A fast and high-precision tuning method for a spectrum analyzer YTF

Abstract

The application provides a YTF fast high-precision tuning method of a spectrum analyzer, and comprises the following steps: S1, judging the state of the spectrum analyzer, if the spectrum analyzer is in a point frequency state, executing S2, if the spectrum analyzer is in a fast scanning state, executing S3; S2, when the YTF tuning point changes, presetting the YTF tuning DAC value to a tuning maximum value; through delay, stabilizing the YTF magnetic field, and setting the YTF tuning DAC value to the position of the current tuning point; S3, when the spectrum analyzer scanning state changes, presetting the YTF tuning DAC value to the tuning maximum value, through delay, starting from a fixed state every time scanning; setting the tuning DAC value to the starting DAC of the current wave band; starting from the wave band starting DAC, accumulating the tuning DAC value to the current tuning point; starting the normal scanning of the whole machine YTF. The YTF fast high-precision tuning method of the spectrum analyzer can effectively improve the tuning precision of the YTF by stabilizing the YTF magnetic field and reducing the influence of hysteresis on the YTF tuning precision.

Description

Technical Field

[0001] This invention relates to the field of electronic measuring instrument technology, specifically to a fast and high-precision tuning method for a YTF spectrum analyzer. Background Technology

[0002] YIG tunable bandpass filters, or YTFs for short, are widely used in the RF front-end of spectrum analyzers. They are tunable bandpass filters made of magnetic materials. Their hysteresis characteristics cause the frequency response to always lag behind the tuning current during spectrum analyzer tuning, severely impacting the tuning speed and accuracy of the YTF. The tuning speed, tuning accuracy, and tracking stability of the YTF significantly affect the overall scan speed and signal amplitude stability of the analyzer. Fast and high-precision scanning is a key performance characteristic of spectrum analyzers, affecting user testing efficiency. With the development of automated testing, users have increasingly higher requirements for the scan speed and amplitude stability of spectrum analyzers.

[0003] The existing technical solution is the YTF demagnetization scheme. The flowchart of this scheme is as follows: Figure 1 As shown: When tuning point A changes to tuning point B, demagnetization is performed first, and then the tuning DAC for tuning point B is set. The main purpose of this technical solution is to eliminate the magnetic field of the YTF. When the frequency or state of the spectrum analyzer changes, a switch is used to ground one end of the YTF drive circuit, allowing the current on the YTF to be discharged from the ground, thus keeping the state of the YTF consistent in each case and achieving tuning of the YTF under different states.

[0004] Figure 2 For the demagnetization process of this scheme, let M be the tuning voltage input point and N be the tuning current output point, with switches K1 and K2 set between M and N. Switching from state A to state B, assume the tuning voltage corresponding to state A is U. A The tuning voltage corresponding to state B is U. B First, change the tuning voltage at point M by U. A Change to U B Then, K1 is opened while K2 is closed, and this is called state C. A duration is set for state C. In state C, because switch K2 is closed and K1 is open, the drive applied to the YIG filter is zero. The residual magnetism of the YIG filter will gradually disappear or remain at a very small constant during state C; this process is called demagnetization. After demagnetization, the system immediately returns to state B, at which point switch K2 is open and K1 is closed. Thus, regardless of states A or B, the actual tuning path always jumps from state C to state B, and is independent of state A. The duration of state C is called the demagnetization time.

[0005] The tuning accuracy of the above-mentioned technical solution mainly depends on the demagnetization time of the YTF. If the demagnetization time is too short, the demagnetization effect will be poor, and the tuning accuracy will be very poor. If the existing technical solution has a demagnetization time that is too long, the YTF retracement waiting time will be too long, which will seriously affect the scanning speed of the spectrum analyzer. Summary of the Invention

[0006] To address the aforementioned problems, this invention provides a fast and high-precision tuning method for a YTF spectrum analyzer. This method is rationally designed, overcomes the shortcomings of existing technologies, and achieves excellent results.

[0007] To achieve the purpose of the invention, the following technical solution is adopted:

[0008] A fast and high-precision tuning method for a YTF spectrum analyzer includes the following steps:

[0009] S1. Determine the state of the spectrum analyzer. If the spectrum analyzer is in the spot frequency state, execute S2. If the spectrum analyzer is in the fast scan state, execute S3.

[0010] S2. When the YTF tuning point changes, the process includes the following sub-steps: S21. First, preset the YTF tuning DAC value to the maximum tuning value; S22. Stabilize the YTF magnetic field by delaying, i.e., waiting for a period of time at the maximum tuning value; S23. Finally, set the YTF tuning DAC value to the current tuning point position through software and hardware program settings.

[0011] S3. When the spectrum analyzer scanning state changes, the following sub-steps are included: S31. First, preset the YTF tuning DAC value to the maximum tuning value and wait for a period of time at the maximum tuning value to stabilize the YTF magnetic field, so that each scan starts from a relatively fixed magnetic field environment; S32. Set the tuning DAC value to the starting DAC of the current band; S33. Through software and hardware settings, the tuning DAC value is accumulated from the starting DAC of the band until the scan start point; S34. Start the normal scanning of the entire YTF.

[0012] Furthermore, the YTF tuning DAC value is preset to the maximum tuning value, so that the YTF tuning current is maximized and the magnetic field is strongest.

[0013] Furthermore, in S3, the YTF tuned DAC is accumulated at a constant speed to the scan start point according to the current scan speed.

[0014] Furthermore, the spectrum analyzer divides the received signal into n bands, with each band corresponding to an initial DAC value.

[0015] The beneficial effects of this invention are:

[0016] The proposed method for fast and high-precision YTF tuning in a spectrum analyzer reduces the impact of hysteresis on YTF tuning accuracy by stabilizing the YTF magnetic field during point-frequency operation. It also effectively solves the problem of unstable amplitude at the band start point during rapid scanning, thus improving YTF tuning accuracy. Compared with YTF demagnetization schemes, this invention significantly reduces the YTF retrace time during spectrum analyzer scanning, thereby increasing the spectrum analyzer's scanning speed. Attached Figure Description

[0017] Figure 1 The flowchart below shows the YTF demagnetization scheme in the background technology.

[0018] Figure 2 The diagram below shows the demagnetization circuit schematic of the YTF demagnetization scheme in the background technology.

[0019] Figure 3 This is a flowchart of the YTF point frequency preset method in this invention;

[0020] Figure 4 This is a schematic diagram of the YTF point frequency preset method in this invention;

[0021] Figure 5 This is a flowchart of the YTF fast scan preset method in this invention; Detailed Implementation

[0022] The specific embodiments of the present invention will be further described below with reference to specific examples:

[0023] A fast and high-precision tuning method for a YTF spectrum analyzer includes the following steps:

[0024] S1. Determine the state of the spectrum analyzer. If the spectrum analyzer is in the spot frequency state, execute S2. If the spectrum analyzer is in the fast scan state, execute S3.

[0025] S2. When the YTF tuning point changes, the process includes the following sub-steps: S21. First, preset the YTF tuning DAC value to the maximum tuning value; S22. Stabilize the YTF magnetic field by delaying, i.e., waiting for a period of time at the maximum tuning value; S23. Set the YTF tuning DAC value to the current tuning point position through software and hardware program settings.

[0026] The YTF module is affected by hysteresis. When returning to the same tuning frequency via different paths, although the tuning current remains unchanged, the center frequency position of the YTF shifts due to the path difference. Even though the tuning current is the same in states A and B, the different tuning paths cause the tuning center point of the YTF module to shift, resulting in inconsistent amplitudes between the two tuning points. Reducing the impact of hysteresis on the tuning accuracy of the YTF is a key factor in achieving high-precision YTF tuning.

[0027] Since the tuning accuracy of a YTF module is related to the path process, assuming that the YTF module traverses the same path before each tuning, the hysteresis effect of the YTF module remains relatively consistent during each tuning, effectively reducing the impact of different magnetic paths and thus minimizing the influence of hysteresis on the YTF tuning accuracy. Based on this idea and combined with the magnetic characteristics of the YTF module, the above-mentioned YTF point frequency preset design method is proposed, such as... Figure 3 As shown.

[0028] Because the higher the frequency of the YTF, the larger the tuning DAC, and the stronger the magnetic field of the YTF, such as... Figure 4 As shown, when the tuning point changes from tuning point A to tuning point B, the YTF tuning point is first preset to its maximum value, and after a delay, the tuning DAC is set to the tuning value of tuning point B. Through this process, regardless of how the tuning point changes before the change, the final change is always from the maximum value of the YTF tuning DAC to tuning point B, ensuring that the magnetic field change to tuning point B is the same each time. This method effectively reduces the impact of hysteresis on the tuning accuracy of the YTF, ensuring that the shape of the YTF remains essentially unchanged regardless of the state from which it returns, as long as the tuning drive current remains constant. This effectively improves the tuning accuracy of the YTF, thereby achieving high-precision tuning of the YTF.

[0029] S3. When the spectrum analyzer scanning state changes, the following sub-steps are included: S31. Preset the YTF tuning DAC value to the maximum tuning value. At this time, the YTF tuning current is the largest and the magnetic field is the strongest. Wait for a period of time at the maximum tuning value to stabilize the YTF magnetic field, so that the YTF starts from a relatively fixed magnetic field environment each time it scans; S32. Set the tuning DAC value to the starting DAC of the current band. In this embodiment, 8GHz to 50GHz is divided into 4 bands: 8GHz to 18GHz, 18GHz to 27GHz, 27GHz to 40GHz, and 40GHz to 50GHz. Each band corresponds to a starting DAC value; S33. Through software and hardware settings, the tuning DAC value is accumulated from the starting DAC of the band until the current tuning point. Its function is to make the YTF tuning DAC accumulate at a uniform speed to the scanning start point according to the current scanning speed, so that the state of each frequency point at the scanning start end tends to be stable; S34. Start the normal scanning of the entire YTF.

[0030] To improve the amplitude accuracy of YTF in fast scanning mode, based on the YTF point frequency preset method proposed in S2, and through extensive experimental verification, the above-mentioned YTF fast scanning preset method is proposed, such as... Figure 5 As shown, this effectively solves the problem of unstable amplitude at the starting point of the band during rapid scanning, thus achieving high-precision tuning during YTF scanning.

[0031] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A fast and high-precision tuning method for a YTF spectrum analyzer, characterized in that, Includes the following steps: S1. Determine the state of the spectrum analyzer. If the spectrum analyzer is in the spot frequency state, execute S2. If the spectrum analyzer is in the fast scan state, execute S3. S2. When the YTF tuning point changes, the process includes the following sub-steps: S21. First, preset the YTF tuning DAC value to the maximum tuning value; S22. Stabilize the YTF magnetic field by delaying, i.e., waiting for a period of time at the maximum tuning value; S23. Finally, set the YTF tuning DAC value to the current tuning point position through software and hardware program settings. S3. When the spectrum analyzer scanning state changes, the following sub-steps are included: S31. First, preset the YTF tuning DAC value to the maximum tuning value and wait for a period of time at the maximum tuning value to stabilize the YTF magnetic field, so that the YTF starts from a relatively fixed magnetic field environment each time it scans; S32. Set the tuning DAC value to the starting DAC of the current band; S33. Through software and hardware settings, the tuning DAC value is accumulated from the starting DAC of the band until the scanning start point; S34. Start the normal scanning of the entire YTF.

2. The method for fast and high-precision tuning of a YTF spectrum analyzer according to claim 1, characterized in that, The YTF tuning DAC value is preset to the maximum tuning value, so that the YTF tuning current is maximized and the magnetic field is strongest.

3. The method for fast and high-precision tuning of a YTF spectrum analyzer according to claim 1, characterized in that, In step S3, the YTF tuned DAC accumulates at a constant speed to the scan start point according to the current scan speed.

4. The method for fast and high-precision tuning of a YTF spectrum analyzer according to claim 1, characterized in that, The spectrum analyzer divides the received signal into n bands, and each band corresponds to a starting DAC value.

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