A Broadband Filter Phase Shifter Based on The Load Line

In this paper, a broadband filter phase shifter based on the load line is proposed and simulated. The problem that the filter phase shifter cannot achieve broadband and low phase shift error at the same time is solved. The filter phase shifter adopts a dual-channel structure, including the main path and the reference path, which are composed of loaded line resonators. The phase shift value is the phase difference between the main path and the reference path. In this paper, the resonant characteristics of the load line resonator are studied by odd-even mode analysis and transfer matrix analysis. By adjusting the position of the resonant point, the main path and the reference path form a band-pass network with similar performance. By adjusting the impedance ratio between the load line and the main transmission line, the phase-shift value will fluctuate, and its linear transformation law will be changed to realize the broadband phase-shift function. The simulation results show that this structure can achieve the filtering bandwidth of 1.5GHz to 2.5GHz, the return loss is better than 16dB, and the phase shift of 90 ° ± 2 ° can be achieved.