Design And Implementation Of Filter Based On LTCC

With the increasing demand for miniaturization and integration of microwave and millimeter wave systems,In the packaging design of passive device structure and microwave integrated system,the three-dimensional packaging structure based on LTCC technology will play a key role,which will further promote the development of microwave circuit system to the direction of small size,good reliability and easy integration.The filter is an important part of the RF front-end,and its performance have a great impact on the system.The characteristic of small sizes?low insertion and high out-of-band rejection is the important development direction of the filter.Stepped impedance resonator(SIR)filter and substrate integrated waveguide(SIW)filter is a research hotpot in recent years,it can take into account the miniaturization and high performance of the filter.Combining LTCC technology with filter can realize multilayer circuit design of filter and greatly reduce the size of filter.After in-depth study on the LTCC technology,the design and processing of substrate integrated waveguide filter and stepped impedance resonator filter by LTCC technology were carried out.Finally,two filters based on LTCC technology were achieved.The main contents of this paper include:1.Study on SIW filter based on LTCC technology.Firstly,the structure and characteristics of SIW are briefly described.By studying the transition structure of substrate integrated waveguide and microstrip,a transition feed structure suitable for SIW filter is designed.Then the substrate integrated waveguide lambda g/2 coupled resonant band pass filter is analyzed,and the coupling coefficient of the Ku band SIW filter is extracted.Based on the coupling coefficient,the multi-layer miniaturized SIW filter in the Ku band is designed.Finally,the feasibility of ltcc-based multilayer miniaturized SIW bandpass filter in Ku band is verified by simulation analysis.The experimental results show that each index of the filter design meets the requirements and meets the requirements of high-performance miniaturized filter.2.Research on SIR filter based on LTCC technologyFirstly,the structural principle of SIR is analyzed,focusing on the structural theory of lambda /4 wavelength SIR resonator.The structure of a stepped impedance resonatorwith a quarter wavelength is simulated and analyzed using electromagnetic simulation software.The physical structure size of the stepped impedance resonator resonator unit is determined to determine the series of SIR resonator.The test results show that the insertion loss in the frequency band of 3.1 GHz ~ 3.4GHz is less than 3.5 dB,while the reflection loss in the passband is greater than 18 dB,and the attenuation at 2.7GHz reaches 45 dB.The test results are roughly the same as the simulation results,but the insertion loss is slightly larger than the simulation data.This is due to machining errors,loss of SMA joints,and welding and calibration is not ideal for many reasons.