SU1420549A1 - Method of determining amplitude-frequency characteristics of input and output filters of ideal model of non-linear four-pole network as a standard radio engineering component - Google Patents

Abstract

The invention relates to a pulse technique. The method of determining the amplitude-frequency characteristics of the input and output filters of the nonlinear quadrupole model (LFC) as a typical radio link is that the LFC is supplied with a two-frequency signal with given amplitude level (A) of the components at the frequencies, and f and their ratio The output is measured by A harmonic components and their ratio is determined. At the same time, the levels of the components in the test signal are measured at frequencies f and h f, the A harmonic components are measured at the same frequencies and their ratio is determined. The obtained values of the ratio A are compared. In case of their inequality, the ratio of the component levels in the test signal at frequencies f and f is repeated and the tests are repeated until equality, after which the ratio of the transmission coefficient modules at frequencies f and „is determined for the output filter of a typical radio link , as the ratio A of the components at the output of the LTP, and for the input filter as the value inverse to the ratio A of the components of the test signal, then change the frequency f, and repeat the steps to obtain the dependence awns modulation transmission ratio of the frequency coefficients. The method has high measurement accuracy. 1 il.

Description

 11420549

The invention relates to a measurement technique-and can be used to analyze the amplitude-frequency characteristics (AFC) of elements of an ideal model of a non-linear quadrupole (for example, a multiresonator klystron) as a typical radio link (TRD), which is a serial connection of an input linear filter, without ; nonlinear element (BNE) and the output linear filter.

The purpose of the invention is to improve the accuracy of determining the frequency response of the elements of the SFS. The drawing shows a block diagram of a device that implements the method.

The device contains generators 1

ten

15

test signal will not become rymi. When equality is achieved, the ratio of the moduli of the transmission coefficients at frequencies f and f is determined, for the output filter as the ratio of the amplitudes of the components at the output of the DFZ to the frequencies f, and f, and for the input filter as the reciprocal of the amplitudes the input test signal at frequencies f, and f To obtain the entire frequency response of the elements of the TP, change the frequency f, and repeat these operations.

The method is based on the properties of the elements that make up the SSS. If an input of a BNE, apply a two-frequency test signal consisting of

: And 2 signals (for example, type GA-76A), 20 components with equal amplitudes

thirty

the outputs of which through the adder 3 are connected to the input of the attenuator 4, the quadrupole under study 5, the analyzers 6 and 7 of the spectrum, and terminals 8 and 9 of the device for connecting the 25 nonlinear quadrupole under study.

In order to implement the method, oscillators 1 and 2, which generate single-frequency signals with adjustable amplitude, and adder 3, form a dual-frequency test signal.

The attenuation of the attenuator 4 is set so that the level of the test signal at the output of the studied quadrupole 5 corresponds to the upper limit of its dynamic range. The frequencies of the generators f,: and f, should be in the frequency band of interest for this study (for example, in the working frequency band of the klystron). Spectrum analyzer 6 measures the amplitudes of the harmonic components of the signal at the output of the quadripole 5 at frequencies f and f and calculate their ratio. The level of the test signal is changed by increasing the attenuation of the attenuator 4 by a predetermined amount, and the amplitude of the harmonic components 50 is measured again at the output of the quadrupole 5 at frequencies f, and f, j, and the ratio of these amplitudes is determined. This ratio is compared with the previous one, and if these ratios are not equal, then the amplitude ratio in the test signal 55 is changed and the above operations are repeated until the amplitude ratios are at two levels

35

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at frequencies f and f, then at the output of the BNE the amplitudes of the components at frequencies f and fj are also equal regardless of the level of the input signal. The input and output filters are linear signals, therefore, ensuring the equality of the amplitudes of the components at the BNE input, the ratios of the amplitudes of the components at frequencies f and f at the input and output of the DF, uniquely determine the ratio of the modules of the transmission coefficients of the filters at the corresponding frequencies, and the achievement the equality of the amplitudes of the components at the input of the BNE can be determined by the equality of the ratios of the amplitudes of the components at the frequencies f, and f at the output of the DTH when the level of the test signal changes, since due to the linearity It also does not depend on the level of the input signal.

Claims (1)

Invention Formula The method for determining the amplitude-frequency characteristics of the input and output filters of an ideal model of a non-linear quadrupole in the form of a typical radio engineering link, based on the supply of test signals of different frequencies to the input of the quadrupole examined, measuring the amplitudes of the harmonic components at the output of the four-pole and determining the ratio of the transmission coefficient different frequencies and transmission coefficient at one of the frequencies, characterized in that. 0 five The test signal will not become equal. When equality is achieved, the ratio of the moduli of the transmission coefficients at frequencies f and f is determined, for the output filter as the ratio of the amplitudes of the components at the output of the dispenser to the frequencies f, and f, and for the input filter as the reciprocal of the amplitudes of the input test signal at frequencies f, and fj. In order to obtain the entire AFC of the elements of the DG, the frequency f is changed, and the indicated operations are repeated. ; The method is based on the properties of the elements that make up the SSS. If a two-frequency test signal is applied to the BNE input, consisting of 0 five 0 5 five 0 at frequencies f and f, then at the output of the BNE the amplitudes of the components at frequencies f and fj are also equal regardless of the input signal level. The input and output filters are linear signals, therefore, ensuring the equality of the amplitudes of the components at the input of the BNE, the ratios of the amplitudes of the components at frequencies f and f at the input and output of the DF unambiguously determine the ratio of the modules of the transmission coefficients of the filters at the corresponding frequencies, and . The equality of the amplitudes of the components at the input of the BNE can be determined by the equality of the ratios of the amplitudes of the components at the frequencies f, and f at the output of the DG when the level of the test signal changes, since, due to the linearity of the input and output filters, it also does not depend on the level of the input signal. Invention Formula A method for determining the amplitude-frequency characteristics of the input and output filters of an ideal model of a non-linear quadrupole in the form of a typical radio engineering link, based on applying test signals of different frequencies to the input of a quadrupole, measuring amplitudes of the harmonics at the output of the quadrupole and determining the ratio of the transfer coefficient at different frequencies and transmission coefficient at one of the frequencies, characterized in that. In order to increase accuracy, a two-frequency test signal with a given level of component amplitudes at frequencies f, and fj and their ratio is fed to the input of a test-cell terminal, and their ratio is measured at the output of the quadrupole at frequencies f, and fj and then the levels of the components in the test signal are changed simultaneously at frequencies and the amplitudes are again measured The above-mentioned operations until the two amplitude ratio values at the two component level values in the test signal become equal, when their equality is achieved, the ratio of the transmission coefficient modules at the frequencies and f for the output filter of the typical radio link as the ratio of the amplitudes of the components at frequencies f, and fj at the output of the studied quadrupole, and for the input filter as a value inverse to the ratio of the amplitudes of the components at frequencies f, and f of the test signal at the output, quadrupole, then change the frequency f. and repeat the above mentioned operations to obtain 15 f, and 1 harmonic components on the chistotes, and fj determine their ratio, then compare the obtained amplitude ratio values, in case of amplitude ratio inequality values, change the ratio of component levels in the test signal — the ratio of the coefficient modulus at frequencies f and f and repeat the transmission samples from the frequency. mute above operations until the two amplitude ratio values at the two component level values in the test signal become equal when they are equal. determine the ratio of the moduli of the transmission coefficients at frequencies and f for the output filter of a typical radio technical link. As the ratio of the amplitudes of the components at frequencies f, and fj at the output of the quadrupole under study, and for the input filter as the reciprocal of the amplitudes of the components at frequencies f, and f of the test signal at the output of the tested quadrupole, then change the frequency f. and repeat the above mentioned operations to obtain five The dependence of the ratio of the transmission coefficient modulus on the frequency.