissioning results. Conference Proceedings. PAF2016 Phased Array Feed Workshop, .
  • Cortes-Medellin, G., Parshley, S., Campbell, D. B., Warnick, Karl Foster, Jeffs, Brian D, & Rajagopalan, G.. (9 August 2016). Concept design of an 80-dual polarization element cryogenic phased array camera for the Arecibo Radio Telescope. Conference Proceedings. Proceedings of SPIE 9908, SPIE. Ground-based and Airborne Instrumentation for Astronomy VI, 99085F doi:10.1117/12.2233899
  • Higgs, Jessica M., Petersen, Brae V., Lammert, Stephen A., Warnick, Karl F., & Austin, Daniel E.. (5 February 2016). Radiofrequency trapping of ions in a pure toroidal potential distribution. Journal Article, Academic Journal. International Journal of Mass Spectrometry, . 395 , 20-26. doi:http://dx.doi.org/10.1016/j.ijms.2015.11.009
  • Sahawneh, Laith R, Spencer, Jonathan, Beard, Randal Winston, & Warnick, Karl Foster. (January (1st Quarter/Winter) 2016). Minimum Required Sensing Range for UAS Sense and Avoid Systems. Conference Proceedings. AIAA Infotech@Aerospace, AIAA. , 2016-1982.
  • Spencer, J., & Warnick, Karl Foster. (2015). A compact X-band collision avoidance phased array radar system for unmanned aerial systems. Conference Proceedings. Antennas and Propagation & USNC/URSI National Radio Science Meeting, 2015 IEEE International Symposium on, . , 1514–1515.
  • Sahawneh, Laith R, Mackie, James, Spencer, Jonathan, Beard, Randal Winston, & Warnick, Karl Foster. (2015). Airborne Radar-Based Collision Detection and Risk Estimation for Small Unmanned Aircraft Systems. Journal Article, Academic Journal. Journal of Aerospace Information Systems, . , 1–11.
  • Higgs, J., Petersen, B., Wu, Q. H., Lammert, S. A., Warnick, Karl Foster, & Austin, Daniel E. (No date available). Behavior of ions in radiofrequency ion traps representing pure toroidal harmonics. Journal Article, Academic Journal. International Journal of Mass Spectrometry, .
  • Yang, Zhenchao, & Warnick, Karl Foster. (2015). Jones matrix and S-parameter analysis using an equivalent circuit model for intrinsically dual circularly polarized microstrip antennas. Conference Proceedings. Antennas and Propagation & USNC/URSI National Radio Science Meeting, 2015 IEEE International Symposium on, . , 1880–1881.
  • Belostotski, Leonid, Veidt, Bruce, Warnick, Karl Foster, & Madanayake, Arjuna. (2015). Low Noise Amplifier Design Considerations For Use in Antenna Arrays. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, IEEE. 63 , 2508-2520.
  • Diao, Junming, Black, Richard, Brady, Jay, Sypherd, Josh, Warnick, Karl Foster, & Jeffs, Brian D. (2015). Modeling and system development for the FLAG L-band phased array feed for large-dish astronomical observations. Conference Proceedings. IEEE Antennas and Propagation Society, Piscataway, NJ, USA. doi:10.1109/USNC-URSI.2015.7303647
  • Wu, Yifeng, Black, Richard A, Jeffs, Brian D, & Warnick, Karl Foster. (August 2015). Cancelling non-linear processing products due to strong out-of-band interference in radio astronomical arrays. Conference Proceedings. Signal Processing and Signal Processing Education Workshop (SP/SPE), 2015 IEEE, IEEE Signal Processing Society, Piscataway, NJ, USA. , 272–277. doi:10.1109/DSP-SPE.2015.7369565
  • Black, Richard A, Jeffs, Brian D, Warnick, Karl Foster, Hellbourg, Gregory, & Chippendale, Aaron. (August 2015). Multi-tier interference-cancelling array processing for the ASKAP radio telescope. Conference Proceedings. Signal Processing and Signal Processing Education Workshop (SP/SPE), 2015 IEEE, IEEE Signal Processing Society, Pscataway, NJ, USA. , 261–266. doi:10.1109/DSP-SPE.2015.7369563
  • Roshi, D Anish, Warnick, Karl Foster, Brandt, Joe, Fisher, J Richard, Ford, Pam, Jeffs, Brian D, Marganian, Paul, McLeod, Morgan, Mello, Melinda, Morgan, Matthew, & others, . (July (3rd Quarter/Summer) 2015). A 19 element Cryogenic Phased Array Feed for the Green Bank Telescope. Conference Proceedings. 2015 IEEE International Symposium on Antennas and Propagation and CNC/USNC-URSI Meeting, IEEE Antennas and Propagation Society, Piscataway, NJ, USA. doi:10.1109/APS.2015.7305077
  • Roshi, D. A., Warnick, Karl Foster, Brandt, J., Fisher, J. R., Ford, P., Jeffs, Brian D, Marganian, P., McLeod, M., Mello, M., Morgan, M., Norrod, R., Shillue, W., Simon, R., & White, S.. (July (3rd Quarter/Summer) 2015). A 64 element 70-95 GHz focal plane phased array. Conference Proceedings. 2015 IEEE International Symposium on Antennas and Propagation and CNC/USNC-URSI Meeting, .
  • Cortes-Medellin, German, Viswash, Amit, Parsley, Steven, Campbell, Donald B., Perilat, Phil, Black, Richard, Brady, Jay, Warnick, Karl Foster, & Jeffs, Brian D. (June 2015). A Fully Cryogenic Phased Array Camera for Radio Astronomy. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, IEEE, Piscataway, NJ, USA. 63 (6) doi:10.1109/TAP.2015.2415527
  • Morin, Matt, Yang, Zhenchao, & Warnick, Karl Foster. (2014). Compact dual circularly polarized `eleven’ feed over EBG for reflector antennas. Journal Article, Academic Journal. Forum for Electromagnetic Research Methods and Application Technologies, . , 4.
  • Warnick, Karl Foster, & Russer, Peter. (2014). Differential forms and electromagnetic field theory. Journal Article, Academic Journal. Progress in Electromagnetics Research, . 148 , 83-112.
  • Khan, Mahrukh, & Warnick, Karl Foster. (November 2014). Noise figure reduction by port decoupling for a dual circular polarized microstrip antenna. Journal Article, Academic Journal. Electonics Letters, . 50 (23) , 1662-1664.
  • DeFranco, Patrick, Mackie, James, Morin, Matt, & Warnick, Karl Foster. (October (4th Quarter/Autumn) 2014). Bio-inspired electromagnetic orientation for UAVs in a GPS-denied environment using MIMO channel sounding. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 62 (10) , 5250-5259.
  • Elmer, Mike, Jeffs, Brian D, & Warnick, Karl Foster. (September 2014). Reducing relative gain and noise response variations for phased array feed imaging of radio astronomical sources. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, IEEE. 62 (12) , 6067-6080.
  • Khan, Mahrukh, Yang, Zhenchao, & Warnick, Karl Foster. (August 2014). Dual circular polarized high efficiency antenna for Ku band satellite communication. Journal Article, Academic Journal. IEEE Antennas and Wireless Propagation Letters, . 13 , 1624-1627.
  • Warnick, Karl Foster, Jeffs, Brian D, Diao, J., Black, R., Brady, J., Roshi, A., Shillue, B., White, S., Simon, B., & Fisher, R.. (3 August 2014). Experimental Tests and Signal Processing for a Cryogenic L-band Phased Array Feed on the Green Bank Telescope. Conference Proceedings. Proceedings of the IEEE 2014 International Conference on Electromagnetics in Advanced Applications (ICEAA-14), IEEE, Piscataway, NJ, USA.
  • Mackie, J, Spencer, J, & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2014). Compact FMCW radar for a UAS sense and avoid system. Conference Proceedings. 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI Meeting, .
  • Yang, Zhenchao, & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2014). Effect of mutual coupling on the sensitivity of dual polarized receivers in satellite communications. Conference Proceedings. 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI Meeting, . , 1528-1529.
  • Eck, James, Morin, Matt, & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2014). Meta-reflector antenna with annular pattern for electromagnetic orientation in UAS applications. Conference Proceedings. 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI Meeting, . , 993-994.
  • Zhenchao, Yang, & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2014). Multiband dual-polarization high-efficiency array feed for Ku/Reverse Band satellite communications. Journal Article, Academic Journal. IEEE Antennas and Wireless Propagation Letters, . , 1325-1328.
  • Lammert, S, Lee, E, Waite, R, Oliphant, J, Austin, D, Higgs, J, Warnick, Karl Foster, & Tolley, D. (June 2014). Toroidal multipole expansion for the design of circular ion traps. Conference Proceedings. ASMS Conference on Mass Spectrometry and Allied Topics, .
  • Young, Andre, Warnick, Karl Foster, & Davidson, David. (April (2nd Quarter/Spring) 2014). Evaluation of an electronic derotation scheme for a phased array fed reflector antenna. Conference Proceedings. European Conference on Antennas and Propagation (EuCAP), .
  • Young, Andre, Davidson, David, & Warnick, Karl Foster. (March 2014). Noise figure reduction by port decoupling for a dual circular polarized microstrip antenna. Conference Proceedings. Calibration and Imaging Workshop (CALIM), .
  • Heo, D, & Warnick, Karl Foster. (October (4th Quarter/Autumn) 2013). A low phase error X-band eight-channel SiGe PIN diode based array receiver. Conference Proceedings. European Microwave Week, .
  • Heo, D, & Warnick, Karl Foster. (October (4th Quarter/Autumn) 2013). An 8-channel Ku band transmit beamformer with low gain/phase imbalance between channels. Conference Proceedings. European Microwave Week, .
  • Yang, Z, Warnick, Karl Foster, & Holloway, C. (July (3rd Quarter/Summer) 2013). A high radiation efficiency microstrip array feed for Ku band satellite communications. Conference Proceedings. 2013 USNC-URSI National Radio Science Meeting, .
  • deFranco, P, Mackie, J, & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2013). Electromagnetic orientation using MIMO channel sounding in a GPS-denied environment. Conference Proceedings. 2013 USNC-URSI National Radio Science Meeting, .
  • Blankenagel, B, Khadka, S, Hawkins, Aaron R, Warnick, Karl Foster, & Mazzeo, Brian A. (July (3rd Quarter/Summer) 2013). Radio-frequency microfluidic interferometer in printed circuit board process. Journal Article, Academic Journal. Microwave and Optical Technology Letters, . 55 (7) , 1616-1618.
  • Wu, Y, Warnick, Karl Foster, & Jin, C. (June 2013). Design study of an L-band phased array feed for wide-field surveys and vibration compensation on FAST. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, IEEE. 61 (6) , 3026-3033.
  • Warnick, Karl Foster, Gottula, R B, Shrestha, S, & Smith, J. (February 2013). Optimizing power transfer efficiency and bandwidth for near field communication systems. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, IEEE. 61 (2) , 927-933.
  • Tran, B, & Warnick, Karl Foster. (January (1st Quarter/Winter) 2013). Broadband, high efficiency dielectric resonator antenna array for satellite communication. Conference Proceedings. URSI National Radio Science Meeting, , Boulder, CO.
  • Browning, K, & Warnick, Karl Foster. (January (1st Quarter/Winter) 2013). Low cost, electronically steered array feed system for Ku band satellite communication. Conference Proceedings. URSI National Radio Science Meeting, , Boulder, CO.
  • Jeffs, Brian D, & Warnick, Karl Foster. (January (1st Quarter/Winter) 2013). Spatial array processing methods for radio astronomical RFI mitigation. Conference Proceedings. URSI National Radio Science Meeting, , Boulder, CO.
  • Warnick, Karl Foster, & Jeffs, Brian D. (January (1st Quarter/Winter) 2013). Tutorial: Phased Array Antennas for Radio Astronomy. Conference Proceedings. 2013 USNC-URSI National Radio Science Meeting, IEEE, Piscataway, NJ, United States. , T.B.D..
  • Elmer, Michael J, Jeffs, Brian D, & Warnick, Karl Foster. (January (1st Quarter/Winter) 2013). Long-term Calibration Stability of a Radio Astronomical Phased Array Feed. Journal Article, Academic Journal. The Astronomical Journal, American Astronomical Society, IOPscience, Philadelphia, PA, USA. AJ, 145,24 (January 2013) , 11.
  • Elmer, Michael J., Jeffs, Brian D, Warnick, Karl Foster, Fisher, James Richard, & Roshi, D. Anish. (September 2012). Calibration and Field Flattening for Single Dish Astronomical Phased Array Feed Radio Camera Imaging. Conference Proceedings. Electromagnetics in Advanced Application (ICEAA), 2012 International Conference on, IEEE, Piscatway, NJ, United States. (DOI: 10.1109/ICEAA.2012.6328775) , 958-961.
  • Warnick, Karl Foster, Webb, Taylor, Adhikari, M., Jeffs, Brian D, Elmer, Michael J., Asthana, Vikas, Fuller, Megan, Jin, Chengjin, Yang, Wu, Roshi, R. Anish, & Fisher, James Richard. (September 2012). Progress in high sensitivity phased array feeds for large single-dish radio telescopes. Conference Proceedings. Electromagnetics in Advanced Applications (ICEAA), 2012 International Conference on, IEEE, Piscataway, NJ, United States. (doi: 10.1109/ICEAA.2012.6328620) , 199-201.
  • Maaskant, R, Ivashina, M, Wijnholds, S, & Warnick, Karl Foster. (August 2012). Efficient prediction of array element patterns using physics-based expansions and a single far-field measurement. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, IEEE. 60 (8) , 3614-3621.
  • Yang, Z, & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2012). A planar passive dual band array feed antenna for Ku band satellite communication terminals. Conference Proceedings. Proceedings of USNC/URSI National Radio Science Meeting, .
  • Warnick, Karl Foster, Ivashina, M, Maaskant, R, & Woestenburg, B. (July (3rd Quarter/Summer) 2012). Noise-based antenna terms for active receiving arrays. Conference Proceedings. Proceedings of USNC/URSI National Radio Science Meeting, .
  • Landon, Jonathan, Jeffs, Brian D, & Warnick, Karl Foster. (March 2012). Model-Based Subspace Projection Beamforming for Deep Interference Nulling. Journal Article, Academic Journal. IEEE Transactions on Signal Processing, IEEE Signal Processing Society, Piscataway NJ, USA. 60 (3) , 1215-1228.
  • Landon, Jonathan, Jeffs, Brian D, Warnick, Karl Foster, Fisher, J. Richard, & Norrod, Roger D.. (February 2012). Beamformer Design Methods for Radio Astronomical Phased Array Feeds. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation,, IEEE Antennas and Propagation Society, Piscataway NJ, USA. 60 (2) , 903-914.
  • Warnick, K F, & Warnick, Karl Foster. (January (1st Quarter/Winter) 2012). Efficient snapshot calibration for polarimetric phased array radiometers. Conference Proceedings. URSI National Radio Science Meeting, .
  • Warnick, Karl Foster, Ivashina, M, Wijnholds, S, & Maaskant, R. (January (1st Quarter/Winter) 2012). Polarimetry with phased array antennas: theoretical framework and definitions. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, IEEE.
  • Giradu-Carrier, Matthieu C, Moon, Kyra, Teng, Eric, Hawkins, Aaron R, Warnick, Karl Foster, & Mazzeo, Brian A. (August 2011). Broadband RF Impedance Spectroscopy in Micromachined Microfluidic Channels. Conference Proceedings. IEEE Engineering in Medicine and Biology, IEEE.
  • Ivashina, M V, Wijnholds, S J, Maaskant, R, & Warnick, Karl Foster. (August 2011). Performance of polarimetric beamformers for phased array radio telescopes. Conference Proceedings. URSI General Assembly, .
  • van Capellen, W A, Bij de Vaate, J G, Warnick, Karl Foster, Veidt, B, Gough, R G, Jackson, C A, & Roddis, N. (August 2011). Phased array feeds for the Square Kilometre Array. Conference Proceedings. URSI General Assembly, .
  • Warnick, Karl Foster, Carter, D, Webb, T, Landon, J, Asthana, V, Elmer, M, Jeffs, B, Norrod, R, & Fisher, J R. (August 2011). Towards a high sensitivity, cryogenic phased array feed antenna for the Green Bank Telescope. Conference Proceedings. URSI General Assembly, .
  • Warnick, Karl Foster, Carter, D., Webb, T., Landon, J., Elmer, M., & Jeffs, Brian D. (July (3rd Quarter/Summer) 2011). Design and characterization of an active impedance matched low noise phased array feed. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation,, . 59 (6) , 1876-1885.
  • Warnick, Karl Foster, Jeffs, Brian D, Landon, J, Elmer, M, Carter, D, Webb, T, Asthana, V, Fisher, J R, Norrod, R, Roshi, A, & Cortes, G. (May 2011). Recent PAF developments at BYU/NRAO. Conference Proceedings. 2011 Workshop on Phased Array Feeds for the Square Kilometre Array (PAFSKA2011), .
  • Sorensen, T, & Warnick, Karl Foster. (March 2011). Image quality for diffraction tomography, holographic backpropagation, and regularized sampling with noisy data. Journal Article, Academic Journal. Inverse Problems in Science and Engineering, . 19 (2) , 203-221.
  • Landon, J, Jeffs, Brian D, Warnick, Karl Foster, Carter, D, Webb, T, Elmer, M, Norrod, R, & Fisher, J R. (January (1st Quarter/Winter) 2011). An interference canceling phased array feed for the Green Bank Telescope. Conference Proceedings. URSI National Radio Science Meeting, .
  • Warnick, Karl Foster, & Jeffs, Brian D. (January (1st Quarter/Winter) 2011). Progress in phased array feeds for wide-field radio astronomical observations at Brigham Young University. Conference Proceedings. Snowbird Workshop on Particle Astrophysics, Astronomy, and Cosmology, .
  • Warnick, Karl Foster, Jeffs, Brian D, Carter, David, Webb, Taylor, Elmer, Michael, Norrod, Roger, & Fisher, Richard. (October (4th Quarter/Autumn) 2010). Active impedance matching, calibration, and interference mitigation for the BYU/NRAO L-Band Phased array feed. Conference Proceedings. IEEE International Symposium on Phased Array Systems & Technology, IEEE.
  • Odabasi, H, Teixiera, F, & Warnick, Karl Foster. (October (4th Quarter/Autumn) 2010). Anisotropic metamaterial blueprints for cladding control of waveguide modes. Journal Article, Academic Journal. Journal of the Optical Society of America B, . 27 (8) , 1603-1609.
  • Warnick, Karl Foster. (September 2010). Numerical Methods for Engineering with MATLAB and Computational Electromagnetics Examples. Book, Textbook. Scitech, Raleigh, NC, USA. , 343.
  • 4. M. V. Ivashina, S. J. Wijnholds, Maaskant, R., Warnick, Karl Foster, & Jeffs, Brian D. (August 2010). Polarimetric beamforming methods for PAF systems. Conference Proceedings. CALIM 2010: The 5th SKA Workshop on Calibration and Imaging, .
  • Warnick, Karl Foster, Ivashina, M, Maaskant, R, & Woestenburg, B. (June 2010). Unified definitions of efficiencies and system noise temperature for receiving arrays. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, IEEE. 58 (6) , 2121-2125.
  • Warnick, Karl Foster, Carter, D. E., Webb, T., Jeffs, Brian D, Norrod, R., & Fisher, J. R.. (May 2010). Active impedance matched dual-polarization phased array feed for the GBT. Conference Proceedings. International Workshop on Phased Array Antenna Systems for Radio Astronomy, .
  • Elmer, M., Jeffs, Brian D, & Warnick, Karl Foster. (May 2010). Beamformer design methods for phased array feeds. Conference Proceedings. International Workshop on Phased Array Antenna Systems for Radio Astronomy, .
  • Landon, J., Jeffs, Brian D, & Warnick, Karl Foster. (May 2010). Deep nulling interference cancelation for phased array feeds. Conference Proceedings. International Workshop on Phased Array Antenna Systems for Radio Astronomy, .
  • Cortes-Medellin, G., Warnick, Karl Foster, & Jeffs, Brian D. (May 2010). Obtaining the simulated response of a 19 element focal phased array for the feasibility study for the Arecibo radio telescope. Conference Proceedings. International Workshop on Phased Array Antenna Systems for Radio Astronomy, .
  • Norrod, R., Fisher, J. R., Jeffs, Brian D, & Warnick, Karl Foster. (May 2010). Steps toward a cryogenic L-band phased array feed for reflector antennas. Conference Proceedings. International Workshop on Phased Array Antenna Systems for Radio Astronomy, .
  • Landon, J., Elmer, M., Waldron, J., Jones, D., Stemmons, A., Jeffs, Brian D, Warnick, Karl Foster, Fisher, J. R., & Norrod, R. D.. (March 2010). Phased array feed calibration, beamforming, and imaging. Journal Article, Academic Journal. Astronomical Journal, American Astronomical Society, Philadelphia, PA. 139 , 1154-1167.
  • Warnick, Karl Foster, Carter, D., Webb, T., Jeffs, Brian D, Landon, J., Elmer, M., Fisher, J. R., & Norrod, R.. (January (1st Quarter/Winter) 2010). Sensitivity optimization and signal processing for the BYU/NRAO L-band phased array feed. Conference Proceedings. URSI National Radio Science Meeting, .
  • Sun, X., Li, D., Woolley, Adam T, Farnsworth, Paul Burton, Tolley, Harold Dennis, Warnick, Karl Foster, & Lee, Milton L. (December 2009). Bilinear electric field gradient focusing. Journal Article, Academic Journal. Journal of Chromatography A, . 1216
  • Sun, X., Farnsworth, Paul Burton, Tolley, Harold Dennis, Warnick, Karl Foster, Woolley, Adam T, & Lee, Milton L. (2009). Performance optimization in electric field gradient focusing. Journal Article, Academic Journal. Journal of Chromatography A, . 1216 , 159-164.
  • Warnick, Karl Foster, & Teixeira, F. L.. (June 2009). Metamaterial claddings for homotopic control of waveguide modes. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, IEEE.
  • Warnick, Karl Foster. (June 2009). MIMO communications and inverse scattering. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium,, IEEE.
  • Warnick, Karl Foster, Woestenburg, E. E. M., Belostotski, L., & Russer, P.. (June 2009). Minimizing the noise penalty due to mutual coupling for a receiving array. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 57 , 1634-1644.
  • Warnick, Karl Foster. (June 2009). Optimal noise matching for a phased array feed. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, IEEE.
  • Jeffs, Brian D, & Warnick, Karl Foster. (April (2nd Quarter/Spring) 2009). Spectral bias in adaptive beamforming with narrowband interference. Journal Article, Academic Journal. IEEE Transactions on Signal Processing, . 57 , 1373-1382.
  • Jeffs, Brian D, & Warnick, Karl Foster. (April (2nd Quarter/Spring) 2009). Spectral bias in adaptive beamforming with narrowband interference. Journal Article, Academic Journal. IEEE Transactions on Signal Processing, IEEE Signal Processing Society, Piscataway NJ. 57 , 1373-1382.
  • Warnick, Karl Foster, Jeffs, Brian D, Landon, J., Waldron, J., Jones, D., Fisher, J. R., & Norrod, R.. (March 2009). Beamforming and Imaging with the BYU/NRAO L-Band 19-Element Phased Array Feed. Conference Proceedings. Canadian Radio Sciences Meeting, ANTEM/URSI 2009, Proc. of the 13th International Symposium on , Banff, AB, Canada. DOI: 10.1109/ANTEMURSI.2009.4805125 , 4.
  • Warnick, Karl Foster, Jeffs, Brian D, Landon, J., Waldron, J., Jones, D. A., Fisher, R., & Norrod, R.. (February 2009). Beamforming and imaging with the BYU/NRAO L-band phased array feed. Conference Proceedings. Proceedings of the 13th International Symposium on Antenna Technology and Applied Electromagnetics, .
  • Warnick, Karl Foster, & Jeffs, Brian D. (October (4th Quarter/Autumn) 2008). Efficiencies and system temperature for a focal plane array. Journal Article, Academic Journal. IEEE Antennas and Wireless Propagation Letters, IEEE Antennas and Propagation Society, Piscataway, NJ. 7 , 564-567.
  • Warnick, Karl Foster. (October (4th Quarter/Autumn) 2008). Numerical Analysis for Electromagnetic Integral Equations. Book, Scholarly. Artech House, Norwood MA. , 219.
  • Jeffs, Brian D, Warnick, Karl Foster, Landon, J., Waldron, J., Jones, D., Fisher, J. R., & Norrod, R. D.. (October (4th Quarter/Autumn) 2008). Signal processing for phased array feeds in radio astronomical telescopes. Journal Article, Academic Journal. IEEE Journal of Selected Topics in Signal Processing, . 2 , 635-646.
  • Jeffs, Brian D, Warnick, Karl Foster, Landon, J., Waldron, J., Jones, D., Fisher, J. R., & Norrod, R. D.. (October (4th Quarter/Autumn) 2008). Signal processing for phased array feeds in radio astronomical telescopes. Journal Article, Academic Journal. IEEE Journal of Selected Topics in Signal Processing, IEEE Signal Processing Society, Piscataway, NJ. 2 , 635-646.
  • Warnick, Karl Foster, Jeffs, Brian D, Landon, J., Waldron, J., Jones, D., Fisher, R., & Norrod, R.. (August 2008). BYU/NRAO 19-element phased array feed modeling and experimental results. Conference Proceedings. Proceedings of URSI General Assembly, .
  • Landon, J. C., Jeffs, Brian D, Warnick, Karl Foster, Fisher, J. R., & Norrod, R. D.. (August 2008). Improved low INR interference cancellation using phased array feeds. Conference Proceedings. Proceedings of URSI General Assembly, .
  • Elmer, M. J., Landon, J., Jeffs, Brian D, Warnick, Karl Foster, Fisher, R., & Norrod, R.. (August 2008). Optimizing phased array feeds to reduce elevation dependant spillover noise in radio telescopes. Conference Proceedings. Proceedings of URSI General Assembly, .
  • Jeffs, Brian D, & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2008). Bias corrected PSD estimation for an adaptive array with moving interference. Journal Article, Academic Journal. IEEE Transactions on Signal Processing, . 56 , 3108-3121.
  • Jeffs, Brian D, & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2008). Bias Corrected PSD Estimation for an Adaptive Array with Moving Interference. Journal Article, Academic Journal. IEEE Transactions on Signal Processing, IEEE Signal Processing Society, Piscataway, NJ. 56 , 3108-3121.
  • Waldron, Jill, Jones, D. A., Warnick, Karl Foster, & Jeffs, Brian D. (July (3rd Quarter/Summer) 2008). Effects of focal plane array offset and beam steering on sensitivity. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, .
  • Waldron, J. S., Jones, D. A., Warnick, Karl Foster, & Jeffs, Brian D. (July (3rd Quarter/Summer) 2008). Effects of focal plane array offset and beam steering on sensitivity. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, .
  • Chew, W., Davis, Cheryl Barnett, Warnick, Karl Foster, Nie, Z., Yan, S., & Gurel, L.. (July (3rd Quarter/Summer) 2008). EFIE and MFIE, why the difference. Journal Article, Academic Journal. Proceedings of IEEE Antennas and Propagation Society International Symposium, .
  • Jones, D. A., Warnick, Karl Foster, Jeffs, Brian D, Landon, J., & Waldron, J.. (July (3rd Quarter/Summer) 2008). Modeled and measured mutual impedances, element patterns, and sensitivity for a 19 element focal plane array. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, IEEE Antennas and Propagation Society.
  • Warnick, Karl Foster, & Russer, P.. (July (3rd Quarter/Summer) 2008). Quantifying the noise penalty for a mutually coupled array. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, .
  • Ullrich, C., Warnick, Karl Foster, & Russer, P.. (July (3rd Quarter/Summer) 2008). Radiation from a monopole antenna in an aperture backed by an absorbing body using a hybrid MoM/UTD approach. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, .
  • Jones, D. A., Warnick, Karl Foster, Jeffs, Brian D, Landon, J., & Waldron, J.. (June 2008). Modeled and measured mutual impedances, element patterns, and sensitivity for a 19 element focal plane array. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, .
  • Lin, S., Li, Y., Woolley, Adam T, Lee, Milton L, Tolley, Harold Dennis, & Warnick, Karl Foster. (March 2008). Programmed elution and peak profiles in electric field gradient focusing. Journal Article, Academic Journal. Electrophoresis, . 29 , 1058-1066.
  • Li, Y., -L. Lin, S., Warnick, Karl Foster, Tolley, Harold Dennis, & Lee, Milton L. (March 2008). Programmed elution and peak profiles in electric field gradient focusing. Conference Proceedings. Pittcon Proceedings, .
  • Landon, J., Jones, D., Jeffs, Brian D, Warnick, Karl Foster, Fisher, R., & Norrod, R.. (January (1st Quarter/Winter) 2008). Interference cancellation and sensitivity optimization using an L-band focal plane array on the Green Bank 20m Telescope. Conference Proceedings. Proceedings of URSI National Radio Science Meeting, Boulder CO. Jan 3-6, 2008, .
  • Warnick, Karl Foster, Jones, D., Jeffs, Brian D, & Jensen, Michael Allen. (January (1st Quarter/Winter) 2008). Noise penalty due to mutual coupling for receive arrays. Conference Proceedings. Proceedings of the 2008 USNC/URSI National Radio Science Meeting, . , BS11-5.
  • Warnick, Karl Foster, Jones, D., Jeffs, Brian D, & Jensen, Michael Allen. (January (1st Quarter/Winter) 2008). Noise penalty due to mutual coupling for recieve arrays. Conference Proceedings. Proceedings of URSI National Radio Science Meeting, Boulder, CO, Jan. 3-6 2008, .
  • Sun, Xufei, Farnsworth, Paul Burton, Woolley, Adam T, Tolley, Harold Dennis, Warnick, Karl Foster, & Lee, Milton L. (January (1st Quarter/Winter) 2008). Poly(ethylene glycol)-Functionalized Devices for Electric Field Gradient Focusing. Journal Article, Academic Journal. Analytical Chemistry, . 80 , 451-460.
  • Nagel, J. R., Warnick, Karl Foster, Jeffs, Brian D, Fisher, J. R., & Bradley, R.. (December 2007). Experimental verification of radio frequency interference mitigation with a focal plane array feed. Journal Article, Academic Journal. Radio Science, American Geophysical Union (AGU). 42 , doi:10.1029/2007RS003630.
  • Nagel, J. R., Warnick, Karl Foster, Jeffs, Brian D, Fisher, J. R., & Bradley, R.. (2007). Experimental verification of radio frequency interference mitigation with a focal plane array feed. Journal Article, Academic Journal. Radio Science, doi:10.1029/2007RS003630. 42
  • Warnick, Karl Foster, Waldron, J., Landon, J., Lolrose, M., & Jeffs, Brian D. (November 2007). Experimental results on interference mitigation with a 19 element array feed. Conference Proceedings. Proceedings of 2nd European Conference on Antennas and Propagation, Edinburgh, UK, Nov. 11-16, 2007, .
  • Warnick, Karl Foster, & Jensen, Michael Allen. (November 2007). Signal and noise analysis of small antennas terminated with high impedance amplifiers. Conference Proceedings. Proceedings of 2nd European Conference on Antennas and Propagation, Edinburgh, UK, Nov. 11-16, 2007, .
  • Warnick, Karl Foster, & Jensen, Michael Allen. (November 2007). Signal and noise analysis of small antennas terminated with high-impedance amplifiers. Conference Proceedings. Proceedings of 2007 European Conference on Antennas and Propagation, . , 1-5.
  • Johnson, J. T., Warnick, Karl Foster, Xu, P., & Tsang, L.. (August 2007). On the geometrical optics (Hagfors' Law) and physical optics approximations for scattering from exponentially correlated surfaces. Journal Article, Academic Journal. IEEE Transactions on Geoscience and Remote Sensing, IEEE. 45 , 2619-2629.
  • Warnick, Karl Foster, & Peterson, A. F.. (June 2007). 3D MFIE accuracy improvement using regularization. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, IEEE. , 4 pages.
  • Sorensen, T., & Warnick, Karl Foster. (June 2007). Inverse scattering image quality as a function of SNR. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, IEEE. , 4 pages.
  • Warnick, Karl Foster, & Jensen, Michael Allen. (June 2007). Optimal noise matching condition for mutually coupled antenna arrays. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, IEEE. , 4 pages.
  • Warnick, Karl Foster, & Jensen, Michael Allen. (June 2007). Optimal noise matching condition for mutually coupled antenna arrays. Conference Proceedings. 2007 IEEE AP-S International Symposium Digest, IEEE, New York. , 2953-2956.
  • Warnick, Karl Foster, & Jensen, Michael Allen. (June 2007). Optimal noise matching for mutually-coupled arrays. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, IEEE. 55 , 1726-1731.
  • Warnick, Karl Foster, & Jensen, Michael Allen. (June 2007). Optimal noise matching for mutually-coupled arrays. Journal Article, Academic Journal. IEEE Trans. Antennas Propagation, IEEE, New York. 55 , 1726-1731.
  • Jeffs, Brian D, & Warnick, Karl Foster. (April (2nd Quarter/Spring) 2007). Bias Corrected PSD Estimation with an Interference Canceling Array. Conference Proceedings. Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP-2007, IEEE Signal Processing Society, Piscataway, NJ. II , 1145-1148.
  • Warnick, Karl Foster, & Jeffs, Brian D. (December 2006). Gain and Aperture Efficiency for a Reflector Antenna With an Array Feed. Journal Article, Academic Journal. IEEE Antennas and Wireless Propagation Letters, IEEE Antennas and Propagation Society. 5 , 499-502.
  • Warnick, Karl Foster, & Jeffs, Brian D. (October (4th Quarter/Autumn) 2006). Gain and aperture efficiency for a reflector antenna with an array feed. Journal Article, Academic Journal. IEEE Antennas and Wireless Propagation Letters, . 5 , 499-502.
  • Warnick, Karl Foster, & Russer, P.. (August 2006). Problem Solving in Electromagnetics, Microwave Circuits, and Antenna Design for Communications Engineering. Book, Textbook. Artech House, Norwood, MA. , 372.
  • Nagel, J. R., Lillrose, M. A., Warnick, Karl Foster, & Jeffs, Brian D. (July (3rd Quarter/Summer) 2006). Prototype platform for array feed development. Abstract. Proceedings of USNC/URSI National Radio Science Meeting, IEEE. , 1 page.
  • Warnick, Karl Foster, & Russer, P.. (July (3rd Quarter/Summer) 2006). Solving Maxwell's equations using fractional wave equations. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, IEEE.
  • Warnick, Karl Foster, & Russer, P.. (June 2006). Green's theorem in electromagnetic field theory. Journal Article, Academic Journal. Proceedings of the European Microwave Association, . 2 , 141-146.
  • Millet, F. W., Warnick, Karl Foster, Nagel, J. R., & Arnold, D. V.. (June 2006). Physical optics-based electromagnetic bias theory with surface height-slope cross-correlation and hydrodynamic modulation. Journal Article, Academic Journal. IEEE Transactions on Geoscience and Remote Sensing, . 44 , 1470-1483.
  • Warnick, Karl Foster, & Russer, P.. (January (1st Quarter/Winter) 2006). Two, three, and four-dimensional electromagnetics using differential forms. Journal Article, Academic Journal. Turkish Journal of Electrical Engineering and Computer Sciences, . 14 , 153-172.
  • Warnick, Karl Foster. (December 2005). An intuitive error analysis for FDTD and comparison to MOM. Journal Article, Academic Journal. IEEE Antennas and Propagation Magazine, . 47 , 111-115.
  • Poulsen, A. J., Jeffs, Brian D, Warnick, Karl Foster, & Fisher, R.. (December 2005). Programmabel Real-time Cancellation of GLONASS Interference with the Green Bank Telescope. Journal Article, Academic Journal. Astronomical Journal, American Astronomical Society, Washington D.C.. 130
  • Poulsen, A. J., Jeffs, Brian D, Warnick, Karl Foster, & Fisher, J. R.. (December 2005). Programmable real-time cancellation of GLONASS interference with the Green Bank Telescope. Journal Article, Academic Journal. Astronomical Journal, . 130 , 2916-2927.
  • Millet, K. F., Warnick, Karl Foster, & Arnold, David Verl. (2005). Electromagnetic bias at off-nadir incidence angles. Journal Article, Academic Journal. Journal of Geophysical Research-Oceans, . 110 , 13 pages.
  • Warnick, Karl Foster, & Jensen, Michael Allen. (August 2005). Effect of mutual coupling on interference mitigation with a focal plane array. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 53 , 2490-2498.
  • Warnick, Karl Foster, & Jensen, Michael Allen. (August 2005). Effect of mutual coupling on interference mitigation with a focal plane array. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 53 , 2490-2498.
  • Warnick, Karl Foster, & Jensen, Michael Allen. (August 2005). Effects of mutual coupling on interference mitigation with a focal plane array. Journal Article, Academic Journal. IEEE Trans. Antennas and Propagation, Special Issue on Applications of Antennas and Propagation, . 53 , 2490-2498.
  • Davis, C. P., & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2005). 3D MFIE solution improvement by regularization. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, . , 4 pages.
  • Warnick, Karl Foster, & Jensen, Michael Allen. (July (3rd Quarter/Summer) 2005). Mutual coupling analysis of a focal plane array feed. Conference Proceedings. Proceedings of IEEE Antennas and Propagation International Symposium, . , 4 pages.
  • Warnick, Karl Foster, & Jensen, Michael Allen. (July (3rd Quarter/Summer) 2005). Mutual coupling analysis of a focal plane array feed. Abstract. 2005 USNC/URSI National Radio Science Meeting Digest, . , 1.
  • Davis, C. P., & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2005). On the physical meaning of the Sobolev norm in error estimation. Journal Article, Academic Journal. Journal of the Applied Computational Electromagnetics Society, . 20 , 144-150.
  • Hansen, C. K., Warnick, Karl Foster, Jeffs, Brian D, Fisher, J. R., & Bradley, R.. (June 2005). Interference mitigation using a focal plane array. Journal Article, Academic Journal. Radio Science, . 40 , 14 pages.
  • Davis, C. P., & Warnick, Karl Foster. (April (2nd Quarter/Spring) 2005). 2D MFIE solution improvement by regularization. Conference Proceedings. Proceedings of IEEE/ACES International Conference on Wireless Communications and Applied CEM, .
  • Warnick, Karl Foster, Millet, F. W., & Arnold, David Verl. (March 2005). Physical and geometrical optics for 2D rough surfaces with power-law height spectra. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 53 , 922-932.
  • Jeffs, Brian D, Li, L., & Warnick, Karl Foster. (February 2005). Auxiliary Antenna-Assisted Interference Mitigation for Radio Astronomy Arrays. Journal Article, Academic Journal. IEEE Transactions on Signal Processing, IEEE, Piscataway, NJ. 53 (2005) , 439-451.
  • Jeffs, Brian D, Li, L., & Warnick, Karl Foster. (February 2005). Auxiliary assisted interference mitigation for radio astronomy arrays. Journal Article, Academic Journal. IEEE Transactions on Signal Processing, . 53 , 439-451.
  • Davis, C. P., & Warnick, Karl Foster. (January (1st Quarter/Winter) 2005). Error analysis of 2D MoM for MFIE/EFIE/CFIE based on the circular cylinder. Journal Article, Academic Journal. IEEE Transactions on Antennas and Propagation, . 53 , 321-331.
  • Warnick, Karl Foster, Francom, S. J., Humble, Paul H., Kelly, R. T., Woolley, Adam T, Lee, Milton L, & Tolley, Harold Dennis. (January (1st Quarter/Winter) 2005). Field gradient electrophoresis. Journal Article, Academic Journal. Electrophoresis, . 26 , 405-414.
  • Warnick, Karl Foster, & Chew, W. C.. (December 2004). Error analysis of the moment method. Journal Article, Academic Journal. IEEE Antennas and Propagation, . 46
  • Jensen, Michael Allen, & Warnick, Karl Foster. (2004). Comment on 'Coulomb torque---a general theory for electrostatic forces in many body systems. Journal Article, Academic Journal. Journal of Physics A: Mathematical and General, Institute of Physics, London. 37 , 6415-6417.
  • Davis, C. P., & Warnick, Karl Foster. (2004). High order convergence with a low order discretization of the 2D MFIE. Journal Article, Academic Journal. IEEE Antennas and Wireless Propagation Letters, IEEE, Piscataway, NJ. 3 , 355-358.
  • Hansen, C., Warnick, Karl Foster, Jeffs, Brian D, Fisher, R., & Bradley, R.. (July (3rd Quarter/Summer) 2004). Interference Mitigation Using an Array Feed. Conference Proceedings. Workshop in Mitigation of Radio Frequency Interference in Radio Astronomy, Proceedings of RFI2004, IUCAD DRAO Workshop in Mitigation of Radio Frequency Interference in Radio A, Penticton, British Columbia.
  • Millet, F. W., & Warnick, Karl Foster. (July (3rd Quarter/Summer) 2004). Validity of rough surface backscattering models. Journal Article, Academic Journal. Waves in Random Media, Institute of Physics, London. 14 , 327-347.
  • Jensen, Michael Allen, & Warnick, Karl Foster. (June 2004). Comment on `Coulomb Torque - A General Theory for Electrostatic Forces in Many-body Systems'. Journal Article, Academic Journal. Journal of Physics A: Mathematical and General, Institute of Physics. 37 , 6409-6411.
  • Davis, C. P., & Warnick, Karl Foster. (June 2004). Error analysis of moment method solutions for 3D scattering problems. Conference Proceedings. USNC/URSI National Radio Science Meeting, Proceedings of USNC/URSI National Radio Science Meeting, Monterey, CA. , 280.
  • Hansen, C. K., Warnick, Karl Foster, & Jeffs, Brian D. (June 2004). Interference cancellation using an array feed design for radio telescopes. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, IEEE, Piscataway, NJ. , 539-542.
  • Hansen, C. K., Warnick, Karl Foster, & Jeffs, Brian D. (June 2004). Interference cancellation using an array feed design for radio telescopes. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, IEEE, New York. 1 , 539-542.
  • Davis, C. P., & Warnick, Karl Foster. (June 2004). The physical meaning of the Sobolev norm in error estimation. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, IEEE, Piscataway, NJ. , 3377-3380.
  • Warnick, Karl Foster, Millet, F. W., & Arnold, David Verl. (March 2004). Validity of backscattering models for Gaussian and power-law rough surfaces. Conference Proceedings. Progress in Electromagnetics Research Symposium, Proceedings of Progress in Electromagnetics Research Symposium, Pisa, Italy. , 28-31.
  • . (2003). Electromagnetic bias estimation using in situ and satellite data part I: RMS long wave slope. Journal Article, Academic Journal. Journal of Geophysical Research-Oceans, . 108 , 10 pages.
  • . (2003). Electromagnetic bias estimation using in situ and satellite data part II: A nonparametric approach. Journal Article, Academic Journal. Journal of Geophysical Research-Oceans, . 108 , 10 pages.
  • . (June 2003). Adaptive interference cancellation using an array feed design for radio telescopes. Conference Proceedings. Proceedings of the USNC/CNC/URSI North American Radio Science Meeting, Columbus, OH, June 22-27,2003, . , 642.
  • . (June 2003). Convergence rates of 2D moment method solutions for the MFIE and EFIE. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, Columbus, OH, . 2 , 1080-1083.
  • . (June 2003). Real-time adaptive cancellation of GLONASS interference in OH signal observations at the Green Bank Telescope. Conference Proceedings. Proceedings of the USNC/CNC/URSI North American Radio Science Meeting, Columbus, OH, June 22-27,2003, . , 641.
  • . (June 2003). Validity study of rough surface scattering models. Conference Proceedings. Proceedings of IEEE Antennas and Propagation Society International Symposium, Columbus, OH, . , 565-568.
  • . (May 2003). Electromobility focusing of proteins in small channels. Conference Proceedings. 26th International Symposium on Capillary Chromatography and Electrophoresis, Las Vegas, NV, May, .
  • . (May 2003). Improved interference cancellation in synthesis array radio astronomy imaging using auxiliary antennas. Conference Proceedings. Proceedings of IEEE International Conference on Acoustics, Speech, and Signal Processing, Hong Kong, . , V77-V80.
  • . (January (1st Quarter/Winter) 2003). Voltage controlled separation of proteins by electric field gradient focusing in a dialysis hollow fiber. Journal Article, Academic Journal. Journal of Chromatography A, . 985 , 455-462.