Small Cavity Filter Design Technology Research

With the development of modern communications and electronic counter measures technologies, the wireless communication frequency resources have become more stringent and the frequency intervals allocated to each communication system are becoming narrower, thus the precise choice of the radio wave band by the filters is considered as the focus in many design questions of the radio technology. The different frequencies can be separated or combined by using the filters.The cavity filter is one of the filters, which has the characters of solid structure, high operating frequency, low insertion loss and high power supporting capability. It has been widely used in variety of military and civil electronic systems. Thus the study on the design technique of the cavity filter has great significance whether in theory or in practical applications.The cavity filter is a kind of pure structure device, its Properties and credibility to all be decided by the structure characteristic of its own. This article sets out from the structure first, carried on a discussion to the cavity filter, and put forward some structures projects which are advantageous to raising the cavity filter function performance and credibility, and also put forward a kind of methods that has no bolt to fix to cover in order to let up the cavity filter physical volume further.Then, make use of"Couplefil"computer aided design software; make use of"HFSS"3D imitating software,a kind of simple, most direct, most effective cavity filter design step and method is given out.Most important of all, by using these design methods of cavity filter, I have successfully completed a cavity filter with the frequency of 16 GHz.