论文信息 - Coupling behaviors of quarter-wavelength impedance transformers for wideband CPW bandpass filters

Coupling behaviors of quarter-wavelength impedance transformers for wideband CPW bandpass filters

Quarter-wavelength coplanar waveguide (/spl lambda//4-CPW) impedance transformers with low and high characteristic impedance are characterized via fullwave method of moments short-open calibration (MoM-SOC) approach and further utilized as alternative K- and J-inverter networks with enhanced coupling. Network parameters are obtained and compared with those of two traditional lumped-CPW elements, demonstrating tightened coupling behaviors. The two improved /spl lambda//4 CPW bandpass filters are then constructed and their performances are optimized via cascaded topology. Predicted results show us a few attractive features, i.e., wide passband and first-order harmonic suppression as confirmed by experiment.

W. Menzel | Lei Zhu | Huamin Shi

[1] Dylan F. Williams,et al. Design and Performance of Coplanar Waveguide Bandpass Filters , 1983 .

[2] A miniaturized end-coupled bandpass filter using /spl lambda//4 hair-pin coplanar resonators , 1998, 1998 IEEE MTT-S International Microwave Symposium Digest (Cat. No.98CH36192).

[3] Lei Zhu,et al. Fullwave MoM-SOC Technique for Extraction of Equivalent Circuit Models of Coplanar Waveguide Discontinuities: CPW- and CSL-Mode Cases , 2003 .

[4] Ke Wu,et al. Short-open calibration technique for field theory-based parameter extraction of lumped elements of planar integrated circuits , 2002 .

[5] Jeremy Everard,et al. High performance direct coupled bandpass filters on coplanar waveguide , 1993 .

[6] Atsushi Sanada,et al. Design of the CPW in-line /spl lambda//4 stepped-impedance resonator bandpass filter , 2001, APMC 2001. 2001 Asia-Pacific Microwave Conference (Cat. No.01TH8577).

[7] Coplanar Resonators,et al. A MINIATURIZED END-COUPLED BANDPASS FILTER , 1998 .

[8] W. Menzel,et al. Investigation of coupling structures for coplanar bandpass filters , 1995, Proceedings of 1995 IEEE MTT-S International Microwave Symposium.

[9] Lie Zhu,et al. Unified 3-D definition of CPW- and CSL-mode characteristic impedances of coplanar waveguide using MOM-SOC technique , 2003 .