Matching circuit chip, filter with matching circuit, duplexer and cellular phone

摘要

The present matching circuit chip has an integrated shape comprising a first transmission line, a second transmission line and a third transmission line, wherein one end of the first transmission line, one end of the second transmission line and one end of the third transmission line are connected to one another, a first filter connection terminal is connected to the other end of the first transmission line, an antenna terminal is connected to the other end of the second transmission line, and a second filter connection terminal is connected to the other end of the third transmission line, whereby the second transmission line converts the characteristic impedances of the first and third transmission lines so that the impedance matching between the antenna terminal and the first filter connection terminal can be attained, and so that the impedance matching between the antenna terminal and the second filter connection terminal can be attained.