| The multiplexer is an important passive component which is widely used in FM ra-dio, antenna combiner technology and military interference in modern communicationsand microwave systems. With the continuous development of communication technology,the required targets of multiplexer become higher and higher, hoping that the multiplexerowns lower insertion loss, smaller adjacent channel interference and more compactstructure. From the view of bionics, to design a multi-coupler modeling on the structureof human cochlea is the latest concept abroad in recent years. In order to explore newmultiplexer structure, this paper will focus on the cochlea-based RF channelizing filters.Firstly, this paper introduces some typical structures of traditional multiplexer, andcompared their strengths and weaknesses. Then, it starts from the physical structure ofthe cochlea to deduce its mechanical model and circuit model step by step. Clarifyinghow to extract parameter from the circuit model, it gives an important simulation exam-ple by225~400MHz to prove the correctness of the design method. In order to verify thatthe tubular structure is suitable as the channel filters, this paper achieved two tubular fil-ters each in the VHF and UHF band. The measured results meet the design objectivesand verify that such structure owns the characteristics: It behaves capacitive when belowthe center frequency and inductive higher than that, and it owns small input susceptanceaway from the pass band and low affection of common terminal impedance. Finally, inorder to achieve a225~300MHz six-channel cochlear-multi-coupler, it calculates thecircuit parameters, and simulates it in circuit-level and structure-level using microwavesimulation tools, and then debugs the PCB board using the network analyzer.The final test results meet the design requirements, namely that, FBW=5%;IL<2.5dB,3.5dB overlap adjacent channels, VSWR<3,≥30dB@(1±10%)f0sidebandsuppression, it confirms that such a new multiplexer structure can be realized. |
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