DC-to-150 GHz Bandwidth InP HBT Mixer Module With Upper-Sideband Gain-Enhancing Function

This article presents a wideband (WB) mixer module for next-generation optical communications. The mixer module includes 0.8- and 1-mm coaxial connector interfaces and implements an active mixer IC fabricated using indium phosphide (InP) double hetero-junction bipolar transistor (DHBT) technology. For the mixer IC, we devised an upper-sideband (USB) gain-enhancing technique using a common-mode-gain boosted differential pair and differential local oscillator (LO) signals with a phase offset. The fabricated mixer module achieved a conversion gain (CG) of −4 dB and an RF bandwidth of 150 GHz, from direct current (dc) to 150 GHz, which is the widest bandwidth ever reported.