Patent ID: 7012479
Filing Date: 2006-03-14
Classification: H01P

Abstract:
1. A filter circuit for filtering unnecessary frequency components within a signal, comprising: a first line pattern having two ends, one of which is connected to an input terminal and the other is opened or grounded; a second line pattern having two ends, one of which is connected to an output terminal and the other is opened or grounded; and a closed loop pattern portion, which is interposed between the first and the second line pattern, having two or more closed loop patterns and each of the closed loop patterns having an electromagnetic coupling portion coupled to each of the first and the second line pattern, wherein the output terminal is located opposite to the input terminal, wherein two or more closed loop patterns are disposed in such a manner that the distance between every two neighboring closed loop patterns is N times of a wavelength at a resonant frequency, N being a positive integer.