ELECTROMAGNETIC WAVE FREQUENCY FILTER

摘要

In this electromagnetic wave frequency filter, an electromagnetic wave of a predetermined frequency matching a resonant frequency of a resonator 41 is transmitted from an input waveguide 2 to an output waveguide 3 through the resonator 41, and is outputted from a drop port P31. This filter has an input--waveguide-side reflector 211 and an output-waveguide-side reflector 31 1, which reflect the electromagnetic wave of the predetermined frequency. The electromagnetic wave frequency filter satisfies the following relation: Q inb/(1-cos .theta.1) << Q v, Q inb/(1-cos .theta.1) = Q inr/(1 -cos .theta.2), .theta.1, .theta.2 ~ 2N .pi. (N=0, 1, ...), where .theta.1 is a phase shift amount of the electromagnetic wave reflected by the input-waveguide-side reflector 21 1, .theta.2 is a phase shift amount of the electromagnetic wave reflected by the output-waveguide-side reflector 31 1, Q inb is a Q-factor between the resonator 4 1 and the input waveguide 2, Q inr is a Q- factor between the resonator 4 1 and the output waveguide 3 1, and Q v is a Q-factor between the resonator 4 1 and free space.