Research And Design Of Electro-mechanical Coupling Of Electrically Tuned Cavity Filters

Electronic tuning cavity filter is one of the core components of communication system,with the development of the 5G mobile communication technology,electronic tuning cavity filter development in the direction of high frequency,high integration and miniaturization,cavity filter structure parameters and the influence of manufacturing tolerance to filter performance is particularly outstanding,the traditional design method of mechanical and electrical separation lead to long development period,low cost and high performance.Aiming at the above problems,the electromechanical coupling model of cavity filter is established based on the method of field-path coupling.The thermal effect of the cavity filter is analyzed,and the thermal deformation caused by the temperature change of the cavity filter is obtained by numerical fitting method.The relationship between structure parameters and capacitance inductance in equivalent circuit is studied under the joint action of temperature field and mechanical manufacturing factors,and the expression between structure parameters and electrical performance is deduced,and the effect of structure parameters on resonance frequency and quality factor is analyzed.Secondly,a robust optimization design method of the adaptive proxy model was proposed,and the robust optimization design model of the cavity filter was established.By optimizing the structural design variables,the requirements of manufacturing accuracy were relaxed while the electrical performance of the cavity filter was guaranteed.On this basis,the method of adaptive proxy model is adopted to realize the efficient solution of robust optimization model.The optimized minimum manufacturing accuracy was substituted into the model for electrical performance simulation analysis to verify the correctness of the robust optimization design method.By robust optimization analysis,the allowable tolerances of the position degree,the perpendicularity between the tuning screw and the cavity were reduced by 22.2%,31.6% and 15.5%,respectively,while the electrical properties met the requirements.Finally,a compact and efficient electric tuning mechanism and drive control system are designed to achieve high efficiency and high precision adjustment of filter passband.The experimental prototype of electric tuning device was made,and the performance accuracy test and reliability test were carried out to ensure that it can work stably and reliably in engineering practice.