A High Linearity SiGe D-Band Diode Ring Mixer

Although the SNR and thus the maximum range of FMCW radar systems benefit from high output powers, they can conventionally be limited by the receiver linearity. As a solution, we propose a fully integrated diode-based down-conversion ring mixer designed in Infineon's B11HFC 130nm SiGe BiCMOS technology. Excellent port isolation allows this architecture to be used throughout the D-band up to the power range substantially exceeding the state-of-the-art. The mixer exhibits a measured, maximum 1 dB compression point of 11.9dBm and a minimum voltage loss of 1.1 dB. Complemented by a matching network and optimized for connection to an operational amplifier, it represents a competitive alternative to conventional, active approaches.