Compensation system for batch test of G sensitivity of quartz crystal oscillator

Abstract

The invention discloses a batch test compensation system for G sensitivity of a quartz crystal oscillator, and belongs to the technical field of electronics. Comprising a three-axis orthogonal rotation test frame and an upper computer. The triaxial orthogonal rotation testing frame is provided with a testing plate serving as a crystal oscillator carrier, and the testing plate realizes the functions of orientation, pitching and polarization rotation through the triaxial orthogonal rotation testing frame; the rotation rate and the current real-time rotation angle of the three-axis orthogonal rotation test frame can be output; the upper computer performs algorithm fitting calculation on the acquired data, calculates a linear relation between crystal oscillator frequency change and acceleration change, and obtains a compensation function based on three axial acceleration values # imgabs0 #; and the upper computer acquires data and writes an obtained compensation function into a register in the crystal oscillator. The frequency offset of the crystal oscillator is corrected through the digital compensation technology, the test compensation process is simple and convenient, and batch production can be achieved.

Description

Technical Field

[0001] The invention relates to the field of electronic technology, and in particular to a batch test compensation system for G sensitivity of a quartz crystal oscillator. Background Art

[0002] The quartz crystal oscillator (hereinafter referred to as "crystal") is the core component of the frequency reference. Its extremely high frequency stability makes it the reference frequency source for various communication systems and radio equipment, ensuring the accuracy of communication and signal processing. However, due to its own physical characteristics, the quartz crystal oscillator is easily affected by external shocks, vibrations, or acceleration caused by falls in different directions, which causes the frequency stability of the quartz crystal oscillator output to deteriorate.

[0003] In the prior art, the quartz crystal oscillator is only subjected to vibration reduction or its stability is enhanced, thereby reducing the intensity of the crystal oscillator being subjected to shock, vibration and falling in different directions, without correcting the deviation of the crystal oscillator frequency accuracy. Summary of the invention

[0004] Based on the above-mentioned demand for high frequency accuracy of crystal oscillators, the present invention provides a batch test and compensation system for the G sensitivity of quartz crystal oscillators. The system corrects the frequency deviation of the crystal oscillator through digital compensation technology. The test and compensation process is simple and can be mass-produced.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A batch test compensation system for G sensitivity of a quartz crystal oscillator, comprising a three-axis orthogonal rotation test frame and a host computer;

[0007] The three-axis orthogonal rotation test frame is provided with a test board as a crystal oscillator carrier, and the test board is used by the three-axis orthogonal rotation test frame to realize the functions of azimuth, pitch and polarization rotation; and can output the rotation rate and current real-time rotation angle of the three-axis orthogonal rotation test frame;

[0008] The host computer performs algorithm fitting calculation on the collected data, calculates the linear relationship between the crystal oscillator frequency change and the acceleration change, and obtains the linear relationship between the crystal oscillator frequency change and the acceleration change based on the , , Compensation function for three axial acceleration values;

[0009] The crystal oscillator under test and the three-axis orthogonal rotation test frame are both connected to the upper computer circuit, and the upper computer collects data, and the upper computer writes the obtained compensation function into the register inside the crystal oscillator.

[0010] Furthermore, the specific process of the host computer calculating the compensation function is as follows: the host computer collects the rotation angle and acceleration value output by the crystal oscillator itself and the rotation rate and current real-time rotation angle of the three-axis orthogonal rotation test frame;

[0011] According to the Cartesian coordinate system principle, the crystal oscillator is defined as orthogonal , , The direction of the axis;

[0012] When a certain axis of the test board flips from facing away from the center of the earth to pointing toward the center of the earth, the acceleration to which the crystal oscillator is subjected rotates from -g to +g, and the frequency generated at this time also changes accordingly;

[0013] Calculate the frequency relative to acceleration using the least squares method Rate of change , the rate of change of each axis frequency relative to acceleration is as follows:

[0014]

[0015]

[0016]

[0017] in , and is the crystal frequency measured when the quartz crystal oscillator rotates around the x-axis, y-axis, and z-axis, , and It is the measurement value of the acceleration sensor inside the crystal oscillator when the quartz crystal oscillator rotates around the x-axis, y-axis and z-axis. , and is the calculated linear relationship between the change in crystal frequency and the change in acceleration;

[0018] When the crystal oscillator changes its spatial position, its output frequency accuracy remains unchanged; at different spatial positions, the crystal oscillator measures its own acceleration values ​​in each axis through the internal acceleration sensor. ; In order to compensate for the frequency deviation caused by the acceleration in this direction, the frequency deviation needs to be compensated. The compensation amount for each axis and the total compensation amount are as follows:

[0019]

[0020]

[0021]

[0022]

[0023] in , and is the real-time value of acceleration of each axis collected in the crystal oscillator. , and is the frequency compensation value required for each axis, The total amount of compensation for the crystal oscillator to compensate for gravity acceleration;

[0024] The crystal oscillator has a built-in voltage frequency modulation function, which can compensate the frequency Converted into a voltage adjustment value, the crystal oscillator frequency is compensated in real time through the built-in DAC of the crystal oscillator; the ratio of DAC output voltage to frequency adjustment is Finally, the function for compensating G sensitivity in the crystal oscillator is:

[0025]

[0026] in To compensate the crystal frequency in real time, the voltage-controlled voltage output is used. When the spatial position of the crystal changes, The output of the value ensures that the crystal frequency remains unchanged. is a constant, , and This is an inherent property of every crystal oscillator.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] 1. The system has multi-channel batch testing capabilities.

[0029] 2. Data testing and collection are completed through the host computer, which improves the efficiency and accuracy of the test.

[0030] 3. This system compensates for the frequency deviation of the crystal oscillator caused by acceleration changes. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the three-dimensional structure of a three-axis orthogonal rotation test stand according to an embodiment of the present invention;

[0032] Figure 2 It is a block diagram of the data acquisition principle of an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of writing a compensation function into a crystal oscillator register according to an embodiment of the present invention;

[0034] Figure 4 Schematic diagram of orthogonal x, y, and z axes of a crystal oscillator according to an embodiment of the present invention.

[0035] Figure 5This is a curve diagram of the change of the crystal oscillator frequency f during the process of the x-axis rotating from -g to +g in an embodiment of the present invention;

[0036] Figure 6 This is a curve diagram of the change of the crystal oscillator frequency f during the process of the y-axis rotating from -g to +g in an embodiment of the present invention;

[0037] Figure 7 This is a curve diagram of the change of the crystal oscillator frequency f during the process of the z-axis rotating from -g to +g in an embodiment of the present invention;

[0038] Figure 8 This is a curve diagram of the change of the crystal oscillator frequency f during the process of the z-axis rotating from -g to +g after compensation in an embodiment of the present invention. DETAILED DESCRIPTION

[0039] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0040] This embodiment discloses a system for batch testing and compensating the G sensitivity of a quartz crystal oscillator, including: a quartz crystal oscillator with integrated acceleration detection and frequency adjustment functions, a three-axis orthogonal rotation test frame for rotating the quartz crystal oscillator, and an upper computer for implementing data acquisition and data compensation algorithms.

[0041] Three-axis orthogonal rotation test frame, each axis can rotate continuously independently, and has communication function, which can enable the crystal oscillator to communicate with the host computer, and has multi-channel batch testing capabilities. For details, refer to Figure 1 .

[0042] The quartz crystal oscillator under test has a three-axis acceleration sensor, a digital-to-analog converter (DAC) for adjusting the crystal frequency, and a communication interface integrated inside. When the quartz crystal oscillator is tested on a three-axis orthogonal rotation test frame, the crystal oscillator detects its own angle and acceleration value in real time.

[0043] The host computer receives the acceleration value data in the crystal oscillator and receives its frequency data through the frequency meter. The host computer obtains the relationship between frequency change and acceleration change through the fitting algorithm. Figure 2 , the host computer stores the relationship between the crystal oscillator frequency change and the acceleration change in the crystal oscillator register. For details, refer to Figure 3 ,;When the crystal oscillator acceleration changes, the microcontroller in the crystal oscillator adjusts the DAC voltage output to compensate for the frequency offset based on the relationship between the crystal oscillator frequency and acceleration, thereby ensuring the accuracy of the crystal oscillator output frequency.

[0044] The host computer compensation algorithm mainly adopts the least square method. According to the Cartesian coordinate system principle, the quartz crystal oscillator orthogonal , , The direction of the axis, see Figure 4When one axis of the three-axis orthogonal rotating test frame flips from facing away from the center of the earth to pointing toward the center of the earth, the acceleration of the crystal oscillator rotates from -g to +g, and the frequency generated at this time also changes accordingly. The frequency relative to the acceleration can be calculated by the least squares method. Rate of change , the rate of change of each axis frequency relative to acceleration is as follows:

[0045]

[0046]

[0047]

[0048] in , and is the crystal frequency measured when the quartz crystal oscillator rotates around the x-axis, y-axis, and z-axis, , and It is the measurement value of the acceleration sensor inside the crystal oscillator when the quartz crystal oscillator rotates around the x-axis, y-axis and z-axis. , and is the calculated linear relationship between the change in crystal frequency and the change in acceleration.

[0049] Figures 5 to 7 It is the crystal frequency collected by the test system and the acceleration value collected in the crystal oscillator when the quartz crystal oscillator rotates around the x-axis, y-axis and z-axis.

[0050] When the crystal oscillator changes its spatial position, its output frequency accuracy remains unchanged. At different spatial positions, the crystal oscillator measures its own acceleration values ​​in each axis through the internal acceleration sensor. In order to compensate for the frequency deviation caused by the acceleration in this direction, the frequency deviation needs to be compensated. The compensation amount for each axis and the total compensation amount are as follows:

[0051]

[0052]

[0053]

[0054]

[0055] in , and is the real-time value of acceleration of each axis collected in the crystal oscillator. , and is the frequency compensation value required for each axis, The total amount of compensation for gravity acceleration by the crystal oscillator.

[0056] The quartz crystal oscillator has a built-in voltage frequency modulation function, which can compensate the frequency The DAC built into the crystal oscillator is used to convert the voltage into a voltage adjustment value, and the crystal oscillator frequency is compensated in real time. The ratio of the DAC output voltage to the frequency adjustment is Finally, the function for compensating G sensitivity in the crystal oscillator is:

[0057]

[0058] in To compensate the crystal frequency in real time, the voltage-controlled voltage output is used. When the spatial position of the crystal changes, The output of the value ensures that the crystal frequency remains unchanged. is a constant, , and It is a unique property of each crystal oscillator. The calculated compensation coefficient needs to be written into the internal register of the crystal oscillator through the host computer.

[0059] Figure 8 It is the relationship between the crystal frequency collected by the test system and the acceleration value collected in the crystal when the compensated quartz crystal oscillator rotates around the z-axis. As can be seen from the figure, after frequency compensation according to the algorithm, when the acceleration of the crystal changes, the output frequency accuracy of the crystal remains unchanged.

[0060] The interface of the host computer includes communication interface settings, test channel selection, crystal oscillator position and acceleration sampling, frequency testing, compensation coefficient calculation and writing of coefficients into crystal oscillator registers, etc.

[0061] The system of this embodiment can realize the test of multiple devices at one time, and no longer needs to repeat the test of a single device. Data measurement, calculation and writing of compensation values ​​are all realized by the upper computer software.

[0062] The present invention is not limited to the above embodiments, but may include more other equivalent embodiments without departing from the concept of the present invention. The scope of the present invention is determined by the scope of the appended claims.

Claims

1. A batch test compensation system for quartz crystal oscillator G sensitivity, characterized in that: Including three-axis orthogonal rotation test frame and host computer; The three-axis orthogonal rotation test frame is provided with a test board as a crystal oscillator carrier, and the test board is used by the three-axis orthogonal rotation test frame to realize the functions of azimuth, pitch and polarization rotation; and can output the rotation rate and current real-time rotation angle of the three-axis orthogonal rotation test frame; The host computer performs algorithm fitting calculation on the collected data, calculates the linear relationship between the crystal oscillator frequency change and the acceleration change, and obtains the linear relationship between the crystal oscillator frequency change and the acceleration change based on the Compensation function for three axial acceleration values; The crystal oscillator under test and the three-axis orthogonal rotation test frame are both connected to the upper computer circuit, and the upper computer collects data, and the upper computer writes the obtained compensation function into the register inside the crystal oscillator.

2. A batch test and compensation system for G sensitivity of quartz crystal oscillators according to claim 1, characterized in that: The specific process of the host computer calculating the compensation function is as follows: the host computer collects the rotation angle and acceleration value output by the crystal oscillator itself and the rotation rate and current real-time rotation angle of the three-axis orthogonal rotation test frame; According to the Cartesian coordinate system principle, the crystal oscillator is defined as orthogonal The direction of the axis; When a certain axis of the test board flips from facing away from the center of the earth to pointing toward the center of the earth, the acceleration to which the crystal oscillator is subjected rotates from -g to +g, and the frequency generated at this time also changes accordingly; Calculate the frequency relative to acceleration using the least squares method Rate of change , the rate of change of each axis frequency relative to acceleration is as follows: ； ； ； in , and is the crystal frequency measured when the quartz crystal oscillator rotates around the x-axis, y-axis, and z-axis, , and It is the measurement value of the acceleration sensor inside the crystal oscillator when the quartz crystal oscillator rotates around the x-axis, y-axis and z-axis. , and is the calculated linear relationship between the change in crystal frequency and the change in acceleration; When the crystal oscillator changes its spatial position, its output frequency accuracy remains unchanged; at different spatial positions, the crystal oscillator measures its own acceleration values ​​in each axis through the internal acceleration sensor. ; In order to compensate for the frequency deviation caused by the acceleration in this direction, the frequency deviation needs to be compensated. The compensation amount for each axis and the total compensation amount are as follows: ； ； ； ； in , and is the real-time value of acceleration of each axis collected in the crystal oscillator. , and is the frequency compensation value required for each axis, The total amount of compensation for the crystal oscillator to compensate for gravity acceleration; The crystal oscillator has a built-in voltage frequency modulation function, which can compensate the frequency Converted into a voltage adjustment value, the crystal oscillator frequency is compensated in real time through the built-in DAC of the crystal oscillator; the ratio of DAC output voltage to frequency adjustment is Finally, the function for compensating G sensitivity in the crystal oscillator is: ； in To compensate the crystal frequency in real time, the voltage-controlled voltage output is used. When the spatial position of the crystal changes, The output of the value ensures that the crystal frequency remains unchanged. is a constant, , and This is an inherent property of every crystal oscillator.

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