Title :
A New Wideband Elliptic Bandstop Filter With Cross Coupling
Author :
Si-Wei Ren ; Lin-Sheng Wu ; Hong-Li Peng ; Jun-Fa Mao
Author_Institution :
Key Lab. of Minist. of Educ. of Design & Electromagn. Compatibility of High-Speed Electron. Syst., Shanghai Jiao Tong Univ., Shanghai, China
Abstract :
A novel fifth-order elliptic cross-coupled wideband bandstop filter (BSF) is proposed and designed in this letter. It is devised by introducing additional electric coupling into two nonadjacent quarter-wavelength shunt stubs of a conventional commensurate line BSF. The selectivity and stopband rejection can be effectively enhanced by two extra transmission zeros generated from the coupling. The proposed BSF is designed directly from the normalized lowpass prototype by using the design formulas, which are derived based on the rigorous correspondence between the BSF and its lumped prototype in the S-plane. In order to demonstrate our design, a BSF example is developed, with a measured 27.2 dB stopband over a fractional bandwidth of 141.7%.
Keywords :
band-stop filters; coupled circuits; elliptic filters; low-pass filters; poles and zeros; conventional commensurate line BSF; electric coupling; fifth-order elliptic cross-coupled bandstop filter; lumped prototype; nonadjacent quarter-wavelength shunt stubs; normalized lowpass prototype; transmission zeros; wideband elliptic bandstop filter; Attenuation; Couplings; Filtering theory; Passband; Prototypes; Wideband; Wireless communication; Bandstop filter (BSF); cross coupling; elliptic response; lumped prototype; wideband;
Journal_Title :
Microwave and Wireless Components Letters, IEEE
DOI :
10.1109/LMWC.2015.2463098
