1.2 V OPERATION POWER HETEROJUNCTION FET FOR DIGITAL CELLULAR APPLICATIONS

This paper describes 950 MHz power performance of 1.2 V drain bias ope ration n-AlGaAs/InGaAs/n-AlGaAs heterojunction FET's (HJFET) for perso nal digital cellular (PDC) applications, The fabricated HJFET with a 0 .8-mu m long WSi gate exhibited an on-resistance (r(on)) of 2.1 Ohm.mm and a maximum drain current of 640 mA/mm, Operated at 1.2 V drain bia s voltage, the HJFET with gate width of 28.0 mm demonstrated an output power of 30.0 dBm (1.0 W) and a power-added efficiency of 51.5% with an adjacent channel leakage power at 50 kHz off-center frequency of -5 0.8 dBc. Class A operation analysis, which shows a good coincidence wi th the measured PDC power performance, revealed that the excellent pow er performance with the relatively small gate width was due to the low r(on) of the fabricated HJFET.