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• Main Authors: Wei-chung Hung, 洪維鍾
• Other Authors: Wen-hua Tu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/41929875312797884021

碩士 === 國立中央大學 === 電機工程學系 === 102 === Distributed coupling technique and stepped-impedance resonators is employed to realize multi-band diplexer. Due to the low loading effect from distributed coupling technique, the proposed circuits can design many channels without the use of complicated matching network. The first three circuits include a dual-band diplexer, tri-band diplexer and quad-band diplexer. The circuits consist of half-wavelength stepped-impedance resonators, a common feeding line and output feeding lines. Each passband is controlled by respective pair of resonators to increase design freedom. Due to the low loaded effect, each passband can be design respectively, and finally combine bandpass filters into multi-band diplexers. The circuits have high isolation and wide stopband performance. The isolation is more than 29 dB and the 20-dB stopband up to 7.6 × the lowest operation center frequency. In last circuit, distributed coupling technique and two pairs of stepped-impedance resonators is employed to realize dual-band diplexer. Each pairs of resonator is designed to a dual-band performance, so the circuit size can be smaller than before. The channel isolation is more than 29 dB.