Design Of TM₀₁ Mode Dielectric Resonator Filter

The rapid development in information technology today, along with the fifthinformation technology revolution development of wireless communication technology,wireless communication technology have entered rapid development period.Thecommunication frequency spectrum is more finer, communication is more and more higher,the requirements for microwave filters are also getting higher and higher, at the same time,mobile communication and portable terminal miniaturization, lightweight, high reliabilityof direction, has also put forward higher requirements on microwave dielectric ceramicmaterials based on microwave devic.Therefore, in the3G mobile communication basestation, miniaturization, high Q value, high stability of the dielectric cavity filter becomes ahotspot at present.We designed and made a working at WCDMA frequency band is used in3G mobilecommunication base station above the six pole cross coupling dielectric cavity filter using thedielectric resonator and filter theory in this paper,the dielectric resonator filter’s working modeis TM01mode.Through theoretical calculation and simulation combining, we give the six polecross coupling dielectric cavity filter specific size, and processing production, actuallymeasured properties:2.22GHz center frequency, bandwidth of80MHz, pass band insertion lossis less than0.5dB, out-of-band rejection than80dB dielectric resonator filter, the measuredperformance to satisfy our needs index, and it can be used in industrial production.Based on the production of six pole cross coupling dielectric cavity filter, we designeda four pole of tunable dielectric resonator filter by using the high frequency simulationsoftware Ansoft HFSS12in this paper.The structure of the tunable dielectric resonator filteris novel, the center frequency is5GHz, and the mode of separation characteristics betweeneigenmodes and parasitic mode are good. We creative using of the "three segment type"step adjustment method, the relative bandwidth changes a little, the band rejection is higherunder the premise, the tuning range up to1GHz, relative tuning range reached20%, withgeneral adjustable filter tuning range of the phase ratio is less than10%, greatly increasedthe tunable filter tuning range.