Research On Silicon-based Millimeter-wave Multifunctional Amplifier Integrated Circuits

With the rapid development of mobile communication technology in recent years,exploring millimeter wave spectrum resources has become a development trend..The high-frequency characteristics of silicon-based semiconductor process active devices have been improved year by year,and low-cost,easy-to-integrate silicon-based milli-meter wave circuits have become a research hotspot.The silicon-based millimeter-wave variable gain amplifiers need to meet high-precision amplitude adjustment with a wide tuning range to reduce system amplitude errors.It is necessary to study the broadband matching imbalance principle and compensation methods of amplifier.The traditional bidirectional amplifiers use switch architectures for function switching and signal iso-lation,but millimeter wave switching loss is large.It is necessary to further explore new switchless circuit architectures to avoid switching loss and its non-ideal characteristics and reduce the chip size.It is necessary to explore the mapping relationship between the node impedance variation and the matching circuit impedance under different bias states of the transistor,to achieve a high isolation switchless bidirectional amplifier.The thesis investigates the existing achievements of silicon-based variable gain amplifiers and bidirectional amplifiers,analyzes the design principle of millimeter wave amplifier.The silicon-based millimeter-wave high-precision variable gain ampli-fier circuits and the switchless symmetric bidirectional amplifier circuits are proposed.（1）Aiming at the high-precision and wide-range tuning requirements of millimeter wave variable gain amplifiers,a new type of gain frequency response compensation circuit structure is proposed to improve the gain flatness in the tuning process,and a high-precision digital control bias circuit is designed.In order to verify the theory,based on Si Ge Bi CMOS 0.13μm process,the variable gain stage and the fixed gain stage cascade structure are used to complete the design and test of the 21.5～36 GHz variable gain amplifier.The test results show that the circuit has achieved a gain tuning range of-16.0～16.0 d B,the gain resolution is 0.5 d B,the output 1 d B compression point can reach 9.6 d Bm,and the chip power consumption is 23.5 m W,the chip area is 0.64mm×0.4 mm.The working bandwidth of the chip covers 5G NR n257 and NR n258bandwidth standard,which can be applied to the 5th generation communication high-precision radar phased array system.（2）Aiming at the switchless and high isolation requirements of millimeter wave bidirectional amplifiers,a bidirectional matching network structure that integrates the parasitic parameters of transistors in different working states is proposed to further re-duce the overall circuit area,realize the mirror symmetry layout of the chip layout and the optimization of signal isolation.In order to verify the theory,based on the Si Ge Bi CMOS 0.13μm process,the design and simulation of the 210 GHz switchless bidi-rectional amplifier have been completed,and the design has been taped out.The simu-lation results show that the bidirectional amplifier achieves a signal gain of 28.0 d B,the isolation can reach 92.0 d B,the noise figure is 16 d B,the output 1 d B compression point is-4.6 d Bm.The return loss of the matching network S₁₁ is-13.6 d B,S₂₂ is-15.5d B in the.The chip power consumption is 63.0 m W and the chip area is only 0.64 mm×0.26 mm.For the first time,a switchless silicon-based bidirectional amplifier chip with a working frequency above 200 GHz has been realized.The design method and chip achievement can be applied to the new switchless bidirectional miniaturization system.