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Study On The Design Technique Of Micro Integrated RF Filter

Posted on:2021-02-25Degree:MasterType:Thesis
Country:ChinaCandidate:Z Y SunFull Text:PDF
GTID:2428330614463652Subject:Electromagnetic field and microwave technology
Abstract/Summary:PDF Full Text Request
As a key component in wireless communication system,the size and performance of the filter determine the comprehensive performance of the system.Driven by the demand of various ultra-thin,ultra-light and ultra-miniature RF modules,more and more RF products in the industry have put forward higher and even demanding requirements on the miniaturization of filters,which promotes the development of Integrated Passive Device?IPD?technology,especially the thick film IPD technology represented by LTCC technology,and is widely used in various miniaturized RF filter products.However,with the further improvement of the comprehensive performance requirements of RF modules,the processing of LTCC technology with a minimum line width of100um has gradually shown a trend that it is difficult to meet the future high-end high-density RF integration requirements,and the new technology of miniaturization,ultra-thin and lightweight micro intergrated filters is urgently needed.Therefore,this article will focus on this pain point and face the new micro integrated ideas of breakthrough filters,and research the new miniaturization design technology of filters based on thin film IPD technology.The main work contents and innovations are as follows:1. Through the research and analysis of the second-order source-load coupled bandpass filter with two finite transmission zeros?direct coupling of inductance between two LC resonators?and its equivalent circuit?spatial coupling of inductance between two LC resonators?,firstly based on the schematic of the second-order bandpass filter with inductive direct coupling,a second-order micro integrated bandpass filter with center frequency f0 of 2.8GHz is designed by using thin film IPD technology.And the physical area dimension of the proposed filter is1.46mm×1.43mm×0.1mm?0.0136?0×0.0133?0?.Based on the analysis of the physical model of the filter and its equivalent circuit,it is found that the directly coupled inductance is too large to be suitable for precise design,so as to introduce unexpected parasitism.2. In order to solve the parasitic problem caused by excessively large direct coupling inductance in 1,based on the schematic of the second-order band-pass filter with inductance spatial coupling and thin film IPD technology,a second-order micro integrated bandpass filter with physical size of0.85mm×1.1mm×0.1mm?0.0079?0×0.01?0?is designed and its equivalent circuit is analyzed.Because the direct coupling inductance is replaced by the inductance space coupling,the filter is more compact in structure,smaller in size and less parasitic.3. In order to further improve the filter suppression ability,based on the second-order filter with quasi-elliptic function response in 2,the cascade technology of filter is studied.In order to solve the problem of impedance mismatch caused by cascade,capacitance matching and series LC loop matching are adopted.The former uses fewer components,while the latter can introduce a controllable transmission zero to specifically improve the filter suppression ability.Aiming at two different matching methods,two high-order micro integrated band-pass filters with multiple transmission zeros are designed.Their physical dimensions are 1.8mm×1.1mm?0.0167?0×0.01?0?and 1.8mm×1.4mm?0.0167?0×0.0127?0?.4. In order to achieve further miniaturization,the 3D integrated thin film IPD fusion design technology based on Ball Grid Array?BGA?was studied,and a new multi-zero 3D miniature integrated filter physical model was designed by using the designed cascade filter circuit topology.Its size is 1.5mm×1.1mm×0.27mm?0.0139?0×0.01?0?,and the electromagnetic simulation results show that it can obtain more than 40d B suppression in the frequency range from 1.21 f0 to 11.57 f0.
Keywords/Search Tags:Bandpass Filter, Cascade, Thin Film IPD, Micro Integrated, 3D
PDF Full Text Request
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