Fully metallic frequency selective surface (FSS) circular polarizer based on cost‐effective chemical etching manufacturing technique

Abstract This letter presents a fully metallic circular polarizer based on a bandpass frequency selective surface (FSS) that converts linear polarization (LP) to circular polarization (CP) in the Ka‐band. The proposed FSS circular polarizer consists of three cascaded identical perforated metal screens. The Jerusalem slot is used as the element of the FSS circular polarizer to produce an entirely metallic screen with a compact footprint. The Jerusalem slot allows the all‐metallic design to be realized without mechanical issues. A 35 × 35 elements prototype has been designed and manufactured using a cost‐effective chemical metallic etching technique, and performed measurements agree well with the numerical simulations. At broadside direction (θ=0∘), the proposed polarizer operates from 27.5–30.1 GHz, while at the oblique angle of incidence θ=20∘, the operating frequency is reduced to 27.7–29.4 GHz. The manufactured prototype has a low insertion loss (IL), i.e. ILmax≤1 dB and a good axial ratio performance, i.e. AR ⩽ 2 dB at the desired operating frequency band. Thus, based on a cost‐effective manufacturing technique, the proposed circular polarizer demonstrates an excellent approach to devising all‐metallic FSS polarizers with good IL