| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a dual band-supporting radio communication module which can switch between different two bands by a simple structure without the need for sending a control signal for band switching from a communication module of a main body side.SOLUTION: A radio communication module comprises: a directional coupling circuit 4; a first switch circuit 3 connected with a signal transmission line 4a of the directional coupling circuit 4; a first transmission circuit 1 for a first frequency band and a second transmission circuit 2 for a second frequency band which are connected with the first switch circuit 3; and a power detection circuit 5 connected with a coupling output port 4c of the directional coupling circuit 4. In radio communication module, the electric power of a transmit signal at an input port of the directional coupling circuit 4 is fixed in quantity regardless of a frequency; in a path between the input port of the directional coupling circuit 4 and an input port of the power detection circuit 5, the power attenuation of the first frequency band is made different from the power attenuation of the second frequency band in quantity; and the first switch circuit 3 is switched according to a magnitude of electric power detected by the power detection circuit 5.</p> |
