First Demonstration of Distributed Amplifier MMICs With More Than 300-GHz Bandwidth

Abstract

This article reports on the first demonstration of distributed amplifier monolithic microwave integrated circuits (MMICs) with a bandwidth (BW) of more than 300 GHz. The three presented circuits utilize a uniform traveling-wave amplifier topology with six, eight, and ten unit cells, respectively. In this article, the impact of the connection between the gate line and the transistors on the achievable performance is investigated. It is demonstrated that a short connection clearly provides a more favorable combination of BW, input matching, and losses on the gate line. Thus, it is possible to extend the BW beyond 300 GHz while utilizing transistors with a gate width of 2 × 10 µm. The MMICs are fabricated in a 35-nm gate-length InGaAs metamorphic high-electron-mobility transistor technology. The MMIC with six unit cells exhibits a noise figure (NF) between 3.5 and 8.2 dB for a noise-optimized bias from 1 GHz up to the measurement limit of 308 GHz. The MMIC with ten unit cells achieves a minimum NF of 2 dB for frequencies of around 50 GHz and stays below 10 dB for the entire band. Furthermore, for a power-optimized bias, the same circuit generates an output power between 8.7 and 14.8 dBm for a frequency range from 1 to 250 GHz.

670-GHz Cascode Circuits Based on InGaAs Metamorphic High-Electron-Mobility Transistors

“…Using the lowest metal layer MET1 as RF and DC ground, the implementation of compact thin-film matching networks is feasible with these layer stacks and utilized in this work. A detailed description of the BEOL and possible layer sequences for thin-film wiring-including the corresponding transmission-line characteristics-are given in [12].…”

“…In this work, our 35-nm InGaAs-channel metamorphic HEMT (mHEMT) technology is used for the investigation of cascode-based amplifier TMICs around 670 GHz. Using this mHEMT technology, distributed amplifier circuits with a bandwidth in excess of 300 GHz have been demonstrated recently in [12]-based on cascode gain cells. Furthermore, Manuscript received August 10, 2021; revised October 11, 2021; accepted December 09, 2021.…”

A 1–170-GHz Distributed Down-Converter MMIC in 35-nm Gate-Length InGaAs mHEMT Technology

“…The MMICs are designed and fabricated in a 35-nm gate-length metamorphic high-electron-mobility transistor (mHEMT) technology [19] and utilize thin-film microstrip transmission lines (TFMSLs) using the first metal This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/ layer as ground plane and the 2.7-μm-thick third metal as signal strips [1].…”

High-Gain 670-GHz Amplifier Circuits in InGaAs-on-Insulator HEMT Technology

“…For more information, see https://creativecommons.org/licenses/by/4.0/ dc and RF ground, thin-film-microstrip lines (TFMSLs) with a MET2 and MET3 signal line are utilized for the routing of the matching and bias insertion networks, independent of the Si substrate. A more detailed description of the BEOL process and possible layer configurations for compact TFMSL networks are, furthermore, given in [7] and [8].…”