A circularly polarized printed antenna using an asymmetric open‐slot is designed in this paper. The presented antenna consists of conducting ground plane with open wide‐slot, fed electromagnetically by a microstrip feedline. The slot and feedline are positioned at the edge of the ground plane and substrate, hence making the antenna asymmetric. The measured results show that the |S₁₁| < −10 dB impedance bandwidth is 125% (3.2‐14 GHz) and the broadband axial ratio bandwidth is 61% (3.2‐6 GHz). The antenna is very simple and has a small size of 25 mm × 25 mm, making it attractive for compact wireless WLAN, ISM, WiMAX, and C‐band applications.

A novel miniature wideband microstrip antenna is presented. The proposed miniature design is achieved by exploiting the idea of a quasi‐radiator. Here, a part of the radiator is connected to the ground plane through a shorting pin or via. The proposed antenna achieves a starting frequency of 1.8 GHz with a small antenna area of 20 mm ² . An electrical size of 0.05 λ is realised leading to a miniaturised design. The proposed antenna is broadband, compact, and produces stable radiation patterns.

This paper presents the design of a simple dual-band circularly polarized monopole antenna using characteristic mode analysis. First, a dual-band elliptically polarized “L”-shaped monopole antenna with a partial ground is designed; then, a rectangular stub and a parasitic structure on the ground plane are implemented to achieve dual-band CP operation. To enhance impedance bandwidth and generate circular polarization in the upper band, the rectangular stub is attached to the “L”-shaped strip. The parasitic structure is employed for simultaneous dual-band CP radiation. Characteristic mode analysis is undertaken to predict the performance of the antenna before excitation. The modal analysis which is undertaken before excitation shows the natural modes that can be excited by the antenna structure to generate a dual-band CP response. The analysis gives approximate bandwidths that can be achieved by the antenna even before excitation. The overall dimension of the antenna , where is the corresponding free-space wavelength at 5.7 GHz. The measured -10 dB impedance bandwidth (ZBW) is realized to be 75.9% (4.5 GHz–10 GHz). The measured 3 dB axial ratio bandwidths (ARBW) at the lower and upper bands are 6% (5.6 GHz–5.95 GHz) and 28% (6.65 GHz–8.82 GHz), respectively. The proposed antenna features a simple and compact structure for Wi-Fi, WLAN, WiMAX, and C band applications.