Based On The Research Of High Frequency Nizn Ferrite Broadband Filter Components

With the huge development of mobile communication, electronic countermeasure and navigation technology, variety of electronic systems for microwave filters has placed enormous demands and new changes. The prominent features of the subject is the extremely wide frequency band covering three bands shortwave, ultrashort wave, microwave, in which that the filter inductor is the use of our own NiZn ferrite material that has the advantage of high frequency, low loss.Firstly this paper analyzes the elements determining the main performance of NiZn ferrite material in theory such as initial permeability, quality factor, dielectric properties and so on, it provides an important theoretical guidance for the latter part of the material testing in order to control and improve these magnetic properties. The way for the production of NiZn ferrite is the oxide method in the traditional process. By adjusting the different content of Co replacing, different Bi2O3-doped ferrite and sintered at different temperature changes in NiZn ferrite, the conclusion is that the initial permeability of the material will reduce and the cutoff frequency will rise along with content of Co replacing increases. On the basis of a certain amount of Co replacing, the doping level increases at a certain sintered temperature has little effect on the initial permeability, but a significant improvement in the phenomenon of the lower cutoff frequency. Finally we get the appropriate formula and process which meeting the requirements, and produce the NiZn ferrite materials and magnetic core inductance has1GHz cutoff frequency for the band-pass filter.As a research object, we produce nine channels of LC band-pass filter and three channels of the microstrip line band-pass filter from10MHz to2GHz. This paper describes the design process of the broadband band-pass filter components including the choice of filter types, the design of the LC filter and the microstrip line band-pass filter design, and PCB board production filter process. In the design process, we can improve the accuracy of the design and processingthrough the method of combining the classic formula of the filter and the ADS simulation software.After the PCB board production, we tested the filters by the vector network analyzer and obtained the notes of the results,then debugged them based on related indicators, produced and tested again, and ultimately get the correct results meeting our requirements to achieve the functionality required to confirm the practicality and feasibility of the filter design method of the NiZn ferrite material.