An active frequency doubler with DC-100GHz range

A broadband, active doubler based on asymmetrically biased differential pairs delivers conversion gain (CG) from DC to 100 GHz. Measured CG is >10 dB up to 50 GHz, >6 dB up to 80 GHz, and >0 dB up to 100 GHz. Second-harmonic (4× the input) suppression is -28 dBc at 50 GHz. Implemented in a 90 nm SiGe technology, the 0.371 mm
²
multiplier core consumes 25 mA from a 4.5 V supply.