Axial ratio bandwidth improvement of compact planar monopole antenna with dual‐band and dual‐sense.

Summary: A small size, dual‐band and dual‐sense monopole antenna is proposed to improve the axial ratio bandwidth (ARBW). The proposed antenna is considered on a low‐cost lossy FR4 substrate with parasitic strips (PSs) and partial ground plane of half guided wavelength dimensions. The dimension of the antenna in terms of wavelength is 0.27λ0×0.29λ0×0.02λ0, where λ0 is the wavelength at the lowest resonant frequency. The circularly polarized (CP) mode is created for strong orthogonal electric fields EX and EY. The obtained phase difference (PD) between two electric fields EX and EY is varied from 86° to 96° under ARBW. The achieved ARBW is 3.68–3.8 GHz, 4.84–12.58 GHz, and impedance bandwidth (IBW) is 3.51–3.82 GHz and 4.28–15 GHz. The applications of the proposed antenna are International Telecommunication Union (ITU) for 5G, C‐band IEEE 802.11a wireless local area network (WLAN) at 5 GHz (5.15–5.825 GHz) and X‐band wireless systems. [ABSTRACT FROM AUTHOR]