| 摘要 |
PCT No. PCT/SE80/00312 Sec. 371 Date Jul. 31, 1981 Sec. 102(e) Date Jul. 31, 1981 PCT Filed Dec. 4, 1980 PCT Pub. No. WO81/01616 PCT Pub. Date Jun. 11, 1981.A device for measuring the frequency of a pulsed carrier signal in which the carrier frequency is situated within the frequency range and to give a continuous signal whose frequency is equal to the measured carrier frequency. A frequency discriminator (3) gives an analog voltage via a track-and-hold circuit (4) and a DC-amplifier (15) to one input of a comparator (6) whose second input receives the analog voltage from the discriminator (3). The difference value from the comparator (6) is supplied to a voltage controlled oscillator (8). This is via a directional coupler or duplexer (9) and a controllable switch (1) connected to the frequency discriminator (3) which alternatively receives the input signal to the device and the output signal from the voltage controlled oscillator (8). |
