2017 Volume 14 Issue 9 Pages 20170245
A Q band sub-harmonic mixer with wideband radio frequency (RF) and high intermediate frequency (IF) is proposed. The mixer employs a short-circuited band-pass filter (BPF) and a RF-IF diplexer, which provide proper terminations for the IF, RF, and local-oscillator (LO) signals simultaneously, and reject the major unwanted mixing products. A Q-band sub-harmonic mixer is designed and fabricated. The measured results show that the proposed sub-harmonic mixer can operate from 40 to 50 GHz for RF and support up to 10 GHz for IF bandwidth. As a down-conversion mixer, the measured conversion-loss is less than than 10.5 dB over the available RF band, while the minimum conversion-loss is about 6.8 dB at an RF of 45 GHz and IF of 5 GHz. As an up-conversion mixer, the measured conversion-loss is less than 11 dB over the available IF band, while the minimum conversion-loss is about 7.5 dB at an RF of 45.5 GHz and IF of 5.5 GHz.