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The design of a wideband circularly polarized pixelated dielectric resonator antenna using a real-coded genetic algorithm (GA) is presented for far-field wireless power transfer applications. The antenna consists of a dielectric resonator (DR) which is discretized into 8 × 8 grid DR bars. The real-coded GA is utilized to estimate the optimal heights of the 64 DR bars to realize circular polarization. The proposed antenna is excited by a narrow rectangular slot etched on the ground plane. A prototype of the proposed antenna is fabricated and tested. The measured −10 dB reflection and 3 dB axial ratio bandwidths are 32.32% (2.62–3.63 GHz) and 14.63% (2.85–3.30 GHz), respectively. A measured peak gain of 6.13 dBic is achieved at 3.2 GHz.

Abstract-In this paper, a novel circularly polarized Spidron fractal slot antenna array developed for broadband satellite communication in the Ku-band is discussed. A Spidron fractal slot configuration was utilized as a single radiating element to achieve circularly polarized radiation. The effects of altering the feeding position on the resonance behavior and the radiative characteristics were assessed.As a consequence, the design was expanded from a single element to a 2×2 subarray and further to a 4×4 array in order to enhance the bandwidth performance of the antenna when integrated with a sequential feeding network. Two prototype arrays were fabricated and tested, and measurements revealed that the 2×2 subarray has a 10-dB reflection coefficient bandwidth between 10 and 14.28 GHz, 3 dB axial ratio bands between 10.15 and 11.15 GHz and between 11.75 and 13.92 GHz, and a maximum gain of 11.4 dB at 13 GHz. The results for the 4×4 array indicated that both the 10-dB reflection coefficient and 3 dB axial ratio bandwidths cover the entire operating frequency from 10 to 15 GHz in the Ku-band. The maximum gain for the 4×4 array was 15.63 dB at 12.6 GHz.

A printed ultra-wideband (UWB) antenna with dual band-notched characteristics based on electromagnetic band-gap (EBG) structure is presented. To produce dual-band rejection, the microstrip feed line is placed between two pairs of EBG cells which are designed to act as stop-band filters. The final design of the antenna satisfies the voltage standing wave ratio (VSWR) requirement of less than 2.0 in a bandwidth spreading from 2.275 GHz to 10.835 GHz, which entirely covers UWB frequency band allocated from 3.1 to 10.6 GHz. The antenna also shows dual band-notched performance at the frequency bands of 3.375 − 3.875 GHz for WiMAX and 5.325 − 6.150 GHz for WLAN, while possessing omni-directional characteristic in the whole operating frequency band. The results show good agreement between simulation and measurement.

A compact single-fed circularly polarized dielectric resonator antenna (DRA) with an enhanced 3-dB axial ratio bandwidth (ARBW) and gain is proposed. The DRA is implemented by joining a smaller dielectric resonator (DR) to one side wall of a main rectangular DR and is excited by an offset vertical metallic strip. With this configuration, two sets of degenerate orthogonal modes, the TE 111 mode and TE 113 mode, are simultaneously excited to realize wideband circular polarization operation. Furthermore, by removing a small DR portion from the lower corner of the main DR, the boresight gains at higher frequencies are significantly enhanced. An antenna prototype is fabricated and measured to verify the performance of the proposed design. The experimental results illustrate that the proposed antenna achieves a measured 3-dB ARBW of approximately 44.73% (3.68-5.80 GHz) in conjunction with a broad −10 dB impedance bandwidth of 69.66% (2.9-6.0 GHz). The measured boresight gain is found to be 5.49±0.85 dBic within the passband with a maximum value of 6.34 dBic at 4.7 GHz. Moreover, reasonable agreement between the simulated and measured results is achieved. INDEX TERMS Bandwidth enhancement, circular polarization, dielectric resonator antenna, higher order mode, wideband antenna.