High-Performance HEMT with an Offset-Gate Structure for Millimeter-Wave Monolithic Microwave ICs

Abstract

A process technology for a pseudomorphic high electron mobility transistor (P-HEMT) with an offset-gate structure has been developed for millimeter-wave monolithic microwave ICs (MMICs). A HEMT with the offset-gate structure showed both reduced gate-to-drain capacitance and drain conductance compared with a device with a non-offset-gate structure. The device showed a maximum available gain (MAG) of 9 dB at 77 GHz. The device was applied to a 77 GHz three-stage power amplifier, which showed a small-signal gain of 16.5 dB. Under preliminary life testing, this amplifier showed a stable small-signal gain for over 160 hours of testing at 175°C.

Investigation of impact ionization and flicker noise properties in indium aluminum arsenide/indium gallinum arsenide metamorphic high electron mobility transistors with various work function-gate metals

“…8(b) plots the measured f T and f max as functions of V DS , where V GS is biased at the Gm peak position. Clearly, f T of the Ti metal gate sample suddenly drops from 30.5 to 26.6 when the applied V DS exceeds to 1.5 V. Generally, the following well-known equation is shown as follows [23]:…”

Low-Frequency Noise Generated from High-Field Region in AlGaAs/InGaAs HEMTs

“…1) In nonlinear circuits such as mixers and oscillators, low-frequency noise (LFN) in HEMTs is upconverted to an intermediate frequency or a high frequency. Therefore, LFN in HEMTs is one of the major limitations on the performance of high-frequency analog circuits.…”

“…AlGaAs/InGaAs high-electron-mobility transistors (HEMTs) are widely used in millimeter-wave and optical communication systems due to their excellent high-frequency performance. 1) In nonlinear circuits such as mixers and oscillators, low-frequency noise (LFN) in HEMTs is upconverted to an intermediate frequency or a high frequency. Therefore, LFN in HEMTs is one of the major limitations on the performance of high-frequency analog circuits.…”