A Fundamental Upconverting Gilbert Mixer for 100 GHz Wireless Applications

The design and characterization of an up-converting double balanced Gilbert cell mixer in a 0.5 μm InP DHBT process for applications in the 81-102 GHz range is presented. The process features a 4-metal layer stackup that invites to more complex designs compared to most III-V technologies. The presented mixer is a double balanced Gilbert cell design and includes an LO buffer amplifier as well as RF and LO Marchand baluns integrated on chip. The Gilbert cell mixer show excellent results in terms of; conversion gain of 13 dB, LO-RF isolation of 47 dB, output P1dB equals -10 dBm and the total power consumption is 170 mW. The frequency bandwidth covers 81 to 102 GHz.