MMIC power amplifier with on-chip bias current controlling circuit for W-CDMA mobile handset

A new on-chip bias current controlling circuit for efficiency enhancement has been devised and implemented to a W-CDMA InGaP/GaAs HBT MMIC power amplifier. It supplies a quiescent current of 86 (54) mA for a high (low) power mode operation. The reduced quiescent current at the low power mode operation improves the PAE as much as 21.6% at the output power of 20 dBm and 59.2% under 0 dBm output power compared to the high power mode operation only.