RF bandwidths for cellular systems such as AMPS, TACS, GSM,
TDMA, and CDMA range from 800MHz to 1.0GHz. To provide RF
transmissions over this range of frequencies, Gallium Arsenide
(GaAs) has become the technology of choice and offers several
advantages over silicon technology: a much higher cutoff fre-
quency, higher breakdown voltage, lower noise figure, and higher
power-added efficiency. This translates to lower power dissipation
and longer talk time for cellular subscribers. AN808
UsingtheTC1142forBiasingaGaAsPowerAmplifier
APPLICATION CIRCUIT
Author: Patrick Maresca,
Microchip Technology, Inc. Figure1showsatypicalapplicationcircuitforbiasingaGaAsPA
inacellularsubscriberunit’stransmitter.Eachkeycomponentof
thecircuitisdescribedbelow.
INTRODUCTION
RFbandwidthsforcellularsystemssuchasAMPS,TACS,GSM, ……
