SU1571787A1 - Bipolar signal regenerator - Google Patents

Abstract

The invention relates to telecommunications and can be used in discrete information transmission systems. The purpose of the invention is to improve the accuracy of signal regeneration when exposed to interference. To achieve this goal, the first rectifier 3, the first low-pass filter 4, the second matching block 5, the second rectifier 6, the second adder 7 and the second low-pass filter 8 are entered into the regenerator. Each of the rectifiers 3, 6 includes the first - the third transistors and the first - the fourth resistors, and each of the adders 2, 7 includes the first - the third transistors, a capacitor, and the first - the fourth resistors. Two-stage signal regeneration — separately for each half-wave of the signal — is effective for distortions that reach 100% of the amplitude of the input signal. Spurious high-frequency interference due to the inertia of the circuit elements is eliminated by low-pass filters 4 and 8. 2 hp f-ly, 5 ill.

Description

B

The invention relates to the Electrology and can be used in pictures of the transmission of discrete information.

sci.

The purpose of the invention is to improve the accuracy of signal regeneration in the presence of interference.

FIG. 1 shows the structure of the electric circuit of the regenerator.

dyurna bipolar signals; in fig. 2 and 3 schematic diagrams of the rectifier and adder, respectively, included in its composition; in fig. 4 and 5 - time diagrams of signals, according to the description of the work of the regenerator.

Bipolar Regenerator

contains the first matching block

one

and the first adder 2, as well as the first rectifier 3, the first low-pass filter 4, the second matching unit 5, the second rectifier 6, the second adder 7 and the second filter 8 of the lower frequencies.

Rectifier 3 (6), part of the regenerator and shown in FIG. 2 includes the first - third transistors 9-11 and the first - fourth resistors 12-15. The adder 2 (7) shown in FIG. 3 includes the first to third transistors 16-18, the capacitor 19 and the first to fourth resistors 20-23.

The regenerator of bipolar signals works as follows.

The input signal (diagram of Fig. 4a) is fed to the input of the first matching unit AND, which together with the first rectifier 3, the adder 2 and the low-pass filter 4, forms the regeneration cascade A. The regeneration cascade B, including the second matching unit 5, the rectifier 6, the adder 7 and the low pass filter 8 are similar to the cascade A according to the device and the operating principle, therefore it is possible to limit the operation to only one cascade, for example A.

The signal from the output of the first matching unit 1 is fed to the input of the first adder 2 and the input of the first rectifier 3, operating in two-half-period rectifier mode. As a result of the addition of two signals in the adder 2, the elimination of the constant component, and the filtering of the high-frequency components in the first low-pass filter 4, the signal at the output of the cascade A takes the form shown in FIG. 46. With this polo

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five

0

five

0

five

0

five

The strong half-waves of the regenerated signal are completely cleared of parasitic modulation (distortions), and the distortions of the negative half-waves doubled.

After passing the signal through stage B, in which the polarity of the rectified voltage is reversed (with respect to stage A), the signal at the output of the regenerator (diagram of Fig. 4c) is undistorted. A characteristic feature of the regenerator is the ability to work in conditions of significant distortion, reaching up to 100% of the amplitude of the input signal. Consider the regeneration of such a signal with the help of concepts.

Rectifier 3 (6) shown in FIG. 2, works as follows.

When a positive half-wave signal arrives, the first transistor 9 opens, and the second 10 third transistors 11 are closed. The collector voltage of the transistor 9 is determined by the ratio of the first 12 and second 13 resistors. When the negative half-wave of the regenerated signal is applied, the first transistor 9 closes, but the second 10 and third 11 transistors open. The voltage at the output of the rectifier 3 (6) in this case is already determined by the ratio of the first 13 and fourth 15 resistors. The third resistor 14 sets the same voltage level at the output of the rectifier to t both half-waves of the input signal. The signal at the output of the rectifier for the case in question is depicted in the diagram of FIG. 56.

A schematic diagram of the adder 2 (7) is shown in FIG. 3. At the same time, its first input must be connected to the output of the rectifier 3 (6), and the second input through an adjustable resistor (not shown) to the input of the rectifier 3 (6). The second transistor 17, the capacitor 19, and the resistors 20 and 23 produce a bias voltage proportional to the level of the signal constant. At the summation point, the level of the constant component supplied through the third transistor 18 can be controlled by the second resistor 21. The level of the output signal fed to the summation point through the first transistor 16 is determined by the value of the third resistor 22. As a result of two signals and exclusion of a constant component of the signal at the output of the adder has the form shown in FIG. 5c.

To regenerate the distorted negative half-waves of the signal in stage B, it is necessary to change the polarity of the rectified voltage to the opposite. At the same time, the type of conduction of the transistors of the rectifier and the adder and the polarity of the supply voltages must be changed to the opposite. In this case, the signal at the output of the rectifier corresponds to the diagram of FIG. 5g, and the signal at the output of the regenerator - the diagram of FIG. 5e.

To compensate for the residual distortion of the negative half-waves of the regenerated signal, you can use another stage of regeneration, consisting of two stages, similar to those considered, as shown in FIG. one .

The multistage regenerator, as it follows from the diagram in FIG. 5, in principle, can regenerate signals with distortions greater than 100% amplitude.

The diagrams in FIG. 4 and 5 are valid only when executing rectification and summation without inertia. Practically, due to the delay introduced in the signal transition region, spurious high-frequency interference occurs, which, however, are easily eliminated by low-pass filters connected to the outputs of the adders.

In the simplest case, a capacitor can be used as a filter, connected between the output of the adder and the common power wire.

Claims (3)

Invention Formula 1. A bipolar signal regenerator containing the first matching unit and adder connected in series, the input of the first matching unit being the input of the regenerator, characterized in that, in order to improve the regeneration accuracy under the influence of interference, a first rectifier and ten 15 20 25 thirty 35 40 45 50 55 the first lowpass filter, the second matching unit, the second rectifier, the second adder and the second lowpass filter, the output of which is the regenerator output, the input of the first lowpass filter is connected to the output of the first adder, the second input of the second adder is connected to the output the second matching unit, and the second input of the first adder through the first rectifier connected to the output of the first matching unit. 2. The regenerator according to claim 1, characterized in that the rectifier contains three transistors and four resistors, the emitters of the first and second transistors being connected to a common power supply bus through the first resistor, and the collectors of the first and third transistors are connected to the negative terminal of the source the power supply, the collector of the second transistor and the base of the third transistor through the third resistor are connected to the positive terminal of the power source to which the third transit emitter is connected through the fourth resistor The bases of the first and second transistors are the inputs of the rectifier, the output of which are the collectors of the first and third transistors. 3. The generator according to claim 1, characterized in that the adder contains three transistors, a capacitor and four resistors, the emitter of the first transistor connected to the base of the second transistor, the base of the third transistor connected to the collector of the second transistor and the first terminals of the capacitor and the first resistor, the second terminals which are connected to the positive terminal of the power source and the first terminal of the second resistor, the second terminal of which is connected to the emitter of the third transistor, the collector of which is connected to the collector of the first transistor The torus, the base of which is the first input of the adder, the second input and output of which is the collector of the third transistor, while the emitters of the first and second transistors are connected to the negative terminal of the power source through the third and fourth resistors. Q + Ј Fig 2 ffx.2 fig.Z OHi about M 0K- N Y V4 HN-HN-V f 1-f fig a