| 摘要 |
PURPOSE:To facilitate remarkably assembling by adopting the constitution that two kinds of filter sections whose center frequencies differ from each other are incorporated continuously and an input/output shared pin is inserted to a position between both the filters where phases are matched properly so as to reduce number of components and simplify the structure. CONSTITUTION:Two kinds of filter sections 32, 34 whose center frequencies differ from each other are incorporatedly and continuously in the lengthwise direction. In combining the phases of both the filters 50, 52, a distance X1 between the input/output pin 54 and a reception hole 56 is obtained so as to make the impedance at the center frequency at the reception side infinite as to the transmission side filter 50 and the distance Y1 is obtained similarly as to the reception side filter 12 separately from sizes of resonance holes and coupling holes. Both the filters are incorporated based on the distances X1, Y2 obtained in this way. Distances X2, Y2 for the incorporation arc obtained by multiplying a factor (k) with the distances X1, Y1. The factor (k) is obtained in advance by experiments from the relation of the both.
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