A 275 GHz amplifier in 0A3μm SiGe

This paper presents a 275 GHz amplifier in an advanced 0.13 μm SiGe technology, which has been developed during the European funding project DOTSEVEN, featuring a f_T/f_max of 350/550 GHz. Thus the amplifier operates at 1 f_max. Utilizing a pseudo-differential common-base topology, it employs an inductive series-series feedback element at the single stage level to increase the maximum available gain while maintaining unconditional stability over the whole measured frequency band. To convert the differential input and output of the amplifier to single-ended ones for on-wafer measurements, a new wideband Marchand balun has also been developed and is presented here. Including balun losses of 5 dB in total, the amplifier has measured 10 dB gain at 275 GHz with a 3 dB bandwidth of 7 GHz. It consumes 69.3 mA from a 1.77 V supply. To the authors best knowledge, this amplifier has the highest operational frequency reported to date in any SiGe technology.