SELECTIVE NARROW-NOTCH FILTERING FOR WIDE BANDWIDTHS

IN NOTCH FILTERS, HISTORICAL DESIGN HAS PLACED EMPHASIS ON HIGH UNLOADED Q TO OBTAIN HIGH REJECTION AT NOTCH FREQUENCY. THIS TYPICALLY RESULTS IN DESIGNS USING LARGE CAPACITANCE VALUES IN RELATION TO INDUCTANCE. THE RESULTING LC RATIOS YIELD HIGH Q BUT POOR RESPONSE (STEEPNESS OF THE CURVE). TO IMPROVE THE RESPONSE SEVERAL ADDITIONAL RESONATORS MUST BE COUPLED AS A NETWORK. MICRO SYSTEMS CONSULTANTS HAS DEVELOPED A TECHNIQUE TO OVERCOME THE RATIO MISMATCH PROBLEM THAT INHERENTLY CAUSE NOTCH FILTERS TO PERFORM POORLY AND BE LARGER AND DIFFICULT TO ADJUST. OUR DESIGN USES A LOSSLESS RESONATOR THAT WILL PROVIDE NOTCH FILTERING WITH A REJECTION OF 60 DB AT THE NOTCH FREQUENCY. THE FILTER WILL BE COMPACT, LOW COST AND DIGITALLY CONTROLLED. IT WILL PROVIDE ELECTRONICALLY TUNABLE NARROW BAND NOTCH FILTERING WITH WIDE PASSBANDS AROUND THE NOTCH. THE DESIGN ALLOWS FOR FAST FREQUENCY HOPPING AND CAN BE USED WITH FREQUENCY AGILE (HOPPING) COMMUNICATION OR RADAR RECEIVERS TO ENHANCE RECEIVER PERFORMANCE IN A JAMMING ENVIRONMENT.