A broadband reflectarray with combination of subwavelength phasing elements

Abstract

A compact reflectarray antenna is presented here, consisting of different element types. Periodicity of the proposed unit cell smaller than 0.5λ in both directions is studied here. Non-resonant behavior of unit cells leads to solve the problem of inherently narrow bandwidth of such antenna. Main aim of unit cell design is focused to get phasing elements fitted in subwavelength grid size as well as to get full range of 360 degree reflection phase angle. The proposed array is fabricated on a low loss PTFE substrate of thickness 0.053 λ at 5 GHz and illuminated by an offset feed horn antenna. Radiation pattern results show a very précised far-field beam with 3-db beamwidth of 7.5 and 7.3 degree for two principle planes respectively with a gain of 24 dB at 5 GHz.