Mixed Cavity Filter And Duplexer

Along with the development of modern microwave communication, radar, the development of electronic countermeasure technology, the frequency range was used more and more, and the inter band interval is getting smaller and smaller, especially in the 4G and 5g wireless communication technical field, microwave filter as a passive frequency selection device, the effect of the performance of the whole system is very important.Development of low cost, miniaturization, microwave filters with low loss and high frequency selectivity, has become a major goal of current development. In order to achieve proximal high inhibition, the general need to introduce multiple transmission zeros, coaxial cavity filter traditional due to its Q value is limited, near the proximal inhibition of the passband insertion loss is very high edge zone, influence the effective bandwidth of filter. This paper proposes a kind of medium and the coaxial cavity filter, can effectively improve the collapse phenomenon of proximal shoulder curbs in the volume and the cost remains unchanged under the premise,improve the rectangular coefficient filter.This paper first introduces the basic theory of hybrid resonator filter, and the equivalent circuit model of the circuit topology is different, with high Q value of the resonator filter curve, found on the band edge insertion loss of elevation the largest case; in order to realize the coupling of coaxial cavity with a dielectric cavity with the characteristics of all kinds of mixing chamber, coupling structure is studied, including its polarity(positive and negative coupling coupling, couplingbandwidth) andtunable; finally, a simulation is carried out using the coupling structure, design a coaxial with the medium mixed double multiplexer, and processed into real debugging, filter curve and circuit simulation results, fully verified the feasibility of the mixing cavity filter and in the improvement of shoulder function collapse phenomenon.