The Research And Design Of A C-band 6-bit Digital Phase Shifter Using CMOS Technology

T/R module is the key component of phased array radar system.How to improve the performance of T/R module has become a hot research topic in the field of communication.As an important part of T/R module,the performance of digital phase shifter directly affects the performance of components and phased array system.The traditional passive structure phase shifter is usually realized by using III-V compound semiconductor materials.Large area and high cost always restrict its integration in phased array system.With the development of integrated circuit technology and the improvement of design level,the characteristic frequency of silicon-based CMOS transistors can meet the requirements of RF integrated circuits.The advantages of silicon-based technology,such as high integration and low cost,can effectively solve the problem of difficult integration of compound semiconductor material phase shifters,which makes the requirements of high performance,high integration and low cost for phased array transceiver chips come true.In this context,a five-bit active digital phase shifter using SMIC 0.13μm RF CMOS technology is designed.The main achievements in this paper are as follows:1.Based on the principle of vector synthesis,the orthogonal signal generator and analog adder,which are two key components of vector modulated phase shifter,are studied theoretically and topologically.The quadrature signal generator is realized by orthogonal all-pass filter and the analog adder is realized by two Gilbert units.2.An on-chip Barron with stacked topology is designed,which has the advantages of low loss,high differential port symmetry and small size.The simulation results of electromagnetic field show that the phase difference of the differential port signal is less than6 degrees,the insertion loss is 2.33 dB,the insertion loss error is less than 0.6 dB,and the area is 314μm*126μm.3.Based on orthogonal all-pass filter,two-way Gilbert cell analog adder and stacked on-chip Barron,a C-band 5-bit vector modulated digital phase shifter is successfully designed.The joint simulation results of ADS and Cadence software show that the phase shifter achieves 32 phase-shifting functions in 4.5-7.5 GHz band.The minimum phase-shifting function is 11.25 degrees,the insertion loss(IL)-8.5 dB~-11.7 dB,the input echo loss(S11)is better than-10.6 dB,the output echo loss(S22)is better than-9.9 dB,the phase accuracy error of RMS is lower than 3.5 degrees,the insertion loss fluctuation of RMS is better than1.3 dB,chip area is 1.66*0.74mm~2,static power loss is 14.11mW.In this paper,the vector modulated phase shifter chip has obvious advantages in power consumption and area with the same phase shift number and accuracy.