Research And Design Of On-chip Active Vector-sum Phase Shifter

The active vector phase shifter based on CMOS technology has the advantages of low cost and high integration,which can greatly reduce the cost and volume of the phased array system.In this paper,three phase shifters are designed for low error,broadband and high gain performance,respectively.The main research contents and innovations are as follows:An active balun structure based on RC regulation is proposed to reduce the error of differential signals at high frequencies by adjusting the RC module of the common source branch.For the vector adder,a tail current source structure of the parallel MOS transistor array is proposed to achieve accurate phase shift control.In the Ku band,the differential signal has a phase error of less than 1.25° and an amplitude error of less than 20mdB.The 5bit phase shifter is manufactured and shows a measured root mean square(RMS)phase error of 5-7.3°,amplitude error of 0.71-0.83 dB and the chip size is 0.67 mm2 including all bond pads and ESD rings.A parallel MOS transistor array VGA is proposed to simplify the parameter conversion process of gain control to reduce error.A balun structure based on subtractor calibration is proposed,which realizes a differential signal with wideband and low error.And the use of cascaded broadband technology so that 3dB bandwidth covers the entire Ku band.In the Ku band,the differential signal has a phase error of less than 0.25° and an amplitude error of less than 30mdB.In the layout simulation of the 6bit phase shifter,at 10-20 GHz,the RMS insertion loss error is of 0.22-0.33dB,and the phase error is of 1.5-3.4°.A gm-C quadrature signal generator with inductor peaking technology is used to achieve the entire Ku band quadrature signal gain greater than zero at a power consumption of 5.7mW.And the input impedance is high that can maintain the voltage gain of the active balun.The 6bit phase shifter has a maximum gain of up to 15dB at a bandwidth of 3GHz.