SU905870A2 - Frequency measuring device - Google Patents

Description

This invention relates to microwave radio engineering, which can be used in radio devices with a sweeping frequency generator (HGP).

According to the main author. St. No. 789857, a device for frequency measurement is known, comprising a spectrum generator, a mixer, a comparison unit, adders, a control key, a pulse counter, a reset unit, signal conditioners, a trigger, differentiating elements, and markers 1.

The disadvantages of the known device are a decrease in accuracy and reliability with a large change in the level of the heterodyne signal.

The purpose of the invention is to improve the accuracy and reliability of measurements when changing the level of the heterodyne signal.

This goal is achieved by the fact that in a frequency measurement device containing a mixer, the first input of which is connected directly to the input of the device and through a comparison unit with the first input of the key, the second input of the mixer is connected to the output of the spectrum generator, and the output through the tag conditioners to the inputs of adders The outputs of which are connected to the inputs of the corresponding signal conditioners, the output of each of which is connected to one of the separate trigger inputs, the output of which is connected to the second input of the key, the output of the key and the output of the reset unit is connected respectively to the counting and setting inputs of the counter, the output of which is the output of the device, is entered into detector level, the input of which is connected to the output of the mixer, and the output to potential inputs of signal conditioners.

The drawing shows the structural scheme of the device.

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The device for measuring the frequency contains a spectrum generator 1, a mixer 2, a comparison unit 3, adders 4-6, a control key 7, a pulse counter 8, a reset unit 9, a signal generator 10 and 11, a trigger 12, differentiating elements 13 and 14, Formers 15-19 labels and detector 20 level, the input connected to the output of the mixer 2, and the output connected to the potential inputs of the drivers 10 and 11 signals. Signal conditioners 10 and 11 can be implemented, for example, in the form of level limiters with adjustable 30 when adjusted by thresholds. The output of detector 20 is summed. with voltage thresholds and signals from the outputs of adders 4 and 5 at the inputs of drivers 10 and 11.

The device works as follows.

At a constant level of the GKCH signal in the operating range of the Frequency, the signal from the GCF output of the selective converter (not shown in the drawing) is sent to the input of the mixer 2 and unit 3. A pulse from the output of the same selective converter is applied to the input of the key 7 at the time of its tuning to the frequency of the input signal. The input of block 9 is given a pulse from the output of the tuning block (not shown) of the same selective converter, the reverse of its tuning. "The output signals are removed from the outputs of counter 8. When the dial is tuned, frequency marks appear at the output of markers 15-19. extracted from the oscillations at the output of the mixer 2 of the difference frequency between the tunable frequency GCF and the harmonics of frequency F, generator 1 of the spectrum. These frequency markers separated by frequency and time, passing through adders 4 and 5 and shapers 10 and 11 signals (for example, limiters) f cause alternate changes in the states of the outputs of trigger 12. The shape of the rectangular pulses at the outputs of trigger 12 has a duty cycle of 2, therefore, after differentiation using differentiating elements 13 and 14 and summing of unipolar pulses by adder b, the output of the latter produces pulsed frequency labels, the separation between which by jacTOTe is equal to Fo / 2 (nl). th reference frequency comparing unit 3 corresponding to the initial frequency band selective transducer, the output of comparator 3 is a block impulse This pulse opens pre

the private key 7 also permits the passage of pulses from the output of the diagator 6 to the input of the counter 8. The initial state of the counter 8 is predetermined before the start of the counting with the help of block 9, a pulse at its input. When the selective converter is tuned to the frequency of the input signal, a pulse arrives at the device input, which closes key 7. Pulses from the adder 6 to the input of counter 8 and stop 8 from tuning to the initial frequency until tuning to the frequency of the input signal determines the frequency of the input signal .

An increase in the levels of the GCh signal and its harmonics in the working frequency range increases the level at the output of the detector 20 and the total voltages of the response thresholds of the drivers 10 and 11 of the signals. This reduces the width of the signals at the outputs of the formers 10 and 11 and the frequencies of the trigger 12, as well as eliminates the by-products of the trigger 12 of the by-products of the mixer 2, which increases the accuracy and reliability of measurements with a large change in the level of the heterodyne signal.

Claims (1)

1. USSR author's certificate 789857 according to application code 2675651 / 18-21, 18.09.78.