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

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 time300 μs,insertion loss-2.3 dB,loss fluctuation ±0.7 dB