JP2006287450A - Harmonic suppression circuit and signal amplifier circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a harmonic suppression circuit and a signal amplifier circuit capable of simplifying and downsizing a circuit while improving the efficiency of harmonic suppression. <P>SOLUTION: The harmonic suppression circuit comprises: 1st to 4th ports 51-54; a transmission line 61 having the length of a 1/2 wavelength and connecting the 1st port 51 and the 2nd port 52; a transmission line 62 having the length of a 1/4 wavelength and connecting the 1st port 51 and the 3rd port 53; a transmission line 63 having the length of a 1/4 wavelength and connecting the 2nd port 52 and the 4th port 54; a transmission line 64 having the length of the 1/2 wavelength and connecting the 3rd port 53 and the 4th port 54; and a terminating resistor 70 provided on the intermediate point of the transmission line 61. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to, for example, a microwave generator used in a space solar power generation system in which a huge solar cell panel is spread in outer space and the generated electric power is transmitted to the ground with microwaves. The present invention relates to a harmonic suppression and signal amplification circuit that suppresses harmonics of a transmission signal.

In recent years, environmental problems such as global warming and energy problems such as depletion of fossil fuels have been highlighted as the amount of carbon dioxide emissions increased due to the use of fossil fuels. For this reason, the demand for clean energy is increasing year by year, and the SSPS (Space Solar Power System) plan is cited as one of the solutions to these problems.
In the SSPS plan, as shown in FIG. 5, an artificial satellite equipped with a huge solar cell panel is launched above the equator, and electric power generated by sunlight is converted into microwaves by a transmission module in the solar cell panel. Then, the microwave 100 is transmitted from the microwave power transmission unit 101 to the ground power receiving base 102 provided on the ground, and converted into electric power again on the ground and used.
As a result, clean energy can be stably supplied without being influenced by the weather and time zone, which are disadvantages of solar power generation. In order to realize this plan, high power transmission, microwave beam control, reduction of operation cost, and the like are cited as technical issues, and as one of various technologies for satisfying them, the microwave power transmission unit 101 is used. In order to transmit microwaves with high efficiency, it has been proposed and studied to employ push-pull amplifiers and class F operational amplifiers.

In the class F operational amplifier, for example, as shown in FIG. 6, it is studied to suppress harmonic components and increase output efficiency by providing a harmonic component stub in the matching circuit. (For example, refer nonpatent literature 1 etc.).
Yukiko Kobayashi et al., `` A Circuit Element Reduction Method for Class-F Ultra-High-Efficiency Amplifiers with Reactance-Compensation Circuits '', 2002 Asia-Pacific Microwave Conference Proceedings WEOF18, November 2002, Japan

By the way, in the above-mentioned space solar power generation system, the antenna, circuit, etc. are required to have a small and simple structure while maintaining high performance because the storage space of the transport rocket is limited. .
However, in the above-described class F operational amplifier, since it is necessary to provide stubs for harmonic components corresponding to the respective harmonic components, the amplification circuit becomes large and the antenna size as a whole increases. There was a problem that the mass increased.
In addition, when the mounting size of the semiconductor amplifier adjustment stub is limited, such as in an array antenna, harmonic components cannot be sufficiently suppressed, system efficiency is reduced, and unnecessary waves are radiated from the antenna. There was a possibility.

  The present invention has been made to solve the above-described problem. A harmonic suppression circuit and a signal capable of simplifying and miniaturizing a circuit while achieving high efficiency by suppressing harmonics at the same time as high output. An object is to provide an amplifier circuit.

In order to solve the above problems, the present invention employs the following means.
The present invention includes a first port to which a first signal is input, a second port to which a second signal having an opposite phase to the first signal is input, the first signal and the second signal A third port from which a combined signal with the signal is output, a fourth port from which the combined signal of the first signal and the second signal is output, and a length of (n + 1/2) λ ( n is an integer including 0, λ is the wavelength of the fundamental wave, and so on. The first transmission line connecting the first port and the second port, and (n + 1/4) ) Having a length of λ, a second transmission line connecting the first port and the third port, a length of (n + 1/4) λ, and the second port A third transmission line connecting to the fourth port; and a length of (n + 1/2) λ, and the third port And a fourth transmission line connecting the fourth port and a termination resistor provided at an intermediate point of the first transmission line.

According to the above configuration, the first port and the second port are connected by the first transmission line, the second port and the fourth port are connected by the third transmission line, and the fourth port And the third port are connected by the fourth transmission line, and the third port and the first port are connected by the second transmission line, so that a ring-shaped loop circuit is formed.
The first signal and the second signal input from the first port and the second port are divided into a clockwise direction and a counterclockwise direction, respectively, and first to fourth transmission lines connected in a ring shape The above is transmitted to reach the third port and the fourth port.
In this case, the first and fourth transmission lines have a length of (n + 1/2) λ, and the second and third transmission lines have a length of (n + 1/4) λ. In addition, since the first signal and the second signal have opposite phases, when the fundamental wave of the first signal and the fundamental wave of the second signal reach the third port and the fourth port, , They are in phase with each other and strengthen each other. In contrast, when the second harmonic of the first signal and the second harmonic of the second signal reach the third port and the fourth port, they are in opposite phases and weaken each other. It becomes. Since the even-order harmonics can be said to be the same as the second-order harmonics, the even-order harmonics are weakened at the third port and the fourth port.
From the above, it is possible to output a signal in which even-order harmonics are suppressed from the third port and the fourth port.

  The harmonic suppression circuit described above may further include a short stub provided at an intermediate point of the fourth transmission line.

  According to the above configuration, since the short stub is provided at the midpoint of the fourth transmission line, even-order harmonics can be efficiently removed. As a result, even-order harmonics contained in signals output from the third port and the fourth port can be further suppressed.

  Further, the present invention includes one input terminal and two output terminals, and outputs the first signal having the same phase as the input signal input from the input terminal from the one output terminal. A power distributor that outputs a second signal having a phase opposite to that of the signal from the other output terminal, a first amplifying unit that receives the first signal and outputs a third signal obtained by amplifying the signal; and A push-pull circuit including a second amplifying unit that receives the second signal and outputs a fourth signal obtained by amplifying the second signal; and a harmonic suppression circuit provided on the output side of the push-pull circuit; The harmonic suppression circuit includes a first port to which the third signal is input, a second port to which the fourth signal is input, the third signal, and the fourth signal. A third port from which a combined signal with the signal is output, and the third port A fourth port from which a combined signal of the signal and the fourth signal is output, and a length of (n + 1/2) λ (n is an integer including 0, and λ is the wavelength of the fundamental wave. The first transmission line connecting the first port and the second port, and having a length of (n + 1/4) λ, and the first port and the third port A second transmission line connecting the ports, a third transmission line having a length of (n + 1/4) λ and connecting the second port and the fourth port, (n + 1 / 2) A length of λ, a fourth transmission line connecting the third port and the fourth port, and a termination resistor provided at an intermediate point of the first transmission line A signal amplifier circuit is provided.

According to the above configuration, the push-pull circuit is employed as the amplifier circuit that amplifies the first signal and the second signal output from the phase shifter, thereby reducing the size and efficiency of the device. Is possible.
In addition, a harmonic suppression circuit which is a ring-shaped loop circuit including two input terminals each including a first port and a second port and including the first to fourth transmission lines having the transmission line length is provided. By connecting to the subsequent stage of the push-pull circuit, even-order harmonic components contained in the signal output from the push-pull circuit can be efficiently suppressed by a small circuit.

  According to the harmonic suppression circuit of the present invention, it is possible to achieve simplification and miniaturization of the circuit while improving the efficiency of harmonic suppression.

Hereinafter, an embodiment in which a signal amplification circuit according to the present invention is applied to SSPS will be described with reference to the drawings.
FIG. 1 is a block diagram showing a schematic configuration of a signal amplifier circuit according to an embodiment of the present invention. The signal amplifying circuit according to the present embodiment amplifies a microwave output from a microwave generator (not shown) and outputs a signal while suppressing harmonic components. As shown in FIG. (Power distributor) 1, a push-pull circuit 2, and a harmonic suppression circuit 3 are provided.

  The rat race ring 1 includes, for example, four ports 11 to 14 and four transmission lines 21 to 24 as shown in FIG. The port 11 and the port 12 are connected by a transmission line 21 having a quarter wavelength length. Port 12 and port 13 are connected by a transmission line 22 having a length of a quarter wavelength. The port 13 and the port 14 are connected by a transmission line 23 having a length of three quarter wavelengths. The port 14 and the port 11 are connected by a transmission line 24 having a length of a quarter wavelength.

  In the present embodiment, in the rat race ring configured as described above, as shown in FIG. 13 is selected, and ports 14 and 12 are selected as output terminals. As a result, the outputs of the port 14 and the port 12 are in opposite phases. In the present embodiment, the port 11 is not used.

The respective signals output from the port 14 and the port 12 which are output terminals of the rat race ring 1 are input to the push-pull circuit 2 provided in the subsequent stage.
The push-pull circuit 2 includes two amplifiers 31 and 32. The input terminal 41 of the amplifier 31 is connected to the output port 14 of the rat race ring 1 described above. On the other hand, the input terminal 42 of the amplifier 32 is connected to the output port 12 of the rat race ring 1. The amplifier 31 amplifies the signal input from the input terminal 41 and outputs it from the output terminal 43. The amplifier 32 amplifies a signal having an opposite phase to the input signal from the input terminal 41 input from the input terminal 42 and outputs the amplified signal from the output terminal 44.

In this way, the signals of opposite phases output from the push-pull circuit 2 are input to the harmonic suppression circuit 3 provided in the subsequent stage.
As shown in FIG. 3, the harmonic suppression circuit 3 is a ring-shaped loop circuit, and includes a first port 51, a second port 52, a third port 53, and a fourth port 54. . As shown in FIG. 1, the first port 51 is connected to the output terminal 43 of the amplifier 31 included in the push-pull circuit 2 described above. The second port 52 is connected to the output terminal 44 of the amplifier 32 included in the push-pull circuit 2 described above. Further, the third port 53 and the fourth port 54 are used as output terminals for outputting synthesized signals obtained by synthesizing signals input from the first port and the second port, respectively, in opposite phases.

Returning to FIG. 3, the first port 51 and the second port 52 are connected by a transmission line (first transmission line) 61 having a length of ½ wavelength. The first port 51 and the third port 53 are connected by a transmission line (second transmission line) 62 having a quarter wavelength length. The second port 52 and the fourth port 54 are connected by a transmission line (third transmission line) 63 having a quarter wavelength length. The third port 53 and the fourth port 54 are connected by a transmission line (fourth transmission line) 64 having a length of a half wavelength. A terminating resistor 70 is provided at an intermediate point of the transmission line 61 described above. The termination resistor 70 is composed of a capacitor and a resistor. For example, a capacitor with 1 pF is used, and a resistor with 47Ω is used.
On the other hand, a short stub 80 is provided at the intermediate point of the transmission line 64, that is, at a distance of a quarter wavelength from the third port 53 and the fourth port 54, respectively. The short stub 80 is for efficiently suppressing even-order harmonics.

Then, as shown in FIG. 4, an open stub group 4 is provided in the subsequent stage of the harmonic suppression circuit 3 described above. The open stub group 4 is provided on the output side of the third port 53 and the fourth port 54, respectively. Each open stub group 4 includes a plurality of open stubs corresponding to suppression of odd-order harmonic components such as third, fifth, and seventh orders.
On the output side of these open stub groups 4, for example, an antenna array 5 is provided for the purpose of forming an active integrated antenna. This antenna array 5 is E-phase reversed-phase arranged so that the signals of opposite phases output from the output terminals 91 and 92 of each open stub group 4 are in-phase.

Next, the operation of the microwave amplifier circuit having the above-described configuration will be described.
First, a microwave output from a microwave oscillator (not shown) is input to the port 13 of the rat race ring 1 shown in FIG. This microwave is divided clockwise and counterclockwise, reaches the port 14 via a transmission line having a length of ¾ wavelength, and passes through a transmission line having a length of ¼ wavelength. Then, the port 12 is reached. As a result, the signal appearing at the port 14 and the signal appearing at the port 12 are in opposite phase.

The signal output from the port 14 of the rat race ring 1 is input to the input terminal 41 of the amplifier 31 included in the push-pull circuit 2, amplified by the amplifier 31, and output from the output terminal 43 to the subsequent harmonic suppression circuit 3. Is done.
Similarly, a signal output from the port 12 of the rat race ring 1 is input to the input terminal 42 of the amplifier 32 included in the push-pull circuit 2, is amplified by the amplifier 32, and is output from the output terminal 44 to the subsequent harmonic suppression circuit. 3 is output.

  As a result, the signal output from the output terminal 43 (hereinafter referred to as “first signal”) is input to the first port 51 of the harmonic suppression circuit 3, and the output terminal is input to the second port 52. The signal output from 44 (hereinafter referred to as “second signal”) is input. Here, the first signal and the second signal have the same amplitude and wavelength, and are opposite phase signals.

  The first signal input to the first port 51 is divided clockwise and counterclockwise at the first port 51 and reaches the third port and the fourth port. Similarly, the second signal having the opposite phase to the first signal input to the second port 52 is divided clockwise and counterclockwise at the second port 52, and the third and fourth ports are divided. To the port.

  At this time, since the transmission lines 61 and 64 have a length of 1 / 2λ and the transmission lines 62 and 63 have a length of 1 / 4λ, they are input from the first port and the second port, respectively. The fundamental waves of the first signal and the second signal having opposite phases are in phase with each other when they reach the third port and the fourth port. As a result, the fundamental waves of the first signal and the second signal strengthen each other in the third port and the fourth port.

  In contrast, the second harmonic of the first signal input from the first port and the second harmonic of the second signal input from the second port are the third port and the fourth When reaching these ports, the wavelengths are opposite to each other and weaken each other.

  Since the same thing can be said for other even-order harmonics such as fourth-order and sixth-order harmonics, the third-order harmonics in the first and second signals are the third. And the fourth port weaken each other.

From the above, the combined signal of the first signal and the second signal in which even-order harmonic components are suppressed is output from the third port 53 and the fourth port 54, respectively.
Note that the phase difference between the combined signals output from the third port 53 and the fourth port 54 is still 180 °.

And the signal output from the 3rd port 53 and the 4th port 54 of the harmonic suppression circuit 3 mentioned above is each input into each open stub group 4 as FIG. 4 shows. Thereby, in the signals output from the third port 53 and the fourth port 54, odd-order harmonic components excluding the fundamental wave are suppressed.
As a result, when the even-order and odd-order harmonic components are suppressed, anti-phase signals are output from the output terminals 91 and 92 of each open stub group 4, and these signals constitute, for example, an active integrated antenna. Are input to the antenna array 5. The anti-phase signals input to the antenna array 5 are arranged on the ground from the antenna array 5 as shown in FIG. Power is transmitted to the ground power receiving base 102.

As described above, according to the harmonic suppression circuit 3 according to the present embodiment, even harmonic components of the input signal can be suppressed by this circuit. In comparison with the case where a stub is installed correspondingly, the entire circuit can be reduced in size. Thereby, a harmonic component can be efficiently suppressed with a small circuit.
Further, by adopting a push-pull circuit as an amplifier circuit that amplifies the signal output from the rat race ring 1, it is possible to further reduce the size and increase the efficiency of the device.

As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
First, the transmission line length described above is an example, and a transmission line having a half-wavelength is, for example, a length of (n + 1/2) λ (n is an integer including 0). And λ is the wavelength of the fundamental wave.) Similarly, a transmission line having a length of a quarter wavelength is, for example, a length of (n + 1/4) λ (n is 0). Including λ and the wavelength of the fundamental wave.

It is a figure which shows schematic structure of the signal amplifier circuit which concerns on one Embodiment of this invention. It is a figure which shows an example of the rat race ring which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the harmonic suppression circuit which concerns on one Embodiment of this invention. It is a figure which shows the outline of the open stub group and antenna array which concern on one Embodiment of this invention. It is explanatory drawing shown about the space solar power generation system. It is explanatory drawing shown about the harmonic component stub provided in the matching circuit of the conventional class F operation amplifier.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rat race ring 2 Push pull circuit 3 Harmonic suppression circuit 4 Open stub group 5 Array antenna 51 1st port 52 2nd port 53 3rd port 54 4th port 61, 62, 63, 64 Transmission line 31 32 Amplifier

Claims (3)

A first port to which a first signal is input;
A second port to which a second signal having an opposite phase to the first signal is input;
A third port from which a combined signal of the first signal and the second signal is output;
A fourth port from which a combined signal of the first signal and the second signal is output;
(N + 1/2) λ (where n is an integer including 0, λ is the wavelength of the fundamental wave, and so on), and the first port connects the first port to the second port. 1 transmission line;
A second transmission line having a length of (n + 1/4) λ and connecting the first port and the third port;
A third transmission line having a length of (n + 1/4) λ and connecting the second port and the fourth port;
A fourth transmission line having a length of (n + 1/2) λ and connecting the third port and the fourth port;
A harmonic suppression circuit comprising: a terminating resistor provided at an intermediate point of the first transmission line.   The harmonic suppression circuit according to claim 1, further comprising a short stub provided at an intermediate point of the fourth transmission line. One input terminal and two output terminals, and outputs a first signal having the same phase as the input signal input from the input terminal from one of the output terminals and a first signal having a phase opposite to that of the first signal. A power distributor that outputs the signal of 2 from the other output terminal;
A first amplifying means for inputting a first signal and outputting a third signal obtained by amplifying the first signal; a second amplifying means for outputting a fourth signal obtained by inputting the second signal and amplifying the second signal. A push-pull circuit comprising two amplification means;
A harmonic suppression circuit provided on the output side of the push-pull circuit,
The harmonic suppression circuit is
A first port to which the third signal is input;
A second port to which the fourth signal is input;
A third port from which a composite signal of the third signal and the fourth signal is output;
A fourth port from which a composite signal of the third signal and the fourth signal is output;
(N + 1/2) λ (where n is an integer including 0, λ is the wavelength of the fundamental wave, and so on), and the first port connects the first port to the second port. 1 transmission line;
A second transmission line having a length of (n + 1/4) λ and connecting the first port and the third port;
A third transmission line having a length of (n + 1/4) λ and connecting the second port and the fourth port;
A fourth transmission line having a length of (n + 1/2) λ and connecting the third port and the fourth port;
A signal amplifier circuit comprising: a terminating resistor provided at an intermediate point of the first transmission line.

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