A SiGe MMIC variable gain cascode amplifier

A silicon-germanium variable gain cascode amplifier has been developed to combine the functionality of an amplifier and an attenuator into one monolithic microwave integrated circuit (MMIC). The cascode amplifier, which was designed for a 7-11 GHz frequency range, achieved a gain of 12.5 dB, an input return loss of 7.5 dB, and an output return loss of 12.5 dB. The cascode amplifier exhibited 16 dB of gain control.