REFRACTORY WNX W SELF-ALIGNED GATE GAAS POWER METAL-SEMICONDUCTOR FIELD-EFFECT TRANSISTOR FOR 1.9-GHZ DIGITAL MOBILE COMMUNICATION-SYSTEM OPERATING WITH A SINGLE LOW-VOLTAGE SUPPLY/
M. Nagaoka et al., REFRACTORY WNX W SELF-ALIGNED GATE GAAS POWER METAL-SEMICONDUCTOR FIELD-EFFECT TRANSISTOR FOR 1.9-GHZ DIGITAL MOBILE COMMUNICATION-SYSTEM OPERATING WITH A SINGLE LOW-VOLTAGE SUPPLY/, JPN J A P 1, 33(1B), 1994, pp. 767-770
We have developed a refractory WNx/W self-aligned gate GaAs power meta
l-semiconductor field-effect transistor (MESFET) for use in L-band dig
ital mobile communication systems. This power MESFET operates with hig
h efficiency and low distortion at a gate bias of 0 V and a low drain
bias of 2.7 V, because of its small drain knee voltage, high transcond
uctance and sufficient breakdown voltage. This power MESFET is quite p
romising for a highly efficient linear power amplifier IC operating wi
th a single low-voltage supply. Good output characteristics of the pow
er MESFET with 1 mm gate width were attained for pi/4-shifted quadratu
re phase shift keying (QPSK) modulated input signals in the 1.9-GHz ba
nd, such as an output power of 18.4 dBm, a power gain of 19.0 dB and a
high power-added efficiency of 26.4% when a sufficiently low adjacent
channel leakage power of -58 dBc was obtained.