A novel compact CPW (coplanar waveguide-fed) CPSS (Circularly polarized square slot) antenna is presented. The proposed single-layer antenna is composed of a rectangular ground plane embedded with two equal-size patches along two orthogonal directions. Equal amplitudes with 90˚ phase difference values of two patches is capable are generating a resonant mode for exciting two orthogonal E vectors. Axial ratio (AR) bandwidth is significantly enhanced due to slot corner modification. The designed CPSS antenna is compact in nature with volume of 0.37λ0× 0.34λ0 × 0.012λ0 mm3 (λ0= free space wavelength at centre frequency of the CP bandwidth). It has impedance bandwidth between 4.65-6.72 GHz (36.41%) and 3-dB axial-ratio bandwidth of 520 MHz (4.85-5.37 GHz), which covers 4.9 GHz (802.11j) WLAN for public safety ranging from 4.94 GHz to 4.99 GHz and WLAN (U-NII-1 and U-NII-2A) ranging from 5.150-5.350 GHz for indoor use. The gain variation for the frequencies within the CP bandwidth is also observed to be less than 0.6 dBic. The design is successfully implemented, and measured results are compared with the simulated ones, which are found in good agreement.
2. Balanis, C. A., Antenna Theory Analysis and Design, Wiley, Hoboken, NJ, USA, 2005.
3. Babakhani, B., S. K. Sharma, and G. Mishra, "Wideband circularly polarized his backed fan-shaped antenna with directional patterns covering L1-L5 gps bands," Microw. Opt. Technol. Lett., Vol. 59, 497-500, 2017.
4. Chandu, D. S. and S. S. Karthikeyan, "A novel broadband dual circularly polarized microstrip-fed monopole antenna," IEEE Trans. Antennas Propag., Vol. 65, 1410-1415, 2017.
5. Sadeghi, P., J. Nourinia, and C. Ghobadi, "Square slot antenna with two spiral slots loaded for broadband circular polarisation," IEEE Electronics Lett., Vol. 52, 787-788, 2016.
6. Xu, R., J. Y. Li, J. J. Yang, K. Wei, and Y. X. Qi, "A design of U-shaped slot antenna with broadband dual circularly polarized radiation," IEEE Trans. Antennas Propag., Vol. 65, 3217-3220, 2017.
7. Lai, X. Z., Z. M. Xie, Q. Q. Xie, and X. L. Cen, "A dual circularly polarized RFID reader antenna with wideband isolation," IEEE Antennas And Wireless Propagation Lett., Vol. 12, 1630-1633, 2013.
8. Yang, F. and Y. R. Samii, "A reconfigurable patch antenna using switchable slots for circular polarization diversity," IEEE Microw. and Wireless Components Lett., Vol. 12, 96-98, 2002.
9. Zhao, G., L. N. Chen, and Y. C. Jiao, "Design of a broadband dual circularly polarized square slot antenna," Microw. Opt. Technol. Lett., Vol. 50, 2639-2642, 2008.
10. Zhang, C., X. Liang, X. Bai, J. Geng, and R. Jin, "A broadband dual circularly polarized patch antenna with wide beamwidth," IEEE Antennas and Wireless Propagation Lett., Vol. 13, 1457-1460, 2014.
11. Jiang, L. T., S. X. Gong, T. Hong, and W. Jiang, "Broadband CPW-fed slot antenna with circular polarization," Microw. Opt. Technol. Lett., Vol. 52, 2111-2114, 2010.
12. Wong, K. L., J. Y. Wu, and C. K. Wu, "A circularly polarized patch-loaded square-slot antenna," Microw. Opt. Technol. Lett., Vol. 23, 363-365, 1999.
13. Jeevanandham, N., Nasimuddin, K. Agarwal, and A. Alphones, "Dual-band circularly polarized hexagonal-slot antenna," European Microwave Conference (EuMC 2012), Amsterdam RAI, The Netherlands, Oct. 29-Nov. 02, 2012.
14. Nasimuddin, A. Alphones, and N. Jeevanandham, "Circularly polarized slot antennas with wideband performance," Asia-Pacific Microwave Conference (APMC 2015), Nanjing, China, Dec. 06–Dec. 09, 2015.
15. Chen, W. S., K. L. Wong, and C. K. Wu, "Inset microstripline-fed circularly polarized microstrip antennas," IEEE Trans. Antennas Propag., Vol. 48, 1253-1254, 2000.
16. Sung, Y. J., "Circularly polarized Mercedes-Benz logo antenna for gps applications," Microw. Opt. Technol. Lett., Vol. 58, 2308-2311, 2016.
17. Fairouz, M. and M. A. Saed, "A sequentially rotated, circularly polarized microstrip antenna array with reduced mutual coupling," Journal of Electromagnetic Waves and Applications, Vol. 36, 422-433, 2016.
18. Pourahmadazar, J. and V. Rafii, "Broadband circularly polarised slot antenna array for L- and S-band applications," IEEE Electronics Lett., Vol. 48, 542-543, 2012.
19. Karamzadeh, S., V. Rafii, M. Kartal, and H. Saygin, "Compact UWB CP square slot antenna with two corners connected by a strip line," IEEE Electronics Lett., Vol. 52, 10-12, 2016.
20. Chen, J. M. and J. S. Row, "A simple design for slotted patch antennas with broadband circular polarization," Microw. Opt. Technol. Lett., Vol. 57, 1854-1857, 2015.
21. Deng, I. C., J. B. Chen, Q. X. Ke, J. R. Chang, W. F. Chang, and W. T. King, "A circular CPW-fed slot antenna for broadband circularly polarized radiation," Microw. Opt. Technol. Lett., Vol. 49, 2728-2733, 2007.
22. Shekhawat, S. and V. Sharma, "Circularly polarized square patch microstrip antenna with Y-shaped slot for Wi-Max application," Euro. J. Adv. Engg. Tech., Vol. 1, 65-72, 2014.
23. Rana, B. and S. K. Parui, "Microstrip line fed wideband circularly-polarized dielectric resonator antenna array for microwave image sensing," IEEE Sensors Lett., Vol. 1, 3500604, 2017.
24. Campbell, E., "Bluetooth radio design considerations for cellular handset application,", RF Global net.
25. Majidzadeh, M., J. Nourinia, and C. Ghobadi, "Compact CPW-fed antenna with circular polarization characteristics in WLAN frequency band," Applied Computational Electromagnetics Society (ACES), Vol. 28, No. 10, 938-943, 2013.
26. Nasimuddin, Z. N. Chen, and X. Qing, "Symmetric-aperture antenna for broadband circular polarization," IEEE Trans. Antennas Propag., Vol. 59, No. 10, 3932-3936, Oct. 2011.
27. Nasimuddin, Z. N. Chen, and X. Qing, "Wideband circularly polarized slot antenna," European Microwave Conference (EuMC 2012), Amsterdam RAI, The Netherlands, Oct. 29-Nov. 02, 2012.
28. Puttaswamy, P., P. S. K. Murthy, and B. A. Thomas, "Analysis of loss tangent effect on Microstrip antenna gain," Int. Journal of Applied Sciences and Engineering Research, Vol. 3, No. 6, 2014.