CMOS RFIC平面螺旋差分变压器参数化等效电路建模

Scalable Equivalent Circuit Model of Planar Spiral Differential Transformers for CMOS RFIC's

对现今常用的八边形CMOS RFIC平面螺旋差分变压器进行了参数化的2-π集总参数等效电路建模。所建模型包含随频率变化的各种损耗效应,各元件值均可根据工艺参数和器件几何尺寸以参数化的解析表达式得出。将电路仿真值与ADS Momentum器件仿真值进行对比,两者在DC^20 GHz谐振点前的频率范围内都得到了较好的拟合效果。在此基础上,对同样结构的巴仑也进行了建模和仿真。从仿真结果分别得出两者符合实际应用需要的频段。

A scalable 2-n lumped-element equivalent circuit model of octagonal-shaped planar spiral differential transformers for CMOS RFIC＇s was presented Variable parasitics were considered in the model. All the elements can be calculated using scalable analytical expressions according to the process parameters and the device geometric dimensions. Circuit simulation results were compared with those of device simulation using ADS Momentum, which demonstrated that they were well-fitted in the frequency range from DC to 20 GHz before self-resonant frequency. Modeling and simulation of baluns with the same configurations were also performed on the basis of the previously＇ proposed model, and the frequency range that meets specifications for practical applications can be extracted respectively.