A strong-field microwave millimeter wave mode measuring device and method

Abstract

The application discloses a kind of strong field microwave millimeter wave mode measuring device and method, the device is set on the side of the closed box for shielding transmission waveguide, corresponding with transmission waveguide in the box is provided with heat-sensitive target, heat-sensitive target side is provided with thermal imager, temperature field distribution formed by heat-sensitive target heating is recorded by thermal imager shooting, the radiation field distribution of microwave millimeter wave is obtained by calculation by the temperature field distribution of change, and the microwave millimeter wave mode in transmission waveguide is obtained by backstepping radiation field distribution;The application can quickly and accurately carry out quantitative measurement of microwave millimeter wave strong field distribution (corresponding mode) under the condition of thermal measurement strong field according to the relationship between strong field distribution and heat and temperature distribution.

Description

Technical Field

[0001] This invention belongs to the field of microwave and millimeter wave technology, specifically relating to a strong field microwave and millimeter wave mode measurement device and method. Background Technology

[0002] To obtain the precise distribution of microwave and millimeter-wave field strength within the transmission line of a microwave and millimeter-wave system under thermal measurement experimental conditions, it is necessary to conduct mode measurements under thermal field conditions.

[0003] Due to the limitations imposed by strong fields, near-field scanning methods cannot be applied to thermal mode measurements in strong fields. Therefore, common mode measurement methods currently include image display, radiation field measurement, and mode-selective coupling. However, these methods all suffer from low resolution and slow response speed, making it difficult to meet the quantitative testing requirements for strong field microwave and millimeter-wave mode distributions.

[0004] Therefore, it is necessary to study rapid and accurate quantitative measurement techniques for models that meet the requirements of thermal strong field conditions. Summary of the Invention

[0005] In view of this, the present invention proposes a strong field microwave millimeter wave mode measurement device and method. The device is based on the truncated mode diagnostic technology of infrared imaging to achieve accurate measurement of microwave millimeter wave modes under strong field conditions, and solves the problem of rapid and accurate quantitative measurement of modes under thermal strong field conditions.

[0006] To achieve this objective, the first aspect of the present invention provides a strong field microwave millimeter wave mode measurement device, the device comprising: a housing, a transmission waveguide, a thermal target, and a thermal imager;

[0007] The enclosure is a sealed enclosure located on the outside of the device;

[0008] The transmission waveguide is disposed on one of the side walls of the enclosure;

[0009] The thermal target, track, and thermal imager are all located inside the box.

[0010] The thermal target is set on a first track via a second track, which can change the relative distance between the thermal target and the transmission waveguide, and the target surface of the thermal target is opposite to the transmission waveguide; the thermal imager is set on a second track via a third track, which can change the relative distance and angle between the thermal imager and the thermal target, and the thermal imager is located on the side of the thermal target away from the transmission waveguide.

[0011] Preferably, the second track moves in a straight line along the first track, and the third track is connected to the second track at one end and moves in an arc along the second track.

[0012] Preferably, the thermal target is installed at the connection between the third track and the second track.

[0013] Preferably, the device further includes a laser rangefinder for measuring the relative distance between the transmission waveguide, the thermal target, and the thermal imager.

[0014] Preferably, the laser rangefinder includes: a first laser rangefinder and a second laser rangefinder disposed on the thermal target surface, and a third laser rangefinder disposed on the thermal imager mounting bracket.

[0015] Preferably, there are multiple first laser rangefinders, all of which are mounted on the thermal target surface.

[0016] Preferably, the transmission waveguide is any one of a circular waveguide, a rectangular waveguide, or an elliptical waveguide, and the material of the transmission waveguide has metallic properties.

[0017] Preferably, the thermal target is supported by a non-metallic support.

[0018] A method for measuring strong-field microwave and millimeter-wave modes, the method being based on the aforementioned strong-field microwave and millimeter-wave mode measurement device, includes the following steps:

[0019] S1: Measure the distance between the thermal target and the plane where the transmission waveguide port is located by using multiple first laser rangefinders set on the surface of the thermal target, and obtain the parallelism between the thermal target and the plane where the transmission waveguide port is located.

[0020] S2: After completing the parallelism measurement, remove all the first laser rangefinders;

[0021] S3: The microwave and millimeter waves to be tested are radiated onto the thermal target through a transmission waveguide, and the temperature field distribution formed by the heating of the thermal target is captured and recorded using a thermal imager.

[0022] S4: The radiation field distribution of microwaves and millimeter waves can be calculated by the changing temperature field distribution;

[0023] S5: The microwave and millimeter-wave modes within the transmission waveguide are obtained by inversely deducing the radiation field distribution.

[0024] Preferably, S3 further includes: a second track moving along the first track to test the distance between the thermal target and the transmission waveguide using a second laser rangefinder; a third track rotating along the second track and the thermal imager moving along the third track to test the distance between the thermal target and the thermal imager using a third laser rangefinder.

[0025] The working principle of the strong-field microwave and millimeter-wave mode measurement device of the present invention is as follows: The microwave and millimeter-wave source to be measured extends into the device through an opening on the left side of the housing via an output waveguide, and radiates towards the thermal target of the device through the transmission waveguide port. When the radiated microwave and millimeter-wave pass through the thermal target, the thermal target heats up, forming a changing temperature field distribution. The thermal imager of the device captures and records the temperature field distribution on the thermal target. The strong-field microwave and millimeter-wave after passing through the thermal target is absorbed by the load, and a small amount of scattered microwave and millimeter-wave is absorbed and shielded by the housing. The change in the temperature field distribution on the thermal target corresponds to the electric field (energy) distribution of the microwave and millimeter-wave. The radiation field distribution of the microwave and millimeter-wave can be obtained through the change in temperature field distribution; the microwave and millimeter-wave mode in the transmission waveguide can be deduced from the radiation field distribution.

[0026] The beneficial effects of the present invention are: the strong field microwave millimeter wave mode measurement device and method disclosed in the present invention can quickly and accurately perform quantitative measurement of microwave millimeter wave strong field distribution (corresponding mode) under thermal strong field conditions based on the relationship between strong field distribution and heat and temperature distribution. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the strong field microwave millimeter wave mode measurement device in an embodiment of the present invention;

[0028] In the diagram: 1. Box 2. Output waveguide 3. Thermal target 4. First laser rangefinder 5. Second laser rangefinder 6. First track 7. Second track 8. Third track 9. Thermal imager. Detailed Implementation

[0029] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of the invention, and should be understood that the scope of protection of the invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the technical teachings disclosed in this invention without departing from the spirit of the invention, and these modifications and combinations are still within the scope of protection of this invention.

[0030] The present invention and its advantages will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] This embodiment proposes a method such as Figure 1 The strong-field microwave and millimeter-wave mode measurement device shown includes: a housing 1, a transmission waveguide 2, a thermal target 3, a track, and a thermal imager 9; wherein the housing 1 is a sealed housing, which serves to shield microwave and millimeter-wave radiation, and is located on the outermost side of the device. Figure 1 The complete structure of the enclosure 1 is not shown; only one side wall of the enclosure 1 where the transmission waveguide 2 is installed is shown. The rest of the components of the device are inside the enclosure 1.

[0032] The aforementioned tracks include: a first track 6, a second track 7, and a third track 8. The thermal target 3 is positioned on the first track 6 via the second track 7, allowing for adjustments to the relative distance between the thermal target 3 and the transmission waveguide 2. The target surface of the thermal target 3 faces the outlet of the transmission waveguide 2, ensuring that the thermal target 3 can receive the microwave and millimeter-wave radiation output from the transmission waveguide 2. The thermal imager 9 is positioned on the second track 7 via the third track 8, allowing for adjustments to the relative distance and angle between the thermal imager 9 and the thermal target 3. The thermal imager 9 is located on the side of the thermal target 3 furthest from the transmission waveguide 2.

[0033] As an example, the first track 6 is set as a straight track. At one end of the second track 7, a thermal target 3 is installed on the first track 6, so that the second track 7 moves in a straight line along the first track 6, thereby changing the relative distance between the thermal target 3 and the transmission waveguide 2. The other end is set as an arc track. The third track 8 is similar to a guide rod. One end of the third track 8 is connected to the end of the second track 7 where the thermal target 3 is installed, and the other end is connected to the thermal imager 9. The end of the third track 8 where the thermal imager 9 is installed is also installed in the arc track of the second track 7, so that the third track 8 moves in an arc along the second track, thereby changing the relative distance and angle between the thermal imager 9 and the thermal target 3.

[0034] Those skilled in the art should know that the first track 6 is not limited to a straight track. Any structure that enables the second track to move in a straight line relative to the first track falls within the scope of protection of this application. Other deformations that enable the third track to move in a circular arc relative to the second track also fall within the scope of protection of this application.

[0035] As an embodiment, the device proposed in this application further includes a laser rangefinder, which includes: a first laser rangefinder 4 and a second laser rangefinder 5 disposed on the surface of the thermal target 3, and a third laser rangefinder disposed behind the thermal imager. The first laser rangefinder 4 is used to measure the parallelism between the thermal target 3 and the plane containing the port of the transmission waveguide 2. Therefore, multiple first laser rangefinders 4 can be disposed, all located on the surface of the thermal target. The parallelism between the two is obtained by measuring the distance between the thermal target 3 and the plane containing the port of the transmission waveguide 2 through multiple first laser rangefinders 4. The second laser rangefinder 5 is used to measure the distance between the thermal target 3 and the plane containing the port of the transmission waveguide 2 during the measurement in the strong field microwave millimeter wave mode. The third laser rangefinder is used to measure the distance between the thermal target and the thermal imager.

[0036] In this embodiment, the microwave and millimeter wave source to be tested and its transmission waveguide 2 extend into the housing of this device through the opening on the housing 1. The transmission waveguide 2 can be of different types such as circular waveguide, rectangular waveguide, and elliptical waveguide, and its material can be metal or other materials with metallic conductivity.

[0037] The thermal target 3 in this embodiment is used to characterize the radiation field distribution of microwave and millimeter waves. It is a non-metallic material with low reflectivity and has an absorption effect on microwave and millimeter waves. The thermal target is supported by a non-metallic bracket and is mounted on the second track 7 through a metal bracket. The thermal imager 9 in this embodiment is used to quickly identify and record the temperature field distribution on the thermal target 3. It is usually a cooled infrared thermal imager with high resolution, high speed and stable performance.

[0038] In this embodiment, the housing 1 has a length of 2.6m, a width of 1.8m, and a height of 1.6m. The absorbing material meets the frequency range of millimeter waves from 20GHz to 60GHz, the height of the absorbing material is no more than 10cm, and the absorbing material laid inside the housing can withstand an average power of no less than 3kW / ㎡. The dimensions of the thermal target plate are 1m × 1m. The usable length of the first track is 100cm, the target plate can move within a range of 5cm to 100cm, and the minimum step is no more than 0.1mm.

[0039] The third instrument track can be 180cm long, and the movable range between the thermal imager and the target plate is 5cm to 180cm, with a minimum step of no more than 0.1mm.

[0040] The angle adjustment range of the arc track on the second track is 0° to 25°, and the adjustable step is no more than 1°.

[0041] The thermal imager used is a cooled thermal imager with a resolution of 640×512, a frame rate greater than 100Hz, a temperature measurement accuracy of ±1°, and a thermal sensitivity of 30mk.

[0042] The first laser rangefinder consists of three handheld laser rangefinders with real-time display capabilities. The rangefinders are spaced 400 mm apart and have a resolution of 0.1 mm.

[0043] The second and third laser rangefinders are both laser rangefinders with remote data transmission capabilities and a resolution of 0.1 mm.

[0044] In this embodiment, the control processing computer is an industrial control computer with a gigabit network card (GiGE interface) for quickly and in real time to collect, store, and analyze test data, and to control the track.

[0045] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

[0046] The method for mode measurement using the aforementioned strong-field microwave millimeter-wave mode measurement device is as follows:

[0047] S1: Measure the distance between the thermal target and the plane where the transmission waveguide port is located by using multiple first laser rangefinders set on the surface of the thermal target, and obtain the parallelism between the thermal target and the plane where the transmission waveguide port is located.

[0048] S2: In order to remove the obstruction of the thermal target by the first laser rangefinder, the first laser rangefinder needs to be removed after the parallelism measurement is completed. Then, the second laser rangefinder is used to measure the distance between the thermal target and the transmission waveguide in real time after the first laser rangefinder is removed. The third laser rangefinder set on the thermal imager bracket is used to measure the distance between the thermal imager and the thermal target in real time.

[0049] S3: The microwave and millimeter waves to be tested are radiated onto the thermal target through a transmission waveguide, and the temperature field distribution formed by the heating of the thermal target is captured and recorded using a thermal imager.

[0050] S4: The radiation field distribution of microwave and millimeter waves is calculated by using the changing temperature field distribution and the distances measured by the second and third laser rangefinders. Within a certain radiation area, the radiation energy of microwave and millimeter waves is proportional to the square of the electric field amplitude. Assuming that the absorption coefficient of the thermal target is constant, its temperature change (temperature rise) is proportional to the absorbed heat. Therefore, the temperature change of the thermal target is proportional to the square of the electric field amplitude of the microwave and millimeter waves. Thus, by using the temperature field distribution recorded by the thermal imager at two moments, the distribution of temperature change (temperature rise) can be obtained, and the far-field electric field distribution of microwave and millimeter waves radiated onto the thermal target can be calculated.

[0051] S5: Microwave and millimeter-wave modes within the transmission waveguide are derived by inversely calculating the radiation field distribution. Using normalized data of the far-field radiated electric field distribution of various known standard modes (such as TE11, TE21, TE01, TE02, TM01, TM11, etc.), a series of hypothetical far-field radiated electric field distributions are obtained through a mode analysis algorithm, i.e., by sequentially setting the proportions of different mode components. Utilizing the rapid iterative calculation capabilities of an industrial control computer, the tested radiation field distribution data is compared with the hypothetical far-field radiated electric field distributions to analyze and obtain the main modes and their proportions within the radiation waveguide, as well as the possible components and proportions of other modes.

Claims

1. A method for measuring strong-field microwave millimeter-wave modes, characterized in that, The method is based on a strong-field microwave millimeter-wave mode measurement device and includes the following steps: S1: Measure the distance between the thermal target and the plane where the transmission waveguide port is located by using multiple first laser rangefinders set on the surface of the thermal target, and obtain the parallelism between the thermal target and the plane where the transmission waveguide port is located. S2: After completing the parallelism measurement, remove all the first laser rangefinders; S3: The microwave and millimeter waves to be tested are radiated onto the thermal target through a transmission waveguide, and the temperature field distribution formed by the heating of the thermal target is captured and recorded using a thermal imager. S4: The radiation field distribution of microwaves and millimeter waves can be calculated by the changing temperature field distribution; S5: Microwave and millimeter-wave modes within the transmission waveguide are obtained by inversely calculating the radiation field distribution; The device includes: a housing, a transmission waveguide, a thermal target, and a thermal imager; The enclosure is a sealed enclosure located on the outside of the device; The transmission waveguide is disposed on one of the side walls of the enclosure; The thermal target, track, and thermal imager are all located inside the box. The thermal target is set on a first track via a second track, which can change the relative distance between the thermal target and the transmission waveguide, and the target surface of the thermal target is opposite to the transmission waveguide; the thermal imager is set on a second track via a third track, which can change the relative distance and angle between the thermal imager and the thermal target, and the thermal imager is located on the side of the thermal target away from the transmission waveguide. The device also includes a laser rangefinder for measuring the relative distance between the transmission waveguide, the thermal target, and the thermal imager; The laser rangefinder includes: a first laser rangefinder and a second laser rangefinder mounted on the thermal target surface, and a third laser rangefinder mounted on the thermal imager mounting bracket.

2. The method for measuring strong-field microwave millimeter-wave modes according to claim 1, characterized in that, The S3 further includes: a second track moving along the first track, using a second laser rangefinder to test the distance between the thermal target and the transmission waveguide; a third track rotating along the second track and the thermal imager moving along the third track, using a third laser rangefinder to test the distance between the thermal target and the thermal imager.

3. The method for measuring strong-field microwave millimeter-wave modes according to claim 1, characterized in that, The second track moves in a straight line along the first track, and the third track is connected to the second track at one end and moves in an arc along the second track.

4. The method for measuring strong-field microwave and millimeter-wave modes according to claim 1, characterized in that, The thermal target is installed at the connection between the third track and the second track.

5. The method for measuring strong-field microwave millimeter-wave modes according to claim 1, characterized in that, There are multiple first laser rangefinders, all of which are mounted on the thermal target surface.

6. The method for measuring strong-field microwave millimeter-wave modes according to claim 1, characterized in that, The transmission waveguide can be any one of a circular waveguide, a rectangular waveguide, or an elliptical waveguide, and the material of the transmission waveguide has metallic properties.

7. The method for measuring strong-field microwave millimeter-wave modes according to claim 1, characterized in that, The thermal target is supported by a non-metallic support.

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