Design of high-efficiency SiGe hetrojunction bipolar transistor linear power amplifier with new adaptive bias configuration

This study shows a 2.4 GHz linear power amplifier (PA) design with a new adaptive bias configuration using TSMC 0.35 μm SiGe hetrojunction bipolar transistor (HBT) technology, for wireless communication applications such as WLAN. The proposed bias configuration adequately compromises the consumed current and the output power to avoid dramatic current increases in the high-input power condition, while the output power capability is also maintained to achieve optimal efficiency through a proper size selection for the bias HBT. The final designed PA displays P_{1 dB} of 23.76 dBm and 29.76% power-added-efficiency (PAE) with a 33.1 dBm output-intercept-point in the third order (OIP3). The saturated output power is 27.54 dBm with 39.12% in PAE, while the chip size is 0.91 × 0.83 mm².