CN112650043A - Compact cold atomic clock for ground - Google Patents
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Abstract
The invention provides a compact cold atomic clock used on the ground, wherein the axes of two microwave action areas on a microwave cavity form a certain included angle with the horizontal plane, and then the cold atoms cooled and decelerated by a cooling module are obliquely thrown out at a set throwing angle, so that the cold atoms sequentially pass through the two microwave action areas on a parabolic track in the process of doing parabolic motion and have microwave action with the microwave action areas to complete the transition of the atoms; therefore, the cold atomic clock for obtaining the low-speed atoms can be applied to the ground with the gravity environment by obliquely polishing and adopting the improved microwave cavity, and the defect that the existing compact cold atomic clock can only be used for the space microgravity environment is overcome.
Description
Technical Field
The invention belongs to the field of time and frequency measurement and the technical field of vacuum, and particularly relates to a compact cold atomic clock used on the ground.
Background
The ground compact atomic clock adopts a thermal atom beam, such as a magnetic-separation cesium atomic clock, metal cesium is heated to about 100 ℃, cesium atoms are sprayed out of a collimator in the form of the beam, and enter a Ramsey cavity with a U-shaped structure after state preparation, and perform two resonance actions with microwaves, wherein the two resonances occur at different positions to generate Ramsey transition. The time interval of resonance determines the width of the Ramsey central peak, and the larger the Ramsey central peak width is, the narrower the Ramsey central peak width is, and the more favorable the index of an atomic clock is. At present, for a compact thermal beam atomic clock, the time interval can reach 1-2 ms. However, increasing the time interval further will encounter difficulties because the atomic velocity of the heat beam atomic clock is large, typically exceeding 120 m/s.
One solution to this difficulty is to reduce the atomic rate. In the last 90 s of the century, laser cooling of atoms was developed, which can reduce the atomic velocity by more than two orders of magnitude, and cool atoms with velocity of more than 100m/s to less than 1 m/s. With this technique, the time interval between resonances can be greatly extended. The recently developed cesium fountain clock utilizes the technology, so that the time interval of two actions can reach 1s magnitude, and the structural characteristic of the clock is that the two actions of atoms occur at the same position. The microgravity cold cesium atomic clock in the "space atomic clock system for space in europe" (ACES) and the PARCS project of the american space and space administration (NASA) adopt a structure similar to the ground compact cesium atomic clock, the action of atoms occurs at different positions, the action interval can reach 10s, and the cold atomic rubidium clock realized by the domestic maritime optical machinery is also the structure and is successfully carried on a space station. Unfortunately, such compact cold atomic clocks can only be applied to microgravity or zero gravity environments like space stations, and cannot be applied to the ground. If the method is applied to the ground, atoms make horizontal projectile motion under the action of gravity, and when the atom velocity is low, the atoms cannot normally pass through microwave action areas at two different positions, so that normal Ramsey resonance cannot be realized.
Disclosure of Invention
In order to solve the problems, the invention provides a compact cold atomic clock used on the ground, so that the cold atomic clock can be applied to the ground with a gravity environment, and the problem that the existing compact cold atomic clock can only be used in a space micro-gravity environment is solved.
A compact cold atomic clock used on the ground comprises a laser system part, a circuit part and a physical part, wherein the physical part comprises a cooling module, a microwave cavity and a detection module, the microwave cavity is provided with two mutually symmetrical microwave action areas, the included angles between the axes of the two microwave action areas and the horizontal plane are both beta, cold atoms obliquely move upwards in a parabolic manner at a set ejection position at a set ejection angle alpha, and the two microwave action areas are symmetrically distributed on the parabolic movement locus of the cold atoms, wherein,
l is a set distance between the central points of the two microwave action areas, and S is a horizontal set distance between the projection position of the cold atom and the central point of the first microwave action area;
meanwhile, the value of the set projectile angle alpha is directly determined according to an empirical value or is obtained by calculation according to a given maximum projectile height h, and
wherein, when the value of the set projectile angle alpha is directly determined according to the value after the experiment, the speed of the cold atoms at the set projectile position is
Wherein g is the acceleration of gravity, and the cold atoms are obtained by cooling the hot atoms in a cooling module by cooling laser generated by the laser system part; when the value of the set projectile angle alpha is calculated according to the given maximum projectile height h, the speed of the cold atoms at the set projectile position is
Further, the microwave action regions at both ends of the microwave cavity are bent upward.
Further, microwave action regions at two ends of the microwave cavity are bent downwards.
Further, after the cold atoms are thrown from the throwing position at the set throwing angle alpha, the maximum throwing height and the set throwing angle alpha of the cold atoms meet the following relation:
wherein h (α) is the maximum projectile height.
Further, after the cold atoms are thrown from the throwing position at the set throwing angle alpha, the time interval of the cold atoms in the two microwave acting areas for microwave action and the set throwing angle alpha satisfy the following relation:
wherein T (alpha) is the time interval of the microwave action of the cold atoms in the two microwave action areas.
Furthermore, through holes for cold atoms to enter and leave are formed in the cavity walls of the microwave action areas at the two ends of the microwave cavity, meanwhile, stop waveguides are installed at the through holes, and the axes of the stop waveguides are tangent to the movement tracks of the throwing lines of the cold atoms.
Further, the microwave cavity is a U-shaped cavity, a cylindrical cavity or an annular cavity.
Has the advantages that:
1. the invention provides a compact cold atomic clock used on the ground, wherein the axes of two microwave action areas on a microwave cavity form a certain included angle with the horizontal plane, and then the cold atoms cooled and decelerated by a cooling module are obliquely thrown out at a set throwing angle, so that the cold atoms sequentially pass through the two microwave action areas on a parabolic track in the process of doing parabolic motion and have microwave action with the microwave action areas to complete the transition of the atoms; therefore, the invention ensures that the cold atomic clock for obtaining low-speed atoms can be applied to the ground with a gravity environment by obliquely polishing and adopting the improved microwave cavity, and overcomes the defect that the existing compact cold atomic clock can only be applied to a space microgravity environment.
2. The invention can also provide the relationship between the maximum projectile height and the set projectile angle alpha, and the relationship between the time interval of the cold atoms in the two microwave action areas for microwave action and the set projectile angle alpha, so that testers can conveniently determine the radial size of the physical part of the compact cold atom clock and the Ramsey central peak line width.
Drawings
FIG. 1 is a schematic structural diagram of a ground compact cold atomic clock;
FIG. 2 is a U-shaped microwave cavity of a conventional thermal atomic beam applied to the ground;
FIG. 3 is a microwave cavity of a compact cold atomic clock for ground application;
FIG. 4 is another microwave cavity of a compact cold atomic clock for ground application;
FIG. 5 is a movement trace of an atom in a skew polishing process;
FIG. 6 is a three-dimensional view of a conventional U-shaped microwave cavity;
FIG. 7 is a schematic illustration of the Ramsey cavity effect region after atom polishing through modification;
fig. 8 is a schematic diagram of a Ramsey cavity effect region after atom polishing through another modification.
Detailed Description
In order to make the technical solutions better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.
Example one
In order to enable the compact cold atomic clock technology to be applied to the ground, the invention provides a method which can enable the action time interval of Ramsey resonance to reach dozens or even hundreds of ms. In the method, atoms are cooled and then thrown out at an angle to the ground, so that the motion trail of the atoms under the action of gravity is a throwing line, and the atoms respectively act with microwaves in a microwave cavity at two sides of the vertex of the parabola; in addition, in order to make atoms smoothly pass through the microwave action region, the microwave cavity needs to be improved, so that an included angle is formed between the two action regions of the microwave cavity, and finally, the C field is slightly modified, which is described in detail below:
as shown in FIG. 1, the compact cold atomic clock for ground consists of three parts, wherein the laser system part is used for generating cooling laser and detecting laser; a circuit part for locking the atomic transition signal on the crystal oscillator; and the physical part is used for cooling the thermal atoms through cooling laser generated by the laser system part in the cooling module, then pushing the cooled cold atoms to the Ramsey cavity, namely completing atom transition in the microwave cavity and outputting transition signals. In order to enable the atomic clock to operate on the ground, a new design scheme needs to be provided for the third part, namely the physical part, and the core content of the invention is also needed.
Before detailing the present disclosure, two design parameters are defined: and S and L, wherein S is the horizontal distance between the cast position of the atom and the central point of the first microwave action region, and L is the horizontal distance between the central points of the two microwave action regions.
The first improvement of the present invention is that the cooled atoms are thrown at an angle to the horizontal (i.e., obliquely) and the atoms move parabolically under the action of the gravitational field. In this step, the velocity magnitude (velocity) of the cooled atoms needs to be determined. There are two cases: given the casting angle α, in accordance with
Determining the cooling rate of the atoms, wherein g is the acceleration of gravity; given a projection height h, then
Determining the cooling rate of the atoms in accordance with
The casting angle is determined.
A second improvement of the present invention resides in the modification or improvement of the conventional Ramsey cavity. The axes of the two microwave active zones conventionally coincide and are parallel to the horizontal plane, see fig. 2. The modified Ramsey cavity requires that the axes of the two active areas have an included angle with the horizontal plane, the included angle being formed by
Are determined and also form an angle with each other, see fig. 3. It should also be noted that the manner of forming the angle is not limited to the manner in which the two microwave active regions are curved upward as shown in fig. 3, but other manners are possible, such as the manner in which one of the two microwave active regions is curved downward as shown in fig. 4.
A third improvement of the present invention is to decide whether to make a change to the C field. Because the two action areas form an included angle, the C field on the inner axis of the action areas slightly changes along the axis, if the influence of the change on the index of the atomic clock exceeds the requirement, the C field needs to be redesigned, and if the influence does not exceed the requirement, the original C field scheme can be adopted.
The first and second modifications of the present invention will be further described below.
First, the first modification will be explained.
The atoms enter a first microwave action area along a parabolic track, leave after reacting with microwaves, continue to move along the parabolic track, enter a second microwave action area after a certain time, react with the microwaves again, and complete Ramsey transition. The difference between the step and the traditional compact atomic clock is that the traditional atomic clock sends thermal atoms into two microwave action areas along a straight line to complete Ramsey transition. For a thermoatomic clock, although the atoms are thrown in the horizontal direction, the velocity is very high, exceeding 120m/s, due to the absence of cooling, and the thermal atoms drop only about 10 microns through the two microwave action zones, passing almost straight through the two action zones. If the thermal atoms of the traditional atomic clock are cooled and decelerated and then directly applied to the ground, the motion trail of the cold atoms moves downwards under the action of gravity, so that the cold atoms cannot pass through two microwave action areas which are horizontally arranged in the traditional atomic clock, and further cannot generate atom transition.
The atoms are ejected from the point of ejection at an angle α, see fig. 5, assuming a velocity magnitude (velocity) of the atoms after cooling of V, where the point of ejection is the origin of coordinates O. The atoms reach the first microwave action area A along a parabola, then reach the highest point H, the distance between the H and the x axis is H, then move to the second microwave action area B, the horizontal distance between the two points O, A is S, and the horizontal distance between the two points A, B is L.
It is assumed that the physical part is designed with the angle of the projectile α first given. Different values of α will correspond to different rates V, and the functional relationship between V and α is derived below.
The parabolic parametric equations are first written. At O point, the velocity in the vertical direction of the atom is VyV sin θ, the horizontal velocity is VxSince V · cos θ, the parabolic parametric equation is
Where t is a time parameter.
As can be seen from FIG. 5, the ordinate of A, B indicates that the two points are equal, i.e., y (t)A)＝y(tB) Taking into account tA＝S/(Vcosα)， tBFrom the second parametric equation in (1), the value (S + L)/(Vcos α) can be obtained
Is solved from the above formula
This is a functional relationship between velocity V and the angle of the projectile α, indicating that the velocity of the atom after cooling must be given by equation (2) for a given angle of the projectile α.
In addition, the invention also providesThe maximum upper throw height h is obtained as a function of the angle of throw alpha, since h is (Vsin alpha)22g, by bringing formula (2) into and simplifying to give
Wherein the maximum upper throw height h (α) may be used to determine the radial dimension of the physical portion.
The invention can also find the functional relation between the time interval T of the microwave action of the atoms and the two microwave action areas and the polishing angle alpha. Due to the fact that
The formula (2) is introduced and simplified to obtain
T (α) is the time interval T, which is related to the angle of the projectile α.
It is assumed that the physical part is designed with the projectile height h first given. Different h correspond to different V, and the functional relationship between the maximum projectile height h and V is deduced below.
Can reverse-resolve tan alpha from (3)
Thus, it is possible to provide
Substituting the formula into (2) can obtain the functional relationship between V and h
The angle of the projectile being derived directly from (5)
Substituting (5) into (4) the functional relationship between the available time interval and the upward polishing height
It should be noted that the time interval T can be used to determine the Ramsey central peak line width.
Next, a second modified aspect of the present invention will be described.
The Ramsey cavity can adopt a U-shaped cavity, a cylindrical cavity, an annular cavity and the like, and the cavities have the common characteristic that two action areas are arranged, and the axes of the action areas are on the same straight line. In order to allow the atoms to enter and leave, the walls of the microwave active region of the Ramsey cavity are provided with small holes, the size of which is about a few millimeters by a few millimeters, and in addition, in order to prevent microwave leakage, a cut-off waveguide is installed at the small hole, which is illustrated in fig. 6 by taking a three-dimensional view of a conventional U-shaped cavity as an example.
When the velocity of the atoms is reduced and thrown in a parabolic fashion, there is a risk that the atoms will not normally pass through the microwave cavity if a conventional microwave cavity is directly used. Of course, in the case of a small angle of the projectile, it is possible for some of the atoms to pass through both microwave active zones, considering that the truncated waveguide and the aperture have a cross section of limited size, but some of the atoms cannot pass through. If the atoms are cooled further, and the angle of the projectile needs to be increased, the number of atoms that can pass through is further reduced, and when the angle of the projectile is increased to a certain angle, all the atoms cannot pass through, and no transition signal is generated.
The solution of the present invention is to place the axis connecting the microwave active region to the waveguide on the tangent of the parabolic curve, as a result of which the active region axis forms an angle with the horizontal, which is denoted by β, resulting in an improved Ramsey cavity, where atoms can normally pass through the active region, see fig. 7 and 8.
The expression β, i.e., the angle between the tangent line at two points A, B in fig. 5 and the x-axis, is obtained as follows. Since A, B are two points of symmetry of a parabola, it is sufficient to consider only a.
Differentiating the formula (1) to obtain
Thus is provided with
Will be provided with
Substituting for human, the tangent of beta can be obtained
Substituting (2) into (9) and simplifying to obtain
Thus is provided with
It is also advantageous to have the two microwave active areas at an angle to the horizontal. The distribution of the microwave magnetic field in the Ramsey cavity changes along with the change of the position, and generally when the Ramsey cavity is designed, the magnetic field in the microwave action area becomes uniform along the axis, so that atoms can act with the uniform magnetic field when passing through the microwave action area, and the Ramsey traction is reduced. When the atoms move parabolically, if the Ramsey cavity is not changed, and the conventional cavity is continuously adopted, the atoms cannot pass through the uniform region. If the microwave action zone forms an included angle, so that the axis of the microwave action zone becomes the tangent of a parabola, atoms can act with a uniform magnetic field, and the problems are naturally solved.
It should be noted that the present invention has been described only by taking a U-shaped microwave cavity as an example, but the present disclosure is also applicable to a cylindrical cavity and a ring cavity. The cylindrical cavity and the annular cavity are modified so that the axis of the cavity, truncated to the waveguide, is tangent to the parabola at points on both sides of the vertex of the parabola, and the angle is determined by equation (11).
Therefore, the invention provides a compact cold atomic clock used on the ground, the axes of two microwave action areas on a microwave cavity form a certain included angle with the horizontal plane, and then the cold atoms cooled and decelerated by a cooling module are obliquely thrown out at a set throwing angle, so that the cold atoms sequentially pass through the two microwave action areas on a parabolic track in the process of doing parabolic motion and have microwave action with the microwave action areas to complete atomic transition; that is to say, the invention adopts the improved microwave cavity through the inclined polishing, and simultaneously changes the structure of the C field according to the actual situation, so that the cold atomic clock for obtaining the low-speed atoms can be applied to the ground with the gravity environment, and the problem that the existing compact cold atomic clock can only be used for the space microgravity environment is solved.
Example two
The invention is further described below by taking a compact cold cesium atomic clock as an example, wherein the cold cesium atomic clock is composed of three parts, namely a laser system part, a circuit part and a physical part, and the physical part adopts the core content of the invention, which is shown in figure 1.
In the present example, S is 10cm and L is 17cm, and in the design of the physical part, the angle α of the projectile is given as 2 °.
Firstly, the cooling rate of the atoms is determined according to the first step, and the size is obtained according to the formula (2)
It follows that the atomic velocity is reduced by more than an order of magnitude compared to a conventional thermal beam atomic clock.
The corresponding time interval can be determined according to equation (4)
In the case where V has already been determined, the interval can also be formulated
And more concise solution is achieved. The time interval of the atomic clocks of the heat beams is about 1.5ms, and it can be seen that the action interval of this example is increased by a factor of approximately 16, and it is expected that the Ramsey peak will be squeezed by a factor of approximately 16.
The atom height of the top throw can also be found using equation (3):
secondly, according to the second step, the included angle of the microwave action area is determined, and the included angle is calculated by the formula (11):
therefore, the improved U-shaped microwave cavity needs to incline the two arms inwards or outwards by 0.92 degrees as shown in figure 7, so that an included angle is formed between the two microwave action areas and is respectively formed by 0.92 degrees with the horizontal plane.
In this example, since the angle β is small, the positional variation of the microwave action region is small, and the influence on the C field is not large, the C field scheme is not changed.
The design of the laser system part and then the design of the circuit part can be determined according to the velocity magnitude value after the atoms are cooled, the design of the two parts is conventional, and the invention is not described in detail.
The present invention is capable of other embodiments, and various changes and modifications can be made by those skilled in the art without departing from the spirit and scope of the invention.
Claims (7)
1. A compact cold atomic clock used on the ground comprises a laser system part, a circuit part and a physical part, wherein the physical part comprises a cooling module, a microwave cavity and a detection module, and is characterized in that the microwave cavity is provided with two mutually symmetrical microwave action areas, the included angles between the axes of the two microwave action areas and the horizontal plane are both beta, cold atoms make parabolic motion in the set ejection position in an inclined upward direction at a set ejection angle alpha, the two microwave action areas are symmetrically distributed on the parabolic motion trail of the cold atoms, wherein,
l is a set distance between the central points of the two microwave action areas, and S is a horizontal set distance between the cast position of the cold atom and the central point of the first microwave action area;
meanwhile, the value of the set projectile angle alpha is directly determined according to an empirical value or is obtained by calculation according to a given maximum projectile height h, and
wherein, when the value of the set projectile angle alpha is directly determined according to the empirical value, the speed of the cold atom at the set projectile position is
Wherein g is the acceleration of gravity, and the cold atoms are obtained by cooling the hot atoms in a cooling module by cooling laser generated by the laser system part; when the value of the set ejection angle alpha is calculated according to the given maximum ejection height h, the speed of the cold atoms at the set ejection position is
2. A compact ground-based cold atomic clock as claimed in claim 1, wherein the microwave active region at each end of the microwave cavity is curved upward.
3. A compact ground-based cold atomic clock as claimed in claim 1, wherein the microwave-active regions at the ends of the microwave cavity are curved downward.
4. A compact ground-based cold atom clock as claimed in claim 1, wherein the maximum projectile height of the cold atom after being ejected from the projectile position at the set ejection angle α satisfies the following relationship with the set ejection angle α:
wherein h (α) is the maximum projectile height.
5. A compact ground-based cold atom clock as claimed in claim 1, wherein the time interval between microwave activation of the cold atoms in the two microwave activation zones after the cold atoms are ejected from the ejection position at the set ejection angle α satisfies the following relationship with the set ejection angle α:
wherein T (alpha) is the time interval of the microwave action of the cold atoms in the two microwave action areas.
6. The compact cold atom clock for ground use as claimed in claim 1, wherein the walls of the microwave action zones at both ends of the microwave cavity are provided with through holes for cold atoms to enter and leave, and the through holes are provided with cut-off waveguides, and the axes of the cut-off waveguides are tangential to the parabolic motion trajectories of the cold atoms.
7. A compact ground-based cold atomic clock according to claim 1, wherein the microwave cavity is a U-cavity, a cylindrical cavity or a ring cavity.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114370813A (en) * | 2021-12-28 | 2022-04-19 | 北京无线电计量测试研究所 | U-shaped microwave cavity electricity symmetry detection device |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090302957A1 (en) * | 2008-06-02 | 2009-12-10 | Filippo Levi | Atomic beam tube with counter optical or atomic beams |
| US20100033256A1 (en) * | 2008-08-11 | 2010-02-11 | Honeywell International Inc. | Cold atom micro primary standard |
| CN101807043A (en) * | 2010-03-19 | 2010-08-18 | 中国科学院上海光学精密机械研究所 | Microwave cavity of cold atomic clock under microgravity environment |
| CN101847994A (en) * | 2010-05-05 | 2010-09-29 | 中国科学院武汉物理与数学研究所 | Method and device for implementing Ramsey-CPT atomic frequency standard by microwave periodic On-Off modulation VCSEL |
| CN102981396A (en) * | 2012-12-11 | 2013-03-20 | 中国科学院武汉物理与数学研究所 | Dual-modulation mutual-injection coherent two-color light source generating device |
| CN105788011A (en) * | 2016-02-25 | 2016-07-20 | 武汉长江通信智联技术有限公司 | System and method for radio frequency positioning based on dedicated short-range communication |
| CN107561916A (en) * | 2017-10-10 | 2018-01-09 | 兰州空间技术物理研究所 | A kind of rubidium atom microwave clock based on faraday's laser pumping |
| CN108983591A (en) * | 2018-08-30 | 2018-12-11 | 中国科学院上海光学精密机械研究所 | Collect the microwave cavity of laser cooling, state selection and atom probe |
-
2020
- 2020-12-01 CN CN202011380508.0A patent/CN112650043B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20090302957A1 (en) * | 2008-06-02 | 2009-12-10 | Filippo Levi | Atomic beam tube with counter optical or atomic beams |
| US20100033256A1 (en) * | 2008-08-11 | 2010-02-11 | Honeywell International Inc. | Cold atom micro primary standard |
| CN101807043A (en) * | 2010-03-19 | 2010-08-18 | 中国科学院上海光学精密机械研究所 | Microwave cavity of cold atomic clock under microgravity environment |
| CN101847994A (en) * | 2010-05-05 | 2010-09-29 | 中国科学院武汉物理与数学研究所 | Method and device for implementing Ramsey-CPT atomic frequency standard by microwave periodic On-Off modulation VCSEL |
| CN102981396A (en) * | 2012-12-11 | 2013-03-20 | 中国科学院武汉物理与数学研究所 | Dual-modulation mutual-injection coherent two-color light source generating device |
| CN105788011A (en) * | 2016-02-25 | 2016-07-20 | 武汉长江通信智联技术有限公司 | System and method for radio frequency positioning based on dedicated short-range communication |
| CN107561916A (en) * | 2017-10-10 | 2018-01-09 | 兰州空间技术物理研究所 | A kind of rubidium atom microwave clock based on faraday's laser pumping |
| CN108983591A (en) * | 2018-08-30 | 2018-12-11 | 中国科学院上海光学精密机械研究所 | Collect the microwave cavity of laser cooling, state selection and atom probe |
| US20200076441A1 (en) * | 2018-08-30 | 2020-03-05 | Shanghai Institute Of Optics And Fine Mechanics, Chinese Academy Of Sciences | Microwave resonant cavity for laser cooling, microwave interrogation and atomic state detection in situ |
Non-Patent Citations (2)
| Title |
|---|
| 杨晶: "CPT原子钟物理系统的研究与探索", 《中国博士学位论文全文数据库 基础科学辑》 * |
| 陈大勇 等: "CPT原子钟VCSEL波长锁定环路的设计与实现", 《原子能科学技术》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114370813A (en) * | 2021-12-28 | 2022-04-19 | 北京无线电计量测试研究所 | U-shaped microwave cavity electricity symmetry detection device |
| CN114370813B (en) * | 2021-12-28 | 2023-11-14 | 北京无线电计量测试研究所 | U-shaped microwave cavity electrical symmetry detection device |
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