SU1437962A1 - Balance modulator - Google Patents

Abstract

The invention relates to radio engineering. The purpose of the invention is to expand the operating frequency range while reducing the output voltage components with combination frequencies and harmonics. A resistor 13, an adjustable resistor 19, transistors 22-24, and an output rp-p- are inserted into the balanced modulator to achieve the target. 26, phase splitters 27, 25. Transistors 22 and 23 are used as an asset for the first elements of two stages with low input resistances needed to reduce the inertia of switching transistors 1-4 and reduce the effect of the change in load impedance on the operation of the device. To suppress the components, a nonlinearity correction circuit is used, made on transistor 2A. As a result of the use of cascades on transistors 22 and 23 and phase splitters 27, an extension of the frequency modulated voltage range is achieved. signal. 1 il. fff / jro / 5S (L with

Description

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The invention relates to radio engineering and can be used in frequency converters of selective voltmeters, selective voltage level meters, voltage spectrum analyzers, as well as in frequency converters of radio receivers and multichannel telecommunications equipment.

The purpose of the invention is to expand the operating frequency range while reducing the output voltage components with combination frequencies and harmonics,

The drawing shows a circuit diagram of the proposed balanced modulator.

The balance modulator contains the first - the sixth transistors 1-6, the fifth, the second, the third, the fourth, the first 1-capacitors 7-P, the third, the tenth, the first, the second, the fifth, the eighth, the ninth resistors 12-18, the second adjustable resistor 19, the sixth resistor 20, the first adjustable resistor 21, the seventh to ninth transistors 22–24, the second phase / horn 25, the output transformer 26, the first phase horn 27, the fourth and seventh resistors 28, 29.

The balance modulator operates as follows.

Transistors 1 and 2 form the first current switch, and transistors 3 and 4 form the second similar current switch. The transistors 5, 6 are active elements of the two sources of currents, the first of which is up ° C. Its output current has increments that are proportional to the modulating voltage. The quiescent current is determined by the resistance of the resistor 20. The coefficient for converting the modulating voltage to the collector current increments of the transistor 5 is determined by the resistance of the resistor 16. The capacitors 7 and 8, as well as 9 and 10 are separators. The capacitor 11 blocks the AC resistor 29. Resistors 12, .13 provide the supply to the bases of transistors G, 2, 3, 4 voltage from the voltage divider formed by resistors 14, 15. The resistance of resistor 17 determines the amplitude values of the variable component of the current of the emitter of transistor 24, its value is close to the value of the resistor 16 resistors 18, 19 are used for

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stabilizing and setting the quiescent current of the transistor 24. Resistor 21 sets the quiescent current of transistor 6 close to that of transistor 5 and corrects the degree of suppression of the component output voltage of the modulator with the voltage frequency of the modulated signal. The transistors 22 and 23 are used as active elements of two stages with low input impedances, which are necessary for decreasing. The inertia of switching transistors 1–4 and reducing the effect of a change in load impedance on the operation of a balanced modulator. The resistors 28, 29 form a voltage divider from which it arrives at the bases of the transistors 22 and

23 Constant voltage. Transistor

24 is an element of a non-linearity correction circuit converting the modulating voltage to the collector current increments of the transistor 5.

Under the action of the output voltage of the phase splitter 25, an alternating current, proportional to the modulating voltage, flows through the resistor 16, whose resistance is much greater than the input resistance of the transistor 5. This current creates an increment in the current of the emitter and the collector current of transistor 5, proportional to the modulating voltage. Due to the fact that the input impedance of the transistor 5 is nonlinear s at the emitter-base junction of this transistor, there are components of the voltage proportional to the second, third, fourth, and t, d. power of modulating voltage. These components lead to the appearance in the output voltage spectrum of a balanced modulator of components with harmonic frequencies and with the modulation frequency of the modulating voltage, Jp suppression of these components using a nonlinearity correction circuit implemented on the emitter-base This trSistor generates a quiescent current of the transistor 5 and an alternating ITOK proportional to the modulating voltage, which is close to the same. current flowing in the transistor 5. As a result of connecting the resistor 17 to the inverting output of the phase splitter 25 and using the transistor 24, whose structure is opposite to the structure of the other transistors,

the time base components of the emitter transistors 5 and 24 are subtracted. Therefore, the components of the alternating voltage with combinational frequencies and harmonic voltages applied to the resistor 16 are reduced.

Controlled by the output voltage of the phase splitter 27, the first current switch, made on transistors 1 and 2, periodically, at the frequency of the modulated signal, transistors 22 and 23 switches the output then of transistor 5 in half of the primary winding of the output transformer 26. This modulates the modulated signal. The suppression of the component with the frequency of the modulated signal is provided by the second switch, made on the transistors 3 and 4, by switching the collector current of the transistor 6 through the transistors 22 and 23.

As a result of using cascades on transistors 22 and 23 and phase splitter 27, the frequency range of the modulated signal voltage is expanded.

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Claims (1)

Invention Formula  Balance modulator containing the first, second, third and fourth transistors, the base of the first transistor connected to the base of the fourth transistor, the base of the second transistor connected to the base of the third transistor, the collector of the first transistor connected to the collector of the third transistor, the collector of the second transistor connected to the collector of the fourth transistor the fifth transistor whose collector is connected to the emitters of the first and second transistors; the sixth transistor whose collector is connected to the emitters of the third and the fourth transistors are connected in series with the first and second resistors, the second output of the perEuzo resistor is connected to the positive power supply bus, and the second output of the second resistor is connected to the common bus, the third resistor that is connected between the base of the fourth transistor and the first output of the first resistor, the fourth resistor, the first the output of which is connected to the second output of the first resistor, connected in series to the fifth and sixth resis 15 20 7962 tori, the seventh resistor and the first capacitor connected in series, the second output of which is connected to the common bus, the eighth resistor and the second capacitor connected in series, the third capacitor, the first output of which is connected to the base of the first transistor, the ninth resistor, the first adjustable resistor, the first output of which is connected with the emitter of the sixth transistor, the fourth and fifth capacitors, characterized in that, in order to expand the operating frequency range while reducing the output voltage components with a combination ion frequencies and harmonics, a seventh transistor is inserted in it, the emitter of which is connected to the collector of the first transistor, the eighth transistor, the emitter of which is connected to the collector of the fourth transistor, and the base to the base of the seventh transistor, to the second terminal of the fourth resistor and to the first terminal of the seventh resistor, the ninth transistor, the emitter of which is connected to the base of the fifth transistor, with the second transistor 35 40 with the water of the eighth resistor and with the first output of the ninth resistor, the output transformer, the first and second primary windings of which are connected respectively to the collector of the seventh transistor and to the collector of the eighth transistor, and diverting from the midpoint to the first output of the fourth resistor, the first phase splitter, the direct and inverse outputs of which are connected respectively to the second output of the third capacitor and to the first output of the fourth capacitor, the second phase splitter, direct to the inverse; the first outputs of which connect Ina respectively with the second vyshod 45 of the second capacitor and the first transistor of the fifth capacitor, the tenth resistor, the first output of which is connected to the second output of the fourth capacitor and the base of the second transistor, and the second output to the first output of the second resistor, the second adjustable resistor, the first output and removal of which it is connected to the first one of the fourth resistor, and the second output is to the second 55 of the output of the ninth resistor, while the second output of the seventh resistor is connected to the common bus, the base of the sixth transistor and the base of the ninth transistor are connected to the common bus, the emitter 514379626 The second transistor is connected to the first power supply, and the second is the fifth The output of the first resistor, the collector capacitor is connected to the second terminal of that transistor, connected to the second home of the first resistor, the first and The eye of the sixth resistor with the second-second phase splitters is the drain and the outlet of the first regulator responsibly modulated and resistive and with negative modulating signals.