An Output Coupler for a W-Band High Power Wideband Gyroamplifier

An output coupler for a W-band high power wideband gyroamplifier has been designed, manufactured, and experimentally measured. It consists of a high performance sin
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-parallel corrugated horn integrated with a broadband multilayer window. The major design requirements are that the horn/window combination must have an input return loss lower than -30 dB over a 10-GHz bandwidth, provide a high quality output beam pattern, and operate under ultrahigh-vacuum conditions. The coupler converts a circular waveguide TE11 mode into the free space Laguerre Gaussian LG00 mode over the frequency band of 90-100 GHz with a measured return loss of between -30 and -40 dB and a simulated Gaussian coupling efficiency of over 99% at 94 GHz.