摘要
介绍了星载L波段高效固态功率放大器设计。放大器由EPC电源和射频链系统组成。电源主要提供射频电路和低频控制电路所需工作电压,同时接受母线控制指令以及遥测数据。射频链由驱动级、中功率放大器和高功率电路组成,同时还包括控制电路、检波电路、隔离器等。为了获得大功率和高效率,整机中高功率模块采用CREE公司的CGH40045氮化镓器件为放大单元,利用其大信号模型和ADS电路设计软件,采用L型阻抗变换网络,把输出阻抗的虚部电抗结合到输出匹配电路中,完成基波匹配和二次谐波的调谐。设计中还包括消除低频和射频振荡的电路。在连续波测试中,末级放大器模块在Vds为28V、Vgs为-2.8V、工作频率1.2GHz条件下,模块输出功率58W,效率68%,增益为19dB。在100MHz带宽内,增益平坦度小于0.8dB。放大器整机在1.15~1.25GHz范围内输出功率大于50W,效率大于50%,整机增益大于47dB。在从-20~60°C全温范围内,放大器整机功率最大变化小于0.6dB。
A high efficiency and high output power GaN power amplifier for L-band space application is presented.The amplifier is composed of Electric Power Condition（EPC）and RF System.The EPC can provide the RF circuit and control circuit with work voltage,and then receive the control instruction and remote testing instruction from the main bus.The RF system consists of the driver power amplifier,middle power amplifier and high power amplifier and is incorporated of control circuit,power monitor circuit and high power isolator.In order to obtain high power and efficiency,the high power amplifier module was developed using GaN high electron mobility transistor（HEMT）of Cree Company.The L-section ladder network was designed with a largesignal model and ADS software.The output capacitance was embedded into the output network,and the source impedance and load impedance were transformed to system impedance.The fundamental matching and second harmonic tuning were implemented.Circuits for eliminating the low frequency oscillation and RF oscillation were also designed.Under Vds=28V,Vgs=58Wpower amplifier achieves a 68% PAEat 1.2GHz under CW operating conditions.The gain flatness is0.8dB in the band.Besides,the RF performances of this power amplifier are output power of 50 W with the efficiency of 50%,and the gain of 47 dB.Its output power changes 0.6dB from -20℃ to 60℃.
出处
《固体电子学研究与进展》
CAS
CSCD
北大核心
2014年第5期440-444,454,共6页
Research & Progress of SSE
