| 摘要 |
<p>An embodiment includes a first directional coupler (DC1) connected on a path of a transmission antenna part (A1); a second directional coupler (DC2) connected on a path of a reception antenna part (A2); and a determining part (4) for determining, based on monitor outputs from these antenna parts, both a scattering parameter (S<SUB>11</SUB>) corresponding to the reflection property at the transmission antenna part (A1) and a scattering parameter (S<SUB>21</SUB>) corresponding to the transfer property from the transmission antenna part (A1) to the reception antenna part (A2) and further for outputting a warning signal (Dout2) when at least one of the scattering parameter (S<SUB>11</SUB>) and scattering parameter (S<SUB>21</SUB>) continuously exhibits a value outside its respective predetermined range over a predetermined time period.</p> |
