| 摘要 |
A damping circuit is described for the antenna resonance circuit (28) of a radio transmitter-receiver (10) which in a transmitting phase transmits a time-limited high-energy interrogation pulse and in a receiving phase following the transmitting phase is ready to receive high-frequency response signals coming from a responder (26) which transmits said response signals as reaction to the reception of the interrogation pulse. In the damping circuit (24) a damping member (R4, R5, R6) is provided which is adapted to be connected to the antenna resonance circuit and disconnected therefrom. A switching means (T4, T5) on receiving a switching voltage applies the damping member (R4, R5, R6) to the antenna resonance circuit (28). A first energy-storage element (Cl) chargeable by the HF interrogation pulse serves for furnishing the switching voltage and a second energy-storage element chargeable by the HF interrogation pulse in dependence upon the time profile of the HF interrogation pulse enables the application of the switching voltage present at the first energy-storage element to the switching means (T4, T5).
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