Pd. Tseng et al., A 3-V monolithic SiGeHBT power amplifier for dual-mode (CDMA/AMPS) cellular handset applications, IEEE J SOLI, 35(9), 2000, pp. 1338-1344
A dual-mode (CDMA/AMPS) power amplifier has been successfully implemented b
y using a monolithic SiGe/Si heterojunction bipolar transistor (HBT) foundr
y process for cellular handset (824-849 MHz) applications. The designed two
-stage power amplifier satisfies both CDMA and AMPS requirements in output
power, linearity, and efficiency. At V-cc = 3 V, the power amplifier shows
an excellent linearity (first ACPR < -44.1 dBc and second ACPR < -57.1 dBc)
up to 28 dBm of output power for CDMA applications. Under the same bias co
ndition, the power amplifier also meets AMPS handset requirements in output
power (up to 31 dBm) and linearity (with second and third harmonic to fund
amental ratios lower than -37 dBc and -55 dBc, respectively). At the maximu
m output power level, the worst power-added efficiencies (PAEs) are measure
d to be 36% for CDMA and 49% for AMPS operations. The power amplifier also
tolerates severe output mismatch (VSWR >12:1) up to V-cc = 4 V, with spurs
measured to be < -22 dBc in CDMA outputs at two specific tuning angles, but
with no spur in AMPS outputs at any tuning angle.