This communication presents a novel compact and wideband circularly polarized (CP) slot antenna fed by microstrip feedline. The proposed antenna consists of a corner-truncated square-ring slot patch and a novel bent strip. The CP radiation is formed by using the bent strip to excite CP resonance modes. By intruding several open stubs to the corners of the square-ring slot patch, the impedance matching and axial ratio (AR) bandwidth are improved. The measured results show that the proposed antenna has the advantage of wideband characteristics in terms of an impedance bandwidth of 90.59% (3.2-8.5 GHz) and 3-dB axial ratio bandwidth of 84.2% (3.3-8.1 GHz). The principle as well as simulated and measured results of the proposed antenna is revealed.
2. Nosrati, M. and N. Tavassolian, "Miniaturized circularly polarized square slot antenna with enhanced axial-ratio bandwidth using an antipodal Y-strip," IEEE Antennas and Wireless Propagation Letters, 2605099, 2016.
3. Sze, J.-Y. and W.-H. Chen, "Axial-ratio-bandwidth enhancement of a microstrip-line-fed circularly polarized annular-ring slot antenna," IEEE Transactions on Antennas and Propagation, Vol. 59, No. 7, 2011.
4. Jan, J.-Y., C.-Y. Pan, K.-Y. Chiu, and H.-M. Chen, "Broadband CPW-fed circularly-polarized slot antenna with an open slot," IEEE Transactions on Antennas and Propagation, Vol. 61, No. 3, 2013.
5. Yeung, S. H., K. F. Man, and W. S. Chan, "A bandwidth improved circular polarized slot antennausing a slot composed of multiple circular sectors," IEEE Transactions on Antennas and Propagation, Vol. 59, No. 8, 2011.
6. Zhang, H., Y.-C. Jiao, L. Lu, and C. Zhang, "Broadband circularly polarized square-ring-loaded slot antenna with flat gains," IEEE Antennas and Wireless Propagation Letters, Vol. 16, 2017.
7. Karamzadeh, S., V. Rafii, M. Kartal, and H. Saygin, "Compact UWB CP square slot antenna with two corners connected by a strip line," Electronics Letters, Vol. 52, No. 1, 10-12, 2016.
8. Ellis, M. S., Z. Zhao, J. Wu, X. Ding, Z. Nie, and Q.-H. Liu, "A novel simple and compact microstrip-fed circularly polarized wide slot antenna with wide axial ratiobandwidth for C-band applications," IEEE Transactions on Antennas and Propagation, Vol. 64, No. 4, 2016.
9. Pourahmadazar, J., Ch. Ghobadi, J. Nourinia, N. Felegari, and H. Shirzad, "Broadband CPW-fed circularly polarized square slot antenna with inverted-L strips for UWB applications," IEEE Antennas and Wireless Propagation Letters, Vol. 10, 2011.
10. Pan, Y. and K. W. Leung, "Wideband circularly polarized trapezoidal dielectric resonator antenna," IEEE Antennas and Wireless Propagation Letters, Vol. 9, 2010.