A 2.4-V low-reference-voltage operation, InGaP HBT-MMIC power amplifier module for CDMA applications

This paper describes circuit design and measurement results of a newly developed InGaP/GaAs HBT MMIC power amplifier module (PA) which can operate with 2.4-V low reference (V_ref) and supply voltages of its on-chip bias circuits. To achieve the low-V_ref operation, the following two new circuit design techniques are incorporated into the IC: (i) two different kinds of bias feeding (current feed, and voltage-/current-feed) to AC-coupled power stages, and (ii) successful implementation of a diode linearizer built in the power stage. Measurement results at 900 MHz, a 3.5-V V_cc , and a 2.4-V V_ref show that the PA meets J-/W-CDMA power and distortion specifications sufficiently over a wide temperature range from -10 to 90degC while keeping a low quiescent current of less than 65 mA. For J-CDMA modulation, the PA can deliver a 27.5-dBm P_out, a 40% PAE, and a -50-dBc ACPR, while a 28-dBm P_out , a 42% PAE, and a -42-dBc ACLR are achieved for W-CDMA modulation