A Study of a Broadband Difference Phase Shifter for a Corrugated Waveguide

Radio telescopes for future observations need to have outstanding capacities and high levels of versatility. It is also important to enlarge detection fields of radio telescopes through increasing efficiencies and sensitivities. A waveguide polarizer is the most important device in a radio receiver, and a phase shifter is a key component of a waveguide polarizer. A high-performance phase shifter can enhance astronomical applications of a radio receiver. Based on a detailed analysis of characteristics of a phase shifter for a corrugated waveguide we propose a design to optimize the structure of a difference phase shifter working in 32GHz-48GHz (7mm-band) for a corrugated waveguide. Our simulations show that it can generate phase shifts within 90°±7.5° throughout a relative bandwidth of 40% with its VSWR (Voltage Standing Wave Ratio) only about 1.02. The design is expected to help development of receiver systems in radio astronomy given the small size, broad working bandwidth, and high performance of the phase shifter.