Analysis and Design of High Gain-Bandwidth CMOS Distributed Amplifier Utilizing a Cascaded Pseudo Differential Distributed Amplifier

Abstract

Distributed amplifiers (DAs) are one of the most important and common wideband amplifiers that can use various arrangements in their gain cell structure. One of the gain cells that can be effective in increasing the bandwidth of a distributed amplifier is the pseudo-differential amplifier (PDA). Although pseudo-differential distributed amplifiers (PDDAs) have a wide bandwidth and amplify DC, they have a small voltage gain. In this paper, various circuits with the same power and chip area are proposed to improve the performance of PDDAs. For evaluating and comparing the performance of the proposed circuits, they are implemented in 0.18[Formula: see text][Formula: see text]m RF-CMOS technology. The simulation results reveal that two cascaded PDDAs with three stages have a better performance than three cascaded PDDAs with two stages; in two cascaded PDDAs with three stages, a gain of 9[Formula: see text]dB can be achieved for a bandwidth of 50[Formula: see text]GHz in 0.18[Formula: see text][Formula: see text]m RF-CMOS technology. In this amplifier, parameters S[Formula: see text], S[Formula: see text] and S[Formula: see text] are [Formula: see text]12, [Formula: see text]10 and [Formula: see text]18 dB, respectively; noise figure is 4.3–5.8[Formula: see text]dB, and [Formula: see text] is +4[Formula: see text]dBm. This amplifier consumes 220[Formula: see text]mW power and has a chip area of 0.58[Formula: see text]mm2.