Single 3.4 V operation power heterojunction FET with 60% efficiency for personal digital cellular phones

The authors describe the 950 MHz power performance of a double-doped AlGaAs/InGaAs/AlGaAs heterojunction FET (HJFET), operated at a single 3.4 V bias voltage. The developed 1.0 μm gate-length HJFET exhibited an on-resistance of 2.3 Ω·mm and a threshold voltage of -0.25 V. While operating with a single 3.4 V bias supply, a 16 mm gate-width HJFET exhibited an output power of 1.42 W (31.5 dBm) and 60.1% power-added efficiency with an adjacent channel leakage power of -48.2 dBc at an off-centre frequency of 50 kHz. The developed HJFET is promising for single-bias voltage operation power modules of personal digital cellular phones with a single Li-ion battery supply