APPARATUS AND METHODS FOR SPLIT-FEED COUPLED-RING RESONATOR-PAIR ELLIPTIC-FUNCTION FILTERS

摘要

The filter couples a pair of resonators located in a plane between the distributed supply lines. The filter is also located perpendicular to the signal path. The filter has two pairs of resonators. The coupling extensions of the distributed feed line are substantially parallel to each other. The resonator is coupled with the distributed supply line at the coupling extension. Each pair of resonators is also coupled to each other. The topology effectively forms an elliptic function response bandpass filter with a high proximity frequency rejection capability. The filter is cascaded to provide improved frequency rejection. In addition, this topology can be manufactured at relatively low cost using standard lithography techniques.