A WCDMA 41% power efficiency direct DC coupled hybrid CMOS/GaAs power amplifier with pre-distortion linearization

Abstract

A 1710-1755MHz hybrid power amplifier module (PAM) consisting of a CMOS driver and a GaAs HBT output stage is described. By using multiple parallel CMOS driver stages the gain and bias current expansion needed to maintain the linearity into class C operation of the bipolar output stage is generated. This extends the linear output power range by 0.5 dBm and increases the power added efficiency (PAE) at ACLR1 of -40dBc from 39.0% at 28 dBm output power to 41.3% at 28.5 dBm output power for a WCDMA modulated signal. The PA achieves 43.5% PAE at 29 dBm Pout for an ACLR1 of -37 dBc with a gain of 26 dB and supply voltage of 3.4V.

Initial verification of a bandwidth tunable Ku-band power amplifier designed by the HySIC concept

“…We focus on the HySIC concept which utilizes GaAs monolithic microwave integrated circuit (MMIC) and a Si radio frequency integrated circuit (RFIC) for a design of a bandwidth tunable Ku-band power amplifier. Conventional proposals of the combination of GaAs MMIC and Si RFIC [7,8] were utilized for different power range circuit, for example, low power driver amplifier for Si RFIC and medium or high power amplifier for GaAs MMIC. However, we utilize Si RFIC for frequency tuning function and GaAs MMIC for main circuit of the power amplifier.…”

A multiband power amplifier using combination of CMOS and GaAs technologies for WCDMA handsets

“…To realize cost reduction and acceptable RF performance using CMOS, the combination of CMOS and InGaP HBT technologies has been proposed recently [5]. However, the fabricated PA module is a prototype, where the InGaP HBT chip is directly assembled on the evaluation board and a packaged CMOS is attached on the same board separately.…”