Design of Medium-Bandwidth Band Pass Filter Using Three-Line Microstrip Structures with Unequal Line Width

• Main Authors: Kuei-lin Cheng, 鄭貴臨
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/39671245972880762823

碩士 === 國立高雄第一科技大學 === 電子工程研究所 === 103 === In this paper, the design is mainly about the microwave Band Pass Filter. Its bandwidth is 30%. Many microwave Band Pass Filters are common small bandwidth (20% lower) or large bandwidth (50% upper) as principle. Because of conventional circuit impedance is too small and not easy to implement. This paper use of quarter wavelength three-line microstrip structures to design and same as conventional circuit.Three-line microstrip structure consists of two Asymmetric Spur Lines. The conventional circuit to make the appropriate decomposition.According to the proposed design methods，realizing the purpose of circuit. Design of band pass filter using three line microstrip structures with unequal line width made of two different specifications. The center frequency 1GHz, the element parameters of a low-pass Chebyshev prototype with a 0.01 dB passband ripple and a center frequency of 2.4GHz, the element parameters of a low-pass Chebyshev prototype with a 0.1 dB passband ripple. The first circuit operating at 1GHz，the result of the measurement in frequency range is 830MHz~1.15GHz﹐bandwidth of 32%. The second circuit operating at 2.4GHz，the result of the measurement in frequency range is 1.95GHz~2.68GHz,bandwidth of 30.4%.In this paper that make size reduction and solve lower short-circuit transmission line impedance.