Coupling Modeling And Influence Mechanism Of Microwave Component Transmission Performance Based On Gold Belt Interconnect Process Characterization

In the low frequency band,the transmission line switching interconnection point in the active microwave component only serves as an electrical connection,which is equivalent to a short circuit,and the transmission performance is almost independent of the interconnection point;However,in the high frequency band（microwave millimeter wave band）,the circuit structure size is comparable to the operating wavelength of the transmission line,and its parasitic effects（capacitance and inductance,etc.）will cause changes in signal amplitude and phase,resulting in poor transmission performance.The coupling effect of interconnection process form on transmission performance is more and more prominent,the coupling effect of interconnection process form on transmission performance is more and more prominent,especially in the process of metal strip interconnection.Therefore,the research on the coupling relationship between interconnection process morphology and signal transmission performance and its influencing mechanism has become an important research work in the process of microwave module design phase to assembly phase.In this paper,the gold-belt interconnection process is taken as the research object,and the discrete parameterized representation and modeling method of interconnected morphology is studied to realize the fine control of the interconnection point morphology;Deeply explore the coupling relationship between interconnected morphology parameters and signal transmission performance,and establish the relationship between morphological parameters and transmission performance functions;At the same time,the performance compensation method is explored to solve the impedance mismatch problem caused by introducing discontinuous interconnection region of gold belt.The specific work is as follows:（1）The morphology of microstrip-to-microstrip ribbon interconnection is analyzed and the morphology of flexible ribbon is described mathematically to realize the parametric modeling of interconnection morphology;Based on the theory of discontinuous transmission line and piecewise linear,the piecewise linear discretization of interconnected forms is realized;Based on the microwave network theory,the piecewise equivalent circuit is analyzed,and the coupling model of the whole interconnection structure is constructed by using the cascade characteristics of the network;The model is validated by comparing the results of MATLAB programming calculation and HFSS software modeling analysis.The results show that the circuit coupling model can effectively reflect the return loss S11within the frequency range of 6-50 GHz,which is basically within 3 dB,and only individual points exceed 3 dB.However,although the overall trend is the same for the insertion loss S21,the difference is large.This is because the circuit coupling model in this paper is derived based on the lossless transmission line theory.The effect of loss on performance cannot be considered,that is,the influence of absorption attenuation on performance.Therefore,the insertion loss S21 has a certain deviation.Therefore,the loss varying with frequency is extracted and added into the circuit coupling model.It is found that the new insertion loss S21 curve is in good agreement with the HFSS simulation,especially below 30 GHz.Finally,based on the circuit coupling model,the morphological parameters such as gold arch height,gap and gold strip width are used to quantitatively analyze the influence of morphological parameters on insertion loss and return loss,and obtain the qualitative relationship between morphological parameters and microwave circuit signal transmission performance.Influence the law.（2）Through the analysis and mathematical description of the morphological characteristics of coaxial microstrip strip interconnection,the parametric modeling of the interconnection morphology is realized.Meanwhile modeling and simulation analysis in HFSS.Then,the factor effect design is used to perform the main effect,the interaction effect and the saliency analysis on the interconnected morphological control variables that affect the signal transmission performance,and the key parameters are selected from it;In view of the key parameters,response surface design is further adopted,and the coupling model of coaxial microstrip ribbon interconnection morphological parameters and signal transmission performance paths is constructed by using multiple binomial regression equation.Finally,the circuit coupling model is verified.By calculating the decision coefficient of return loss S11,only 1.18%of the numerical variation distribution can not be explained by the model.The adjusted decision coefficientR²_adj=97.75%is smaller than R²,indicating the return loss S11,The loss regression S11 model can accurately predict the process model;The determination coefficientR²=99.22%of insertion loss S21indicates that only 0.88%of the S21 numerical variation distribution cannot be explained by the model,and the adjusted decision coefficientR²_adj=98.53%is smaller than R²,indicating that the regression model of insertion loss S21 can accurately predict the process model;therefore,there is sufficient reason to explain The accuracy of the circuit coupling model established based on the experimental design.（3）In this paper,the impedance mismatch caused by the discontinuity of interconnection structure between transmission lines is analyzed,and the basic principle and realization form of performance compensation based on impedance matching are introduced.At the same time,taking the coaxial microstrip ribbon interconnection structure as an example,the performance of the structure is compensated by a quarter wavelength converter,a parallel single branch and a linear gradient.The results show that the three compensation methods can reduce the signal reflection,improve the signal transmission performance and the compensation frequency range is wide,and the effect is remarkable.