PULSE FREQUENCY DISCRIMINATOR
FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH
Pagination or Media Count:
A frequency discriminator designed to determine the carrier frequency or duty cycle of short bursts of radio signals is presented. It gives a discrimination characteristic with steep slope, and also reduces the coupling between the discrimination and transient characteristics of existing devices. It uses for transforming the frequency change to a voltage change the slope of the envelope of the frequency spectrum of amplitudes with rectangular frequency characteristics of the filter. The use of this method is desirable with input signals of short bursts. This pulse frequency discriminator is analyzed, using Fourier transforms, by studying the analogy between it and a pulse time discriminator. The output signal of the frequency discriminator is formed by subtracting the symmetrically tuned filter response at the input. In the time discriminator, the output is presented by the difference of the input and gating pulses with a symmetrical time shift. The output signals of the frequency discriminator. With symmetrical tuning, the orthogonal component of the filter can be neglected, and the output signal is considered proportional to the difference of the in-phase components. Thus, this discriminator is an application of synchronous detection.
- Electrical and Electronic Equipment