| 摘要 |
A frequency discriminator comprises a power splitter 2 for splitting an input RF signal 3 intofirst 4 and second 5 paths , wherein the first path 4 provides a first, straight-through signal and the second path 5 includes a frequency-dependent element, such as low-pass filter 8, to provide a second signal with an amplitude that depends on frequency. The frequency discriminator further comprises a circuit 6 configured to compare the first and second signals using a differential amplifier 11 to produce an output 13 indicative of the instantaneous frequency f of the RF input. The low-pass filter has a cutoff frequency fc and so its output is proportional to the difference between the instantaneous frequency f and the cutoff frequency. The low-pass filter may be replaced by a high-pass filter or another frequency dependent component. The discriminator may be used in a radar system. |
