Comparison of two kinds of Ka‐band circular polarisers for use in a gyro‐travelling wave amplifier

This study presents a rigorous theoretical and experimental comparison of two kinds of rectangular waveguide polarisers for use in Ka‐band gyro‐travelling wave amplifier. It is shown how overall field distribution inside of polariser structures having different kinds of corrugation affects the resulting performances. To the best of the authors’ knowledge, this is the first theoretical estimation of the breakdown power (in watts) of sine‐corrugated polariser in competition with conventional polariser having rectangular shaped corrugation. This study also discusses the general practice of smooth structuring in microwave and millimetre‐wave component design.