面向脉冲调制器的S波段高效线性MMIC功率放大器

S⁃band High Efficiency and Linearity MMIC Power Amplifier for Pulse Modulator

针对脉冲调制全数字发射机中高速数字信号难以高效驱动射频功率放大器的问题,提出了一种高效线性MMIC功率放大器设计方法。采用连续F类功率放大器提高数字发射机系统的效率,采用三阶互调抵消改善临近饱和线性度。基于南京电子器件研究所GaAs pHEMT工艺,研制了一款S波段高效率线性功率放大器进行验证。测试结果表明,在3.4~4.0 GHz频段内,当输入功率为-10 dBm时,输出功率为26.2~26.7 dBm,功率附加效率为53.3%~60.7%,功率增益为36.2~36.7 dB。在3.7 GHz频点,输出功率为24.5 dBm,三阶互调失真小于-30 dBc;9 dB峰均比、40 MHz正交频分多路复用的64-QAM调制信号激励下,平均输出功率及对应的功率附加效率分别为20.5 dBm和28%,实现了-30 dBc的邻道功率比及5.5%的误差向量幅度。

A design of high efficiency and linearity monolithic microwave integrated circuit(MMIC)power amplifier(PA)was presented to promote the poor-efficiency of RFPA,which direct-ly driven by high-speed digital signal in pulse-modulated all-digital transmitters.Meanwhile,the con-tinuous class-F PA was implemented to improve the efficiency of the digital transmitter system.More-over,a linearized technique based on third-order intermodulation(IMD3)cancellation was adopted to enhance the linearity performance near saturation.An S-band high efficiency and linearity PA proto-type in Nanjing Electronic Devices Institute GaAs pHEMT technology was realized for verification.The measured results demonstrate that the achieved output power of 26.2-26.9 dBm with 53.3%-60.7%power-added efficiency(PAE)and 36.2-36.7 dB power gain between 3.4 GHz and 4.0 GHz at-10 dBm input power.Especially,the measured IMD3 at 3.7 GHz is below-30 dBc with an output power level of 24.5 dBm.For a 64-QAM orthogonal frequency division multiplexing signal with 40 MHz bandwidth and 9 dB peak-to-average power ratio,the PA exhibits an adjacent channel power ratio of-30 dBc and error vector magnitude of 5.5%when the average output power and PAE are 20.5 dBm and 28%,respectively.