High frequency filter having a solid circular shape resonance pattern with multiple input/output ports and an inter-port waveguide connecting corresponding output and input ports

Abstract

A resonance pattern () made of conductive material and having a circular plan shape is formed over the principal surface of a dielectric substrate. First and second virtual straight lines mutually crossing at a right angle are defined. A first input port () and a first output port () are electromagnetically coupled to the resonance pattern at two cross points between the first virtual straight line and an outer circumference line of the resonance pattern. A second input port () and a second output port () are electromagnetically coupled to the resonance pattern at two cross points between the second virtual straight line and the outer circumference line of the resonance pattern. A first inter-port waveguide () propagates a high frequency signal output to the first output port to the second input port.