Title :
A Parallel Doubly Coupled Dual-Band Bandpass Filter
Author :
Rao, Chen-Mao ; Wong, Tzu-Jung ; Ho, Min-Hua
Author_Institution :
Dept. of Electron. Eng., Nat. Changhua Univ. of Educ.
Abstract :
A parallel doubly coupled stepped impedance resonators (SIRs) structure is proposed in this paper to build a 2.4/5.2 GHz dual-band bandpass filter for a WLAN application. The prototype filter is a three-stage design composed by four SIRs in conjunction with the tapped-line used in the I/O ports to create zeros by the passband skirts. The proposed filter has the advantages of a much wider fractional bandwidth in both the passbands without sacrificing the passband´s insertion losses. The conventional parallel-coupled microstrip line model is applicable in the proposed filter design. The filter has obtained almost twice wider bandwidth compared to that possessed by the counterpart filter of a conventional parallel-coupled line configuration. It is convinced that this filter design can be apply to the 2.4/5-GHz dual-band operation that needs a wider second passband. The experiment is conducted for filter performance validation. A very good agreement is observed between the simulation and the measurements
Keywords :
UHF filters; band-pass filters; microstrip filters; microwave filters; resonators; wireless LAN; 2.4 GHz; 5.2 GHz; UHF; WLAN application; coupled transmission lines; dual-band bandpass filter; insertion loss; microstrip filters; parallel doubly coupled bandpass filter; parallel-coupled microstrip line model; passband skirts; stepped impedance resonators; tapped-line; Band pass filters; Bandwidth; Dual band; Filtering theory; Impedance; Insertion loss; Passband; Prototypes; Resonator filters; Wireless LAN; Coupled transmission lines; bandpass filters; microstrip filters; zero assignment;
Conference_Titel :
Microwave Symposium Digest, 2006. IEEE MTT-S International
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-9541-7
Electronic_ISBN :
0149-645X
DOI :
10.1109/MWSYM.2006.249623