In this paper an oscillator-type GaN HEMT based active integrated antenna is proposed where the active part of the circuit and patch antenna are in series. The patch antenna is designed to offer optimum impedance at second harmonic to generate maximum power at second harmonic and overall negative resistance at fundamental frequency for sustained oscillation. The circuit has been designed, fabricated and characterized. The fundamental frequency of oscillation of this circuit is 1.5 GHz. This circuit has Effective Isotropic Radiated Power (EIRP) of 32.1 dBm at 3 GHz. Power at fundamental frequency is suppressed due to mismatch of input impedance of patch antenna and deviation from optimum load required for maximum radiation at fundamental frequency. The power radiated at fundamental frequency is 15.7 dB lower than the power radiated at second harmonic. This design technique can be used for radiating useful high power much beyond the cutoff frequency of the transition of active device.
2. Mishra, U. K., P. Parikh, and Y.-F. Wu, "AlGaN/GaN HEMTs-an overview of device operation and applications," Proceedings of the IEEE, Vol. 90, No. 6, 1022-1031, Jun. 2002.
3. Van Leeuwen, J. (ed.), Computer Science Today. Recent Trends and Developments. Lecture Notes in Computer Science, Vol. 1000, Springer-Verlag, Berlin Heidelberg, New York, 1995.
4. Kaper, V. S., et al., "High-power monolithic AlGaN/GaN HEMT oscillator," IEEE Journal of Solid-State Circuits, Vol. 38, No. 9, 1457-1461, Sept. 2003.
5. Micovic, M., et al., "GaN MMIC technology for microwave and millimeter-wave applications," IEEE Compound Semiconductor Integrated Circuit Symposium, 2005, CSIC’05, 173-176, Palm Springs, CA, USA, 2005.
6. Hasegawa, N. and N. Shinohara, "C-band active-antenna design for effective integration with a GaN amplifier," IEEE Transactions on Microwave Theory and Techniques, Vol. 65, No. 12, 4976-4983, Dec. 2017.
7. Pengelly, R. S., S. M. Wood, J. W. Milligan, S. T. Sheppard, and W. L. Pribble, "A review of GaN on SiC high electron-mobility power transistors and MMICs," IEEE Transactions on Microwave Theory and Techniques, Vol. 60, No. 6, 1764-1783, Jun. 2012.
8. Kumari, R., A. Basu, and S. K. Koul, "Development of GaN HEMT based high power active integrated antenna," 2018 IEEE MTT-S International Microwave and RF Conference (IMaRC), 1-4, Kolkata, India, 2018.
9. Chang, K., R. A. York, P. S. Hall, and T. Itoh, "Active integrated antennas," IEEE Transactions on Microwave Theory and Techniques, Vol. 50, No. 3, 937-944, Mar. 2002.
10. Qian, Y. and T. Itoh, "Progress in active integrated antennas and their applications," IEEE Transactions on Microwave Theory and Techniques, Vol. 46, No. 11, 1891-1900, Nov. 1998.
11. Choi, D.-H. and S.-O. Park, "Active integrated antenna using T-shaped microstrip-line-fed slot antenna," 2005 IEEE Antennas and Propagation Society International Symposium, 213-216, Washington, DC, 2005.
12. Qin, Y., S. Gao, and A. Sambell, "Broadband high-efficiency circularly polarized active antenna and array for RF front-end application," IEEE Transactions on Microwave Theory and Techniques, Vol. 54, No. 7, 2910-2916, Jul. 2006.
13. Lee, J., C. T. M. Wu, and T. Itoh, "A power efficient active integrated antenna," Microwave and Opt. Technol. Letters, Vol. 55, No. 6, 1240-1243, 2013.
14. Ooi, S. F., S. K. Lee, A. Sambell, E. Korolkiewicz, and S. Scott, "A new approach to the design of a compact high efficiency active integrated antenna," Microwave and Optical Technology Letters, Vol. 50, No. 3, 585-589, Mar. 2008.
15. Wandinger, L. and V. Nalbandian, "Millimeter-wave power combiner using quasi-optical techniques," IEEE Transactions on Microwave Theory and Techniques, Vol. 31, 189-193, Feb. 1983.
16. Ibrahim, S. H., "Design and analysis considerations of 4GHz integrated antenna with negative resistance oscillator," Progress In Electromagnetics Research B, Vol. 13, 111-131, 2009.
17. Choi, D. H. and S. O. Park, "Active integrated antenna using a T-shaped microstrip coupled patch antenna," Microw. Opt. Technol. Lett., Vol. 44, No. 5, 434-436, Mar. 2005.
18. Ma, T., Y. Chang, H. N. Chu, and W. Liao, "Frequency reconfigurable self-oscillating active integrated antenna using metamaterial resonators and slotted ground radiator," 2019 13th European Conference on Antennas and Propagation (EuCAP), 1-5, Krakow, Poland, 2019.
19. Cai, M., X. Li, and G. Yang, "C-band self-oscillating active integrated antenna," 2017 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, 1209-1210, San Diego, CA, 2017.
20. Wu, C. and T. Ma, "Self-oscillating semi-ring active integrated antenna with frequency reconfigurability and voltage-controllability," IEEE Transactions on Antennas and Propagation, Vol. 61, No. 7, 3880-3885, Jul. 2013.
21. Liu, Y. and H. Chang, "Design of a V-band active integrated antenna (AIA) with voltage controlled oscillator," Proceedings of the 2012 IEEE International Symposium on Antennas and Propagation, 1-2, Chicago, IL, 2012.