An integrated 2 GHz 20 dBm 3 V wide band differential power amplifier with microstrip antenna interface

A highly efficient fully differential power amplifier (PA) for mobile terminals around 2 GHz is realized in 0.5 /spl mu/m BiCMOS process. The commonly used interface baluns are replaced by a 180/spl deg/ microstrip power divider and combiner. A microstrip power combiner is used to match the differential output impedance of the power amplifier with the usual 50 /spl Omega/ antenna load. A maximum output power of 20 dBm is obtained from a single 3 V power supply. The amplifier small signal gain is about 20 dB over a 1 GHz bandwidth. The power added efficiency (PAE) is 25%.