A Broadband Reflection-Type Phase Shifter with Low Loss Variation Using Magic-T and Anti-Phase Reflection Loads

This paper presents a design of a broadband reflection-type phase shifter (RTPS) with a low insertion-loss variation. Unlike traditional RTPSs with a 90° hybrid coupler, the proposed one employs a Magic-T to enhance phase shifter performance. Additionally, anti-phase reflection loads are introduced, leading to compactness and broadband operation. The theoretical analysis reveals that the insertion loss is 0.4±0.3 dB in 50% fractional bandwidth, and the relative phase shift is 140°±10. The proposed RTPS is designed using a planar Magic-T, and the back-to-back configuration is tested for proof of concept. The results confirm the loss variation of less than 1.2 dB and the relative phase shift over 290° within 29% bandwidth.