Title :
Enhanced CDMA performance from an InGaP/InGaAsN/GaAs N-p-N double heterojunction bipolar transistor
Author :
Yarborough, R. ; Landini, B. ; Welser, R. ; Yang, J. ; Henderson, T.
Author_Institution :
TriQuint Semicond. Inc., Richardson, TX, USA
Abstract :
We have demonstrated the DC characteristics and CDMA performance of an NpN InGaP/InGaAsN/GaAs double heterojunction bipolar transistor (DHBT) and compared the results to conventional InGaP/GaAs HBTs. A 100 mV reduction in base-emitter turn-on voltage and 35 mV reduction in offset voltage is established relative to InGaP/GaAs HBTs using a low energy-gap InGaAsN alloy base material and optimized heterointerfaces. InGaP/InGaAsN DHBT structures with high p-type doping levels (/spl sim/3/spl times/10/sup 19/ cm/sup -3/) have demonstrated DC current gains of /spl beta/=70 at 350 /spl Omega///spl square/ base sheet resistance. The DC current gain of InGaP/InGaAsN DHBTs has been improved by 46 % by grading the base layer composition. InGaAsN DHBTs have demonstrated 1.9 GHz CDMA IS-95 performance of 21 dBm output power (0.31 mW//spl mu/m/sup 2/ - 933 mW/mm), with 18.5 dB associated gain and greater than 53 % power-added efficiency at 45 dBc ACPR and 3 V operation. This represents an 83 mW/mm increase in output power and 3.8 percentage points improvement in PAE performance relative to InGaP/GaAs HBTs.
Keywords :
III-V semiconductors; UHF bipolar transistors; UHF power amplifiers; cellular radio; code division multiple access; doping profiles; gallium arsenide; gallium compounds; heterojunction bipolar transistors; indium compounds; semiconductor device measurement; 1.9 GHz; 18.5 dB; 3 V; 53 percent; CDMA IS-95 performance; CDMA performance; DC characteristics; DC current gains; InGaP-GaAs; InGaP-InGaAsN-GaAs; InGaP/InGaAsN DHBT structures; InGaP/InGaAsN/GaAs N-p-N DHBT; InGaP/InGaAsN/GaAs N-p-N double heterojunction bipolar transistor; associated gain; base layer composition grading; base sheet resistance; base-emitter turn-on voltage; cellular systems; low energy-gap InGaAsN alloy base material; offset voltage; optimized heterointerfaces; output power; p-type doping levels; power amplifiers; power-added efficiency; wireless handsets; DH-HEMTs; Double heterojunction bipolar transistors; Electrons; Gallium arsenide; Heterojunction bipolar transistors; Multiaccess communication; Photonic band gap; Power generation; Telephone sets; Voltage;
Conference_Titel :
Gallium Arsenide Integrated Circuit (GaAs IC) Symposium, 2002. 24th Annual Technical Digest
Conference_Location :
Monterey, California, USA
Print_ISBN :
0-7803-7447-9
DOI :
10.1109/GAAS.2002.1049076
