US Patent 10340575 Directional coupler

A directional coupler includes an input terminal, an output terminal, a coupling terminal, a termination terminal, a first ground terminal, second ground terminals, a main line, a first sub line, and a second sub line. A first low pass filter is included between the coupling terminal and the first sub line. A second low pass filter is included between the first sub line and the second sub line. The first low pass filter is electrically connected to the first ground terminal, and the second low pass filter is electrically connected to the second ground terminals.