Patent ID: 7902945
Filing Date: 2011-03-08
Classification: H01P

Abstract:
1. A dual-mode filter comprising: a ring resonator; an input feeder and an output feeder disposed substantially orthogonal with respect to each other and with respect to the ring resonator so as to be electromagnetically coupled to the ring resonator; and a dual-mode generating line disposed inside the ring resonator in a manner so that the dual-mode generating line does not overlap either one of a line extending from the input feeder and a line extending from the output feeder, wherein a center of the dual-mode generating line is disposed in a manner so that an angle “θ” defined as an angle formed between a line passing through the center of the dual-mode generating line and a center of the ring resonator and a line extending from the input feeder is 45 degrees±90n degrees (n=0, 1, 2, 3), and the dual-mode generating line includes wherein a length of the dual-mode generating line between coupling points each electromagnetically coupled to the ring resonator is less than one-fourth of a circumference of the ring resonator.