X-band Group Delay Cavity Filter Simulation Design And Development,

The purpose of this paper is to study a simulation design method of using computer software to simulation X band range narrowband group delay filter and according to the computer software simulation design structure, develop a real samples that meets filter design indexes. It will comparison the realistic sample's structure size to computer software simulation design structure size and analysis them, at last, it will find the conclusion.In this paper, the author apply modern microwave filters design theory, using coaxial linear multistage cavity filter solution, by lowpass prototype began using the coupled resonant filter design method, through frequency conversion, and combined with terminal resonators outside Q value and resonators between the coupling coefficient, through the simulation and optimization design, finally met the design objective group delay filter.In this paper the main research results is that solving the two key technical difficulties: one is the low group delay fluctuation design, because group delay fluctuating's requirements and the restraint outside the band requirement is mutual restrictions, so reasonable design appropriate filter bandpass bandwidth becomes the key. If bandwidth is too wide, the restraint outside the band will be short of asks. If bandpass bandwidth is too narrow, the group delay fluctuation will be not ideal. Through trial and error, ultimately we determine the appropriate bandpass bandwidth value, make this two technical indicators have reached contract requirements.Another key technical difficulties is low temperature drift problem, by testing I know that if we does not use any temperature compensation measures, it wil appear that the resonance frequency will reduce at high temperature, and the resonance frequency will increase at low temperature. This phenomenon can cause filter group delay fluctuation and restraint outside the band exceed the indicators, so take proper temperature compensating measures is very necessary. After analysis this reasons, I adopted a method that add some materials in resonance column, to solve the temperature compensation, make filter temperature drift control in a smaller range, so that the filter satisfy temperature stability requirement.On the base of applying micro-coaxial multicavity configuration the design of the X wave narrow band group delay filter also apply technique for solving low extent ripple, low group delay ripple, low temperature excursion and resisting vibrancy and impact. We break through several pivotal technique such as low temperature excursion, low extent ripple, low group delay ripple and resisting vibrancy and impact. At last, we have manufactured low temperature excursion, low extent ripple, low group delay ripple and resisting vibrancy and impact filter.Through the above work, we finally got a method of using computer software to simulation and design X band range narrowband group delay filter, after compares the real samples structure size and computer software simulation structure size, we find the two sizes are consistent.