Title :
High-power high-efficiency X-band AlGaAs/GaAs heterojunction bipolar transistors with undercut collectors
Author :
Hin-Fai Chau ; Wilcox, G. ; Wenliang Chen ; Tutt, M. ; Henderson, Tim
Author_Institution :
Corp. Res. & Dev., Texas Instrum. Inc., Dallas, TX, USA
Abstract :
We report on the power performance of X-band AlGaAs/GaAs heterojunction bipolar transistors with undercut collectors for reduced base-collector capacitance. A 10×(2.8×50) μm2 HBT unit cell exhibited 2.09 W continuous wave (CW) output power (4.18 W/mm power density), 62.2% power-added efficiency, and 7.13 dB associated gain at 10 GHz at a collector bias voltage of 10 V. When tuned for maximum efficiency, the same transistor delivered a CW output power of 1.36 W, a power-added efficiency of 74.2%, and an associated gain of 7.32 dB at the same frequency and collector bias voltage. To our knowledge, this is the first demonstration of high-power (>1.3 W), high-efficiency (>74%) AlGaAs/GaAs HBT´s using a simple collector undercut technique without the need for significant modifications of baseline HBT process.
Keywords :
III-V semiconductors; aluminium compounds; capacitance; gallium arsenide; heterojunction bipolar transistors; microwave bipolar transistors; microwave power transistors; power bipolar transistors; 1.36 to 2.09 W; 10 GHz; 10 V; 62.2 to 74.2 percent; 7.13 to 7.32 dB; AlGaAs-GaAs; SHF; X-band; base-collector capacitance reduction; heterojunction bipolar transistors; high-efficiency type; high-power HBT; power performance; undercut collectors; Capacitance; Etching; Gain; Gallium arsenide; Heterojunction bipolar transistors; Instruments; Power generation; Process design; Substrates; Voltage;
Journal_Title :
Microwave and Guided Wave Letters, IEEE
