Circular polariser for use in a gyro‐travelling wave amplifier

Abstract

A corrugated rectangular waveguide, commonly used in radio frequency antennas applications, was considered for use in a gyro-TWA experiment. This waveguide transducer produced broadband circularly polarised radiation in the Ka-band frequency range (26??40 GHz). Computer simulations, using computer simulation technology Microwave Studio??, were carried out and predicted return losses exceeding 30 dB and a 6° phase variation for 20% bandwidth centred at 31 GHz. Comparison between experimental measurements and simulations showed good agreement. The performance of this polariser was also compared to that of a conventional elliptical converter. Owing to its broadband performance the authors consider some of the technical aspects of applying this component to a Ka-band gyro-TWA experiment

Comments on ‘circular polariser for use in a gyro‐travelling wave amplifier’

“…In [1], the authors explore the technical aspects of using sinusoid‐corrugated rectangular waveguide in the capacity of a circular polariser. The motivation of the work was to build circular polariser suitable for high‐power handling of gyro‐travelling wave amplifier over broadband frequency range.…”

“…However, in [1] the authors have not supported this idea with sufficiently firm proofs. There is neither any experimental nor theoretical estimation of breakdown power (in watt) for sine‐corrugated polariser in [1].…”

“…However, in [1] the authors have not supported this idea with sufficiently firm proofs. There is neither any experimental nor theoretical estimation of breakdown power (in watt) for sine‐corrugated polariser in [1]. Instead, the only substantiation attempt of claimed superior high‐power handling capability in [1] is regarding advantage in the longitudinal electric field strength.…”

“…There is neither any experimental nor theoretical estimation of breakdown power (in watt) for sine‐corrugated polariser in [1]. Instead, the only substantiation attempt of claimed superior high‐power handling capability in [1] is regarding advantage in the longitudinal electric field strength. Indeed, the eigenmode of corrugated waveguide possesses the longitudinally oriented component of the electric field.…”

“…Even if longitudinal component of E‐field is reduced that does not mean that overall high‐power capability becomes superior. Actually the authors of [1] realise fully that transverse E‐field predominates over longitudinal E‐field component (Fig. 5 [1]).…”