In this article, a coplanar waveguide fed ring slot antenna is proposed for the generation of circular polarization. It is shown that the bandwidth can be improved by adding a stub. Characteristics mode analysis is used to understand the wideband behavior and generation of circular polarization in different antenna configurations. Parametric analysis is used to optimize the performance of the antenna. The proposed antenna is fabricated and the measured results are compared with the simulated performance. The measured impedance bandwidth (|S11| ≤ －10 dB) is 64.6% (2.25 GHz–4.4 GHz) and a 3 dB axial ratio bandwidth is 64.6% (2.25 GHz–4.4 GHz).

A coplanar waveguide fed polarization reconfigurable monopole antenna is proposed in this letter. The proposed antenna consists of L‐shaped stubs placed on either side of a monopole, two p‐i‐n diodes and a slot in the ground plane. In the proposed antenna structure, the switching element is not directly connected to the feed line. Depending on the switching state of the p‐i‐n diodes, the antenna either radiates left/right circular polarization or linear polarization. To validate the proposed design, the antenna was fabricated and its performance was measured. Since the ground plane is electrically small, the effect of the cable and SMA connector on the performance of the antenna is also investigated. The measured impedance bandwidth is 66.78% (3.67 GHz to 7.35 GHz) and the axial ratio bandwidth is 13.62% (4.24‐4.86 GHz) for circular polarization and 23.61% (3.81‐4.83 GHz) impedance bandwidth for linear polarization.

A flexible dual‐band dual‐polarised CPW‐fed monopole antenna with discrete‐frequency reconfigurability is presented here. In the proposed antenna, to achieve dual‐band performance, a U‐slot is incorporated within the CPW‐fed monopole. The antenna is fabricated on a flexible and transparent substrate so that it can be used for conformal applications. The effect of antenna bending on its performance is discussed here. Further, the proposed antenna structure is extended to achieve discrete‐frequency reconfigurability. Two p‐i‐n diodes are incorporated within the monopole to achieve reconfigurability of higher band. A simplified equivalent circuit of the reconfigurable antenna is also presented and validated using full wave EM simulation. To validate the proposed structure, dual‐band antenna and discrete frequency reconfigurable antenna have been fabricated and tested.

This study presents a dual‐band circularly polarised (CP) coplanar waveguide fed split‐ring resonator‐loaded rectangular slot antenna. A wide‐frequency ratio (the ratio of the centre frequencies of the two bands) ranging from 1.2 to 2 can be achieved by changing the dimensions of the resonator. To demonstrate the concept, an antenna having two bands, one at 2.4 GHz and the other at 3.5 GHz, is designed and measured input reflection coefficient, axial ratio, and radiation pattern are compared with the simulation results and they are found to be in good agreement. Measured results show that the proposed antenna operates in two frequency bands with overlapping bandwidths of 32.13% (2.22–3.07 GHz) and 2.17% (3.415–3.49 GHz). The axial ratio and impedance bandwidths are used to compare the performance of the proposed antenna with some of the published dual‐band CP antennas.

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