A broadband 10–95 GHz variable gain amplifier in a 130 nm BiCMOS technology

A wideband variable gain amplifier in a 130 nm BiCMOS technology has been designed, manufactured and characterized. The VGA is built of two cascaded differential emitter follower stages, followed by a cascode stage implemented by a common emitter stage and a common base stage. The combination of emitter follower stages with the cascode stage allows a considerably wider frequency response from DC to 110 GHz. It has been shown that a high-pass response can be achieved using emitter follower stages. The high-pass response is cascaded with the low-pass response of the cascode stage to realize a flat broadband output characteristic. This design method requires significantly less chip area than conventional used distributed amplifier for this bandwidth. The area needed for this VGA is 0.024 mm 2 . The amplifier consumes a current of 80 mA at a supply voltage of 3.3 V.