Research On Integrated Switching Filters Based On TSV Technology

In RF systems,superheterodyne receiver RF front-end preselected device can increase the out-of-band suppression,improve the spectrum purity,and optimize the performance of the receiver.Switching filters are widely used as preselected devices in engineering applications due to their intuitive implementation and flexible design options.However,the size of traditional switching filters is relatively large.With the development of system miniaturization,new approaches are urgently needed to reduce its weight and volume.In recent years,three-dimensional(3D)integration based on through-silicon via(TSV)technology has developed rapidly,and this has also brought about an opportunity for the miniaturization.The 2.5D TSV adapter board technology has been widely used since it is most cost-effective for three-dimensional integration technology,which is an important technology to realize miniaturization,light weight,and integration.In this paper,2.5D TSV adapter board technology is integrated with silicon-based integrated passive device(IPD)technology,and silicon-based heterogeneous integration and on-chip integration methods are used to study the miniaturization of 2-10GHz switching filters.The TSV vias serve as the interconnect structure between the middle structures.This design uses a hollow copper filled TSV structure and studies its RF transmission characteristics.Compared with the traditional copper-filled TSV,this structure not only improves the RF transmission characteristics,but also processing is simpler.In order to reduce the size of the filter,four band-pass filters are designed using silicon-based IPD thin-film technology,and are selected using different structural filters,where the microstrip filters are designed by co-simulation using HFSS and Sonnet software.Simulation efficiency is significantly increased.In addition,to improve the overall performance of the filter and reduce the high frequency loss of the transmission line,high-resistance silicon substrates are used in the design.Finally,this design was verified through machining tests,which mainly included the performance testing of integrated passive devices on silicon substrates,the impact of TSV structures on RF transmission signals,the functionality of silicon-based heterogeneous integrated chips,and the performance testing of silicon-based switching board and the chip interconnection between TSV and RF transmission line.The test results proves that a good performance is obtained,the insertion loss of the filter is less than 5dB,and at2-10GHz,the loss of the RF transmission line per millimeter is less than 0.5dB,and the loss of a single TSV RF hole is less than 0.2dB.The overall size of the components designed is less than 14141mm~3.Through the design verification,it can lay a solid theoretical and application foundation for the further realization of three-dimensional integration.