A 182 GHz Triple-Stacked Distributed Amplifier in InP HBT Process

This paper presents a wideband distributed amplifier (DA) in an Indium Phosphide (InP) heterojunction bipolar transistor (HBT) process. The DA integrates eight gain cells, each designed with a triple-stacked topology to achieve high gain and output power. An emitter resistive-capacitive (RC) degeneration is incorporated within each gain cell to reach a broad bandwidth. Furthermore, each cell is equipped with a back-side-via, which facilitates immediate grounding for shunt elements. This feature enables the DA to maintain a flat gain and avoid potential instability issues. The $D A$ achieves an average gain of $12 \mathrm{~dB}$ with a $5 \mathrm{~dB}$ gain peaking at 165GHz compared to the gain at low frequency. The DA demonstrates a 3-dB bandwidth ranging from DC to 182GHz. It outputs a maximum saturated power $\left(P_{s a t}\right)$ of 14dBm and a peak output power at 1-dB compression point $\left(\mathrm{P}_{1 \mathrm{~dB}}\right)$ of 9.8dBm. Within the frequency spectrum of 1-170 GHz, the $D A$ delivers an average $P_{\text {sat }}$ of 12.2dBm.