接地共面波导与芯片级联结构设计与优化

Design and optimization of grounded coplanar waveguide and chip cascade structure

针对传输线与芯片级联时产生阻抗突变,导致传输效率下降的问题,基于接地共面波导与芯片级联结构,提出了一种适用于X~Ka波段的匹配带线解决方法。通过S参数提取芯片的输入阻抗,并对射频电路中的阻抗不连续点进行分析,设计阻抗匹配电路并建立三维仿真模型。通过有限元仿真分析,讨论了匹配电路和键合引线中心间距对射频传输性能的影响,对比分析了不同结构及不同匹配电路的传输性能差异。仿真结果显示:在X~Ka波段范围内,匹配电路可令接地共面波导与芯片级联结构的S11<-21 dB,S21>-0.19 dB。优化后的接地共面波导与芯片级联结构可在降低传输损耗的同时显著提高射频信号的隔离度,减少信道串扰,为厘米波频段下射频电路的设计提供理论参考。

In order to solve the problem of decreasing transmission efficiency due to impedance abrupt change during the cascade between transmission line and chip,a matching band-line method for X~Ka band was proposed based on the ground coplanar waveguide and chip cascade structure.The input impedance of the chip was extracted by S parameter,and the impedance discontinuities in the RF circuit were analyzed.The impedance matching circuit was designed and the 3D simulation model was established.Through finite element simulation,the influence of matching circuit and bonding lead center distance on RF transmission performance was discussed,and the transmission performance difference of different structures and matching circuits was compared and analyzed.The simulation results show that the matching circuit can make S11<-21 dB and S21>-0.19 dB of the grounded coplanar waveguide and chip cascade structure in the X~Ka band.The optimized grounded coplanar waveguide and chip cascade structure can significantly improve the isolation of RF signal and reduce channel crosstalk while reducing transmission loss,which provides theoretical reference for the design of RF circuits in the centimeter-wave band.