UWB Double Ridge Waveguide Coupler with Low Loss

A new ultra-wide band coupler obtained with two crossed double-ridge waveguides coupled through one aperture is proposed. The main features of the coupler include: operating frequency from 6 GHz to 18 GHz; coupling coefficient below -50 dB; return loss of all the ports under -15 dB; minimum directivity 15 dB; small size and low losses, which make it appropriate for high-power applications. The whole structure is simulated with CST and HFSS software, fabricated and measured. Excellent agreement between measured and simulated results was achieved.