RECONFIGURABLE BANDSTOP FILTER WITH AD- JUSTABLE BANDWIDTH AND CENTER FREQUENCY

A bandstop fllter with reconflgurable two-state center frequency and bandwidth is presented. The prototype of the proposed reconflgurable bandstop fllter consists of one section of anti-coupled line short-circuited by an open low-impedance line. By introducing PIN diodes, this bandstop fllter exhibits a lower stopband response centered at a lower frequency in the ON state, and a wider stopband response centered at a higher frequency in the OFF state. Filter using the proposed structure is designed, simulated and measured. The results conflrm the designing method by showing a narrow stopband with the center frequency of 1GHz and a wide stopband of 2.9GHz bandwidth centered at 2.5GHz respectively.