High Efficiency and Linear Dual Chain Power Amplifier without/with Automatic Bias Current Control for CDMA Handset Applications

摘要

New architectures of the dual chain InGaPudMMIC power amplifiers without/with automatic biasudcurrent control (ABC2) have been developed forudimproving efficiency in the low-power region whileudmaintaining the high linearity for all Pout regions. Forudlow standby current less than 25 mA, the amplifiersudinitially operate using small HBT arrays. For smalludchip size, high load impedance in low-power region,udand efficient power combining in high-power region,udphase-compensating L-C matching circuits using lowpassudand high-pass networks are used. A new simpleudpower detection and bias current control circuit isudemployed to the power amplifier, resulting inudautomatic gain control for Pout variation. Theudfabricated ABC2 power amplifier module shows goodudACPR more -48 dBc over all Pouts, and high efficiencyudof 6 % PAE (conventional 3.5~4%) at Pout=9 dBm,udand 37.5 % PAE at Pout=28 dBm.