IMPROVED HIGH REJECTION FOR NOTCH FILTER USING SQUARE RING RESONATOR WITH FLEXIBLE ELECTROMAGNETIC COUPLING

摘要

A novel technique of electromagnetic coupling for microstrip notch filter is reported, It employs a full wave (λ{sub}g) square ring microstrip resonator for 2.4 GHz with one arm (λ{sub}g/4) coupled electromagnetically to a 2-port 50-Ωfeed line, under it. The square ring resonator and feed line are on two separate TMM4 (ε{sub}r = 4.5) substrates. Electromagnetic coupling not only offers improved rejection but also the flexibility in various ways, for example, for easy replacement of resonator.