SU1434536A1 - Power amplifier - Google Patents

Abstract

The invention relates to radio engineering and can be used in radio receiving, transmitting and measuring technology. The purpose of the invention is to reduce the level of the harmonic components of the third order. The power amplifier contains a push-pull amplifier (DU) 1, a phase-split transformer 2, active elements 3 and 4, a resistor (P) 5, cond ry 8 and 9, an output transformer 10. To achieve the goal, P 6, P 7 are entered into the device , power divider 11, phase shifter. 12, matching transformer (ST) 14, DN 13, identical to the first. CT 14 provides for the allocation of even harmonic components arising in. Remote control 13. These components are fed to the common-mode input of remote control 1, which leads to their interaction in the active elements 3 and 4 with the first harmonic of the input signal. In so doing, harmonic components of the third order are formed. With an appropriate choice of their amplitudes, they can significantly suppress the harmonic components of the third order at the output of the device. The necessary phasing of the harmonic components at the common-mode input of the remote control 1 is provided by the phase shifter 12 and CT 14 1 sludge. with ( (/)

Description

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The invention relates to radio engineering and can be used in radio receiving, transmitting and measuring technology.

The purpose of the invention is to reduce the level of the harmonic components of the third order.

The drawing shows an electrical schematic diagram of an amplifier: power.

I Power amplifier contains the first I push-pull amplifier 1, the phase-dissipating transformer 2, the first 3 I and the second 4 active elements, the first: 5, the second 6 and the third 7 resistors, the first 8 and the second 9 capacitors, the output transformer 10 , the power divider 11, the phase shifter 12j the second push-pull amplifier 13 and the matching transformer 141,: The power amplifier works in the following way.

The input signal is divided in divider 11 into two identical signals. The first of them is fed through the phase shifter 12 to the input of the first push-pull amplifier 1, is amplified in it, and transmitted to the output of the amplifier-power 1 through the output transformer 10. I The second part of the input signal comes to the input of the second push-pull | identical to the first push-pull amplifier 1, and amplified in it.

Matching transformer 14 ensures the separation of even harmonic components arising in the second push-pull amplifier 13. Moreover, these components also go to the common-mode input of the first push-pull amplifier 1, which leads to their interaction in the first .3 and second 4 active elements from the first .harmonic input signal. In this case, the harmonic components of the third order are formed. With an appropriate choice of their amplitudes, they can significantly suppress the harmonic components of the third order at the output of the power amplifier by compensating for the distortion of the signals occurring in the first push-pull amplifier 1.

The necessary phasing of the harmonic components at the common-mode input of the first push-pull amplifier 1 is provided by the phase shifter 12 and the matching transformer 14.

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Claims (1)

Invention Formula A power amplifier containing the first push-pull amplifier made on the phase-split transformer, the first and second active elements and the first resistor, while the first output of the primary winding of the phase-split transformer is connected to the common bus and the common electrodes of the first and second active elements, the first and the second terminals of the secondary winding - with the corresponding: input electrodes of the first and. the second active element, and the middle of the secondary winding through the first resistor is connected to the power bus, the output transformer, the terminals of the first -. the primary winding of which is connected to the corresponding output electrodes of the first and second active elements of the first push-pull amplifier, the first and second condensers., characterized in that, in order to reduce the level of harmonics to the third order Qi, a power divider connected in series is inserted into it and a phase shifter, a second two-cycle amplifier identical to the first matching transformer, second and third resistors, the input of the power divider being the input of the power amplifier, the second output the power divider is connected to the input of the second push-pull amplifier, the output of the phase shifter is connected to the input of the first push-pull amplifier, the output electrodes of the first and second active elements of the second push-pull amplifier are connected to each other and connected to the power amplifier power bus, the first output of the second winding the transformer is connected to the common bus through a parallel connected second resistor and the first capacitor, the second output is connected to the middle pin The secondary winding of the phase-split transformer of the first push-pull amplifier, and the secondary terminal of the phase-split transformer of the second push-pull amplifier are connected to the common bus through a parallel connected third resistor and a second condenser – torus. entrance Yu Exit