一种预失真可调InGaP/GaAs HBT射频功率放大器

A New InGaP/GaAs HBT RF Power Amplifier with Programmable Pre-distortion

提出了一种具有可调预失真功能的共集电极放大电路,对其动态偏置点及双负反馈回路进行了分析。AWR Microwave Office仿真表明：该预失真电路产生的增益扩展与负相位偏差可以补偿该功率放大器后级电路产生的增益压缩和正相位偏差,提高其线性度。采用该预失真电路作为输入级,设计了一款功率放大器,并基于截止频率为29.5GHz的2μm InGaP/GaAs HBT工艺成功流片。测试结果表明,该宽带放大器在3.5V偏置电压下和1.3~2.0GHz频段范围内功率增益可达27dB,P1dB为28.6dBm,最大功率附加效率为39%。

A controllable pre-distortion amplifier circuit was proposed,which was a common-collector circuit with dual negative feedback loops.Dynamic bias point of the circuit and its dual negative feedback loops were analyzed.Results from simulation based on AWR Microwave Office showed that this pre-distortion circuit achieved a gain expansion and a negative phase deviation,which could compensate for the gain compression and positive phase deviation of the following output stage.By using the pre-distortion circuit as input stage,a power amplifier was designed and fabricated in 2 μm InGaP/GaAs 29.5 GHz HBT process.Test results showed that,at a bias voltage of 3.5 V,the wideband amplifier had a power gain up to 27 dB,an output power of 28.6 dBm at 1 dB gain compression point and a maximum power added efficiency up to 39% over the frequency range from 1.3 GHz to 2.0 GHz.