十位数控射频移相器的设计与验证

Design and Verification of a 10-Bit Digital RF Phase Shifter

针对GSM超线性前馈功率放大器控制单元对信号相位控制的需求,利用ADS软件仿真并设计了一种射频移相器单元电路,该单元采用一个3dB电桥与4个变容二极管SMV1245组成了一个反射式射频移相网络,工作频率为930MHz～960 MHz,控制电压0～5 V。数字控制部分由ARM7主控芯片与十位数控DA芯片X9119组成。最终以聚四氟乙烯为介质的微带电路板实现、经网络分析仪实际测试可实现在0～147°范围内的相移控制,控制精度为10Bit,状态切换速度<300μs,插入损耗<-2.3dB,损耗波动<±0.7dB。

To meet the phase control requirement of the GSM ultra-linear feedforward power amplifier system, a RF phase shifter unit is designed and simulated by software ADS. In this unit, a reflection phase shift network is formed by a 3dB coupler and 4 varactor diodes SMV1245, working frequency at 930 MHz -960 MHz, control voltage 0 -5 V. An ARM7 main control and a 10 bit DA chip X9119 make up the digital control part. The design is taken into implement on an F4 microstrip board. The unit is tested by an network analyzer. The phase can be controlled in the range 0 147°. The control resolution is 10 bit,the switching time〈300 Ixs,insertion loss〈-2.3 dB ,loss fluctuation 〈＋0.7 dB.