The Research And Design Of Two Typical Combiners In Microwave Circuit

Recently, with the extension of the coverage area of mobile communication networks, the modern wireless communication has the fast development. There has been a shortage of a large number of passive devices in newly-built supermarkets, office buildings, and subway tunnels etc. At the same time in some mobile communication system equipment, miniaturization, high performance, low cost and easier production are common requirements for filters. This thesis mainly discusses the following contents:1. The basic principles and methods for filter designs are introduced.2. Through the analysis of basic principles and methods for directional couplers, a new broadband3dB hybrid with a cross coupled cavity structure is designed. The altitude intercept exists between the mainline conduction band and the subline conduction band, which are cross coupled. Such a structure can minimize the discontinuity of the electrical bridge and improve the index to the bridge design. Therefore the practical need of a project can be well satisfied.3. Elaboration of theoretical knowledge about cross couple with the analysis of the production of transmission zero and its position is made in the thesis. A GSM diplexer of high-performance is designed with the help of related software and the rejection level of harmonic suppression is very good.4. A brief summary of the main studies of the research is given and innovative points of the thesis are also pointed out for further research. This thesis uses the theory to figure out the initial value, which will carry over to the optimal design process of the computer software. With the help of the simulation, structural drawings of3dB recessed bridge and GSM900diplexer are made. Test results of the practical assembling satisfy the design requirements. The two products can both be applied to mobile communication system.