D-band down conversion chipset with I-Q outputs using 0.13μm SiGe BiCMOS technology

This paper presents a D-band down conversion chipset using 0.13μm SiGe BiCMOS technology. The chipset consists of a 62.5GHz doubler and a 2nd sub-harmonic mixer (2× SHM) with I-Q outputs. The doubler uses a push-push topology. The 2× SHM uses SiGe HBT to form a cascode structure and followed with a source follower. The output 62.5GHz signal of the doubler is split into two ways by Wilkinson power divider: one way is fed to a 2× SHM directly, while the other way is fed to a 2× SHM after 45° phase shifting by microstrip line, thus the IF with I-Q output is achieved. The chip size is 1.6×0.85 mm2. The measurement results show that the peak conversion gain is 0.8dB with RF @137GHz (IF@12GHz) and LO @ 31.25GHz and the difference between I/Q output is less than 1 dB with the IF frequency 3-18 GHz.