Design Of TSV Band-pass Filter For High Frequency Applications

With the rapid development of mobile communication and microwave technology,the frequency resources of communication systems have become unprecedentedly crowded.The increasingly complex functional requirements and electromagnetic environment have put forward more stringent requirements for the miniaturization and high-performance integration of microwave systems.Therefore,as a signal frequency selection and processing module in wireless communication systems,high-frequency filters have become the key factor affecting the performance of the entire communication system.The three-dimensional integration technology of Through Silicon Via(TSV)combines the advantages of excellent electrical characteristics and high integration density,providing a new preferred solution for the miniaturization and highperformance design of high-frequency filters.It is expected to alleviate the problems of spectrum congestion and signal processing module integration in current communication systems.This article is based on TSV technology to study the three-dimensional integrated structure design and performance optimization of high-frequency bandpass filters,and has achieved a series of research results.The main research content is as follows:Firstly,this article studies the basic theory and design process of LC filters,and studies the circuit topology and three-dimensional integrated structure of LC filters based on TSV structure.And use ADS simulation software to synthesize a low-pass filter circuit prototype,which is converted into a bandpass filter circuit topology structure through frequency changes.Combined with ANSYS Q3D Extractor(Q3D)and High Frequency Structure Simulator(HFSS),a threedimensional model of the corresponding inductance and capacitance in the circuit schematic diagram was built,and a second-order LC band-pass filter(center frequency is 46.5GHz)was designed,achieving excellent frequency selection characteristics:passband insertion loss is less than 3dB,and return loss is more than 12.5dB.And further analyzed the impact of various design parameters of capacitors and inductors on the capacitance/inductance values and filter performance under high-frequency operating conditions.Secondly,in order to enable LC filters to be applied in higher frequency bands and have excellent performance,this paper also designs a third-order LC bandpass filter(with a center frequency of 62.5GHz)based on the TSV structure,with a passband insertion loss of less than 2dB and a return loss of more than 15dB.The performance comparison with relevant filters shows that the third-order LC bandpass filter designed in this paper meets the performance and indicator requirements of the high-frequency band,and has excellent frequency selection performance.Then,the SIW filter theory and Chebyshev Filter design process are also studied in this paper.Based on the TSV structure,four different SIW filters applied in the terahertz(THz)band are studied.The relationship between the coupling coefficient and the size of the window between the resonators,as well as the relationship between the external quality factor and the slot length of the input and output Coplanar waveguide are analyzed by using HFSS software simulation.On the basis of theoretical calculations,this article also uses HFSS software to construct three three-dimensional finite element structures of fourth-order SIW filters.The simulation results show that the center frequency of the fourth-order tandem SIW filter is 108GHz,the insertion loss of the passband is less than 1.5dB,and the return loss is more than 25dB;The center frequency of the fourth-order folded SIW filter is 102GHz,the insertion loss of the passband is less than 1.5dB,and the return loss is more than 15dB;The center frequency of the fourth-order stacked SIW filter is 107GHz,the insertion loss of the passband is less than 1.5dB,and the return loss is more than 20dB.The simulated S parameters match the theoretical calculation very well.The comparison results between the SIW filter proposed in this article and other literature indicate that the filter designed in this article not only ensures a smaller chip size,but also has better filtering performance.Finally,in order to explore the application of SIW filter in higher frequency band of terahertz field,this paper designs a sixth order SIW filter,with the center frequency of 280GHz,the insertion loss of passband is less than 2dB,and the return loss is more than 7.5 dB.To sum up,in order to meet the application requirements of miniaturization and highperformance integration of high-frequency filters in the communication system,this paper has carried out research on the three-dimensional structure design technology of high-frequency band-pass filters based on TSV technology.Through theoretical modeling,electromagnetic simulation and other means,it has deeply analyzed the relationship between various structural parameters and the key characteristics of inductance,capacitance and filters,and proposed a series of Filter design examples with different structures and different frequency bands,Both have achieved excellent filtering frequency selection characteristics and miniaturized threedimensional integration strategies,providing high-density and miniaturized high-frequency filter solutions for the integration of RF circuits and communication systems.