SU1173347A1 - Panoramic meter of amplitude-frequency characteristics - Google Patents

Abstract

PANORAMIC, AMP-: LITHUDO-FREQUENCY-DIMENSIONAL CHARACTERISTICS, containing a series-connected input cascade, the first amplifier and the first linear detector, whose input through the second amplifier is connected to the input of the second linear detector, the input cascade input is connected to the first input terminal of the meter, a comparator, a reference frequency generator, an output connected to the input of a block of frequency dividers, the outputs of which are connected to the corresponding control inputs of an exponential generator, and whether the generator The current sweep, the last of which is connected to the control input of the vertical beam deviation of the cathode ray tube, the input of the brightness control of which is connected to the output of the pulse addition unit, and the input of the control of the horizontal beam deflection is connected to the second input terminal of the meter, the third input terminal of which is connected to the first input of the block adding pulses, characterized in that, in order to improve the measurement accuracy, four keys and an additional exponential voltage generator, an input which is connected to the third output of the frequency divider unit, the output of the first linear detector through о S is the first key, and the output of the second linear detector is via the second key (L are connected to one of the inputs of the comparator, the second input of which is connected to the corresponding outputs of the exponential generator through the third and quarter keys voltage and an additional exponential voltage generator, and the output of the comparator is connected to the second input of the pulse addition unit, which controls the inputs of the first and third sub-key about 4; They are connected to the fourth output of the frequency divider unit, and the control inputs of the second and fourth keys are connected to the fifth output of the frequency divider unit.

Description

The invention relates to the field of measurement and can be used to measure the amplitude-frequency characteristics (AFC) of channels of communication systems.

The aim of the invention is to improve the measurement accuracy by reducing the errors in the formation of a logarithmic amplitude scale in a given dynamic range.

Figure 1 shows the structural diagram of the meter; 2 shows timing diagrams for his work.

The panoramic meter contains serially connected input cascade 1, first and second amplifiers 2 and 3, first and second linear detectors 4 and 5, a comparator 6, a series-connected frequency generator 7, a frequency divider unit 8, an exponential voltage generator 9, an additional generator 10 exponential voltage, linear sweep generator 11, pulse adding unit 12, electron-beam tube (CRT) 13, keys 14 - 17, first 18, second 19 and third 20 input terminals of the meter.

Panoramic meter works as follows.

The input signal, having passed through the input cascade 1 to the input of the first amplifier 2, is amplified and detected by the first detector 4, then fed to the signal input of the first switch 14. At the same time, the first signal from the output of the first amplifier 2 is additionally amplified by the second amplifier 3, detected by the second detector 5 and arrives at the signal input of the second key 15.

The reference frequency from the output of the generator is fed to the input of block 8, the output of which generates pulse sequences used by the control and synchronization dp (Fig.2 a, 8, d, g, 9). Thus, triggering pulses go to the input of the generator 11 (Fig.2) A periodic linearly varying linear scanning signal is formed at its output (Fig. 2B), which performs vertical scanning of a CRT beam 13. Triggering pulses from the outputs of block 8 are received at the inputs of the generator 9 and the additional generator 10 (Fig. 26.3). At the outputs of the generators 9 and 10 formir The cosiness of the exponentially varying voltages is the signals EIN1 and EIN2 (Fig. 2a, f), respectively. The working stroke of the signal EIN1 (Fig. 27) coincides in time with the first half of the working stroke of the linear sweep, and the working stroke of the signal EIN2 (Fig. 2e) - with the second half of the linear sweep stroke, the other parameters of the signals EIN1 and EIN2 (fig.2g, e) are identical.

The inputs of the generator 9 and the additional generator 10 using the third and fourth keys 16 and 17, the control inputs of which are fed respectively to the pulses of FIG. 2.5), are alternately connected to the second input of the comparator 6 during the working stroke of each signal of the PIR (FIG. 2i) . The first input of the first and second detectors 4 and 5 are alternately connected to the first input of the comparator 6 using the first and second keys 14 and 15. The output of the first detector 4 is connected for the duration of the power stroke of the EIN signal (FIG. 2d) and the output of the second detector 5 for the time working stroke signal EIN2. The gain of the second amplifier 3 is chosen equal to the dynamic range of the working stroke of the EIN signals, the parameters of the first and second detectors 4 and 5 should be identical. With a sufficiently large input signal, the first detector 4 operates on a linear portion of its conversion characteristic (the range of variation of the output voltage of detectors 4 and 5, when operating on the linear portion, must coincide with the range of variation of the EIN1 and EIN2 signals in the working stroke). At the same time, the output voltage Uo of the detector 4 (Fig.2i) lies within the voltage of the working stroke of the signal EIN1, with which it is compared at the comparator 6. The output pulses of the comparator (Fig.2k) go through the block 12 to the CRT modulator 13 for illuminating the beam at the appropriate times for the first half of the linear sweep stroke. Since the signal additionally amplified by the second amplifier 3 is fed to the input of the second detector 5, the second detector 5 operates in a linear region of its conversion characteristic. Its output voltage Ua (Fig. 2k) lies outside the limits of the operating voltage 31

the progress of the signal EIN2, i.e. during the second half of the linear stroke stroke, no pulses are generated at the output of the comparator 6. With a relatively small input signal, the first detector 4 operates below the linear portion of its conversion characteristic, its output voltage Uq lies beyond the limits of the working voltage of the EIN1 signal, and the second detector 5 operates on a 733474

The linear part of its conversion characteristic, its output voltage lies within the voltage of the working stroke of the EIN2 signal, with which it is compared at the comparator 6. The output pulses of the latter, through the block 12, arrive at the CRT modulator 13 to illuminate the beam at the appropriate time moments About the second half of the stroke linear sweep (figure 2 to).

Figure 1 E4-K 4-1Ng4Chg-1.1 and

PiJe. 2 I

Claims (1)

AMP-PANORAMIC METER. OF FREQUENCY FREQUENCY CHARACTERISTICS, comprising a series-connected input stage, a first amplifier and a first linear detector, the input of which through a second amplifier is connected to the input of the second linear detector, the input stage input is connected to the first input terminal of the meter, a comparator, a reference frequency generator, an output connected with the input of the block of frequency dividers, the outputs of which are connected to the corresponding control inputs of the exponential voltage generator and linear sweep generator, the output of the latter is connected to the vertical beam deflection control input of the cathode ray tube, the brightness control input of which is connected to the output of the pulse addition unit, and the horizontal beam deflection control input is connected to the second input terminal of the meter, the third input terminal of which is connected to the first input of the pulse addition unit, which differs in order to increase the accuracy of measurements, four keys and an additional exponential voltage generator, the input of which is connected to the third output of the frequency amplifiers, the output of the first linear detector through the first key, and the output of the second linear detector through the second key are connected to one of the inputs of the comparator, the second input of which is connected through the third and fourth keys to the corresponding outputs of the exponential voltage generator and an additional exponential voltage generator and the output of the comparator is connected to the second input of the pulse addition unit, the control inputs of the first and third keys are connected to the fourth output of the frequency divider unit, and the yayuschie inputs of the second and fourth keys are connected to a fifth output of the frequency divider block. SU „„ 1173347