RU2550561C1 - Wide-band short wave power amplifier - Google Patents

Abstract

FIELD: radio engineering, communication.

SUBSTANCE: amplifier employs a bridge power summation circuit instead of a ballast resistor of an electrical circuit comprising a wide-band matching device, a full-wave rectifier, a storage capacitor, an impedance coil and a clamp diode, which enables to return part of the energy of the useful signal to the power supply of the radio transmitter, thereby increasing efficiency thereof.

EFFECT: converting high-harmonic energy into direct current energy and returning said energy to the power supply.

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Description

The present invention relates to electronics and can be used in broadband radio transmitters.

Broadband power amplifiers, especially those included in high-power radio transmitters, contain a large number of balanced addition bridges with ballast resistors, which are structurally integrated into a common power addition device for individual amplifier modules. The overlap coefficient over the range of such amplifiers in the short-wave frequency range reaches 20. The implementation of such a wide range extremely complicated the practical task of ensuring the uniformity of the amplitude-frequency and phase-frequency characteristics of these amplifiers. For this reason, a significant useful signal power is dissipated in the ballast resistors of the addition bridges.

Known broadband power amplifiers, for example, AC No. 4058329 USSR, H03F 1/32, 02/22/86, AC No. 4075876 USSR, H03F 1/42, 04/16/86, containing power amplifiers, adders, which are bridge circuits providing isolation input circuits and containing ballast resistors, automatic gain control circuits.

The closest in technical essence is the broadband power amplifier AC No. 4346155 of the USSR, H03F 3/24, dated 12/18/87, which contains a preliminary amplifier, two power amplifiers, a power addition bridge and a ballast resistor.

The disadvantage of both analogues and the prototype is that they do not solve the problem of dissipating a significant part of the power on the ballast resistors of the power addition devices of the amplification modules of broadband radio transmitters. As a result, the efficiency of broadband radio transmitters is significantly inferior to the efficiency of resonant-type radio transmitters, whose amplification stages are tuned at each operating frequency.

The aim of the invention is to increase the efficiency of a broadband amplifier containing amplifier modules, by reducing the loss of useful power in the ballast resistors of the bridges of addition of power of the amplifier modules.

This goal is achieved by the fact that in a broadband power amplifier containing a preamplifier, two amplifier modules, a power addition bridge, a broadband matching device, a half-wave rectifier, a storage capacitor, a choke and a limiting diode are additionally introduced, while the input of the wideband matching device is connected to the bridge terminal a power addition device designed to connect a ballast resistor, the output of a broadband matching device is soy dinene with the input of a half-wave rectifier, the output of the half-wave rectifier is connected to the terminal of the storage capacitor and inductor and connected to the inductor in parallel, the other terminal of the storage capacitor is grounded, the output of the inductor is connected to the input of the limiting diode, the output of which is connected to the power source of the radio transmitter.

The block diagram of the device shown in the drawing. In accordance with it, the device consists of the following functional units and elements:

1 - pre-amplifier;

2, 3 - amplifier modules;

4 - power addition bridge;

5 - broadband matching device;

6 - a half-wave rectifier;

C - storage capacitor;

Dr - throttle;

D is a limiting diode.

The operation of the circuit is as follows. The high-frequency signal is fed to preamplifier 1 and, after amplification, is fed to the inputs of amplifier modules 2 and 3. After amplification, the signal from the outputs of amplifier modules 2 and 3 is fed to the 1st and 2nd inputs, respectively, of addition bridge 4. From addition bridge 4 the total useful signal is fed to the output terminal of the bridge. When the bridge is unbalanced, when the balance of amplitudes and phases of high-frequency signals at the bridge inputs is violated, both due to the non-uniformity of the amplitude and phase-frequency characteristics of the amplifier modules, and due to the asymmetry of these characteristics of the input bridge addition circuits in the operating frequency range, a part of the useful signal power is output a bridge connected to a broadband matching device 5. The calculation and operation of broadband matching devices are presented in the work of O. Alekseev "Broadband radio transmitting devices." M .: Svyaz, 1978. From the output of the broadband matching device 5, the signal is fed to the input of a half-wave rectifier 6. A current of unipolar directivity from the output of a half-wave rectifier charges the storage capacitor C until the voltage on it exceeds the voltage of the power source of the radio transmitter. In this case, the limiting diode D opens and the discharge current of the capacitor C is summed with the current of the power source, since the capacitor C and the DC power supply are connected in parallel. In this case, part of the energy of the power source, previously spent on heating the ballast resistor, is returned to the power source, thereby increasing the efficiency of the radio transmitter. The capacitance C and inductor D are a low-pass filter, opaque to the frequency of the ripple current at the output of a half-wave rectifier 6.

Thus, the goal is achieved - increasing the efficiency of broadband radio transmitters using bridges for adding power to amplifier modules.

Claims (1)

A broadband power amplifier comprising a preamplifier, two amplifier modules, a power addition bridge, characterized in that a broadband matching device, a half-wave rectifier, a storage capacitor, a choke and a limiting diode are additionally introduced, while the input of the wideband matching device is connected to the terminal of the bridge power adding device designed to connect a ballast resistor, the output of the broadband matching device is connected to the input of two for a half-wave rectifier, the output of a half-wave rectifier is connected to the terminal of the storage capacitor and inductor and to the inductor connected in parallel, the other terminal of the storage capacitor is grounded, the output of the inductor is connected to the input of the limiting diode, the output of which is connected to the power source of the radio transmitter.