A Novel Type of Rectangular-To-Radial Waveguide Transformer for RWSA at Ka-Band

A novel type of rectangular-radial waveguide transformer for RWSA (radial waveguide slot array antennas) at Ka-band with good stability, low machining difficulty and low insertion loss is designed in this paper. The manufacturing difficulty is enormously reduced by reasonable design of the top part of the transformer. By adjusting and optimizing parameters of the transformer in HFSS continuously, an adequate performance can be obtained. Both the return loss and the ripple feature are measured in this work, and the rectangular waveguide with proposed transformer can excite the dominant mode TEM in the radial waveguide.