JP2001196870A - Power amplifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small-sized power amplifier with an excellent frequency characteristic and low power consumption where a difference in a phase shift of a signal passing through a plurality of amplifier circuits is decreased for each frequency and the loss can be reduced. SOLUTION: A phase shift controller 8 controls a phase shift of phase shifters 3a, 3b so that a difference in the phase shifts of signals passing through amplifier circuits 7a, 7b is minimized for each frequency depending on the frequency in use on the basis of frequency information received from an input terminal 9 are the frequency information.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wide-band, high-output, small-sized power amplifier used for radar equipment.

[0002]

2. Description of the Related Art FIG. 7 is a diagram showing a configuration example of a radar device. In the figure, 19 is a signal generator, 20 is a power amplifier, 21 is a transmission / reception switch, 22 is an antenna, 23
Is a receiver, 24 is a target, and 25 is a transmission power supply.

The radar device amplifies a signal generated by the signal generator 19 to a required output power by a power amplifier 20 and radiates the signal from an antenna 22 to a target 24 through a transmission / reception switch 21. The signal reflected by the target 24 is transmitted to the receiver 23 through the antenna 22 and the transmission / reception switch 21. Further, the power amplifier 20 is required to have a high output in order to detect the distant target 24. Therefore, the power amplifier 20 consumes more DC power than other components, and the DC power is supplied from the transmission power supply 25.

FIG. 8 is a diagram showing a configuration of a conventional power amplifier. Here, a case where two amplifier circuits are used will be described. In the figure, 1 is an input terminal of a power amplifier, 2 is a power divider having an input terminal connected to the input terminal 1 of the power amplifier, and 3a and 3b are each input terminals connected to respective output terminals of the power divider 2. In the phase shifters 4a and 4b, the input terminals are connected to the output terminals of the phase shifters 3a and 3b, and the input terminal is connected to the output terminals of the amplifiers 4a and 4b. The power combiner 6 is an output terminal of the power amplifier connected to the output terminal of the power combiner 5. 7a and 7b are phase shifters 3a and 3b, respectively.
b and an amplification circuit composed of amplification elements 4a and 4b.

Next, the operation will be described. The signal input from the input terminal 1 of the power amplifier 2
And is input to the amplifier circuits 7a and 7b. The signals input to the amplifier circuits 7a and 7b are amplified to required output power and input to the power combiner 5. The input signals are combined by the power combiner 5 and output from the output terminal 6 of the power amplifier. At this time, if the phase shift amounts of the respective signals passing through the two amplifier circuits 7a and 7b are different due to the individual difference between the respective amplification elements 4a and 4b and the manufacturing accuracy, a loss occurs when the power combiner 5 combines the signals. .
Therefore, the amount of phase shift is adjusted by the phase shifters 3a and 3b so as to minimize the loss.

Next, the relationship between the difference between the phase shift amounts of the signals passing through the amplifier circuits 7a and 7b and the loss and the details of the method of adjusting the phase shift amounts will be described with reference to FIGS. 9 (a) to 9 (c). FIG.
FIG. 3B is a diagram illustrating frequency characteristics of the phase shift amount of a signal passing through the two amplifier circuits 7a and 7b, and FIG.
FIG. 7C is a diagram showing a loss when there is a difference in the amount of phase shift of a signal passing through 7b, and FIG. 7C is a diagram showing a method of adjusting the amount of phase shift of a signal passing through two amplifier circuits 7a and 7b. Amplifying elements 4a, 4
b, the two amplifier circuits 7a,
The amount of phase shift of the signal passing through 7b is different as shown in FIG. In the case of the characteristic shown in FIG.
In f3), the phase difference is 40 to 60 degrees, and the loss at that time is
It becomes 10 to 20% from FIG.

Next, a method of adjusting the amount of phase shift will be described. FIG. 9C shows an example in which the phase shifter 3a is set as an initial value, and the phase shifter 3b is adjusted to adjust the amount of phase shift of a signal passing through the two amplifier circuits 7a and 7b. For example, if the difference between the phase shift amounts is adjusted to be the minimum at f2, the difference between the phase shift amounts is large at f1 and f3, that is, the output power is maximum at f2, and the output power is small at f1 and f3, and the frequency characteristic is reduced. Deteriorates. Therefore, as shown in FIG. 9C, the phase shifter 3b is adjusted so that the difference in the amount of phase shift at each frequency is substantially the same.

[0008]

Since the conventional power amplifier is configured as described above, when the frequency band is widened,
It is difficult to reduce the difference in the amount of phase shift over the entire frequency band.
Therefore, use an element having sufficient output power for the amplifying element or increase the number of amplifying circuits to be used so that the required output power is obtained even if the phase shift amounts of the signals passing through the respective amplifier circuits are different. Because of the necessity, there are problems that power consumption and heat generation increase, and it is difficult to reduce the size of the power amplifier.

When the power consumption of the amplification element increases,
There was a problem that the transmission power supply also became large.

[0010] The present invention has been made to solve such a problem, and an object of the present invention is to obtain a small power amplifier having good frequency characteristics and low power consumption.

[0011]

According to a first aspect of the present invention, a power amplifier includes a phase shift controller that controls a phase shifter of each amplifier circuit based on frequency information input from the outside.

Further, a power amplifier according to a second aspect of the present invention includes the above-mentioned phase shift controller provided with a storage device for storing an optimum amount of phase shift for each frequency of each amplifier circuit.

[0013] A power amplifier according to a third aspect of the present invention is a power amplifier, wherein the phase shifter includes a switch operated by a signal from a phase shift controller;
It is provided with a waveguide whose phase shift amount is adjusted for each frequency.

A power amplifier according to a fourth aspect of the present invention includes the above-described phase shifter including a switch operated by a signal from the phase shift controller and a stub circuit adjusted for each frequency.

A power amplifier according to a fifth aspect of the present invention includes a terminal for inputting temperature information to the phase shift controller.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a configuration diagram of a power amplifier according to Embodiment 1 of the present invention. Here, a case where two amplifier circuits are used will be described. In the figure, 1 to 7a and 7b are equivalent to conventional ones.
8 is a phase shift controller for individually controlling the phase shifters 3a and 3b;
Reference numeral 9 denotes an input terminal for frequency information provided in the phase shift controller 8.

Next, the operation will be described. Phase shift controller 8
The phase shifters 3a, 3b are arranged so that the difference between the phase shift amounts of the signals passing through the amplifier circuits 7a, 7b is minimized for each frequency, based on the frequency information input from the frequency information input terminal 9.
Is controlled. Details of this operation are shown in FIGS.
This will be described with reference to FIG. FIG. 3A shows the initial characteristics of the phase shift amounts of the signals passing through the two amplifier circuits 7a and 7b, and FIG. 2B shows the control voltage of the phase shifters 3a and 3b versus the phase shift amounts. FIG. 2C shows the voltage conversion characteristics of the phase shift controller 8, and FIG. 2D shows each amplifier circuit 7 after the phase shift control.
It is a figure which shows the phase shift amount of the signal which passes through a and 7b. Now, it is assumed that the amplifier circuits 7a and 7b have the characteristics shown in FIG. 2A, and the phase shifters 3a and 3b have the characteristics shown in FIG. 2B. Further, frequency information given by a voltage change is input to the phase shift controller 8 as shown in FIG.
2 and f3 correspond to 2V, 6V and 10V, respectively.

Next, a method of adjusting the amount of phase shift will be described. First, the phase shifter 3a is used to make the amplification circuit 7a a reference.
To keep the voltage applied to Then, FIGS. 2A and 2B
Therefore, the voltage applied to the phase shifter 3b is set to 9 V in order to delay the phase shift amount by 60 degrees at the frequency f1. Similarly, if the voltage applied to the phase shifter 3b is set at the frequencies f2 and f3, the phase shift controller 8 can obtain the characteristics shown in FIG.
At this time, the difference between the phase shift amounts of the amplifier circuits 7a and 7b is as shown in FIG.
As shown in (d), the power becomes smaller at each frequency. Therefore, the loss at the time of combining power in the power combiner 5 can be suppressed to be small, and a small power amplifier having good frequency characteristics and low power consumption can be obtained. be able to.

Embodiment 2 FIG. 3 is a configuration diagram of a power amplifier according to Embodiment 2 of the present invention. Here, a case where two amplifier circuits are used will be described. In the figure, 1
To 9 are equivalent to the first embodiment. 10 is a phase shifter 3
This is a storage device for storing data given to a and 3b, and is connected to the phase shift controller 8. The phase shifter is a digital phase shifter whose phase shift amount can be set by a digital signal, and the frequency information is given as a digital signal.

Next, the operation will be described. Storage device 1
The digital phase shifters 3a and 3a when the phase shift amounts of the signals passing through the amplifier circuits 7a and 7b are equalized in advance for each frequency are set to 0.
The data set in b is stored. When the frequency information is input as a digital signal to the phase shift controller 8,
Data to be set in the digital phase shifters 3a and 3b is read from the storage device 10 based on the input frequency information, and the set values of the digital phase shifters 3a and 3b are controlled to optimal values for each frequency.

As described above, the amplification circuit 7
When the phase shift amount of the signal passing through a and 7b is set, the phase shift amount can be accurately controlled in a wide frequency band. Therefore, it is possible to obtain a small power amplifier having good frequency characteristics and low power consumption even in a wide frequency band.

Embodiment 3 FIG. FIG. 4 is a configuration diagram of a phase shifter according to a third embodiment of the present invention. Other configurations are the same as those of the first embodiment. In the figure, 11 is an input terminal of the phase shifter 3, 12 is an output terminal of the phase shifter 3, 13 is a first switch having an input terminal connected to the input terminal 11, and 13a, 13
b is an output terminal of the first switch 13, 14 is a second switch having an output terminal connected to the output terminal 12, 14a and 14b are input terminals of the second switch 14, and 15a and 15b are Each first switch 1
A waveguide connected between the output terminal 3 and the input terminal of the second switch 14, and a control signal input terminal 16 for inputting a signal for switching the first switch 13 and the second switch 14.

Next, the operation will be described. Waveguide 15
Reference numerals a and 15b denote waveguides having different lengths provided for respective frequencies to be used. Since the phase shift amount increases as the length of the waveguide increases, the signal input from the control terminal 16
By switching the first switch 13 and the second switch 14, the phase shift amount of the signal passing through the amplifier circuit can be changed for each frequency used. As described above, when the waveguide is switched by the switch, the amount of phase shift can be controlled at a low price because the structure is simple, the frequency characteristics are good, and the power consumption is small.
A small power amplifier can be obtained.

Embodiment 4 FIG. 5 is a configuration diagram of a phase shifter according to a fourth embodiment of the present invention. Other configurations are the same as those of the first embodiment, and 11 to 16 are the same as those of the third embodiment.
17a and 17b are stub circuits that are connected to or disconnected from the waveguide 15 by the first switch 13 and the second switch 14, and have different lengths and impedances.

Next, the operation will be described. Changing the length and impedance of the stub circuits 17a and 17b can change the amount of phase shift of a signal passing through the amplifier circuit, and at the same time, change the matching state of the amplifier circuit. By selecting each time, the difference between the phase shift amounts of the signals passing through the plurality of amplifier circuits can be reduced, and at the same time, the matching state can be improved, so that the loss can be further reduced. By switching the stub circuit with a switch like this, it is low cost due to its simple structure,
It is possible to obtain a small power amplifier with small loss, good frequency characteristics and low power consumption.

Embodiment 5 FIG. 6 is a configuration diagram of a power amplifier according to a fifth embodiment of the present invention, wherein 1 to 9 are the same as in the first embodiment. Reference numeral 18 denotes an input terminal for temperature information, which is connected to the phase shift controller 8.

Next, the operation will be described. Amplifier circuit 7
In a and 7b, the phase shift amount of the passing signal also changes due to a change in ambient temperature. Therefore, by inputting the information on the ambient temperature from the temperature information input terminal 18 to the phase shift controller 8 and correcting the change in the phase shift amount due to the temperature change, the phase shift amount can be set accurately over a wide temperature range, A small power amplifier with good characteristics and low power consumption can be obtained.

[0028]

According to the first aspect of the invention, by controlling the amount of phase shift passing through the amplifier circuit for each frequency by the plurality of phase shifters, the difference between the amount of phase shift passing through the plurality of amplifier circuits can be reduced. Since the frequency can be reduced, the loss can be reduced, and a small power amplifier with good frequency characteristics and low power consumption can be obtained.

Further, according to the second aspect, the phase shift amounts set in the plurality of phase shifters are stored in the storage device in advance, and the phase shifters are controlled by digital signals, so that the signals pass through the amplifier circuit. It is possible to accurately control the amount of phase shift of a signal, obtain a small power amplifier with good frequency characteristics even in a wide frequency band, and low power consumption.

According to the third aspect of the present invention, the phase shifter is composed of a plurality of waveguides and a switch for switching the waveguides.
A small power amplifier with low power consumption can be obtained.

According to the fourth aspect of the present invention, if the stub circuit connected to the waveguide is switched by a switch, the matching state of the amplifier circuit can be improved along with the phase shift amount with a simple structure.
It is possible to obtain a small-sized power amplifier that is inexpensive, has little loss, has good frequency characteristics, and has low power consumption.

According to the fifth aspect of the present invention, since the information on the ambient temperature input to the phase shift controller can correct the temperature change of the phase shift of the signal passing through the amplifier circuit, the phase shift over a wide temperature range can be corrected. Can be set accurately, and a small power amplifier with good frequency characteristics and low power consumption can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing Embodiment 1 of a power amplifier according to the present invention.

FIG. 2 is a diagram illustrating an operation principle of the first embodiment.

FIG. 3 is a configuration diagram illustrating a power amplifier according to a second embodiment of the present invention;

FIG. 4 is a configuration diagram of a phase shifter according to a third embodiment.

FIG. 5 is a configuration diagram of a phase shifter according to a fourth embodiment.

FIG. 6 is a configuration diagram of a power amplifier according to a fifth embodiment.

FIG. 7 is a configuration diagram of a radar device.

FIG. 8 is a diagram showing a structure of a conventional power amplifier.

FIG. 9 is a diagram illustrating an operation principle of a conventional power amplifier.

[Explanation of symbols]

1 input terminal of power amplifier, 2 power divider, 3 phase shifter, 4 amplifying element, 5 power combiner, 7 amplifying circuit, 8
Phase shift controller, 9 frequency information input terminal, 10 storage device, 13 first switch, 14 second switch, 1
5 waveguide, 16 control signal input terminal of phase shifter, 17
Stub circuit, 18 Input terminal for temperature information.

Continued on front page F term (reference) 5J012 GA03 GA13 5J069 AA04 AA21 AA41 AA54 AC01 CA02 CA36 CA61 FA07 FA19 HA38 KA16 MA20 SA15 TA01 TA03 5J090 AA04 AA21 AA41 CA02 CA36 CA61 CN04 FA07 FA19 FN05 FN07 HA38 HN13 TA01 MA03 MA03 AA21 AA41 CA02 CA36 CA61 FA07 FA19 GR05 HA38 KA16 MA20 SA15 TA01 TA03

Claims (5)

[Claims] A power divider that distributes an input signal to a plurality of output terminals and outputs the output signal; a plurality of phase shifters having input terminals connected to respective output terminals of the power divider; An input terminal is connected to an output terminal of the plurality of amplifying elements for amplifying a signal to a desired level, and respective input terminals are connected to output terminals of the plurality of amplifying elements, and output from the plurality of amplifying elements. A power amplifier, comprising: a power combiner that combines and outputs respective signals; and a phase shift controller that sets a phase shift amount of the phase shifter according to frequency information from the outside. 2. The power amplifier according to claim 1, wherein said phase shifter is a digitally controlled phase shifter. 3. A phase shifter comprising: a plurality of waveguides whose phase shift amounts are adjusted in accordance with a frequency; and a switch for switchingly connecting the plurality of waveguides to input / output terminals of the phase shifter. The power amplifier according to claim 1, wherein the power amplifier is configured. 4. The phase shifter comprises a waveguide, a switch having one end connected to the waveguide, and a plurality of stub circuits connected to the other end of the switch and having different lengths and impedances. The power amplifier according to claim 1, wherein: 5. The power amplifier according to claim 1, wherein a terminal for inputting temperature information is provided in the phase shift controller.