Novel design for differential phase shifter structure by using multi‐section coupled lines

Abstract

In this Letter, a new wideband differential phase shifter is proposed by using a multi-section coupled line structure. S-parameter circuit equations and design parameters are calculated using even/odd mode and transmission line analysis techniques for a set of phase shifters (from 0 to 90 with a step of 10°) of the proposed device. The proposed form is the first work that adds multi-section structures on the coupled line to provide any desired phase shift to the same reference line. In addition, for specific applications such as hyperthermia, the beamforming is ensured to be at small angle steps (10°) to focus the signal to the correct spot. The device is modelled with full-wave electromagnetic simulator Computer Simulation Technology (CST). Ten prototypes of differential phase shifters are designed, manufactured, and tested for the accuracy of simulation results. The simulated and measured results are in good agreement with the theory and show a bandwidth of 20.4%, 1 dB insertion loss across the 2.2–2.7 GHz frequency range.