Low-voltage-operation high-power-density AlGaAs/InGaAs enhancement-mode pseudomorphic high-electron-mobility transistor for personal handy-phone handset application

Abstract

A high-power-density enhancement-mode AlGaAs/InGaAs pseudomorphic high-electron-mobility transistor (E-PHEMT) is developed for the Japanese personal handy-phone system (PHS). The E-PHEMT has a total gate width of 3.36 mm with a gate length of 0.5 mum. The E-PHEMT shows a high power density of 247 mW/mm at 3.6 V, 196 mW/mm at 3 V, 152 mW/mm at 2.4 V and 63 mW/mm at 1.2 V, this is the highest power density reported so far for E-PHEMT with similar device size and bias conditions. When the E-PHEMT was qualified by 1.9 GHz pi/4-shifted quadrature phase shift keying (QPSK) modulated signal for PHS at 2,4 V with idle current of 30 mA. the device shows a linear PAE of 35.1% with associated power gain of 15.5 dB at output power of 22.4 dBm. The adjacent channel leakage power (P(adj)) of the de ice is -56.6 dBc at 600 kHz apart from the center frequency. The E-PHEMT meets PHS specifications and demonstrates high power density, excellent power efficiency and linearity at low bias voltage.