Design and Implementation of Bandstop Filters with Open Stub and Ring Structures

• Main Authors: Wu-Lin Wang, 王玉琳
• Other Authors: Man-Long Her
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/81796492482761165978

碩士 === 逢甲大學 === 電子工程所 === 93 === In this thesis, we proposed and designed two compact bandstop filters with open stub transmission line structure and five bandstop filters with ring structure. Moreover, in simulation, we used Serenade circuit simulation, Sonnet and HFSS EM simulation tools to analyze the characteristic of filters. Their main difference, in addition to the increased accuracy of electromagnetic simulation, is the possibility of realization new element models that are not included in the available libraries of elements. In circuit implementation, we select substrates Rogers 4003C (εr = 3.38). The first part of my thesis, we use the open-stub transmission line to implement the bandstop filter. These have the advantages of spurious-free and miniature features. We used folded method on conventional bandstop filter to reduce the circuit size about 28% ~ 35%. The frequency response depends on the length, width, and gap of shut open-stub. The second part of my thesis, we proposed five types ring resonator to implement the bandstop filter. We also apply an open stub as perturbation to produce a transmission zero, if we arrange the transmission properly, then the width of bandstop would be increased obviously. The circuits we designed and implemented are simple and useful for wireless communication system.