A 250–300GHz Frequency Multiplier-by-8 Chain in SiGe Technology

This paper presents a fully-differential wideband and low power multiplier-by-8 chain covering the frequency band from 250 to 300 GHz, fabricated in a newly developed 130nm SiGe:C BiCMOS technology from IHP featuring ft / fmax of about 470 / 650 GHz. The fully differential multiplier chain consists of a Gilbert cell based frequency quadrupler followed by an amplifier and a frequency doubler. Broadband passive baluns are used both in input and in output for enabling single-ended measurements. The designed circuit achieves a measured 3 dB bandwidth of 50 GHz (18%). The peak saturated output power is -5dBm and the overall power consumption is 125mW, for a drain efficiency of 0.25%, occupying a silicon area of 0.4mm².