JPH0662620U - Power amplifier - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize a power amplification device in which the performance of the amplifier can be fully utilized. In a power amplification device for power-amplifying a generated signal and supplying it to a load, a signal generating means 1a for generating a signal having a variable waveform or a duty, and an amplifying means for power-amplifying a signal generated by the signal generating means 1a. 2, the loss detection means 3 for detecting the loss of the signal amplified by the amplification means 2 and supplied to the load 4, and the detection result of the loss detection means 3, the heat generation of the amplification means 2 falls within a predetermined range. And a control means 1b for controlling the waveform or duty of the signal generated by the signal generation means 1a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a power amplification device capable of efficient power amplification.

[0002]

[Prior art]

 In the case of a general pulse drive type amplifier, the maximum output is set larger than the temperature resistance characteristics of the amplification element and the duty of the pulse is limited to suppress an excessive rise in the junction temperature of the amplification element. It is like this.

On the other hand, in an amplifier to which various loads having different characteristics may be connected, when the load changes, the standing wave ratio changes, and the ratio of reflected waves also increases or decreases. The amount of heat generated inside fluctuates.

In such a case, the temperature of the junction of the amplification element exceeds a certain value, and the amplification element is destroyed. Therefore, in order to prevent such a situation, in the pulse drive type amplifier, the duty of the pulse is limited in advance.

[0005]

[Problems to be solved by the device]

 However, when the output is small, the absolute amount of loss in the amplification element is small, and the temperature rise at the junction is small. Therefore, in the case of a small output, limiting the duty is often useless, and the amplifier performance is not fully utilized.

The present invention has been made in view of the above points, and an object of the present invention is to realize a power amplification device in which the performance of an amplifier can be fully utilized.

[0007]

[Means for Solving the Problems]

 The present invention, which solves the above-mentioned problems, provides a signal generating means for generating a signal having a variable waveform or a duty, and a signal generated by the signal generating means in a power amplifying device for power-amplifying a generated signal and supplying it to a load. Amplification means for power amplification, loss detection means for detecting the loss of the signal amplified by the amplification means and supplied to the load, and the detection result of the loss detection means, the heat generation of the amplification means falls within the specified range. And a control means for controlling the waveform or duty of the signal generated by the signal generation means.

[0008]

[Action]

 The loss when the amplified signal is supplied to the load is detected by the loss detecting means, and the detection result indicates that the waveform or duty of the signal generated by the signal generating means is so that the heat generated by the amplifying means is within a predetermined range. Controlled.

[0009]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram showing a schematic configuration of a main part of a power amplification device according to an embodiment of the present invention. In this figure, the signal generating circuit 1 has a signal generating section 1a for generating a signal having a variable waveform or duty, and a control section 1b for controlling the waveform or duty in consideration of heat generation of an amplifier. The amplification section 2 receives and amplifies the signal generated by the signal generation section 1a. The detector 3 detects the loss from the standing wave ratio or the like when the output of the amplifier 2 is supplied to the load. The detection result of the detector 3 is given to the controller 1b.

The operation of the apparatus of this embodiment having the above configuration is as follows. The signal generator 1a generates a waveform with a predetermined duty, and this waveform is amplified by the amplifier 2. The output of the amplifier 2 is supplied to the load 4 via the detector 3, but the detector 3 does not affect the signal flow. Here, the detector 3 is composed of a directional coupler or the like, and detects the standing wave ratio by detecting the amplitudes of the traveling wave (Ro) and the reflected wave (Rl). The detection result is supplied to the control unit 1b. The control unit 1b refers to the detection result of the detector 3 to obtain the heat generation amount of the amplifier 2. The amount of heat generation is determined by the power loss, which is the difference between the DC input power to the amplifier 2 and the power supplied to the load. The DC input current can be detected from the power source of the amplifier 2, and the power supplied to the load is determined by the traveling wave amplitude and the standing wave ratio obtained from the detector 3, so the loss power, that is, the amount of heat generated by the amplifier is determined. .

In practice, the detection result of the detector 3 and the heat generation coefficient are measured in advance, and this relationship is stored in the control unit 1b as a data table. Then, when the load 4 is connected, the signal generator 1a generates a signal of minute electric power, amplifies it, and supplies it to the load. The control unit 1b receiving the detection result of the detector 3 at this time calculates the heat generation amount, and sets the waveform generated by the signal generation unit 1a so that the optimum signal waveform or duty is obtained under this condition. To do.

By doing so, when a small amount of electric power is output, the amount of heat generated is small, so that the capacity of the amplifier 2 can be used to the maximum without the duty being restricted so much. Further, when the electric power becomes relatively large, the amount of heat generation also increases accordingly, so that the duty or the waveform is limited according to the amount of heat generation.

In the above description, the detector 3 determines the standing wave ratio of the traveling wave / reflected wave amplitude, but the detector 3 may be any one that detects a value related to the loss of the amplifier 2. Absent .

Further, the control unit 1b can perform not only one of the waveform of the signal generated by the signal generating unit 1a and the duty, but also the control of changing both of them.

[0015]

[Effect of device]

 As described in detail above, in the present invention, the heat generation of the amplifying means caused by the change of the load is determined by the impedance of the load or the reflected power, and by referring to this, the temperature of the amplifying means becomes equal to or lower than the set temperature. In addition, by controlling the waveform or duty of the generated signal, it is possible to realize a power amplification device that can make full use of the performance of the amplification means.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of a characteristic part of an embodiment of the present invention.

[Explanation of symbols]

 1 signal generation circuit 1a signal generation unit 1b control unit 2 amplifier 3 detector 4 load

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H03G 5/16 D 9067-5J

Claims (1)

[Scope of utility model registration request] 1. A power amplifier for amplifying the generated signal and supplying the amplified signal to a load, the signal generating means (1a) generating a signal having a variable waveform or duty, and the signal generated by the signal generating means (1a). Amplification means (2) for power amplification of power, loss detection means (3) for detecting the loss of the signal amplified by the amplification means (2) and supplied to the load (4), and detection by the loss detection means (3) In response to the result, the control means (1b) is provided for controlling the waveform or duty of the signal generated by the signal generation means (1a) so that the heat generation of the amplification means (2) falls within a predetermined range. And power amplification device.