A Novel Hybrid-Channel Attenuation Measurement System at 50–110 GHz

A novel hybrid-channel attenuation measurement system has been built for the measurement of Vand W-band waveguide attenuators from 50 to 110 GHz. The measurement system combines two single channels of the V and W bands together into one system. The V-band channel is used as the measurement channel and the W-band channel is used as the synchronization channel when the V-band attenuator is measured and vice versa. The measurement system is free of cross talk between the two channels and removes the need for isolators between the local oscillator and the mixer since the RF signal frequencies in the two channels are different. In addition, a compensation module was designed to cancel the self-mixing produced by the W-band mixer at frequencies above 102 GHz. The expanded uncertainty of the system is evaluated to be 0.004-0.08 dB at frequencies ≤102 GHz and 0.005-0.11 dB at frequencies 102 GHz for an attenuation range from 0 to 80 dB.