| 摘要 |
<P>PROBLEM TO BE SOLVED: To obtain a coupler having flat frequency characteristics of a coupling degree over a wide band. <P>SOLUTION: A directional coupler has: a main line for transmitting a transmission signal; an input port for inputting the transmission signal to the main line; an output port for outputting the transmission signal from the main line; a sub line coupled with the main line in electromagnetic field to extract a part of the transmission signal; a coupling port provided at one end part of the sub line; and an isolation port provided at the other end part of the sub line. A low-pass filter part having a function as a low-pass filter is provided between the sub line and the coupling port. <P>COPYRIGHT: (C)2013,JPO&INPIT |
