| 摘要 |
A frequency discriminator comprises a power splitter 2 for splitting a signal into a plurality of paths 4, at least two of which include filters 12 having different frequency characteristics which are configured to provide filtered signals to power detectors 14. The discriminator further comprises an analogue-to-digital conversion section 8 which provides digital values of the measured powers to a processing section 10, which estimates a value 11 of at least one frequency in the signal. Multiple such frequency detectors can be used together in applications such as radar systems, angle-of-arrival measurement systems or signal source position measurement systems. The device can also be used to detect a signal and, upon determining that the signal strength is greater than a threshold value, transmit the frequency value of the signal together with a unique identifier. Such a system may be used to detect unauthorised mobile phone use in prisons or hospitals. |
