| With the development of science and technology,radio technology continues to improve,especially communication(such as data network,mobile phone),radio frequency identification,Global Positioning System,remote sensing telemetry and detection(radar)technology and so on.How to implement it are related with RF circuits.As we all known,RF circuit contains a large number of passive components,including transmission lines,capacitors,inductors,resistors and transformers,filters and so on.Passive devices are complex in high frequency working state,which performance will be changed with frequency and parasitic effect will be greatly obvious.So how to describe high frequency response of the passive components correctly and establish equivalent circuit model have been a popular research recently.Passive components can be divided into lumped parameter elements and distributed parameter elements according to the applicable frequency range.In the case of high frequency,lumped parameter elements because of encapsulation parameters cannot be suitable for high frequency circuit.Therefore,the lumped parameter elements should be designed as the distributed parameter element in the high frequency circuit.Increased operating frequency is the main reason for the need to implement passive components on a chip or on an integrated circuit substrate.At present,the LTCC(Low Temperature Co-fired Cera)technology has become a common technique of integrated passive components,so the paper research is based on LTCC technology of passive components.In this paper,the frequency conversion characteristics of the components are studied by using the spiral inductor and the vertical interdigitated capacitor based on the LTCC process.The optimal design method is proposed,and the equivalent circuit model of different topologies is established and verified.It is proved that the model is accurate.The study of the band within 12 GHz.The main research contents and achievements are include three aspects.Firstly,the modeling method is established,and the general passive component modeling process is given.Secondly,the study of spiral inductors mainly includes four aspects.(1)Performance study.The performance of the spiral inductor are studied quantitatively and qualitatively,including the resonant frequency,the quality factor and the inductance value.By analyzing,defining and describing the three operating regions of the inductor,and the characteristics of each work area.(2)Optimize the design.The analytical method and the electromagnetic simulation method are used to study the relationship between the inductance performance parameters and the layout parameters,and the reason of the performance change.Through the analysis,the optimal design method is provided.(3)Establish the model and validation.This paper studies and validates the improved single-π type equivalent circuit model and T-type equivalent circuit model,and the parameter extraction method is proposed.Combined with the simulation results of 3.5T hexagonal spiral inductor,3.5T rectangular spiral inductor and 4.5T rectangular spiral inductor,the correctness of these two models is verified and the advantages and disadvantages are compared.(4)Considering the coupling problem in the passive combinational circuit,the coupling between the inductors is simulated and analyzed by HFSS.Thirdly,the study of the vertical interdigitated structure capacitor mainly includes two aspects.(1)Optimize the design method.The influence of layout parameters and process parameters on the capacitance value,quality factor and self-resonant frequency is studied by means of electromagnetic simulation analysis.Through the analysis,the optimal design method is provided.(2)Establish the model and validation.The improved single π structure model is established and the parameter extraction method is proposed.Combined with the simulation results of the five-layer and four-layer vertical interdigital capacitance,the correctness of the model is verified and compared with the equivalent circuit model before improvement. |
