JP5616258B2 - Phase shift correction circuit, phase variable amplifier circuit, phase shift correction method, and phase adjustment method - Google Patents

Description

  The present invention relates to a phase shift correction circuit, a phase variable amplification circuit, a phase shift correction method, and a phase adjustment method, and in particular, a phase difference between an input signal and an output signal of a circuit to be corrected and a target phase difference. The present invention relates to a phase shift correction circuit, a phase variable amplifier circuit, a phase shift correction method, and a phase adjustment method that correct a phase shift occurring between them.

  In an electronic device such as a mobile phone, a received signal wave may contain a lot of noise waves. This noise wave is an electromagnetic wave or the like from the surroundings, and if there are many noise waves, various influences appear when processing the received signal. For this reason, there is a noise cancellation technique for removing this noise wave, that is, canceling the noise wave. Here, the noise cancellation circuit of Patent Document 1 using a general noise cancellation technique will be described.

  The noise cancellation circuit 100 shown in FIG. 6 cancels the noise wave by the following method. First, the EMI noise acquisition unit 109 acquires a noise wave. Then, the phase variable amplifier 102 inverts the phase of the acquired noise wave. Further, the band pass filter 103, the delay processing unit 104, and the VGA 105 adjust the signal output level of the noise wave. Finally, the adder adds the noise wave whose signal output level has been adjusted and the signal wave received by the receiving unit 107. That is, the noise cancellation circuit 100 cancels the noise wave included in the signal wave so as to cancel the noise wave with the phase reversed.

In order to cancel the noise wave in this way, it is necessary to change the phase of the noise wave. For this reason, a phase variable amplifier capable of varying the phase and gain independently is generally used for the noise cancellation circuit. This noise cancellation circuit 100 has a phase variable amplifier 102.
However, the phase characteristics of the phase variable amplifier 102 and the accuracy of making the phase variable generally have a phase error inherent in manufacturing. For this reason, the control unit 101 uses, for example, an algorithm that sequentially compares the phase indicated by the phase setting value set in the phase variable amplifier 102 and the actual phase to set the phase setting value in the phase variable amplifier 102. It is reset. By executing such processing, the control unit 101 drives the phase setting value set in the phase variable amplifier 102 to a phase setting value at which the noise wave is just canceled.

  However, there may be a large phase shift between the phase difference between the input signal and the output signal and the target phase difference. In such a case, the amount of change in the level of the noise wave may be small if the setting of the phase and gain of the phase variable amplifier 102 is slightly changed. For this reason, if there is a phase shift between the phase difference between the input signal and the output signal and the target phase difference, an accurate phase output that can cancel the noise wave It is desirable to correct the phase characteristics of the phase variable amplifier 102 so that the signal is output from the phase variable amplifier 102.

US Patent Application Publication No. 2007/0060059 Specification

  However, in the noise cancellation circuit 100 described above, the phase setting value set in the phase variable amplifier 102 is driven in a state where the phase variable amplifier 102 still contains a manufacturing phase error. For this reason, in the noise cancellation circuit 100, it is relatively difficult to directly detect a phase shift between the phase difference between the input signal and the output signal and the target phase difference. At the same time, it is relatively difficult to directly set the phase setting value set in the phase variable amplifier 102 to the optimum value.

  Therefore, in view of the above problems, the present invention easily detects a phase shift between a target phase difference between an input signal and an output signal of a circuit to be corrected and an actual phase difference, and a phase difference. A phase shift correction circuit, a phase variable amplification circuit, a phase shift correction method, and a phase adjustment method capable of easily correcting the shift of the noise and outputting an output signal having an accurate phase capable of optimally canceling the noise wave The purpose is to provide.

In order to achieve the above object, a phase shift correction circuit, a phase variable amplifier circuit, a phase shift correction method, and a phase adjustment method according to the present invention are configured as follows.
A phase shift correction circuit according to the present invention includes a phase shift detector that detects a signal level of a combined signal obtained by combining an input signal and an output signal of a circuit to be corrected, and a signal level of the combined signal detected by the phase shift detector. A phase shift correction unit that corrects a phase shift between the phase difference between the input signal and the output signal and a target phase difference of 180 ° based on the change of It is provided with.

According to the above phase shift correction circuit, applying the fact that the signal level of the composite signal changes when the phase difference between the input signal and the output signal of the phase variable amplifier or the like that is the circuit to be corrected is changed, The phase shift correction unit corrects the phase shift generated between the phase difference between the input signal and the output signal of the circuit to be corrected and the target phase difference.
That is, in the phase shift correction circuit, the phase shift detection unit converts the phase difference between the input signal and the output signal into the composite signal level, so that the phase difference generated between the actual phase difference and the original phase difference is detected. The shift can be easily detected. At the same time, the phase shift correction circuit changes the phase difference between the input signal and the output signal so that the signal level of the synthesized signal becomes the minimum value by the phase shift correction unit, so that the actual phase difference and the original phase difference are changed. It is possible to easily correct a phase shift occurring between the phase difference and the phase difference.

A first phase variable amplifier circuit according to the present invention includes a phase variable amplifier that changes a gain and a phase between an input signal and an output signal, and a signal level of a combined signal obtained by combining the input signal and the output signal. a phase shift detection unit for detecting, on the basis of the change in the signal level of the detected combined signal by the phase shift detection section, and the phase difference between said input signal and said output signal, the phase difference to be the target And a phase shift correction unit that corrects a phase shift occurring between a certain angle of 180 ° .

According to the first phase variable amplifier circuit, the phase shift detection unit and the phase shift correction unit for easily correcting the phase shift are connected to the subsequent stage of the phase variable amplification unit such as the phase variable amplifier. . For this reason, the phase shift detection unit and the phase shift correction unit can easily detect the phase shift between the actual phase difference between the input signal and the output signal of the phase variable amplification unit and the original phase difference. It can be detected and the phase shift can be easily corrected. That is, it is possible to suppress the occurrence of a phase shift by the phase shift detection unit and the phase shift correction unit.
As a result, the phase variable amplifier circuit can output an output signal having an accurate phase that can optimally cancel the noise wave.

In the second phase variable amplifier circuit according to the present invention, the phase shift correction unit corrects the phase shift based on a signal level of a composite signal with respect to a phase difference between the input signal and the output signal. It is characterized by.
According to the second phase variable amplifier circuit, first, the phase variable amplifier changes the gain and phase between the input signal and the output signal. After that, the phase shift detection unit applies the fact that the signal level of the combined signal becomes the minimum value when the phase between the input signal and the output signal is opposite, that is, when the phase difference is just 180 degrees. The phase shift correction unit corrects the phase shift generated between the phase difference between the input signal and the output signal of the phase variable amplification unit and the target phase difference.
In other words, the phase shift correction unit changes the phase correction value so that the signal level of the composite signal detected when the phase correction value is changed, so that the input signal and output of the phase variable amplification unit It is possible to easily correct a phase shift occurring between the phase difference between the signal and the target phase difference.

  In the third phase variable amplifier circuit according to the present invention, the phase shift detection unit combines the input signal and the output signal, and outputs the combined signal as the combined signal; and A detection unit that detects a signal level of the output synthesized signal, wherein the phase shift correction unit outputs a phase correction value indicating a correction amount when correcting the phase shift, and the detection A level determination unit that determines whether the signal level of the combined signal detected by the unit is higher than the signal level of the combined signal when the previous phase correction value is set, and the control The unit advances the phase correction value to be output until the signal level of the combined signal detected by the detecting unit becomes higher than the signal level of the combined signal when the previous phase correction value is set. Going late or late To be characterized in that the go.

  According to the third variable phase amplifier circuit, the combining unit outputs a combined signal obtained by combining the input signal and the output signal. The detecting unit detects the signal level of the combined signal. Then, the level determining unit determines the magnitude relationship between the signal level of the combined signal detected by the detecting unit and the signal level of the combined signal when the previous phase correction value is set. Then, the control unit outputs the phase correction value based on the determination result so that the signal level of the combined signal becomes the minimum value. Thereby, finally, it is possible to easily correct the phase shift that occurs between the actual phase difference and the original phase difference.

According to a fourth phase variable amplifier circuit of the present invention, the phase shift correction unit includes a phase variable unit capable of changing the phase of the output signal based on the phase correction value output by the control unit. It is characterized by that.
According to the fourth phase variable amplifier circuit, the phase variable unit is connected to the subsequent stage of the phase variable amplifier unit, and the input signal and the output of the phase variable amplifier unit are output based on the phase correction value output from the control unit. It is possible to easily correct a phase shift occurring between the phase difference between the signal and the target phase difference.

In a fifth phase variable amplifier circuit according to the present invention, the phase shift correction unit adds the phase correction value output from the control unit to a phase control signal for controlling the phase of the phase variable amplification unit. It has the part.
According to the fifth phase variable amplifier circuit described above, the adder / subtractor directly adds the phase correction value output from the control unit to the phase value indicated by the phase control signal input to the phase variable unit. As a result, the phase difference between the input signal and the output signal of the phase variable amplification unit and the target phase difference can be obtained in the same manner as when the phase variable unit is used without using the phase variable unit. It is possible to easily correct the phase shift occurring between the two.

In a sixth phase variable amplifier circuit according to the present invention, the phase shift correction unit is configured such that at least the signal level of the combined signal detected by the detection unit is set to the previous phase correction value. A storage unit is provided for storing the phase correction value output from the control unit when the signal level of the combined signal becomes larger.
According to the sixth variable phase amplifier circuit described above, the magnitude relationship between the signal level of the combined signal determined by the level determining unit and the signal level of the combined signal when the previous phase correction value is set These determination results are stored in the storage unit. Thus, the control unit can determine the phase correction value to be output to the phase variable unit based on the determination result stored in the storage unit, and set the phase correction value in the phase variable unit.

In a first phase shift correction method according to the present invention, a phase shift detection unit detects a signal level of a combined signal obtained by combining an input signal and an output signal of a circuit to be corrected, and a phase shift correction unit includes: Based on the signal level of the combined signal detected in the phase shift detection step, a phase difference between the input signal and the output signal occurs between the target phase difference of 180 ° . It has a phase shift correction step for correcting a phase shift.

According to the first phase shift correction method, the same operation as the phase shift correction circuit can be obtained by executing the steps described above.
The second phase shift correction method according to the present invention is characterized in that, before the phase shift detection step is executed, the phase shift correction unit includes a phase initialization step that sets the self correction unit to an initial state.
According to the second phase shift correction method, it is possible to set the phase shift correction unit in an initial state by executing the above steps before executing the phase shift detection step.

In the first phase adjustment method according to the present invention, the phase variable amplification unit changes the gain and phase between the input signal and the output signal, and the phase shift detection unit includes the input signal and the output signal. A phase shift detection step for detecting a signal level of the combined signal, and a phase shift correction unit, based on a change in the signal level of the combined signal detected by the phase shift detection step, the input signal and the output signal And a phase shift correction step of correcting a phase shift generated between the phase difference between the phase difference between the phase difference between the phase difference between the phase difference and the phase difference and the target phase difference of 180 ° .
According to said 1st phase adjustment method, the same effect | action as said 1st phase variable amplifier circuit is acquired by performing said each step.

In the second phase adjustment method according to the present invention, in the phase shift correction step, the phase shift correction unit may determine the phase based on a signal level of a composite signal with respect to a phase difference between the input signal and the output signal. It is characterized by correcting the deviation.
According to said 2nd phase adjustment method, the effect | action similar to said 2nd phase variable amplifier circuit is acquired by performing said each step.

In the third phase adjustment method according to the present invention, in the phase shift detection step, a combining unit combines the input signal and the output signal and outputs the combined signal as the combined signal. Includes a detection step of detecting a signal level of the combined signal output in the combining step, and the phase shift correction step is a phase correction value indicating a correction amount when the control unit corrects the phase shift. Whether the signal level of the combined signal detected in the detecting step is higher than the signal level of the combined signal when the previous phase correction value is set. A level determination step for determining whether the signal level of the combined signal detected by the control unit in the detection step is the previous phase correction value. Until greater than the signal level of the composite signal when had, will not advance the phase correction value output, it is characterized in that or go slow.
According to the third phase adjustment method, the same operations as those of the third phase variable amplifier circuit can be obtained by executing the above steps.

In the fourth phase adjustment method according to the present invention, the phase shift correction step includes a phase variable step in which the phase variable unit changes the phase of the output signal based on the phase correction value output in the control step. It is characterized by that.
According to the fourth phase adjustment method, the same operations as in the fourth phase variable amplifier circuit can be obtained by executing the above steps.

In the fifth phase adjustment method according to the present invention, the phase shift correction step includes adding the phase correction value output in the control step to the phase control signal for the adder to control the phase of the phase variable amplification unit. It has the addition step to add, It is characterized by the above-mentioned.
According to the fifth phase adjustment method, the same operation as the fifth phase variable amplifier circuit can be obtained by executing the steps.

In a sixth phase adjustment method according to the present invention, the phase shift correction step is configured such that the storage unit has at least the signal level of the combined signal detected in the detection step set to the previous phase correction value. And a storage step for storing the phase correction value output in the control step when the signal level becomes higher than the signal level of the synthesized signal.
According to the sixth phase adjustment method described above, the same operations as in the sixth phase variable amplifier circuit can be obtained by executing the above steps.

In a seventh phase adjustment method according to the present invention, before the phase shift detection step is executed, the phase variable amplification unit causes the gain control signal for setting the gain between the input signal and the output signal to zero. A phase control signal input step for inputting a phase control signal for making the phase between the input signal and the output signal opposite to each other, and the phase shift The correction unit includes a phase initialization step in which the correction unit is in an initial state.
According to the seventh phase adjustment method, the same operations as in the second phase shift correction method can be obtained by executing the above steps.

  The phase shift correction circuit and the phase adjustment method according to the present invention convert a phase difference between an input signal and an output signal into a composite signal, and occur between the actual phase difference and the original phase difference depending on the signal level of the composite signal. The phase shift can be easily detected. At the same time, the phase shift correction circuit and the phase adjustment method change the phase difference between the input signal and the output signal so that the signal level of the combined signal becomes the minimum value, thereby making the actual phase difference and the original phase difference. A phase shift occurring between the phase difference and the phase difference can be easily corrected.

  In addition, the phase variable amplifier circuit and the phase adjustment method according to the present invention can easily detect the phase shift by the phase shift detector and the phase shift corrector connected to the phase variable amplifier, and the phase shift can be easily detected. Can be easily corrected. That is, it is possible to suppress the occurrence of a phase shift by the phase shift detection unit and the phase shift correction unit. Thereby, the phase variable amplifier circuit and the phase adjustment method can output an output signal having an accurate phase that can optimally cancel the noise wave.

1 is a block diagram illustrating a configuration of a phase variable amplifier circuit 10 using a phase shift correction circuit 12 according to a first embodiment. It is a graph which shows the signal level of the synthetic | combination signal with respect to the phase difference between an input signal and an output signal. It is a graph which shows the signal level of the synthetic | combination signal with respect to the phase difference between an input signal and an output signal. 4 is a flowchart showing a flow of processing of a phase adjustment method in the phase variable amplifier circuit 10 using the phase shift correction method in the phase shift correction circuit 12 according to the first embodiment. 4 is a flowchart showing a flow of processing of a phase adjustment method in the phase variable amplifier circuit 10 using the phase shift correction method in the phase shift correction circuit 12 according to the first embodiment. It is a block diagram which shows the structure of the phase variable amplifier circuit 20 using the phase shift correction circuit 21 which concerns on 2nd Embodiment. It is a block diagram which shows the structure of the conventional common noise cancellation circuit.

Hereinafter, embodiments of a phase shift correction circuit and a phase variable amplifier circuit to which the present invention is applied will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.
(First embodiment)
(Configuration of Phase Variable Amplifying Circuit 10 Using Phase Deviation Correction Circuit 12)
First, with reference to FIG. 1, a configuration of a phase variable amplifier circuit 10 configured using the phase shift correction circuit 12 according to the first embodiment will be described.

  A phase variable amplifier circuit 10 shown in FIG. 1 includes a phase variable amplifier 11, a phase shift correction circuit 12, an input signal input terminal 13, a gain control signal input terminal 14, a phase control signal input terminal 15, and an output signal output. And a terminal 16. The phase variable amplifier circuit 10 is generated at the subsequent stage of the phase variable amplifier 11 which is a circuit to be corrected, between the phase difference between the input signal and the output signal of the phase variable amplifier 11 and the target phase difference. A phase shift correction circuit 12 having a phase shift correction function for correcting the phase shift is connected. The phase variable amplifier circuit 10 uses the phase variable amplifier 11 as a phase variable amplifier. However, the phase variable amplifying unit may be a circuit other than the phase variable amplifier as long as it can change the gain and phase between the input signal and the output signal.

  The phase variable amplifier 11 inputs a gain control signal via a gain control signal input terminal 14 from a main control unit (not shown) that controls the entire system and apparatus in which the phase variable amplifier circuit 10 is mounted. To do. Further, the phase variable amplifier 11 inputs a phase control signal from the main control unit or the like via the phase control signal input terminal 15. Then, the phase variable amplifier 11 has a gain between the input signal input from the input signal input terminal 13 and the output signal output from the output signal output terminal 16 based on the gain control signal and the phase control signal. Change the phase. For example, if the phase variable amplifier 11 has a phase difference of 180 degrees between the input signal and the output signal, the target phase difference is 180 degrees. If the actual phase difference is not 180 degrees, a phase shift has occurred.

The phase shift correction circuit 12 includes a phase shift detection unit 17 and a phase shift correction unit 18. The phase shift correction circuit 12 corrects a phase shift generated between the phase difference between the input signal and the output signal of the phase variable amplifier 11 and the target phase difference.
The phase shift detection unit 17 includes a synthesis unit 17a and a detection unit 17b.
The synthesizer 17a receives an input signal from the input signal input terminal 13, and receives an output signal whose gain and phase are changed by the phase variable amplifier 11 and the phase variable unit 18d. The combining unit 17a combines the input signal and the output signal, and outputs the combined signal as a combined signal. It should be noted that the signal level of the combined signal becomes a minimum value when there is no phase shift.

The detecting unit 17b detects the signal level of the combined signal output from the combining unit 17a.
As described in the prior art, the detection unit 17b directly detects a phase shift generated between the phase difference between the input signal and the output signal of the phase variable amplifier 11 and the target phase difference. It is relatively difficult to do. Therefore, the synthesizer 17a converts the above-described phase shift to the signal level of the synthesized signal. Thereby, the detection unit 17b can easily detect the phase shift.

The phase shift correction unit 18 includes a level determination unit 18a, a storage unit 18b, a control unit 18c, and a phase variable unit 18d. The phase shift correction unit 18 corrects a phase shift generated between the phase difference between the input signal and the output signal of the phase variable amplifier 11 and the target phase difference.
Whether the signal level of the synthesized signal detected by the detecting unit 17b is higher than the signal level of the synthesized signal when a phase correction value (phase correction code) described later is set one before. Determine whether or not.

  The storage unit 18b is a memory or a trimming circuit for storing the determination result determined by the level determination unit 18a and the phase correction value output by the control unit 18c. Specifically, in the storage unit 18b, the signal level of the synthesized signal detected by the detecting unit 17b is higher than the signal level of the synthesized signal when the previous phase correction value is set. It is remembered. Further, the storage unit 18b stores the phase correction value and the like output from the control unit 18c at that time.

  Based on the determination result stored in the storage unit 18b, the control unit 18c changes and outputs the phase correction value to the phase variable unit 18d. This phase correction value corrects a phase shift occurring between the phase difference between the input signal and the output signal of the phase variable amplifier 11 and the target phase difference in the phase variable unit 18d. The correction amount at the time is shown. The processing procedure in which the control unit 18c outputs the phase correction value to the phase variable unit 18d will be described in detail later.

  The phase variable unit 18 d is connected to the subsequent stage of the phase variable amplifier 11. And the phase correction value output from the control part 18c is set to the phase variable part 18d. The phase variable unit 18d is generated between the actual phase difference between the input signal input to the phase variable amplifier 11 and the output signal whose gain and phase are changed, and the original phase difference. Easily correct phase shifts.

  As described in the prior art, it is relatively difficult for the phase variable unit 18d to directly set the phase setting value of the phase variable amplifier 11 to the optimum value. Therefore, the control unit 18c changes the phase correction value set in the phase variable unit 18d. Furthermore, the level determination unit 18a determines the magnitude relationship between the signal level of the combined signal when the previous phase correction value is set and the signal level of the current combined signal. Based on the determination result, the control unit 18c sets the phase correction value in the phase variable unit 18d so that the signal level of the combined signal becomes the minimum value. Thus, the phase variable unit 18d can easily correct the phase shift.

(Signal level of composite signal with respect to phase difference between input signal and output signal)
Subsequently, the relationship between the phase difference between the input signal and the output signal and the level of the synthesized signal corresponding to the phase difference will be described with reference to FIGS.
The vertical axis of the graphs shown in FIGS. 2 and 3 indicates the signal level of the combined signal output from the combining unit 17a. The horizontal axis of the graph indicates the phase difference between the input signal and the output signal. As indicated by the solid line in FIG. 2, the signal level of the combined signal gradually decreases as the phase difference between the input signal and the output signal increases from 0 degrees. As the phase difference between the input signal and the output signal increases from 180 degrees, the signal level of the synthesized signal gradually increases. That is, when the phase difference between the input signal and the output signal is exactly 180 degrees, the signal level of the combined signal becomes the minimum value.

  However, the phase shift between the actual phase difference between the input signal input to the phase variable amplifier 11 and the output signal output from the phase variable amplifier 11 with the gain and phase changed, and the original phase difference. 2 is generated, the signal level of the combined signal is deviated from the signal level of the combined signal indicated by the solid line, as indicated by a broken line in FIG. That is, even if the phase variable amplifier 11 sets the phase difference between the input signal and the output signal to 180 degrees, the signal level of the combined signal is the minimum value unless the actual phase difference is 180 degrees. do not become.

  First, the phase variable amplifier 11 is initially set so that the gain between the input signal input terminal 13 and the output signal output terminal 16 becomes 0, and the phase difference between the input signal and the output signal becomes 180 degrees. Keep it. Then, the control unit 18c advances the phase correction value of the phase variable unit 18d one by one so that the signal level of the combined signal becomes the minimum value. In this way, it is possible to easily correct the phase shift that occurs between the actual phase difference between the input signal and the output signal of the phase variable amplifier 11 and the original phase difference.

  Contrary to the above, as shown in FIG. 3, the signal level of the combined signal may become the minimum value when the phase difference between the input signal and the output signal is larger than 180 degrees. In this case, the phase correction value of the phase variable unit 18d is delayed one by one so that the signal level of the combined signal becomes the minimum value. In this way, it is possible to easily correct the phase shift that occurs between the actual phase difference between the input signal and the output signal of the phase variable amplifier 11 and the original phase difference.

As described above, in the conventional phase variable amplifier, the phase shift that occurs between the actual phase difference between the input signal and the output signal of the phase variable amplifier 11 and the original phase difference is directly detected. It was relatively difficult to detect or directly set the phase setting value of the phase variable amplifier 11 to the optimum value. However, in the phase variable amplifier circuit 10 using the phase shift correction circuit 12 according to the present embodiment, the phase difference between the input signal and the output signal of the phase variable amplifier 11 is converted into a composite signal level, so that the actual level is obtained. A phase shift generated between the phase difference and the original phase difference can be easily detected. At the same time, in the phase variable amplifier circuit 10, the phase shift can be easily corrected by changing the phase correction value set in the phase variable unit 18d so that the signal level of the combined signal becomes the minimum value. Can be done.
In such a phase adjustment method that optimally adjusts the phase difference between the input signal and the output signal of the phase variable amplifier circuit 10, the phase shift correction circuit 12 causes the actual position of the input signal and the output signal of the phase variable amplifier 11 to be adjusted. A phase shift correction method is used to correct a phase shift that occurs between the phase difference and the original phase difference.

(Processing flow of phase adjustment method using phase shift correction method)
Subsequently, with reference to FIGS. 4A and 4B, the flow of the process of the phase adjustment method in the phase variable amplifier circuit 10 using the phase shift correction method in the phase shift correction circuit 12 according to the first embodiment. explain.
First, initial setting of the phase variable amplifier 11 is performed. For this reason, the phase variable amplifier 11 inputs an input signal from the input signal input terminal 13 (step S101). Next, the phase variable amplifier 11 inputs a gain control signal for setting the gain between the input signal input terminal 13 and the output signal output terminal 16 to 0 (step S102). The phase variable amplifier 11 receives a phase control signal for setting the phase difference between the input signal and the output signal to 180 degrees (step S103). In this way, the gain and phase of the phase variable amplifier 11 are set in advance. As a result, when there is no phase shift due to manufacturing variations, as shown in the graphs of FIGS. 2 and 3, the synthesis is performed when the phase difference between the input signal and the output signal is exactly 180 degrees. The signal level of the signal can be minimized.

  In this initial state, it is necessary to initialize the phase correction value set in the phase variable unit 18d for correcting the phase shift to an initial value indicating that there is no correction amount. For this reason, the control part 18c memorize | stores 0 as a phase correction value in the memory | storage part 18b (step S104). Subsequently, the control unit 18c sets the phase correction value of the phase variable unit 18d to 0 (step S105).

  When the above initial setting is completed, if there is no phase shift due to manufacturing variation, the level of the combined signal at this time is the difference between the input signal and the output signal as shown in the graphs of FIGS. The value when the phase difference between them is exactly 180 degrees, that is, the minimum value is obtained. However, when there is a phase shift in this initial state, the level of the composite signal does not become the minimum value when the phase difference is 180 degrees as shown by the broken line in FIGS. 2 and 3, for example. . In such a case, it is necessary to further correct the phase shift after the above initial setting is completed.

  First, the control unit 18c advances the phase correction value of the phase variable unit 18d by one (step S106). The detector 17b detects the signal level of the combined signal obtained by combining the input signal and the output signal by the combiner 17a (step S107). When the level determination unit 18a determines that the current detection level detected by the detection unit 17b is not higher than the detection level when the previous phase correction value is set (NO in step S108). ), The determination result is stored in the storage unit 18b. Then, the control unit 18c advances the phase correction value set in the phase variable unit 18d by 1 (step S109). The detection unit 17b detects the combined signal level (step S110). Furthermore, the level determination unit 18a determines the magnitude relationship between the current detection level detected by the detection unit 17b and the detection level when the previous phase correction value is set. When the level determination unit 18a determines that the current detection level detected by the detection unit 17b is not greater than the detection level when the previous phase correction value is set (step S111). NO), the determination result is stored in the storage unit 18b. Then, the process returns to step S109 again, and the above processing is repeated.

  In step S111, when the level determination unit 18a determines that the current detection level detected by the detection unit 17b is higher than the detection level when the previous phase correction value is set ( YES in step S111) means that the phase difference between the input signal and the output signal is greater than 180 degrees. For this reason, the level determination unit 18a stores the phase correction value set immediately before in the storage unit 18b (step S112). Finally, the control unit 18c sets the phase correction value stored in the storage unit 18b in the phase variable unit 18d (step S113). As a result, the phase shift is corrected and no phase shift occurs.

  In step S108, when the level determination unit 18a determines that the current detection level detected by the detection unit 17b is higher than the detection level when the previous phase correction value is set ( YES in step S108), the determination result is stored in the storage unit 18b. At this time, the signal level of the synthesized signal becomes the minimum value when the phase difference between the input signal and the output signal is larger than 180 degrees as shown by the broken line in FIG. For this reason, the control unit 18c delays the phase correction value set in the phase variable unit 18d by one (step S114). Further, the detection unit 17b detects the combined signal level at this time (step S115). Further, the level determination unit 18a determines the magnitude relationship between the current detection level detected by the detection unit 17b and the detection level when the previous phase correction value is set (step S116). If the level determination unit 18a determines that the current detection level detected by the detection unit 17b is not greater than the detection level when the previous phase correction value is set (step S116). NO), the determination result is stored in the storage unit 18b. Then, it returns to step S114 again and repeats the above process.

When the level determination unit 18a determines in step S116 that the current detection level detected by the detection unit 17b is higher than the detection level when the previous phase correction value is set. (YES in step S116) means that the phase difference between the input signal and the output signal is smaller than 180 degrees. For this reason, the level determination unit 18a stores the phase correction value set immediately before in the storage unit 18b (step S112). Finally, the control unit 18c sets the phase correction value stored in the storage unit 18b in the phase variable unit 18d (step S113). As a result, the phase shift is corrected and no phase shift occurs.
This completes all the processes of the phase adjustment method using the phase shift correction method.

(Summary of Phase Variable Amplifying Circuit 10 Using Phase Shift Correction Circuit 12)
As described above, in the phase variable amplifier circuit 10 using the phase shift correction circuit 12 according to the first embodiment, the actual phase difference between the input signal and the output signal of the phase variable amplifier 11, By converting the phase shift occurring between the target phase difference and the signal level of the synthesized signal, the phase shift can be easily detected.
Further, in the phase variable amplifier circuit 10, the phase variable unit 18d adjusts the actual phase difference between the input signal and the output signal so that the signal level of the combined signal becomes the minimum value. The deviation can be easily corrected.

(Second Embodiment)
(Configuration of phase variable amplifier circuit 20 using phase shift correction circuit 21)
Next, the configuration of the phase variable amplifier circuit 20 using the phase shift correction circuit 21 according to the second embodiment will be described with reference to FIG.
The phase variable amplifier circuit 20 shown in FIG. 5 is configured to include each unit included in the phase variable amplifier circuit 10 shown in FIG. However, in the phase variable amplifier circuit 20, the circuit configuration of the phase shift correction unit 22 in the phase shift correction circuit 21 is different from the circuit configuration of the phase shift correction unit 18 of the phase shift correction circuit 12. The phase shift correction unit 22 includes an addition unit 18e instead of the phase variable unit 18d included in the phase shift correction unit 18.
The adder 18e directly adds the phase correction value output from the controller 18c to the phase value indicated by the phase control signal input to the phase variable amplifier 11, and then outputs a phase control signal indicating the phase value. To do.

(Processing flow of phase adjustment method using phase shift correction method)
The difference between the phase variable amplifier circuit 20 using the phase shift correction circuit 21 and the phase variable amplifier circuit 10 using the phase shift correction circuit 12 shown in FIG. 1 is only in the components for correcting the phase. . Therefore, also in the phase variable amplifier circuit 20 using the phase shift correction circuit 21, the process flow of the phase shift correction method is substantially the same as that of the phase variable amplifier circuit 10 using the phase shift correction circuit 12.

(Summary of phase variable amplifier circuit 20 using phase shift correction circuit 21)
As described above, in the phase variable amplifier circuit 20 using the phase shift correction circuit 21 according to the second embodiment, the phase variable unit 18d is not used when correcting the phase shift. However, also in the phase variable amplifier circuit 20 using the phase shift correction circuit 21, the phase shift can be easily detected by converting the phase shift into the signal level of the synthesized signal, as in the phase variable amplifier circuit 10. Can do. Therefore, if the phase correction value output from the control unit 18 c is directly added to the phase value indicated by the phase control signal input to the phase variable amplifier 11, the phase variable amplification circuit 20 using the phase shift correction circuit 21. In this case, the phase shift can be easily corrected.

(Summary of phase variable amplifier circuit using phase shift correction circuit according to each embodiment)
In the phase variable amplifier circuit using the phase shift correction circuit according to each embodiment described above, the phase difference between the input signal and the output signal of the phase variable amplifier 11 which is the circuit to be corrected is just 180 degrees. Sometimes, the phase difference between the input signal and the output signal of the phase variable amplifier 11 and its target level are applied by applying the fact that the signal level of the synthesized signal obtained by synthesizing the input signal and the output signal becomes the minimum value. A phase shift occurring between the phase difference and the phase difference is detected and the phase shift is corrected.

Specifically, the phase variable amplifier circuit converts the phase difference between the input signal and the output signal into a composite signal, and the phase level generated between the actual phase difference and the original phase difference depends on the signal level. The deviation can be easily detected. Along with this, the phase variable amplifier circuit changes the phase difference between the input signal and the output signal so that the signal level of the synthesized signal becomes the minimum value, thereby making the difference between the actual phase difference and the original phase difference. The generated phase shift can be easily corrected.
As a result, the phase variable amplifier circuit suppresses the phase shift even in the case where the phase characteristics and phase of the phase variable amplifier are variable and the phase error inherent in manufacturing is included. be able to. For this reason, the phase variable amplifier circuit can output an output signal having an accurate phase capable of canceling the noise wave.

  Phase shift correction circuit and phase variable amplification to output an accurate phase output signal that can optimally cancel the noise wave included in the signal wave in electronic devices such as mobile phones equipped with a noise cancellation function It can be used as a circuit, a phase shift correction method, and a phase adjustment method.

DESCRIPTION OF SYMBOLS 10, 20 Variable phase amplifier circuit 11 Phase variable amplifier 12, 21 Phase shift correction circuit 13 Input signal input terminal 14 Gain control signal input terminal 15 Phase control signal input terminal 16 Output signal output terminal 17 Phase shift detection unit 17a Synthesis unit 17b Detection Units 18, 22 phase shift correction unit 18a level determination unit 18b storage unit 18c control unit 18d phase variable unit 18e addition unit

Claims (16)

A phase shift detector that detects a signal level of a combined signal obtained by combining the input signal and the output signal of the circuit to be corrected;
Based on the change in the signal level of the composite signal detected by the phase shift detector, it occurs between the phase difference between the input signal and the output signal and the target phase difference of 180 °. A phase shift correction unit that corrects a phase shift that is
A phase shift correction circuit comprising: A variable phase amplifier that changes the gain and phase between the input signal and the output signal;
A phase shift detector that detects a signal level of a combined signal obtained by combining the input signal and the output signal;
Based on the change in the signal level of the composite signal detected by the phase shift detector, it occurs between the phase difference between the input signal and the output signal and the target phase difference of 180 °. A phase shift correction unit that corrects a phase shift that is
A phase variable amplifier circuit comprising:   3. The phase variable according to claim 2, wherein the phase shift correction unit corrects the phase shift based on a signal level of a composite signal with respect to a phase difference between the input signal and the output signal. Amplification circuit. The phase shift detector is
A combining unit that combines the input signal and the output signal, and outputs the combined signal as the combined signal;
A detecting unit for detecting a signal level of the combined signal output by the combining unit;
With
The phase shift correction unit is
A control unit that outputs a phase correction value indicating a correction amount when correcting the phase shift;
A level determination unit that determines whether the signal level of the combined signal detected by the detection unit is greater than the signal level of the combined signal when the previous phase correction value is set;
With
The control unit outputs the phase correction value until the signal level of the combined signal detected by the detection unit becomes larger than the signal level of the combined signal when the previous phase correction value is set. The phase variable amplifier circuit according to claim 3, wherein the phase shift is advanced or delayed.   5. The phase shift correction unit according to claim 4, wherein the phase shift correction unit includes a phase variable unit capable of changing a phase of the output signal based on a phase correction value output by the control unit. Phase variable amplifier circuit.   5. The phase shift correction unit includes an addition unit that adds a phase correction value output from the control unit to a phase control signal for controlling the phase of the phase variable amplification unit. The phase variable amplifier circuit according to 1.   The phase shift correction unit, at least when the signal level of the composite signal detected by the detection unit is greater than the signal level of the composite signal when the previous phase correction value is set, The phase variable amplifier circuit according to claim 5, further comprising a storage unit that stores the phase correction value output by the control unit. A phase shift detection step in which the phase shift detection unit detects the signal level of the combined signal obtained by combining the input signal and the output signal of the circuit to be corrected;
Based on the signal level of the combined signal detected in the phase shift detection step, the phase shift correction unit, and the phase difference between the input signal and the output signal and the target phase difference of 180 ° A phase shift correction method comprising a phase shift correction step for correcting a phase shift occurring during the period. Before executing the phase shift detection step,
The phase shift correction method according to claim 8, wherein the phase shift correction unit includes a phase initialization step in which the correction unit is in an initial state. A variable phase amplification step in which the variable phase amplification unit changes the gain and phase between the input signal and the output signal;
A phase shift detection step in which a phase shift detection unit detects a signal level of a combined signal obtained by combining the input signal and the output signal;
The phase shift correction unit is a phase difference between the input signal and the output signal based on a change in the signal level of the combined signal detected by the phase shift detection step, and a target phase difference 180. phase adjustment method characterized by having a phase shift correction step of correcting the in which the phase shift occurs between the °.   In the phase shift correction step, the phase shift correction unit corrects the phase shift based on a signal level of a composite signal with respect to a phase difference between the input signal and the output signal. Item 11. The phase adjustment method according to Item 10. The phase shift detection step includes
A synthesizing unit that synthesizes the input signal and the output signal, and outputs the synthesized signal as the synthesized signal;
The detection unit includes a detection step of detecting a signal level of the combined signal output in the combining step;
The phase shift correction step includes
A control step for outputting a phase correction value indicating a correction amount when the control unit corrects the phase shift;
A level determination step in which the level determination unit determines whether the signal level of the combined signal detected in the detection step is higher than the signal level of the combined signal when the previous phase correction value is set Have
In the control step, until the control unit detects that the signal level of the combined signal detected in the detection step is higher than the signal level of the combined signal when the previous phase correction value is set, The phase adjustment method according to claim 11, wherein the phase correction value to be output is advanced or delayed.   The phase shift correction step includes a phase variable step in which a phase variable unit changes a phase of the output signal based on the phase correction value output in the control step. Phase adjustment method.   The phase shift correction step includes an addition step in which the addition unit adds the phase correction value output in the control step to a phase control signal for controlling the phase of the phase variable amplification unit. The phase adjustment method according to claim 12.   In the phase shift correction step, at least the signal level of the composite signal detected in the detection step is greater than the signal level of the composite signal when the previous phase correction value is set. 15. The phase adjustment method according to claim 13, further comprising a storage step of storing the phase correction value output in the control step when the time is reached. Before executing the phase shift detection step,
A gain control signal input step in which the phase variable amplifier inputs a gain control signal for setting the gain between the input signal and the output signal to 0;
A phase control signal input step in which the phase variable amplification unit inputs a phase control signal for making the phase between the input signal and the output signal opposite to each other;
The phase adjustment method according to claim 10, wherein the phase shift correction unit includes a phase initialization step in which the self correction unit is in an initial state.

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