摘要
In this correspondence,a wideband circular-polarized(CP)transmitarray(TA)in the Ka-band is presented for generating a high-purity vortex beam.The proposed element is composed of two identical combinations separated by an air layer.The subwavelength structure and double-resonance characteristics ensure the stable phase shift of the element within the 1-dB transmission bandwidth of 28.4%.A square aperture TA fed by a horn antenna is fabricated and measured.Owing to the honeycomb arrangement of elements,the mode purity of l=−1 is>0.93 in a wide band from 28.5 to 38 GHz.The measured peak gain is 22.3 dBic,and the 3-dB axial ratio bandwidth is 27.6%.The performance of the proposed antenna demonstrates its potential for high-capacity wireless communication and high-quality radar imaging.
基金
supported by the National Natural Science Foundation of China(No.61971051)。
