In this paper, a new compact dual-polarized microstrip patch antenna is proposed. The patch is of rectangular shape and fed by a gap between the patch edge and a microstrip open end. Gap feeding at the edge of a rectangular patch antenna is proposed for the first time in this paper. This method of feeding occupies a negligible space compared to other feeding methods such as a quarter-wave transformer feeder, an inset feeder, a proximity coupler, and an aperture-coupled feeder. Dual-polarized radiation is realized by feeding a rectangular patch with two orthogonal gaps. First, a single-polarized patch is designed. The impedance matching property of the gap is analyzed using an equivalent circuit. Next, starting from dimensions of the single-polarized patch, a dual-polarized patch antenna is designed by optimizing the patch length and gap width. The designed antenna is fabricated and tested. The fabricated antenna has reflection coefficient less than -10 dB, port isolation greater than 30 dB, over 14.5-15.2 GHz, and a gain of 6.2 dBi at 14.9 GHz.
2. Gosh, S., A. Roy, and A. Chakrabarty, "Estimation of antenna factor of microstrip patch antenna as EMI sensor," Progress In Electromagnetics Research Letters, Vol. 3, 113-122, 2008.
3. Mandal, D., R. S. Kar, and A. K. Bhattacharjee, "Input impedance of rectangular microstrip antennas on non-radiating edges for different feed sizes," Progress In Electromagnetics Research C, Vol. 1, 191-198, 2008.
4. Notis, D. T., P. C. Liakou, and D. P. Chrissoulidis, "Dual polarised microstrip patch antenna reduced in size by use of peripheral slits," Proc. 34th European Microw. Conf, Vol. 1, 125-128, 2004.
5. Binu, P., S. Mridula, C.-K. Aanandan, K. Vasudevan, and P. Mohanan, "Electromagnetically coupled dual port dual band octagonal patch antenna," Proc. IEEE Int. Conf. Personal Wireless Comm., 305-307, 2005.
6. Min, K.-S., S.-H. Park, D.-C. Kim, and H. Arai, "Microstrip patch antenna with dual resonance and dual polarization," Proc. Asia Pacific Microw. Conf., Vol. 1, 158-161, 1999.
7. Simons, R. N., "Suspended rectangular/circular patch antennas with electromagnetically coupled inverted microstrip feed for dual polarization frequency," Proc. IEEE Int. Antennas Propog. Symp., Vol. 4, 2204-2207, 2000.
8. Caso, R., A. Buffi, M. R. Pino, and R. Nepa, "A novel dual-feed slot-coupling feeding technique for circularly polarized patch arrays," IEEE Microw. Wireless Comp. Lett., Vol. 9, 183-186, 2010.
9. Gao, X., H. Zhong, Z. Feng, and M. F. Iskander, "Low-profile planar tripolarization antenna for WLAN communications," IEEE Microw. Wireless Comp. Lett., Vol. 9, 83-86, 2010.
10. Yu, C.-C. and K. Chang, "Transmission-line analysis of a capacitively coupled microstrip ring resonator," IEEE Trans. Microw. Theory Tech., Vol. 45, No. 11, 2018-2024, 1997.
11. Jung, W., Y. Woo, and C. Ha, "Modified inset fed microstrip patch antenna," Proc. Asia Pacific Microw. Conf., Vol. 3, 1346-1349, 2001.
12. Koster, N. H. L. and R. H. Jansen, "The equivalent circuit of the asymmetric series gap in microstrip and suspended substrate lines," IEEE Trans. Microw. Theory Tech., Vol. 30, 1273-1279, 1982.
13. Kirschning, M., R. H. Jansen, and N. H. L. Koster, "Measurement and computer-aided modeling of microstrip discontinuities by an improved resonator method," Proc. IEEE Int. MTT-S Symp., Vol. 83, 495-497, 1983.
14. Balanis, C. A., Antenna Theory: Analysis and Design, 811-862, Wiley, New York, 2005.
15. Hoffmann, R. K., Handbook of Microwave Integrated Citcuits, 185-186, Artech House, Boston, 1987.
16. Edwards, T., Foundations for Microstrip Circuit Design, 2nd Ed., 107-108, John Wiley, New York, 1992.