Deng, K.-L.K.-L.DengTIAN-WEI HUANGHUEI WANG2020-06-042020-06-042003https://www.scopus.com/inward/record.uri?eid=2-s2.0-0242636462&doi=10.1109%2fTMTT.2003.818583&partnerID=40&md5=d38a08ca20f951d9ef92fca5675e0a71Using the concept of traveling-wave gain stages, novel GaAs pseudomorphic high electron-mobility transistor monolithic-microwave integrated-circuit (MMIC) distributed amplifiers (DAs) are demonstrated to achieve high gain and over several octaves of bandwidth performance simultaneously for microwave and millimeter-wave frequency applications. The cascaded single-stage distributed amplifier (CSSDA) is used as traveling-wave gain stages to improve the gain performance of the conventional distributed amplifier (CDA). By adopting the low-pass filter topology between the CDA and CSSDA and tuning the gain shape of CDA and CSSDA separately, a broad-band and high-gain DA, called CDA-CSSDA-2, was accomplished. The detailed design equations are derived for the broad-band matching design of this CDA-CSSDA-2. Two other MMICs, namely, a two-stage CSSDA called 2-CSSDA, and another two-stage design called CDA-CSSDA-1, are also included in this paper. This CDA-CSSDA-2 achieves 22±1.5-dB small-signal gain from 0.1 to 40 GHz with a chip size of 1.5 × 2 mm2. It also produces a gain-bandwidth product of 503 GHz, which is the highest among all reported GaAs-based DAs. The flat group delay also demonstrates the feasibility of this design for future digital optical communications and broad-band pulse applications.Broad-band; Cascaded single-stage distributed amplifier (CSSDA); Conventional distributed amplifier (CDA); Distributed amplifier (DA); Monolithic microwave integrated circuit (MMIC); Traveling-wave gain stage[SDGs]SDG7journal article10.1109/TMTT.2003.8185832-s2.0-0242636462