Coplanar integrated mixers for 77-GHz automotive applications

For integration in receivers at 77 GHz, three passive mixers, a balanced diode mixer, a single ended and a balanced resistive mixer, as well as an active single-ended gate mixer have been realized in coplanar 0.15-mu m PM-HEMT technology on GaAs. The passive mixers achieved conversion losses of about 9 dB. The resistive mixers required an LO power of only 3 dBm and the diode mixer 10 dBm for optimum conversion. The gate mixer obtained a conversion gain of 1 dB for an LO power of 6 dBm but showed higher sensitivity to the IF load.