Patent ID: 8907747
Filing Date: 2014-12-09
Classification: H03H

Abstract:
1. A filter device comprising: an input electronic circuit having an output admittance Yin; an output electronic circuit having an input admittance Yout; a filter having a differential input connected to the input electronic circuit and comprising a plurality of resonators of a first type and a second type connected between an input and an output of the filter, the plurality of resonators of the first type having a resonant frequency Fr1 and an antiresonant frequency Fa1 and the plurality of resonators of the second type having a resonant frequency Fr2 and an antiresonant frequency Fa2 respectively different from the resonant frequency Fr1 and the antiresonant frequency Fa1; and a differential output of the filter connected to the output electronic circuit, wherein: the reciprocal of the real part of the output admittance Yin and the reciprocal of the real part of the input admittance Yout are greater than k times the value of the geometric mean of characteristic impedances of the plurality of resonators, k being a number at least equal to 2, and frequency differences between the antiresonant frequency and the resonant frequency for the resonators of the first type and the plurality of resonators of the second type, Fa1−Fr1 and Fa2−Fr2, respectively, are greater than k′ times the absolute value of the frequency difference Fr1−Fr2, k′ being a number at least equal to 2.