SU505120A1 - Push-pull amplifier - Google Patents

Description

a high-frequency oscillator 11 is connected, and one of the inputs of the controlled phase shifter 12 is connected to the second output. The output of the latter is connected to the second input of the synchronous detector 3. The outputs of the low-frequency filter 2 and voltage divider 5 are the outputs of the amplifier and are connected to two inputs of an additional automatic the switch 13, the control input of which is connected to the second (control) input of the automatic switch 8 and the output of the driver 10 connected to the second input of the synchronous detector 1. The output is additional Automatic switch 13 is connected to interconnected inputs of integrator 14 and resonant amplifier 15. Output of integrator 14 is connected to the second (control) input of voltage divider 5. Output of resonant amplifier 15 is connected via amplitude detector 16 to input of control device 17, output which is connected to the second input (control input) of the controlled phase shifter 12.

The amplifier works as follows.

The IF voltage applied to the device input 9 is: U (t) UmSin (). It is sampled at a frequency w much higher than the frequency of the input voltage Q using an automatic switch 8. As a result, the output voltage of the automatic switch 8 will be U (t) U (t) z (t), where z (t} is the sampling function , obtained by the shaper 10. Discretization voltage through the high-frequency filter 7 is fed to the paraphase amplifier 6, it is amplified, inverted through one of the channels and fed to the inputs of the synchronous detectors 1 and 3 in which it is detected. under Switched to the shaper 10 connected at the input of the generator 11 with a frequency (O. The detected voltages, which are the product of the voltages arriving at the inputs of the synchronous detectors 1, 3, and the voltage z (t) produced by the shaper 10, are fed to the inputs low frequency filters 2 and 4 respectively. Low frequency filters 2 and 4 separate infra-low-frequency paraphase voltages Ui (t)

 UmiSin ((fi) and f / m2Sin (Qt + (p2) SOTTVSTSTVETno. In the general case, the amplitudes of these voltages Umi and Um2 are different, because in general the transmission coefficients of the forward and inverse channels. For aligning the amplitudes of the paraphase infrared low frequency the voltages obtained at the outputs of the low-frequency filters 2 and 4 use a voltage divider 5 controlled by a voltage proportional to the difference in amplitudes Um-Uml - Um2,

which is formed by the integrator 14 connected to the output of the automatic switch 13. After converting in the voltage divider 5, the amplitudes of the voltages at the outputs of the amplifier are equal.

Since, in the general case, the paraphase voltages Ui (t) and Uzit), due to the phase non5 identity of the channels, are shifted relative to each other by an angle of 180 ° different,

AF F2-F1 180 ° - AF,

where AF is the angle determined by the phase nonidentity of the channels, then to exclude the error AF voltage Ui (t) and t / 2 (0 are fed to the input of the additional automatic switch 13, which is sampled, then from the resulting

15, the voltage sampling by the resonant amplifier 15 is extracted and amplified by a high frequency component, the envelope of which, proportional to the cosine of the angle AF, is extracted by the amplitude detector 16 and supplied

20 to the control device 17. The latter generates a control voltage proportional to the phase error of the inversion 6y / Saph, which is fed to the phase shifter 12, changes the phase of the control voltage supplied from the driver 10 to the synchronous detector 3 so that paraphase input voltages provided a phase difference equal to 180 °. As a result, the variable voltages derived from

This output of the device is in antiphase.

Claims (1)

Invention Formula A push-pull amplifier containing two amplification channels, each of which includes a synchronous detector with two inputs and a low-pass filter, a paraphase amplifier whose outputs are connected to the inputs of synchronous detectors, and its input is connected to the output of a two-input automatic switch, and high-frequency oscillator, the output of which is connected to the driver input, characterized in that, in order to reduce the amplitude and phase errors of the output paraphase level voltage, additionally introduced controlled phase shifter with two inputs, serially connected control device, amplitude detector, 0 resonant amplifier; an integrator, a voltage divider with two inputs and an additional automatic switch with three inputs and an output, which is connected to the connection point of the input of the resonant amplifier 5 with the integrator input, one of its inputs is connected to one of the inputs of the main automatic switch and the connection point of the driver's output to one of the inputs of the synchronous detector, the other two inputs of the additional automatic switch are connected to the output of the low-frequency filter of one of the channels directly, and the output of the low-frequency filter of another channel is through a voltage divider, while the output of the controlled phase shifter is connected to the second input of the synchronous detector, and the inputs of the said phase shifter are connected to the output of the driver and the output of the control unit.