A 77–135GHz down-conversion IQ mixer for 10Gbps multiband applications

This paper presents a down-conversion IQ mixer in 0.13-μm SiGe BiCMOS. The mixer exhibits a measured conversion gain of 1.6 dB at f
_LO
= 135 GHz and P
_LO
= -4.2 dBm. It can directly down-convert 10-Gbps modulated millimeter-wave (mmWave) signals to base-band data. Without any design change or DC bias adjustment, the IQ mixer can operate at any frequency between 77 and 135 GHz. The mixer is therefore universal for many mmWave applications such as 77GHz automotive radars, 94GHz imaging, and 122GHz communications.