SU1332545A1 - Device for measuring nonlinear distortions in radio receivers - Google Patents

Abstract

Isophilus provides an increase in measurement accuracy. The device contains a radio receiver 1, two generators 2, 3, four modulators 4-7, three keys 8-10, an adder 11, two band-pass filters 12, 13, a high-frequency filter 14, a high-frequency amplifier 15, a spectrum analyzer 16 and a voltmeter 17. The control signals of the oscillators 2, 3 are added up in the adder 11 and transferred to the high-frequency region by means of the modulator 5. In the band-pass filters 12, 13 the lower and upper sidebands are suppressed. Next, using the modulator 6, the pilot signals are transferred to a higher frequency range. In filter 14, the lower side band is suppressed. The signal transferred by the modulator 7 to an even higher frequency range is amplified by the high-frequency amplifier 15 and fed to the receiving high-frequency path of the radio receiver 1. Amplitude modulator 4 is connected by means of clone 8 to measure the distortion of the cross modulation type. At the same time, the signal of the generator 2 provides the amplitude modulation of the high-frequency signal formed by one of the band-pass filters 12, 13. 1 sludge. (Lg w yu

Description

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The invention relates to the field of radio measurements and can be used to measure nonlinear distortions in modern radio receiving devices.

The purpose of the invention is to increase the measurement fineness.

The drawing shows an electrical functional circuit diagram of the device.

A device for measuring nonlinear distortions in radio receivers contains the measured radio receiver 1, the first and second generators 2 and 3, the first to fourth modulators 4-7, the first one - the third keys 8-10, the adder 1, the first and second bandpass filters 12 and 13, the filter 14 high frequency amplifier 15 high frequency, analyzato 16 spectrum and a voltmeter 17.

The device works as follows.

The control signal from the first generator 2 through the first key 8 is fed to one of the inputs of the adder 11 to the other input of which a control signal is supplied from the second generator 3. From the output of the adder 11, signals are sent to the second modulator 5, to the other input of which the frequency from the third local oscillator is fed the radio receiver to be measured 1. Due to this, the pilot signals are transferred to a region whiter than high frequencies. The signal thus formed is fed through a second switch 9 to a first bandpass filter 12 in which the lower sideband is suppressed, or to a second bandpass filter 13 into which the upper sideband is suppressed. After that, the signal is fed to the third modulator 6, to the other input of which the frequency from the second local oscillator of the measured radio receiver is fed. Due to this, the control signals are transferred to a higher frequency range. In the high-pass filter 14, the lower sideband is suppressed. The signal is then transmitted through the third key 10 to the fourth modulator 7, to another input of which the frequency from the first local oscillator measured by the radio receiver 1 is supplied. Signals transferred to an even higher frequency range are amplified in high frequency amplifier 15 and order 3850/56

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blunt to the input of the receiving high-frequency path of the measured radio receiver 1. From the first output of the measured radio receiver 1, the signal spectrum is estimated by the spectrum analyzer 16 and the voltmeter 17.

The first amplitude modulator 4 is connected using the first key 8 to measure the cross-modulation distortion type. The signal from the first generator 2 through the first key 8 is fed to the input of the first modulator 4 and provides amplitude modulation of the test high-frequency harmonic signal generated depending on the first or second band-pass filter 12 and 13 turned on by the second key 9.

Claims (1)

Invention Formula 25 A device for measuring {non-linear distortions in radio receivers, comprising a first generator, a second generator and an adder in series, a spectrum analyzer and 30 voltmeter whose inputs are the output of the measured radio receiver, characterized in that, in order to increase the measurement accuracy, the first modulator, the first key, the first band pass filter and the second modulator connected in series, the second key, the second band pass filter, the third module torus, high-pass filter, third key, fourth modulator and amplifier vy35 40 low frequency, another output of the second 45 key through the first bandpass filter connected to the input of the third modulator, the output of the adder is connected to the input of the second modulator, and another input through the first key is connected to the output of the first generator, the output of the first key through the first modulator is connected to the input of the four Beptoro mod The output of the high-pass filter is connected to another input of the first modulator. The output of the high-frequency amplifier is the input of the measured radio receiver whose second, third and fourth outputs are respectively inputs of the second, third and fourth a modulator. Irage 638 Subscription 50 55