JPS6231209A - Power amplifier - Google Patents

Abstract

PURPOSE:To improve impedance matching efficiency without losing energy and increasing the size of a device by connecting a distributor and a coupler to the input and output of plural power amplifiers, and selectively driving the required number of power amplifiers to obtain required synthetic power. CONSTITUTION:For instance four power amplifiers 6 with 10dB gain are used and three 90 deg. hybrid couplers 11 are formed in each of the distributor 5 and the coupler 8. Input high frequency power Pin is distributed into four components by the couplers 11 while satisfying the I/O impedance and respective components are amplified by the power amplifiers 6 and then synthesized by the coupler with impedance matching. If electric power is selectively supplied to the required number of amplifiers 6 by a switching part 10 controlled by a control part 9, the synthesized power can be optionally controlled. Thus, the change of the impedance if the power amplifiers does not directly exert influence upon an external device. In addition, amplifiers with comparatively low outputs can be used for individual power amplifiers.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a power amplification device, and in particular, to a power amplification device that distributes high-frequency power to a plurality of outputs and individually controls amplifiers provided in each branch path. The present invention relates to a power amplification device that does not reduce impedance matching and improves reliability by combining power.

[Conventional technology]

For example, in a transponder mounted on an aircraft or a ground radar transmitter facing the transponder, the transmission power is frequently increased or decreased depending on the distance from the aircraft to be searched.

Conventionally, as a transmission power control device, there are devices shown in FIGS. 6(a) and 6(b).

FIG. 6(a) shows an amplifier 1 that amplifies a high-frequency signal from the input side A, a variable attenuator 2 that is connected to the output terminal of the amplifier 1 and that attenuates the output of the amplifier 1, and "attenuation of the variable attenuator 2." It is composed of a control section 3 that controls the amount.

In the above configuration, the input power is once amplified by the amplifier, and then attenuated to a desired amount by the variable attenuator 2 and output to the B side.

FIG. 6(b) is composed of an amplifier 1'' that amplifies a high frequency signal, and a variable power source 4 that increases or decreases the power supply voltage of the amplifier 1''.

In the above configuration, the predetermined amount of power that has entered the amplifier 1'' can be adjusted by the variable power source 4 to change the saturation level in the amplifier 1'' to obtain a desired output power.

[Problem that the invention seeks to solve]

However, in the conventional power control device shown in Fig. 6 (a), the power once amplified to the maximum is wasted in the attenuator, which not only causes large losses and is uneconomical, but also reduces heat dissipation. This has the drawback of increasing the size of the device.

In addition, in the power amount control device shown in Fig. 6 (b), since the power supply voltage of the amplifier is changed, the input impedance changes, resulting in unstable operation due to impedance mismatch.
Alternatively, there is a drawback that unnecessary waves are generated. In particular, it is impossible to use it for products that require strict standards such as aircraft transponders.

[Means and effects for solving the problems] The present invention has been made in view of the above, and aims to improve impedance matching without causing energy loss or increasing the size of the device, thereby increasing the reliability of the device. Therefore, a power amplifier device is provided in which a desired combined power is obtained by disposing a divider and a combiner at the input and output of a plurality of power amplifiers, and selectively driving a required number of the plurality of power amplifiers. It is something to do.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a power amplifier according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating the present invention in detail,
A distributor 5 that distributes the input high frequency power Pin to a plurality of devices, and an output terminal of the distributor 5 connected to its input terminal.
The output terminals of the n power amplifiers 6 and the n power amplifiers 6 are
It is composed of a coupler 8 connected to its input end, a switching section 10 that turns on and off the application of power Vec to the n power amplifiers 6, and a control section 9 that controls the operation of the switching section 1o. Ru.

For the distributor 5 and the coupler 8, for example, a multi-terminal Wilkinson system, a 90' hybrid power puller system, or a branch line coupler system, in which the input connections are reversed, is used.

In FIG. 2, four power amplifiers 6 with a gain of 10 dB are used, and the divider 5 and coupler 8 are connected at an angle of 90° as shown in FIG. 3 (a) and (b).
Each hybrid coupler 11 is configured by connecting three hybrid couplers 11.

3(A) and 3(B) are examples of a 3 dB 90° Vibralift coupler, and FIG. 3(A) shows its structure, including a strip line upper surface pattern 13a printed on a Teflon substrate 12, It is formed by sandwiching the lower surface pattern 13b between the upper and lower metal ground surfaces 14. The length l is
The wavelength λ of the center frequency is A, the coupling is performed between the patterns on the upper surface and the lower surface, and it is three-dimensionally small. Figure 3 (b) shows an equivalent circuit of signal flow in power distribution,
If there is no insertion loss, the voltage applied to the terminal (2) produces an output at each of the terminals (2) and (2) in which half of the input terminal (=-3 dB) is out of phase with each other by 90 degrees. Therefore, it is necessary to consider the phase difference between the divider 5 and the coupler 8 and combine them so that they are opposite to each other, so that the power and output of this power amplifier are out of phase by 180 degrees. Become something.

The operation of the above configuration will be explained.

The high frequency power Pin input to the distributor 5 is distributed to n components while satisfying the human output impedance (in the case of FIG. 2, the power is distributed to 4 components by the 906 hyperisot coupler 11), and each power amplifier 6, each of the signals is subjected to necessary power amplification and then combined into a single power by a coupler 8 under impedance matching.

At this time, the switching section 10 controlled by the control section 9
By arbitrarily selecting and supplying the power to the power amplifier 6, the amount of combined power can be arbitrarily controlled. In other words, if power is supplied to the required one from among multiple power amplifiers, the combined power amount will be gradually smaller than if power is supplied to all of the multiple power amplifiers, and the number of power amplifiers to be selected can be set arbitrarily. This allows the power to be reduced to the desired power.

In the above embodiments, the power amplifiers used have the same gain, but in implementing the present invention, it is not necessary to be limited to this, and it is possible to combine power amplifiers of various sizes and output more finely. It is possible to control the level.

Furthermore, the control method for the power amplifier is not limited to just connecting and disconnecting the power supply, but may also include means for changing the power supply voltage value.
In this way, control close to stepless adjustment can be performed.

If the output power amount is controlled by the method described above, the impedance fluctuation of the power amplifier itself located between the divider and combiner will be reduced.
There is little effect on direct external equipment.

Furthermore, since it is equipped with multiple power amplifiers, even if some trouble occurs such as damage to some of the power amplifiers,
Since this can be compensated for by the remaining parts, it is especially suitable for aircraft that require high reliability.

Also, obtaining high output with one power amplifier is -
Although it is difficult and expensive, if configured as in the present invention, a relatively small output is sufficient and it is economical.

In the embodiment described above, the distributor and combiner have a 90°
Although a hybrid coupler is used, the present invention is not limited to this, and, for example, a 3 dB branch line force Wilkinson system as shown in FIGS. 4 and 5 may be used. Figure 4 (a)
shows its structure, which is composed of microstrip lines or strip lines printed on a substrate (not shown), and the length l is 2 of the wavelength λ of the center frequency.

Figure 4 (b) shows an equivalent circuit in power distribution, and the power OdBm applied to the level terminal
-3 dB is generated between the terminals, and there is a phase difference of 90° between the terminals.

FIG. 5 shows the configuration of the Wilkinson type input terminal. The structure consists of a microstrip line or a strip line and an isolation resistor printed on a substrate (not shown), and the length l is the wavelength A with a center frequency λ. The phases are in phase.

〔Effect of the invention〕

As described above, according to the power amplifying device according to the present invention, a divider and a combiner are arranged in the human outputs of a plurality of power amplifiers, and a required number of the plurality of power amplifiers are selectively driven. In order to obtain the desired combined power, it is possible to improve impedance matching and increase the reliability of the device without increasing the size of the energy loss device.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the principle of an embodiment of the present invention;
Fig. 2 is a block diagram showing a specific embodiment of the present invention, Figs. 3 (a) and (b), Figs. 4 (a) and (b), and Fig. 5 are examples of a distributor and a coupler. An explanatory diagram showing Fig. 6 (a) (
B) is a block diagram showing a conventional power amplifier device. Explanation of symbols 5--------Distributor 6---------
-Power amplifier 8 --------1.-Coupler 9
−・−−−−m−Control unit 10−・−・−・・−Switching unit 11−−・−・−90° hybrid coupler patent Applicant Toyo Tsushinki Co., Ltd. Agent Patent attorney
Nobuyuki Matsubara, Patent Attorney, Kiyoshi Muraki, Patent Attorney, Taira 1) Tadao, Patent Attorney, Atsushi Ueshima - Figure 1 Figure 3 (cl) Figure 4 (A) Figure 4 (0) Figure 5 Figure 6 (Ino Figure θ Figure c)

Claims (1)

[Claims] a power divider having a single input terminal and a plurality of output terminals; a power combiner having a plurality of input terminals and a single output terminal; and a plurality of output terminals of the power divider and a plurality of the power combiners. a plurality of power amplifying means each connected between the input terminals of the power amplifying means, and control for individually controlling the operation of the plurality of power amplifying means to control the amount of power output from the single output terminal of the power combiner. A power amplifying device characterized by comprising means.