Broadband phase shifter for K- and Ka- bands beam-steering networks

Design of microstrip coupled-line phase shifters for millimeter-wave (mm-Wave), K-, and Ka-bands beam-steering and radar applications, is presented in this paper. The proposed design utilizes multilayer printed circuit board (PCB) technology. The design is based on coupled transmission lines that use ring-shaped broadside-coupled patches and an elliptical-shaped slot etched in a common ground layer. The proposed design shows good return and insertion losses with minimum transmission phase imbalance across the frequency band of interest. As a proof the concept, we have designed two phase shifters with different phase shifts, i.e. 45° and 22.5°.