Design and Experiments of a Beam-Steerable Wideband Reflectarray Antenna for High-Power Microwave Applications

Abstract

A beam-steerable wideband reflectarray antenna (WRA) is presented in this communication. The WRA element operated at 3.3–5.5 GHz (relative bandwidth 50%) exhibits a continuous 360° phase coverage, and its power handling capacity (PHC) is estimated to exceed 4.5 GW/m2 in simulation, indicating its potential in high-power microwave (HPM) applications. Moreover, to verify the wideband performance of the WRA, a prototype was successfully designed, simulated, fabricated, and measured in the S- and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$C$ </tex-math></inline-formula> -bands. The WRA prototype is composed of an ultrawideband helical feed antenna, <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$25\times25$ </tex-math></inline-formula> antenna elements, and a dielectric plate as a radome. The results show that in the frequency band of 3.3–5.5 GHz, the WRA can achieve an arbitrary direction of reflection beam within ±60° (120° conical region). Additionally, at the center frequency of 4.4 GHz, its sidelobe level is consistently below −15 dB, while the maximum gain loss is 3.3 dB during beam steering, and the maximum aperture efficiency reaches 67.89% in the direction of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\theta _{0}=0$ </tex-math></inline-formula> ° and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\varphi _{0}=0$ </tex-math></inline-formula> °.