True Broadband Technique for On-Chip-Series Connection of TWAs Using Differential Distributed Amplifiers

A new technique for series connection of monolithic broadband travelling wave amplifiers (TWAs) is presented, using differential distributed architectures. This technique is intrinsically broadband because no series capacitor is used, it starts operating at dc up to cut-off frequency. With a GaAs heterojunction bipolar transistor monolithic microwave integrated circuit process, two on-chip-series coupled 18 dB gain and 23 GHz cut-off frequency TWAs are realized. Our approach avoids packaging steps and hybrid components. This is a very promising result for monolithic high-gain broadband amplifiers.