Ka-band Harmonic Image Rejection Mixer Mmic Design

Monolithic Microwave Integrated Circuits (MMIC) has many advantages such as small size, high reliability, low parasitic, good consistence and low cost with mass-production. So it is the most attractive choice for both military and civil communication systems. Millimeter-wave mixer is a key part in T/R components, and the image rejection mixer can perform well in the condition of low IF signal and broad band. Considering the difficulties and cost of high frequency LO, harmonic mixer is a good solution to these problem with the frequency of LO down to 1/2 or 1/4 of itself.In the design of second harmonic image rejection mixer, the input port of LO and RF are double balun and lange bridge respectively. LO signal is input through balun and mixed with RF signal to wipe off odd harmonic mix frequency. The final simulation result presents that the conversion loss is 11-11.7dB and the image rejection is above 26 dB in the band of 35-37GHz while the frequency of IF is fixed to fo. In the design of forth harmonic image rejection mixer, the input port of LO and RF are Wilkinson power devider and lange bridge respectively. The final simulation result presents that the conversion loss is 12.2-13.7dB and the image rejection is above 28 dB in the band of 34-36GHz while the frequency of IF is 0-1 GHz. And the measured result presents that the conversion loss is 12-16dB and the image rejection is above 16 dB.