A miniaturized double-surface CPW bandpass filter improved spurious responses

A novel miniaturized double-surface coplanar waveguide (CPW) filter has been developed. The filter is constructed by an electrode pattern of half-wavelength resonators on a double-sided circuit board with a high dielectric constant. A miniaturized pattern can be obtained by optimization of the electrode layout without any deterioration in unloaded Q. We use a particular pattern of via holes to reduce spurious responses. The filter is 38% smaller in size than the conventional /spl lambda//4 CPW filter. Spurious responses up to the third harmonic are suppressed by 13 dB, and satisfy the performance level required for industrial-scientific-medical band equipment. The measurement results agree well with the results of simulation.

[1]  Ruey-Beei Wu,et al.  Coplanar waveguide bandpass filter-a ribbon-of-brick-wall design , 1995 .

[2]  W. Menzel,et al.  Compact bandpass filters with improved stop-band characteristics using planar multilayer structures , 1992, 1992 IEEE Microwave Symposium Digest MTT-S.

[3]  W. Menzel,et al.  Multilayer suspended stripline and coplanar line filters , 1994 .

[4]  E. Rius,et al.  A New Uniplanar Bandpass Filter using λg/2 Slotline and λg/4 Coplanar Waveguide Resonators , 1994, 1994 24th European Microwave Conference.

[5]  Sener Uysal,et al.  CPW BANDPASS FILTERS USING END-COUPLED QUARTER-WAVELENGTH RESONATORS , 1997 .

[6]  T. Nishikawa,et al.  A miniaturized bandpass filter with double surface electrodes , 2000, 2000 IEEE MTT-S International Microwave Symposium Digest (Cat. No.00CH37017).

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

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

[9]  C. Nguyen.  Unsymmetrical broadside-coupled coplanar waveguides for loose-and tight-coupling mic and mmic applications , 1996 .

[10]  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).

[11]  K. Wakino,et al.  Microwave Bandpass Filters Containing Dielectric Resonators with Improved Temperature Stability and Spurious Response , 1975 .

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

[13]  M. Aikawa,et al.  Double-sided MICs and their applications , 1989 .