A Dual Wideband Filter Design Using Frequency Mapping and Stepped-Impedance Resonators

• Published in: IEEE transactions on microwave theory and techniques Vol. 56; no. 12; pp. 2921 - 2929
• Main Authors: LIU, An-Shyi, HUANG, Ting-Yi, WU, Ruey-Beei
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.12.2008; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Band pass filters; Bands; Buildings; Circuit properties; Dual band; Dual-band filter; Electric, optical and optoelectronic circuits; Electronic circuits; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Exact sciences and technology; Frequency filters; frequency mapping; Joining; Joining processes; Mapping; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwaves; Narrowband; Oscillators, resonators, synthetizers; Passband; Resonant frequency; Resonator filters; Resonators; slope parameters; stepped-impedance resonator; Susceptance; Testing; Wideband; Inverter; Resonator; frequency mapping; Wide band circuit; Stepped impedance device; slope parameters; Stub line; Mapping; Dual-band filter; Narrow band; Implementation; stepped-impedance resonator; Band pass filter; Band stop filter
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2008.2007357

A dual-wideband filter design implemented by stepped-impedance resonators, which involves the frequency mapping approach, is presented in this paper. The dual-band filter can be divided into two parts: the wideband virtual passband filter and the narrowband virtual stopband filter. Both filters are designed by conventional synthesis methods, under the assumption that the common connecting lines serve as J- and K-inverters simultaneously. The basic building resonators formed by paralleling open- and shorting-stubs are implemented by unbalanced stepped-impedance resonators, exhibiting the desired resonating frequencies and susceptance slope parameters at these two bands. Two filters are tested to validate this design.