SU761956A1 - Apparatus for measuring radioreceiver parameters - Google Patents

Description

The invention relates to radio engineering, in particular to devices used for measuring parameters of radio receivers. cove using instruments to monitor the passage of signals. five

A known device for measuring radio parameters such as ·. ' maximum and real sensitivity '

and attenuation of the reception in the mirror channel, will keep the voltage generator 10 “high frequency with modular audio modulation, high frequency voltage attenuator, switches, high pass filter, amplitude and square-law detectors, voltage meter, arithmetic device 15, tuning and switching unit ranges, control device, number comparator [1].

The main disadvantage of this device is the structural complexity of the block 20 of the adjustment and switching ranges; determined by the need to tune the receiver to the frequencies of test oscillators' high often! · and to carry out operations of ²⁵ approximation in the measurement of the real sensitivity. In addition, the inability to fine-tune test generators on the receiver’s mirror channel together with inaccurate receiver tuning

on the frequency of the test generators lead to large measurement errors and poor reproducibility of the results.

The purpose of the invention is to increase the speed and accuracy of measurements.

This goal is achieved by the fact that, in the device for measuring the parameters of the radio | receiver,: '~ sO'der'ZHEShE ^, ''gyon'or?A'tOr' signals, the output of which is connected to the input of the controlled attenuator, switch, comparator , digital indication unit and adjustment lcd of range switching, additionally a clock pulse generator, an amplifier unit of the mirror channel formers, three switches, two memories, two comparators and a synchronization block, with the clock pulse output connected the input of a controlled attenuator connected to the input of the first switch connected to the input of the controlled receiver directly and through the mirror channel amplifier block; the outputs of the second switch connected to the output of the controlled receiver are connected to the first comparator connected to the first input of the clock pulse generator and to the third switch761956

3 ' _? / ...four

The outputs of which are connected via the first ₍ storage device and directly to the ^- 'inputs of the second comparator connected to the second input of the clock generator, the output of which is connected to the input of the digital display unit and the input of the fourth switch connected directly and through

. the second storage device to the inputs of the third comparator, the output of which is connected to the second input of the digital display unit, and the outputs of the unit SykHr'bNisations are connected to the third inputs of the clock generator, the digital display unit to the second inputs of all. switches and to the input of the block of adjustment of m ере range switches.

The drawing shows a block diagram of the proposed device.

The device contains a signal generator 1, a controlled attenuator 2, the first switch 3, the block 4 of the amplifiers-formers of the mirror channel, a controlled receiver 5, the second switch 6, the first comparator 7, the third switch 8, the first storage device 9, the second comparator 10, the fourth switch 11, the second storage device 12, the third comparator 13, block 14 synchronization, generator / 5-clock pulses, block 16 digital 'display, block 17 tuning and switching ranges, consisting of an asynchronous motor 18, red the detector 19, the tracking switch 20 'and the control unit 21. The noise generator used in the device is a noise generator that generates a noise signal with uniform spectral "density" over the entire frequency range of received signals from monitored receivers (0.1 (5–23.0 mhz).

The device operates according to the following algorithm.

At each point, consistently, the maximum and real sensitivity, attenuation of reception on the mirror / channel are measured.

When measuring the maximum sensitivity, the noise signal of the generator 1 output goes through the attenuator 2 nd first switch 3 to the input of the controlled receiver '5, in the initial position the attenuator is maximal, and the signal at the receiver input does not exceed

1 µV. ^:

The operation of the attenuator 2 controls the clock pulse generator 15 so that each subsequent clock pulse reduces the attenuation of the attenuator

2 and to an increase in the signal at the input of the receiver- ¹ . 5. An increase in the signal at the input of Pryom'gika 5 causes an increase in the signal at its output, proportional to the gain of the receiver at the test frequency. The output of the receiver 5 through the second

“Switch 6 is connected to the first” 7 cage that is triggered, krgDa level of the output signal of the receiver 5 becomes equal to the level corresponding to the allocation of the standard (specified) power in load. At this moment, the output pulse of the comparator 7 stops the clock pulse generator 15. But measures clock pulse, wherein the pre ua ^10x operation of the generator, the digital display indicating unit 16 indicates the maximum sensitivity of the receiver 5 at the measurement frequency. '

When measuring the actual sensitivity ^{of 15} Nosta first measured and stored level of intrinsic receiver noise. At the same time, there is no signal at the receiver input, and its output voltage through the switches 6 and 8 enters the first memory device 9. Then the noise signal from the generator 1 through the attenuator 2 and switch 3 comes to the receiver input; just as in the previous case, the clock pulse generator 15 controls the operation of the attenuator 2, and the output voltage of the receiver 5 through switches 6 and 8 is fed to the second input of the second comparator 10, the output of which is connected to the first input of the memory 9. The comparator 10 operates in the moment when the output voltage of the receiver 5 exceeds the self-noise voltage by a predetermined value. The output pulse of the comparator 10 stops the generator 15, the number of the last clock cycle of whose pulse is indicated by the / ^ digital indication unit and represents the real sensitivity of the receiver. ka at the measurement frequency.

When measuring the attenuation in the mirror channel, the maximum sensitivity of the receiver is first measured, as described above, however, the number of the clock pulse characterizing the maximum sensitivity is transmitted to the second memory device 12 through the fourth switch And then the noise signal from the generator 1 through the attenuator 2 and switch 3 is supplied to the input of block 4, amplifiers-formers of the “mirror” channel, in which it passes through the amplifier-former, which has a frequency response with a large attenuation On the base of the main channel (on the second - Maximum sensitivity is measured) and with a fixed gain at the frequency of the main channel. In this case, the gain At the frequency of the specular channel, “eBotReplies to the attenuation rate of the specular channel. From the output of the amplifier-form-fitting unit, the signal goes to the YH'o'D-controlled "receiver. The output voltage of the’ receiver 5 in this case goes through the second switch 6 to the comparator 7, which is the same as in

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five

in the previous case, it is triggered when the output level of the receiver corresponds to the standard output power. The generator 15 stops, and the number of the last clock pulse goes through the switch // to the second input of the third comparator 43, the first input of which is connected to the storage device 12 {and to the digital display unit 16. If the number of the clock pulse is greater than or equal to the number of the pulse received earlier on the memory 12, then the output of the comparator '///. If the number of the next! pulse is less than the number of the previous one, then a signal appears at the output of the comparator 13, indicating a small amount of selectivity in the image channel.

The sequence of operations provided by the block 14 synchronization.

The technical and co-economic advantages of the device made in accordance with the invention consist in increasing the speed by 4 times and measuring accuracy by 10-15%, which allows to improve the reproducibility of the measurement results and to carry out 100% quality control of the manufactured products at insignificant expenses for the equipment.

Claims (1)

Claim A device for measuring parameters of radio receivers, containing a signal generator, the output of which is connected to the input of a controlled attenuator, a switch, a comparator, a digital display unit and a tuning and switching range unit, which is the purpose of increasing the speed and accuracy of measurements, it additionally introduced a clock generator imyulso.v, block. amplifier shapers mirror ⁵ channels, three switches, two memory devices, two comparators and a synchronization unit, while the output of the clock generator is connected to the input of a controlled attenuator connected to About the input of the first switch connected to the input of the controlled switch no. and indirectly through the block usiliteleyformirovateley mirror (channel outputs of the second switch, Cpd ⁵ "ennogo yield controlled receiver connected to first / comparator connected to the first input of the clock generator and to tretVemu switch, which outputs 0 are connected via the first memory device and directly to the inputs of the second comparator connected to the second input of the clock generator, the output of which is connected to the input of the unit 5 digital display and the input of the fourth switch connected directly and through the second storage device to the inputs of the third comparator, the output of which is connected to the second input About the digital display unit, and the outputs of the synchronization unit are connected to the third inputs of the clock generator, the digital indication unit, to the second inputs of all switches and to the input of the unit 5 adjustment and switching ranges.