Patent ID: 8305164
Filing Date: 2012-11-06
Classification: H01P

Abstract:
1. A method of tuning the stopband attenuation of an absorptive bandstop filter, wherein said absorptive bandstop filter has at least a first and second resonator, wherein said first resonator includes a first tuning element and exhibits a first resonant frequency and wherein said second resonator includes a second tuning element and exhibits a second resonant frequency, and wherein said tuning elements are used to adjust said corresponding resonant frequencies, comprising: adjusting said first resonant frequency by means of said first tuning element; and adjusting said second resonant frequency by means of said second tuning element, wherein both said resonant frequencies are coordinated in order to obtain a selected stopband attenuation level and to thereby realize a frequency-selective variable attenuator, and fixing the operating frequency of said filter at a specific value in order to realize an expanded tuning range of stopband attenuation.