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 mm2. The amplifier consumes a current of 80 mA at a supply voltage of 3.3 V.