MMIC Power Amplifier Applications of Heterojunction Bipolar Transistors(HBTs)(Joint Special Issue on Heterostructure Microelectronics with TWHM 2000)

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概要

• 論文の詳細を見る

• This paper compares the performance of SiGe and GaAs HBT power amplifiers for wireless handset applications. To make a fair comparison, we have designed and characterized monolithic SiGe power amplifiers and compared their performance with similarly designed commercial GaAs power amplifiers for both cellular dual-mode(CDMA/AMPS)and PCS CDMA handsets. The designed SiGe cellular power amplifier, at 824-849MHz, satisfies both CDMA and AMPS requirements in output power, linearity and efficiency. At Vcc=3V, the power amplifier shows excellent linearity(1st ACPR < -44.1dBc and 2nd ACPR < -57.1dBc)up to 28dBm for CDMA applications. Under the same bias conditions, the power amplifier also meets AMPS handset requirements in output power(up to 31dBm)and linearity(with 2nd and 3rd harmonic to fundamental ratios lower than -37dBc and -55dBc, respectively). At the maximum output power level, the worst power-added-efficiences(PAE)are measured to be 36% for CDMA and 49% for AMPS operations. The performance of SiGe cellular power amplifiers is comparable to that of GaAs HBT power amplifiers but with two exceptions: 1)SiGe power amplifier showed a relatively low gain than that of GaAs amplifiers(about 4-6dB). This may be attributed to the use of low-Q inductors(Q<5)for on-chip impedance matching, imprecise device modeling and the higher interconnect parasitics; 2)SiGe power amplifiers survived severe output mismatch(VSWR > 12:1)up to Vcc = 4V but died instantly as Vcc > 4.5V, due to their low breakdown voltages. We also observed inter-modulation spurs(-22dBc)appeared in CDMA outputs at two specific tuning angles, but with no spurs appeared in AMPS outputs at any tuning angle. The possible mechanism for generating those output spurs will be discussed as well. In addition, We also designed and characterized a monolithic SiGe power amplifier for PCS(1850-1910MHz)CDMA handset applications. At Vcc = 3.5V, the SiGe PA satisfies the linearity requirement up to maximum power output 28dBm with a comparable gain(23-26dBm), but has a relatively low PAE(&Sime;25%)compared with that of GaAs counterparts at the high output power end.

• 社団法人電子情報通信学会の論文
• 2001-10-01

著者

• Zhang Liyang

  University Of Electro-communications

• TSENG Pei-Der

  Electrical Engineering Department, University of California

• ZHANG Liyang

  Electrical Engineering Department, University of California

• CHANG Mau-Chung

  Electrical Engineering Department, University of California

• Zhang Liyang

  Electrical Engineering Department University Of California

• Tseng Pei-der

  Electrical Engineering Department University Of California

• Chang Mau-chung

  Electrical Engineering Department University Of California

関連論文

• MMIC Power Amplifier Applications of Heterojunction Bipolar Transistors(HBTs)(Joint Special Issue on Heterostructure Microelectronics with TWHM 2000)

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