Patent ID: 7970447
Filing Date: 2011-06-28
Classification: H01P

Abstract:
1. A high frequency filter comprising: a substrate comprised of dielectric material; a first resonance pattern comprised of conductive material, disposed over a principal surface of the substrate and having a circular plan shape, that is substantially solid; a first input port electromagnetically coupled with the first resonance pattern at one cross point between a first virtual straight line passing through a center of the first resonance pattern and an outer circumference line of the first resonance pattern; a first output port electromagnetically coupled with the first resonance pattern at the other cross point between the first virtual straight line and the outer circumference line of the first resonance pattern; a second input port electromagnetically coupled with the first resonance pattern at one cross point between a second virtual straight line and the outer circumference line of the first resonance pattern, the second virtual straight line passing through the center of the first resonance pattern and crossing the first virtual straight line at a right angle; a second output port electromagnetically coupled with the first resonance pattern at the other cross point between the second virtual straight line and the outer circumference line of the first resonance pattern; a first inter-port waveguide for propagating a high frequency signal from the first output port to the second input port; a second resonance pattern comprised of conductive material, disposed over the principal surface of the substrate and having a same plan shape as the first resonance pattern; a third input port electromagnetically coupled with the second resonance pattern at one cross point between a third virtual straight line passing through a center of the second resonance pattern and an outer circumference line of the second resonance pattern; a third output port electromagnetically coupled with the second resonance pattern at the other cross point between the third virtual straight line and the outer circumference line of the second resonance pattern; a fourth input port electromagnetically coupled with the second resonance pattern at one cross point between a fourth virtual straight line and the outer circumference line of the second resonance pattern, the fourth virtual straight line passing through the center of the second resonance pattern and crossing the third virtual straight line at a right angle; a fourth output port electromagnetically coupled with the second resonance pattern at the other cross point between the fourth virtual straight line and the outer circumference line of the second resonance pattern; a second inter-port waveguide for propagating a high frequency signal from the third output port to the fourth input port; and an inter-stage waveguide for propagating a high frequency signal from the second output port to the third input port, wherein a transmission line length of the inter-stage waveguide is ⅜times a transmission line wavelength corresponding to a fundamental resonance frequency of the first resonance pattern.