| 摘要 |
<p>System for remote measuring a physical variable (v) comprising an RF transceiver (1) arranged for transmitting an RF signal (2) and for receiving a reflection signal (3) derived from the transmitted signal. An RF transponder (4) comprises a dielectric material (7) having a dielectric property which is dependent on the physical variable according to a first function (f(v)). The dielectric material is exposed to the physical variable (v) to be measured. The transponder is arranged to receive the signal (2) transmitted by the transceiver and to reflect a reflection signal (3), or the second and/or higher harmonics of it, which is dependent on the actual dielectric property. Processing means (9) are provided for comparing the signal (2) transmitted by the transceiver and the reflection signal (3) received from the transponder and for converting the comparison result, e.g. the phase shift, into a value which is representative for the physical variable (v) to be measured. The transponder may be e.g. a patch antenna.</p> |
