Patent ID: 8253515
Filing Date: 2012-08-28
Classification: H01P

Abstract:
1. A band-pass filter printed on a printed circuit board, the band-pass filter comprising: an input portion enabling input of an electromagnetic signal; an output portion enabling output of the electromagnetic signal; a plurality of transmission portions electrically connecting the input portion and the output portion to transmit the electromagnetic signal therebetween; and a pair of coupling members each shaping a frequency of the band-pass filter, each of the pair of coupling members comprising a first coupling portion electrically connecting two of the plurality of transmission portions and a second coupling portion electrically connected to the first coupling portion, the first coupling portion in each of the pair of coupling members comprising a pair of parallel coupling microstrip lines of the same size, and the second coupling portion in each of the pair of coupling members comprising a pair of transmission lines of different sizes; wherein one of the pair of transmission lines of the second coupling portion in each of the pair of coupling members roughly shapes the frequency of the band-pass filter, the other of the pair of transmission lines of the second coupling portion precisely shapes the frequency of the band-pass filter.