CERAMIC BANDSTOP MONOBLOCK FILTER WITH COPLANAR WAVEGUIDE TRANSMISSION LINES

摘要

In a ceramic block filter having multiple resonators (241, 245, 150, 255), conductive electrodes called coplanar waveguide transmission lines (243) are placed on the top surface of a ceramic block filter in proximate relation to isolation ground structures, such as isolation holes, ground isolation holes (211, 221, 231), ground fingers (237, 247, 270) and top surface ground planes (252). By placing the top surface conductive electrodes on the top surface of a ceramic block in proximate relation to these ground structures, the frequency response of the surface mount ceramic block filter may be enhanced while maintaining or enhancing the desired output energy level for the filter. For instance, the present invention provides a filter with lower insertion losses in the bandpass region, minimized transition bands between the bandpass and bandstop cut-off frequencies, and greater rejection in the bandstop region.