Frequency discriminator for transmitters and receivers - has comparator operating for duration of each rectangular pulse

摘要

The frequency discrimator has a comparator with an AND-circuit. One input of this AND-circuit is connected to a timer. The second input is connected to the output of a signal shaper. An invertor also has its input connected to the output of the signal shaper. A zero reset pulse shaper has its input connected to the signal shaper. Its output is connected to a counter composed of five units. The minimum number of units which the counter must have is determined by the resolution required of the discriminator. The number of units is determined by the formula p >= 3.4 log (Fo/DELTA F) where p = the number of units of the counter. Fo is the average frequency of the treated signal. DELTA F is the frequency deviation of the treated signal.