Design Of Si-Substrate CMOS Ultra-Wideband Hign Precision Phase Shifter

Using 55 nm CMOS technology,a 6GHz-18 GHz 6bit high precision vector synthesis phase shifter was designed.The circuit includes a quadrature signal generator,an analog adder,a digital-to-analogue converter unit,and an output passive balun.The innovation of this phase shifter design is that the quadrature signal generator adopts the structure of first-order coupled line cascaded with second-order RC multi-phase filter,which has good broadband characteristics and can achieve lower phase shift error while reducing the insertion loss.The analog adder consists of two Gilbert unit circuits with left and right symmetry for transmitting in-phase and differential quadrature signals and vector synthesis,respectively;The digital-to-analog converter unit consists of common source and common gate current mirror circuit,which is used to convert the 6-bit control signal into a tail current ratio to provide the analog adder,and the module has a current tuning bit to reduce the phase shift error caused by processing deviation.The simulation results show that the range of RMS error is 0.41～1.13 degrees in the frequency range of6.7GHz-14 GHz,and 0.42～2.67 degrees in the frequency range of 6GHz-18 GHz,and the insertion loss is about 5d B,and the chip size is 1.4mm*1.2mm,the core size of phase shifter is 0.8mm*0.8mm.The additional modulation amplitude of phase shift is within ± 0.63 d B,the input and output return loss is less than-15 d B and-7d B respectively,the total chip power consumption is less than 12 m W,and the output power1 d B compression point is around-1d Bm.From the measured results,in the frequency range of 6GHz-15 GHz,the range of RMS is 0.5～1.5 degrees;in the frequency range of6GHz-18 GHz,the range of RMS is 0.5～3.2 degrees;the insertion loss is about 5d B,the additional modulation amplitude of phase shift is within ±0.55 d B,the input and output return loss are less than-15 d B and-5d B respectively,and the total power consumption of the chip is less than 12 m W.the simulation and test results are basically consistent.The vector synthesis phase shifter designed in this thesis meets the design requirements well,with the following specifications: in the frequency range of6GHz-18 GHz,the typical value of root mean square phase error(RMS)at room temperature is 2 degrees;Phase shift additional amplitude modulation ≤ ± 1d B;Insertion loss≤10d B;Phase shifter plate X-axis length ≤1mm;Power consumption≤15m W;Input and output return loss≤-10 d B,output power 1d B compression point≥0d Bm;The vector synthesis phase shifter designed in this article meets the design requirements well and achieves good phase shifting performance in the link,which can be applied in phased array systems.