Linearized high efficient HBT power amplifier module for L-band application

A new on-chip linearizer that is applicable to L-band application is proposed. It is composed of base-emitter diode of the active bias transistor and a capacitor for RF signal shorting to the base node of the active bias transistor, which improves the gain compression and phase advance of the power amplifier with no additional DC power consumption, and has negligible signal loss with almost no increase in die area. The linearizer increases the 1 dB gain compression point by 18 dB and phase distortion by 16.49/spl deg/ while maintaining the base bias voltage of the power amplifier. A PCS and W-CDMA dual band power amplifier with single input, single output, and no switch for band selection is implemented by designing the amplifier with broadband characteristics, and exhibits an output power of 28.97(28.3) dBm, PAE of 44.7(37.4)%, and adjacent channel power ratio (ACPR) of -41(-45) dBc at the output power of 28(28) dBm under 3.0 V operation voltage for PCS(W-CDMA) applications.