A switchable microstrip patch antenna for multi-frequency operation is presented. The antenna is fed by a coplanar waveguide via capacitive coupling slot. The antenna allows easy reconfigurability of the frequency band of operation by incorporating switches in the coupling slot. The resonant frequency of the antenna can be adjusted by setting the switches on or off. Two prototypes are presented. The first incorporates two PIN diodes and capable of switching between four frequency bands, over a frequency range of 1.23:1. The second prototype incorporates four PIN diodes and is capable of switching between sixteen frequency bands, over a frequency range of 1.5:1. The structure has a compact and simple biasing circuit. Simulation and measurement indicate that the proposed antennas demonstrate very good impedance matching, stable radiation patterns and good gain at all frequency bands.
2. Krishna, D., C. K. Aanandan, P. Mohanan, and K. Vasudevan, "Electronically switchable circular microstrip antenna with sector-slot for multiple frequency operation," IEEE Antennas and Propagation Society International Symposium, APSURSI' 09, 4277-4280, 2006.
3. Singh, M., A. Basu, and S. K. Koul, "Switchable frequency bands microstrip antennas," IEEE International Workshop on Antenna Technology, IWAT 2009, 1-4, 2009.
4. Tekin, I. and M. Knox, "Reconfigurable dual band microstrip antenna for software defined radio applications," IEEE International Conference on Wireless Information Technology and Systems (ICWIST), 1-4, 2010.
5. Liu, Y.-C. and K. Chang, "Multiband frequency reconfigurable antenna by changing the microstrip connecting element position," Antennas and Propagation Society International Symposium, ASPURI 2009, 1-4, 2009.
6. Sung, Y. J. , B. Y. Kim, T. U. Jang, and Y. S. Kim, "Switchable triangular microstrip patch antenna for dual-frequency operation," Antennas and Propagation Society International Symposium, ASPURI 2004, Vol. 1, 265-268, 2004.
7. Zammit, J. A. and A. Muscat, "Tunable microstrip antenna using switchable patches," Loughbrough Antenna and Propagation Conference, LAPC 2008, 233-236, 2008.
8. Jin, N., F. Yang, and Y. R. Samii, "A novel patch antenna with switchable slot (PASS): Dual frequency operation with reversed circular polarizations," IEEE Transactions on Antennas and Propagation, Vol. 54, No. 3, 1031-1034, 2006.
9. Saed, M., "Reconfigurable broadband microstrip antenna fed by coplanar waveguide," Progress In Electromagnetics Research, Vol. 55, 227-239, 2005.
10. Laheurte, J. M., "Switchable CPW-fed slot antenna for multifrequency operation," Electron. Lett., Vol. 37, No. 25, 1498-1500, Dec. 6, 2001.
11. Luxey, C., L. Dussopt, J. L. Le Sonn, and J. M. Laheurte, "Dual-frequency operation of CPW-fed antenna controlled by pin diodes," Electron. Lett., Vol. 36, No. 1, 2-3, Jan. 6, 2000.
12. Tarboush, H. F. A., S. Khan, R. Nilavan, H. S. Al-rawshidy, and D. Budimir, "Reconfigurable wideband patch antenna for cognitive radio," Loughbrough Antenna and Propagation Conference, LAPC 2009, 141-144, 2009.
13. Sim, C. Y. D., T. Y. Lin, and J. S. Row, "Aperture-coupled antenna with switchable polarisation and frequency agility," Electron. Lett., Vol. 45, No. 17, 865-866, Dec. 6, 2009.
14. Mansour, G., P. S. Hall, P. Gardner, and M. K. A. Rahim, "Switchable multi-band coplanar antenna," Antennas and Propagation Conference, LAPC, 1-4, Loughbrough, Nov. 14-15, 2011.
15. Balanis, C. A., Antenna Theory: Analysis and Design, 2nd Ed., John Wiley & Sons, Inc., New York, USA, 1997.
16. Garg, R., P. Bhartia, I. Bahl, and A. Ittipiboon, Microstrip Antenna Design Handbook, Artech House, Inc., 2001.
17. Giauffrat, L. and J. M. Laheurte, "Parametric study of the coupling aperture in CPW fed microstrip antennas," IEE Proc. Microwaves, Antennas and Propagation, 169-174, 1999.
18. Giauffret, L., J. M. Laheurte, and A. Papiernik, "Study of various shapes of the coupling slot in CPW-fed microstrip antennas," EEE Transactions on Antennas and Propagation, Vol. 45, No. 4, 642-647, 1997.