Circulator power screening test system and method

Abstract

The invention discloses a circulator power screening test system and a circulator power screening test method, which relate to the transmitter technology, and can achieve the effect of scanning 360-degree phase through a method of connecting a sweep frequency signal source to an input port and connecting an open-circuit cable to an output port, thereby being capable of covering an interval with the maximum electric field intensity, simulating the worst working condition, and improving the reliability of the power screening test. The circulator with the ignition risk is effectively screened out; and the operation process is simplified, and the screening efficiency is improved.

Description

Technical Field

[0001] This invention relates to transmitters, and more specifically to a circulator power screening test system and method. Background Technology

[0002] Circulators play a crucial role in radio frequency front-ends. With the development of microwave technology, high-power applications place higher demands on the power capacity of circulators. Insufficient power capacity can easily lead to arcing and breakdown. In one case, the circulator of a certain product arced to zero. The final conclusion was that residual flux inside the circulator altered the field strength distribution, significantly increasing the maximum field strength, which in turn reduced the circulator's power capacity and resulted in breakdown and arcing.

[0003] In the subsequent processing, in order to mitigate risks and ensure the reliable operation of installed products, power screening tests need to be conducted on the installed channels. At the same time, to ensure the reliability of future products, circulator manufacturers are required to add power screening tests to the screening program.

[0004] Therefore, to ensure the reliability of the circulator, an efficient circulator power screening test system or method is needed. Summary of the Invention

[0005] To address the aforementioned problems, the purpose of this invention is to provide a circulator power screening test system and method. By connecting a sweep frequency signal source to the input port and an open-circuit cable to the output port, a 360-degree phase sweep can be achieved, thereby covering the range with the strongest electric field strength, simulating the worst operating conditions, and effectively screening out circulators with arcing risks. Furthermore, the operation process is simplified, and the screening efficiency is improved.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is: a circulator power screening test system, comprising: The signal source is connected to the input port of the circulator via a power amplifier module; The power amplifier module is located between the signal source and the circulator, and is used to amplify the low-power signal output from the signal source to a high-power signal and then output it. Test fixtures are used to secure the power amplifier module and circulator. The power supply provides the necessary power to the power amplifier module. The radio frequency cable connects to the output port of the circulator; Attenuator, used to attenuate power; A power meter is used to measure the power of radio frequency signals.

[0007] In a preferred embodiment of the present invention, the radio frequency cable is disconnected from the attenuator during screening and then reconnected after screening.

[0008] As a preferred embodiment of the present invention, the signal source is a frequency sweep signal source.

[0009] In a preferred embodiment of the present invention, the radio frequency cable is one meter in length.

[0010] The present invention also provides a method for circulator power screening test, using the above-described circulator power screening test system, comprising the following steps: Step 1: Start the frequency sweep signal source, set the frequency sweep range F1-F5, the output power P, and set the sweep period T, which is the time required to sweep from F1 to F5; Step 2: Determine the cable status. When the cable is open-circuited, i.e., the RF cable is disconnected from the attenuator, power on the cable to perform a power screening test. Step 3: After scanning the signal source frequency for two cycles, i.e. 2T, turn off the power; Step 4: Connect the cable to the attenuator, test the power, turn on the signal source and power supply to test, and determine if the power is normal; if normal, the circulator under test passes the screening, otherwise it fails the screening. Step 5: Replace with a new circulator and repeat the test process from Step 1 to Step 4 to continue screening the remaining circulators.

[0011] If the measured power is less than the output power of the power amplifier module, the power is considered normal; otherwise, it is considered abnormal.

[0012] Compared with the prior art, the technical solution adopted in this invention has the following beneficial effects: (1) Traditional power screening tests can only select a limited number of phase loads, which is difficult to cover the range with the largest electric field strength. However, this method can sweep through 360 degrees of phase, so it can simulate the worst working conditions and effectively screen out circulators with arcing risk.

[0013] (2) Traditional power screening methods require frequent disassembly and replacement of loads during operation; while this method only requires connecting an open-circuit RF cable, which simplifies the operation process of power screening test, reduces the difficulty of operation, and improves the test efficiency. Attached Figure Description

[0014] Figure 1 This is a block diagram of a circulator power screening test system provided in this embodiment.

[0015] Figure 2 This is a graph showing the change of the maximum field strength at the second port of the circulator provided in this embodiment as a function of phase when the frequency F3 is fixed.

[0016] Figure 3 This is a diagram showing the relationship between frequency and phase in a simulation of a one-meter-long open-circuit cable provided in this embodiment.

[0017] Figure 4 This is a simulation model diagram of the second port of the circulator connected to a one-meter-long coaxial cable provided in this embodiment.

[0018] Figure 5 This is a simulation diagram of the field strength versus frequency in the circulator second port connection cable provided in this embodiment. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Any modifications made to the technical solutions based on the technical concept proposed in this invention shall fall within the scope of protection of this invention.

[0020] like Figure 1 As shown, this embodiment provides a circulator power screening test system, comprising: The signal source is connected to the input port of the circulator via a power amplifier module; The power amplifier module is located between the signal source and the circulator, and is used to amplify the low-power signal output from the signal source to a high-power signal and then output it. Test fixtures are used to secure the power amplifier module and circulator. The power supply provides the necessary power to the power amplifier module. The radio frequency cable connects to the output port of the circulator; Attenuator, used to attenuate power; A power meter is used to measure the power of radio frequency signals.

[0021] Furthermore, the RF cable is disconnected from the attenuator during screening and reconnected after screening.

[0022] Furthermore, the signal source is a frequency sweep signal source.

[0023] Furthermore, the radio frequency cable is one meter in length.

[0024] This embodiment also provides a method for testing the power screening of a circulator, including the following steps: Step 1: Start the frequency sweep signal source, set the frequency sweep range F1-F5, the output power P, and set the sweep period T, which is the time required to sweep from F1 to F5; Step 2: Determine the cable status. When the cable is open-circuited, i.e., the RF cable is disconnected from the attenuator, power on the cable to perform a power screening test. Step 3: After scanning the signal source frequency for two cycles, i.e. 2T, turn off the power; Step 4: Connect the cable to the attenuator, test the power, turn on the signal source and power supply to test, and determine if the power is normal; if normal, the circulator under test passes the screening, otherwise it fails the screening. Step 5: Replace with a new circulator and repeat the test process from Step 1 to Step 4 to continue screening the remaining circulators.

[0025] The graph shows the variation of the maximum electric field strength of the circulator with phase at a fixed frequency of F3. Figure 2 As shown, through device simulation, under a fixed frequency, taking F3 frequency as an example, with an input power of XXW, total internal reflection at both ends, and a 360° phase sweep, the electric field strength at one phase point will always reach its maximum value, and the electric field strength in a portion of the phase interval will be very close to the maximum field strength. Therefore, for circulators with a risk of arcing, phase sweeping can trigger the arcing condition, thereby filtering out circulators prone to arcing.

[0026] like Figure 3 As shown, when simulating a 1-meter long coaxial cable alone, the insertion loss is close to 0.5dB and the dielectric constant is 2.2. With the end open, the cable becomes a load with a standing wave of about 20. In the frequency range of F1-F5, the phase changes by 1434 degrees, which is almost 4 cycles.

[0027] Depend on Figure 3 It can be seen that for a region where the phase continuously changes from 180° to -180°, if another continuous curve passes through it, there must be at least one intersecting frequency point, and possibly multiple intersecting points. Clearly, if within a certain frequency range, the load phase continuously changes by n×360 degrees, there must exist (n-1) continuous segments from 180° to -180°. By sweeping the frequency, there must be at least (n-1) frequency points where the field strength is strongest due to phase superposition. It can be seen that within three continuous segments from 180° to -180°, by sweeping the frequency, at least three frequency points are where the phase superposition field strength is maximum.

[0028] Establish a model ( Figure 4 Simulations were performed at 41 frequency points between F0 and F5 under the same input power of XXW to obtain the field strength at each frequency point, such as... Figure 5 As can be seen, frequency sweeping with an open-circuit cable yields a maximum electric field strength of approximately 2.2 × 10⁶ V / m; while... Figure 2 For simulation at a fixed F3 frequency, with a standing wave of 20 and phase shift, the maximum field strength is approximately 2.2 × 10⁶ V / m, which is not much different from the previous simulation.

[0029] Therefore, by using this method, the effect of fixed frequency phase shift can also be achieved through frequency sweeping. Based on the above analysis, the screening conditions for frequency sweeping and power testing of circulators connected to a 1-meter open-circuit cable are extremely stringent, which can effectively screen out circulators with arcing risks.

[0030] Although the present invention has been disclosed above with reference to preferred embodiments, the embodiments and accompanying drawings are not intended to limit the invention. Any person skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention, and these changes will also be within the protection scope of the invention. Therefore, the protection scope of the present invention should be defined by the scope of the claims of this application.

Claims

1. A circulator power screening test system, characterized by, It comprises: a signal source connected to the input port of the circulator through a power amplifier module; a power amplifier module arranged between the signal source and the circulator, used to amplify the small power signal output by the signal source to high power and output; a test fixture for fixing the power amplifier module and the circulator; a power supply providing the required power supply for the power amplifier module; a radio frequency cable connected to the output port of the circulator; an attenuator for attenuating power; a power meter for measuring the power of the radio frequency signal.

2. The circulator power screening test system according to claim 1, wherein: the radio frequency cable and the attenuator are disconnected during screening and connected after screening.

3. The circulator power screening test system according to claim 1, wherein: the signal source is a sweep signal source.

4. The circulator power screening test system according to claim 1, wherein: the length of the radio frequency cable is one meter.

5. A circulator power screening test method using the circulator power screening test system according to any one of claims 1 to 4, characterized by, It comprises the following steps: Step 1: Start the sweep signal source, set the frequency scan range F1-F5, the output power P, and the scan period T, i.e. the time required to scan from F1 to F5; Step 2: Determine the cable state, when the cable is open, i.e. the radio frequency cable is disconnected from the attenuator, power on for power screening test; Step 3: After two cycles of frequency scanning by the signal source, i.e. 2T, turn off the power supply; Step 4: Connect the cable to the attenuator, test the power, turn on the signal source and power supply for testing, and determine whether the power is normal; if normal, the tested circulator passes the screening, otherwise it does not pass the screening; Step 5: Replace the new circulator and repeat the test process from step 1 to step 4 to continue screening the remaining circulators.

6. A method of testing a circulator power sieve according to claim 5, wherein, When the measured power is less than the output power of the power amplifier module, it is determined that the power is normal, otherwise it is not normal.

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