SU898338A1 - Digital meter of frequency deviation - Google Patents

Description

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The invention relates to a measurement technique and is intended for use in radio engineering devices; for various applications.

The known device containing the generator, driver, counter, arithmetic unit and indicator 1.

The disadvantage of this device is low measurement accuracy.

The closest in technical essence and the achieved measurement result to the proposed is a deviometer containing a driver, a selector connected to the output with a measuring counter, a reference generator, an analysis circuit implementing the selection of extreme values, a computing unit and an indicator 2.

A disadvantage of the known device is low measurement accuracy.

The aim of the invention is to improve the accuracy of measurement of frequency deviation.

The goal is achieved by the fact that a serially connected delay block, a memory block are inserted into a frequency deviation meter containing a pulse shaper. And a serially connected analysis unit, an arithmetic unit and an indicator.

and an analog-to-digital converter (ADC), the output of which is connected to the input of the analysis unit, while the output of the driver is connected to the input of the delay unit.

FIG. 1 is a block diagram of a frequency deviation meter; in fig. 2 - timing diagrams showing the operation of the deviation meter.

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The deviation meter includes a driver 1, a delay block 2, a memory block 3, an analog-to-digital converter (ADC) 4, an analysis block 5, an arithmetic unit 6, and an indicator 7.

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The device works as follows.

Frequency modulated signal

the intermediate frequency arrives one at a time at the first input of block 3 and through shaper 1 to block 2 of delay. Shaper 1 generates a pulse (Fig. 26) at the time of the signal transition through the selected level Ug

25 (Fig. 2a) in a given direction, the output-block 2 of the delay is connected to the second input of block 3. At the time of the arrival of the delayed ig.pulse (Fig. 2c) block 3 remembers. instantaneous value of sig30 under investigation

U (Fig. 2a) and outputs it to the A / D converter 4 for conversion to a digital code.

The output of the ADC 4 is connected to the input of the analysis unit 5. From the sequence of the generated ADC 4 codes, block 5 selects the maximum and minimum codes that are received in block b for calculating the deviation value. In Fig. 2a, it is clear that the largest instantaneous voltage value corresponds to the smallest instantaneous frequency modulated frequency, and the smallest the instantaneous voltage value is the largest instantaneous frequency value.

The measurement result is displayed on the digital indicator 7.

The proposed device retains the positive qualities of the known, namely, it is not critical to the detuning of the intermediate frequency, its resolution does not depend on the depth of deviation. In addition, it does not require the use of high-speed scaling devices. Chip performance of high-speed ADCs with a number of bits up to

L2 greatly simplifies the implementation of the device and allows for high measurement accuracy.

Claims (2)

1. USSR author's certificate 575578, cl. G 01 R 23/00, 1976. 1 2. USSR author's certificate No. 580521, cl. G 01 R 23/10, 1976 (prototype). . corner 2