JP2013138338A - Synchronization circuit and synchronization system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a synchronization circuit and a synchronization system that are capable of establishing signal synchronization between a plurality of devices.SOLUTION: A synchronization circuit includes: a first frequency converter that squares a waveform of a signal inputted from an input terminal; first, second, and third band-pass filters into which an output signal of the first frequency converter is inputted: a second frequency converter into which an output signal of the first band-pass filter and an output signal of the second band-pass filter are inputted; a phase detector into which the output signal of the first band-pass filter and an output signal of the second frequency converter are inputted; a phase conjugate circuit into which the output signal of the first band-pass filter is inputted; a multiplier into which an output signal of the phase conjugate circuit is inputted; a third frequency converter into which an output signal of third band-pass filter and an output signal of the multiplier are inputted; and a phase shifter into whose control terminal an output signal of the phase detector is inputted and into whose input terminal an output signal of the third frequency converter is inputted.

Description

  The present invention relates to a synchronization circuit and a synchronization system for synchronizing frequencies and phases between a plurality of devices.

  Conventionally, a method using a reference signal having a frequency of about several MHz to several hundreds of MHz has been used as a method of synchronizing signals between a plurality of devices and modules. For example, in Non-Patent Document 1, frequency synchronization is performed by inputting a 10 MHz signal output from one measuring instrument to the other measuring instrument, and two trigger signals are output by using a trigger signal output from a trigger generator. A method for synchronizing the phase of the instrument is described.

“Synchronization of multiple signal sources for MIMO”, application note, Anritsu, September 2007.

However, in the conventional configuration, when the distance between the trigger generator and each device is not the same, the arrival time of the trigger signal differs depending on the distance, so the timing of the signal varies between devices, and the synchronization accuracy deteriorates. There was a problem.
In addition, the conventional technology cannot be applied to a system (for example, a space solar power generation system) in which a distance between devices that cannot use a coaxial cable or the like is long, and there is a problem that signals cannot be synchronized.

  The present invention has been made in view of the above problems, and outputs three sine wave signals having different frequencies from one reference signal transmitter, and receives the three sine waves by a synchronous circuit mounted in each device. By extracting the frequency difference of the received three waves, detecting the phase difference of two waves among the extracted three wave signals, and adjusting the phase of the remaining one wave using the detected phase difference information, Signals having the same frequency and phase can be obtained between devices having different distances from the reference signal transmitter, and signals can be synchronized among a plurality of devices.

The synchronization circuit according to the present invention includes:
An input terminal;
A first frequency converter that squares the waveform of the signal input from the input terminal;
A first bandpass filter to which an output signal of the first frequency converter is input;
A second bandpass filter to which an output signal of the first frequency converter is input;
A third bandpass filter to which the output signal of the first frequency converter is input;
A second frequency converter in which an output signal of the first bandpass filter is input to a first input terminal, and an output signal of the second bandpass filter is input to a second input terminal;
A phase detector in which an output signal of the first bandpass filter is input to a first input terminal, and an output signal of the second frequency converter is input to a second input terminal;
A phase conjugate circuit to which an output signal of the first bandpass filter is input;
A multiplier to which an output signal of the phase conjugate circuit is input;
A third frequency converter in which an output signal of the third bandpass filter is input to a first input terminal, and an output signal of the multiplier is input to a second input terminal;
A phase shifter in which an output signal of the phase detector is input to a control terminal, and an output signal of the third frequency converter is input to an input terminal;
An output terminal for outputting an output signal of the phase shifter;
It is characterized by comprising.

  According to the present invention, there is an effect that a synchronization circuit and a synchronization system capable of synchronizing signals between a plurality of devices can be obtained.

The block diagram which shows the synchronous system by Embodiment 1 of this invention Configuration diagram showing a synchronizing circuit according to a first embodiment of the present invention. The figure for demonstrating operation | movement of the synchronous system by Embodiment 1 of this invention. The figure for demonstrating operation | movement of the synchronous system by Embodiment 1 of this invention. The block diagram which shows the synchronous system by Embodiment 2 of this invention

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a synchronization system according to Embodiment 1 of the present invention. In the figure, 100_0 is a reference signal transmitter, and 100_1 to 100_L are synchronization circuits.
A reference signal transmitter 100_0 that transmits a reference signal and all L devices (L is an integer equal to or greater than 1) (not shown), and L synchronization circuits 100_1 to 100_L are respectively connected to the L devices. The output terminals of the reference signal transmitter 100_0 and the input terminals of the synchronization circuits 100_1 to 100_L are connected one by one.

  FIG. 2 is a diagram showing a detailed configuration of the synchronization circuit 100_1 in FIG. In the figure, 100_1 is a synchronous circuit, 11 is a first frequency converter, 12, 13, and 14 are bandpass filters, 15 is a second frequency converter, 16 is a phase detector, 17 is a phase conjugate circuit, and 18 is A multiplier, 19 is a third frequency converter, and 20 is a phase shifter. Note that all of the synchronization circuits 100_1 to 100_L in FIG. 1 have the same configuration as that shown in FIG. Therefore, only the synchronization circuit 100_1 in FIG. 2 will be described here.

  In FIG. 2, the frequency converter 11 has a first input terminal, a second input terminal, and an output terminal. The phase detector 16 has a first input terminal, a second input terminal, and an output terminal. The second frequency converter 15 has a first input terminal, a second input terminal, and an output terminal. The third frequency converter 19 has a first input terminal, a second input terminal, and an output terminal. The phase shifter 20 has an input terminal, a control terminal, and an output terminal.

  The input terminal of the synchronization circuit 100_1 is connected to the first input terminal and the second input terminal of the frequency converter 11, and the output terminal of the frequency converter 11 is connected to the input terminals of the bandpass filters 12-14. The output terminal of the band pass filter 12 is connected to the first input terminal of the phase detector 16, the first input terminal of the second frequency conversion circuit 15, and the input terminal of the phase conjugate circuit 17. The terminal is connected to the second input terminal of the second frequency converter 15, the output terminal of the second frequency converter 15 is connected to the second input terminal of the phase detector 16, and the output of the phase detector 16 The terminal is connected to the control terminal of the phase shifter 20, the output terminal of the band pass filter 14 is connected to the first input terminal of the third frequency converter 19, and the output terminal of the phase conjugate circuit 17 is the multiplier 18. input The output terminal of the multiplier 18 is connected to the second input terminal of the third frequency converter 19, and the output terminal of the third frequency converter 19 is connected to the input terminal of the phase shifter 20. The output terminal of the phase shifter 20 is connected to the output terminal of the synchronization circuit 100_1.

Next, the operation will be described. Since the synchronization circuits 100_1 to 100_L have the same configuration as described above, only the operation of the synchronization circuit 100_1 will be described here.
The frequency relationship of the signal s (t) output from the reference signal transmitter 100_0 is set as follows:
s (t) = A cos {2π (f ₀ −f ₁ ) t} + B cos {2πf ₀ t} + C cos {2π (f ₀ + f ₂ ) t} (1)
Here, A, B, and C represent amplitude values of frequency components, t represents time, and f ₀ , f ₁ , and f ₂ represent frequencies. Further, there is a relationship of f ₂ = N × f ₁ (N is an integer of 2 or more) and f ₁ ≦ f ₂ << f ₀ . That is, f ₁ and f ₂ are sufficiently lower than f ₀ −f ₁ , f ₀ , f ₀ + f ₂ which are three different carrier frequencies of the reference signal output from the reference signal transmitter 100_0. Yes.

  Here, for simplification of explanation, it is assumed that A = B = C = 1 and N = 2. A, B, and C may be arbitrary real numbers other than 0, and A = B = C = 1 does not affect the following description of the present invention.

Assuming that a signal input to the synchronization circuit 100_1 separated from the reference signal transmitter 100_0 by a distance D is s '(t), s' (t) is
s ′ (t) = cos {2π (f ₀ −f ₁ ) t + φ ₁ } + cos {2πf ₀ t + φ ₂ } + cos {2π (f ₀ + f ₂ ) t + φ ₃ }
(2)
It becomes. Here, φ ₁ , φ ₂ , and φ ₃ represent the amount of phase rotation of each frequency component depending on the distance D,

_{φ 1 = 2π × mod {D} (f 0 -f 1) / c, 1} (3)
φ ₂ = 2π × mod {Df ₀ / c, 1} (4)
_{φ 3 = 2π × mod {D} (f 0 + f 2) / c, 1} (5)
It is expressed. Here, c represents the speed of light (the actual propagation speed when there is a slow wave effect such as a propagation path is a dielectric), and mod (X, Y) represents the remainder of X divided by Y.

The signal s ′ (t) input to the synchronization circuit 100_1 is input to the first input terminal and the second input terminal of the first frequency converter 11. Therefore, since the waveform of the signal input to the frequency converter 11 is squared and output, the output signal s '' (t) of the frequency converter 11 is
s '' (t) = s '(t) × s' (t)
= [cos {2π (f ₀ −f ₁ ) t + φ ₁ } + cos {2πf ₀ t + φ ₂ } + cos {2π (f ₀ + f ₂ ) t + φ ₃ }] ²
= α + β
+ cos (2πf ₁ t + φ ₂ −φ ₁ ) + cos (2πf ₂ t + φ ₂ −φ ₃ ) + cos (2πf ₃ t + φ ₃ −φ ₁ )
(6)
It becomes.

Where α = [cos {4π (f ₀ −f ₁ ) t + φ ₁ } + cos {4πf ₀ t + φ ₂ }
+ cos {4π (f ₀ + f ₂ ) t + φ ₃ } +3] / 2 (7)
β = cos {2π (2f ₀ −f ₁ ) t + φ ₁ + φ ₂ } + cos {2π (2f ₀ + f ₂ ) t + φ ₂ + φ ₃ }
+ cos {2π (2f ₀ -f ₁ + f ₂ ) t + φ ₁ + φ ₃ } (8)
f ₃ = f ₁ + f ₂ (9)
It is.

The signal s ″ (t) is branched into three, one of which is input to the input terminal of the bandpass filter 12.
When characteristics of the band-pass filter 12 is a characteristic with a passband center frequency f ₁ a and pass bandwidth BW _1, the BW ₁ and BW ₁ ≦ 0.5 × _{f 1,} components other than the third term in equation (6) Is blocked, the output signal s ₁ (t) of the bandpass filter 12 is
s ₁ (t) = cos (2πf ₁ t + φ ₂ −φ ₁ ) (10)
It becomes.

One of the remaining two waves of the three-branched signal s ″ (t) is input to the input terminal of the bandpass filter 13.
The characteristics of the band pass filter 13 are those having a center frequency f ₂ and a pass band having a pass band width BW ₂ , where BW ₂ is BW ₂ ≦ 0.5 × f _1. Is blocked, the output signal s ₂ (t) of the bandpass filter 13 is
s ₂ (t) = cos (2πf ₂ t + φ ₃ −φ ₂ ) (11)
It becomes.

The remaining one wave of the three-branched signal s ″ (t) is input to the input terminal of the bandpass filter 14.
When the characteristics of the band pass filter 14 is a characteristic with a passband center frequency f ₃ a and pass bandwidth BW _3, the BW ₃ and BW ₃ ≦ 0.5 × _{f 1,} components other than the fifth term in equation (6) Is blocked, the output signal s ₃ (t) of the bandpass filter 14 is
s ₃ (t) = cos (2πf ₃ t + φ ₃ −φ ₁ ) (12)
It becomes.

The output signal s ₁ (t) of the band pass filter 12 is input to the first input terminal of the phase detector 16 and also input to the first input terminal of the second frequency converter 15.

The output signal s ₂ (t) of the band pass filter 13 is input to the second input terminal of the second frequency converter 15.

Therefore, the output signal s ₂ ′ (t) of the second frequency converter 15 is
s ₂ '(t) = cos (2πf ₁ t + φ ₃ −2φ ₂ + φ ₁ ) (13)
It becomes.

  FIG. 3 is an example of the characteristics of the phase detector 16. The horizontal axis in FIG. 3 is the phase difference between the signals input to the first input terminal and the second input terminal of the phase detector 16, and the vertical axis in FIG. 3 is output from the output terminal of the phase detector 16. Voltage. In the phase detector 16, the output voltage changes according to the phase difference between the input signals, and when the phase difference between the two input signals is zero, the output voltage becomes zero.

The phase difference between the signal at the first input terminal and the signal at the second input terminal of the phase detector 16 is (φ ₃ −2φ ₂ + φ ₁ ) − (φ ₂ − φ ₁ ) = φ ₃ −3φ ₂ + 2φ ₁ At this time, a certain voltage V ₀ is output from the output terminal of the phase detector 16.
V ₀ = X × (φ ₃ -3φ ₂ + 2φ ₁ ) (14)
Is output. Where X is a coefficient.

The output signal s ₃ (t) of the band pass filter 14 is input to the first input terminal of the third frequency converter 19.

Since the output signal s ₁ (t) of the band pass filter 12 is input to the input terminal of the phase conjugate circuit 17, the output signal s ₁ ′ (t) of the phase conjugate circuit 17 is
s ₁ '(t) = cos (2πf ₁ t -φ ₂ + φ ₁ ) (15)
It becomes.

The output signal of the phase conjugate circuit 17 is input to the input terminal of the multiplier 18. Here, when the multiplication number of the multiplier 18 is N + 1, that is, a tripler, the output signal s ₁ ″ (t) of the multiplier 18 is
s ₁ ″ (t) = cos (6πf ₁ t −3φ ₂ + 3φ ₁ )
= cos (2πf ₃ t -3φ ₂ + 3φ ₁ ) (16)
It becomes.

The signal s ₃ (t) is input to the first input terminal of the third frequency converter 19, and the signal s ₁ ″ (t) is input to the second input terminal of the third frequency converter 19. Therefore, the output signal s ₃ ′ (t) of the third frequency conversion circuit 19 is obtained from the equations (12) and (16).
s ₃ '(t) = cos (4πf ₃ t + φ ₃ -3φ ₂ + 2φ ₁ ) (17)
It becomes.

Here, from Equation (3) and Equation (4),
φ ₂ −φ ₁ = 2π × [mod {Df ₀ / c, 1} −mod {D (f ₀ −f ₁ ) / c, 1}]
= 2π × mod {Df ₁ / c, 1} (18)
It becomes. From Equation (4) and Equation (5),
φ ₃ −φ ₂ = 2π × [mod {D (f ₀ + f ₂ ) / c, 1} − mod {Df ₀ / c, 1}]
= 2π × mod {Df ₂ / c, 1}
= 4π × mod {Df ₁ / c, 1} (19)
It becomes. From Equation (3) and Equation (5),
φ ₃ −φ ₁ = 2π × [mod {D (f ₀ + f ₂ ) / c, 1} − mod {D (f ₀ −f ₁ ) / c, 1}]
= 2π × mod {D (f ₂ + f ₁ ) / c, 1}
= 6π × mod {Df ₁ / c, 1} (20)
It becomes.

FIG. 4 is an example of the characteristics of the phase shifter 20. The horizontal axis in FIG. 4 is the control voltage, and the vertical axis in FIG. 4 is the phase change amount of the phase shifter 20. When the phase of the phase shifter 20 is controlled by the voltage Vo output from the phase detector 16, the phase amount changes by φ ₃ −3φ ₂ + 2φ ₁ . Therefore, at this time, the output signal s ₀ (t) of the phase shifter 20 is
s ₀ (t) = cos (6πf ₁ t) (21)
It becomes. This signal is output from the output terminal of the synchronization circuit 100_1.

The operation of the synchronization circuit 100_1 has been described above. Since the synchronization circuits 100_1 to 100_L have the same configuration, the output signals of all the synchronization circuits are s ₀ (t). By using this signal s ₀ (t), for example, by generating a trigger signal based on the zero cross point of the signal s ₀ (t), trigger signals having the same timing are obtained in all the synchronization circuits 100_1 to 100_L. It is possible.

  As described above, signals having the same frequency, phase and timing are output from all the synchronization circuits 100_1 to 100_L regardless of the distance between the reference signal transmitter 100_0 and the synchronization circuits 100_1 to 100_L. It becomes possible to synchronize signals between a plurality of devices.

In the first embodiment, f ₂ = 2f ₁ is set, but the present invention is not limited to this, and f ₂ = N × f ₁ and N may be an integer of 2 or more.
In Embodiment 1, the reference signal transmitter 100_0 and the synchronization circuits 100_1 to 100_L are described as separate devices. However, the reference signal transmitter 100_0 is mounted on any device including the synchronization circuits 100_1 to 100_L. May be.

Embodiment 2. FIG.
FIG. 5 is a block diagram showing a synchronization system according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in FIGS. 1 and 2 denote the same or corresponding parts, and the description thereof is omitted. In FIG. 5, 101_0 and 101_1 to 101_L are antennas. In FIG. 7, the antenna 101_0 is connected to the reference signal transmitter 100_0, and the antennas 101_1 to 101_L are connected to the synchronization circuits 100_1 to 100_L. The reference signal transmitter 100_0 and the L synchronization circuits 100_1 are the antenna 101_0 and the antenna. 101_1 to 101_L are connected wirelessly.

  Since the structure and operation of the synchronization circuit 100_1 are the same as those in Embodiment 1, description thereof is omitted here.

  According to the second embodiment, the reference signal transmitter 100_0 and the synchronization circuits 100_1 to 100_L can be operated even when they are wirelessly connected without using a cable such as a coaxial cable. Therefore, even in systems where the distance between devices that make it difficult to use a synchronization cable is long, the frequency and phase of signals can be synchronized between multiple devices by using this synchronization system and synchronization circuit. Is possible.

100_0 reference signal transmitter, 100_1 to 100_L synchronization circuit, 101_0, 101_1 to 101_L antenna, 11, 15, 19 frequency converter, 12, 13, 14 band pass filter, 16 phase detector, 17 phase conjugate circuit, 18 multiplier 20 Phase shifter

Claims (6)

An input terminal;
A first frequency converter that squares the waveform of the signal input from the input terminal;
A first bandpass filter to which an output signal of the first frequency converter is input;
A second bandpass filter to which an output signal of the first frequency converter is input;
A third bandpass filter to which the output signal of the first frequency converter is input;
A second frequency converter in which an output signal of the first bandpass filter is input to a first input terminal, and an output signal of the second bandpass filter is input to a second input terminal;
A phase detector in which an output signal of the first bandpass filter is input to a first input terminal, and an output signal of the second frequency converter is input to a second input terminal;
A phase conjugate circuit to which an output signal of the first bandpass filter is input;
A multiplier to which an output signal of the phase conjugate circuit is input;
A third frequency converter in which an output signal of the third bandpass filter is input to a first input terminal, and an output signal of the multiplier is input to a second input terminal;
A phase shifter in which an output signal of the phase detector is input to a control terminal, and an output signal of the third frequency converter is input to an input terminal;
An output terminal for outputting an output signal of the phase shifter;
A synchronization circuit comprising: A reference signal transmitter for transmitting a composite signal of sine waves of three different frequencies;
At least one synchronization circuit according to claim 1 for receiving the composite signal transmitted from the reference signal transmitter;
A synchronization system characterized by comprising:   The synchronization system according to claim 2, wherein the reference signal transmitter and the synchronization system are connected by wire.   The synchronization system according to claim 2, wherein the reference signal transmitter and the synchronization system are connected wirelessly. The three different frequencies output from the reference signal transmitter with f ₀ , f ₁ , and f ₂ as frequencies are respectively f ₀ −f ₁ , f ₀ , and f ₀ + f ₂ , and f ₂ = N × 5. The synchronization system according to claim 2, wherein the synchronization system is f ₁ (N is an integer of 2 or more).   6. The synchronization circuit or the synchronization system according to claim 1, wherein an output signal of the phase shifter is used as a trigger signal.

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