| 摘要 |
PROBLEM TO BE SOLVED: To provide a high frequency transmitter-receiver, which is simply protected against surges by using a small number of parts, and to provide a filter element as one of the parts. SOLUTION: An element is used as a filter element 40 having a filter circuit 41, where the filter element 40 is configured between an antena 11, which is connected to a high frequency transmitter-receiver 30 such as a cellular phone and a radio communication machine, and a changing-over switch 13 for this connection, and the filter circuit 41 is inductively linked to an input/output terminal 40a for the anntena 11 and capacitively linked to an input/output terminal 40b for the changing-over switch 13. A surge current generated by a thunder bolt or the like at the antenna 11 passes through the filter circuit 41 to the ground. A DC voltage component and a DC current component in transmitter-receiver circuit 15, 16 will not be applied to the ground through the filter circuit 41.
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