A design method for multi-section sealed high power capacity antenna

Abstract

This invention discloses a design method for a multi-segment sealed high-power capacity antenna, comprising: Step 1, calculating the field strength distribution inside the antenna based on the antenna model: Simulating the antenna model using electromagnetic software, setting the input power of the antenna feed port, calculating the field strength distribution inside the antenna, and obtaining the maximum and minimum field strength values; Step 2, calculating the antenna power capacity: Calculating the antenna power capacity under different medium conditions based on the simulated input power, maximum field strength value, and breakdown field strength under different medium conditions; Step 3, performing multi-segment sealing design based on the field distribution and power capacity; calculating the corresponding air breakdown field strength E inside the antenna, and finding the position where the field strength inside the antenna cavity is exactly equal to E; and then setting the sealing window, the filled gas, and the sealed antenna cover. This invention enables the transmitting antenna to achieve a smaller vacuum / filling chamber and higher power capacity while meeting high gain requirements within a large volume, and also facilitates rapid vacuuming / filling and pressure maintenance.

Description

Technical Field

[0001] The invention relates to the technical field of high-power microwave antenna design, and in particular to a design method for a multi-section sealed high-power capacity antenna. Background Art

[0002] High-power microwave antenna is one of the core components of high-power microwave system. It is directly related to whether the output energy of high-power microwave source can be effectively applied to the target, and is one of the key technologies for applying high-power microwave technology to the military field. In order to meet the power capacity requirements of high-power antenna, the inside of the antenna is generally evacuated or inflated. Usually, the method of adding a radome to the antenna surface is adopted to achieve the airtightness requirements of vacuuming or inflating the high-power microwave antenna.

[0003] However, as the demand for antenna gain in high-power microwave systems increases, the volume / surface area of ​​the antenna is getting larger and larger. If the antenna cover is still used for sealing, on the one hand, the antenna cover has a large area and is difficult to resist deformation and sealing problems under positive / negative pressure, which puts higher requirements on the thickness, material, and sealing process of the antenna cover; on the other hand, the welding method used in antenna processing is difficult to meet the airtightness requirements, and the material processing cost also increases. In addition, there are problems such as the time required for vacuuming / inflating becoming longer. It is difficult to take both high gain and high power capacity into account at the same time.

[0004] In view of the demand for high power capacity and high gain of transmitting antennas in application scenarios such as high-power microwave weapons and high-power pulse environment construction, it is urgent to propose a multi-segment sealed high-power capacity antenna design method, so that the vacuum / inflatable chamber of the transmitting antenna is smaller under large volume conditions that meet the high gain requirements, with higher power capacity, which is also conducive to rapid vacuum / inflation and maintenance of air pressure. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a design method for a multi-segment sealed high-power capacity antenna in view of the defects in the prior art.

[0006] The technical solution adopted by the present invention to solve the technical problem is:

[0007] The present invention provides a method for designing a multi-segment sealed high-power capacity antenna, the method comprising the following steps:

[0008] Step 1. Calculate the field strength distribution inside the antenna according to the antenna model: Use electromagnetic software to simulate the antenna model, set the antenna feed input power, calculate the field strength distribution inside the antenna, and obtain the maximum and minimum field strength values;

[0009] Step 2, calculate the power capacity of the antenna: according to the input power, maximum field strength value and breakdown field strength under different medium conditions calculated by simulation, calculate the power capacity of the antenna under different medium conditions;

[0010] Step 3: Design multi-stage seals according to field distribution and power capacity, including:

[0011] If the input power during actual use is between the antenna's air power capacity and vacuum power capacity, a sealed design can be performed; calculate the corresponding air breakdown field strength E in the antenna, and find the position in the antenna cavity where the field strength is just equal to E;

[0012] If the position of E can be found, a sealing window is set at this position. The sealing window divides the inside of the antenna into two parts. The space near the feed port is evacuated, and the space near the antenna aperture is not processed. An ordinary radome is added to the antenna aperture.

[0013] If the position of E cannot be found, the special gas breakdown field strength E' corresponding to the antenna is calculated according to the gas actually used, and a sealing window is set at this position. The sealing window divides the inside of the antenna into two parts. The space near the feed port is evacuated, and the space near the antenna surface is filled with special gas. A sealed antenna cover is added at the antenna surface.

[0014] Furthermore, the different medium conditions in the method of the present invention include: air, vacuum, special gas; the special gas is an inert gas or directly filled with positive pressure air; the inert gas includes SF 6 、N 2 .

[0015] Furthermore, the formula for calculating the power capacity of the antenna in the three medium conditions of air, vacuum and special gas in the method of the present invention is:

[0016]

[0017]

[0018]

[0019] Among them, the input power P 0 , Simulation maximum field strength value E max , air breakdown field strength E air , vacuum breakdown field strength E va 、Special gas breakdown field strength E S , air power capacity P cair , Vacuum power capacity P cva 、Special gas power capacity P cS .

[0020] Furthermore, in the method of the present invention, the maximum breakdown field strength is selected as 1 / 3 of the theoretical value as the actual breakdown field strength to retain an engineering margin.

[0021] Furthermore, the calculation method of the injected power in the method of the present invention is:

[0022] The formula between input power and field strength in the waveguide cavity is as follows:

[0023]

[0024] in, Ec is the maximum field strength at the input power, the long side a of the waveguide cavity, the wide side b of the waveguide cavity, the wavelength λ, and the dielectric constant ε r .

[0025] Furthermore, the method for calculating the corresponding air breakdown field strength E in the antenna in the method of the present invention is:

[0026] The relationship between power capacity and field strength satisfies the following formula:

[0027]

[0028] Among them, E 1 For the input power P 1 The maximum field strength in the waveguide cavity is E 2 For the input power P 2 The maximum field intensity in the waveguide cavity is

[0029] Substitute the simulation to calculate the input power P 0 , air breakdown field strength E air And input power P in From the formula of the relationship between power capacity and field strength, the air breakdown field strength E corresponding to the antenna can be calculated;

[0030] The method for calculating the breakdown field strength E' of the corresponding special gas in the antenna is:

[0031] Substitute the simulation to calculate the input power P 0 、Special gas breakdown field strength E S And input power P in From the formula of the relationship between power capacity and field strength, calculate the breakdown field strength E' of the special gas corresponding to the antenna.

[0032] Furthermore, the structure of the sealing window in the method of the present invention includes: a ceramic sheet, a waveguide matching structure, and a rectangular waveguide wall.

[0033] Furthermore, the antenna in the method of the present invention is an antenna with high power capacity, including: a horn antenna, a waveguide slot array antenna, and a parabolic antenna.

[0034] Furthermore, in the method of the present invention, if the input power in the actual use process is not satisfied to be between the air power capacity and the vacuum power capacity of the antenna, the following determination is continued:

[0035] If the input power is greater than the vacuum power capacity during actual use, the antenna cannot meet the required power capacity requirements;

[0036] If the input power is less than the antenna's air power capacity during actual use, the antenna can directly meet the power capacity requirement in the air state.

[0037] The beneficial effects produced by the present invention are:

[0038] 1. Based on the existing high-power capacity antennas (horn antennas, waveguide slot antennas), the cavity structure is divided and multi-stage sealed according to the internal field distribution of the antenna. Compared with the overall vacuum / inflation inside the traditional large antenna cover, this method can achieve a high-power capacity antenna with a small vacuum / inflation chamber under the condition of a large volume that meets the high gain requirements, which is easier to implement in engineering;

[0039] 2. Smaller vacuum / inflation chamber is conducive to rapid vacuuming / inflation and maintaining air pressure;

[0040] 3. The process design of the smaller vacuum / inflatable chamber and the ceramic isolation sealing window has lower requirements on the material selection and welding process of the antenna, and achieves better high power capacity effect at a smaller structural cost in engineering. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0042] Figure 1 is a design flow chart of a design method for a multi-segment sealed high power capacity antenna according to an embodiment of the present invention;

[0043] Figure 2 is a simulation diagram of the field strength distribution inside the antenna according to an embodiment of the present invention;

[0044] Figure 3 The different media (air, vacuum, SF 6 ) conditions;

[0045] Figure 4 This is the first segmented sealing solution of the embodiment of the present invention;

[0046] Figure 5 This is the second segmented sealing solution of the embodiment of the present invention;

[0047] Figure 6 Schematic diagram of the ceramic sealing window structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] Example 1

[0050] A multi-section sealed high-power capacity antenna design method according to an embodiment of the present invention calculates the field strength value in the antenna, divides the structure in the antenna cavity according to the breakdown field strength of air, vacuum, and special gas, and uses a sealed ceramic window to isolate the cavity space inside the antenna, thereby achieving vacuuming of the area with high field strength (greater than the breakdown field strength of air) in the antenna, and directly exposing the area with low field strength (less than the breakdown field strength of air) in the antenna to the air, and can also be filled with special gas (SF 6 gas as an example), to achieve an increase in antenna power capacity.

[0051] The specific process of the multi-segment sealed high power capacity antenna design method is as follows: Figure 1 As shown, it is characterized by:

[0052] (1) Calculate the field strength distribution inside the antenna based on the antenna model. Use commercial electromagnetic software to simulate the antenna model and set the antenna feed input power to P. 0 , the calculated field strength distribution inside the antenna is as follows Figure 2 As shown (taking the horn antenna as an example), the maximum field strength value E is obtained max and the minimum field strength value E min .

[0053] (2) Calculate the power capacity of the antenna. Figure 3 The following are the results for different media (air, vacuum, SF 6 ) conditions. In order to retain the engineering margin, 1 / 3 value is generally selected as the actual breakdown field strength. Since the formula between input power and field strength in the waveguide cavity is as follows:

[0054]

[0055] From the above formula, we can see that Where Ec is the maximum field strength at the input power.

[0056] Therefore, the relationship between power capacity and field strength satisfies the following formula:

[0057]

[0058] Among them, E 1 For the case where the input power is P 1 The maximum field strength in the waveguide cavity is E 2 For the case where the input power is P2 The maximum field strength in the waveguide cavity is .

[0059] According to the input power P calculated by simulation 0 , maximum field strength value E max and air breakdown field strength E air , vacuum breakdown field strength E va , SF 6 Breakdown field strength E SF6 , the power capacity of the antenna under different dielectric conditions can be calculated:

[0060]

[0061]

[0062]

[0063] (3) Design a multi-stage sealing scheme based on field distribution and power capacity.

[0064] a) If the input power P during actual use in The antenna air power capacity P cair and vacuum power capacity P cva Between

[0065] P cair <P in <P cva

[0066] Then the sealing solution can be designed.

[0067] b) According to formula (2), substitute it into the simulation to calculate the input power P 0 , air breakdown field strength E air And input power P in , calculate the field strength E corresponding to the antenna, and find the position in the antenna cavity where the field strength is exactly equal to E.

[0068] c) If the position of E can be found, then this position is where the sealing window is located. The sealing solution at this time is Figure 4 As shown, the sealing window divides the interior of the antenna into two parts. The space near the feed port is evacuated, and the space near the antenna surface is not processed. An ordinary antenna cover is added to the antenna surface to prevent dust.

[0069] d) If the location of E cannot be found, it is necessary to substitute the simulation input power P according to formula (2) 0 , sulfur hexafluoride breakdown field strength E SF6 And input power P in , calculate the field strength E' corresponding to the antenna, and find the position in the antenna cavity where the field strength is just equal to E'. This position is where the sealing window is located. The sealing solution at this time is Figure 5 As shown in the figure, the sealing window divides the interior of the antenna into two parts. The space near the feed port is evacuated, and the space near the antenna port is filled with SF6 gas. The filling pressure is based on Figure 3 A sealed radome is added to the antenna surface to prevent dust and ensure air tightness.

[0070] (4) Sealed window structure Figure 6 As shown, it consists of a ceramic sheet and a waveguide matching structure.

[0071] (5) The design method of the present invention is mainly aimed at antennas with high power capacity, such as horn antennas, waveguide slot array antennas, parabolic antennas, etc.; since the spatial dimension from the antenna feed port to the radiating surface gradually increases, the corresponding field strength distribution also gradually changes from large to small (except for some aperture couplings), such as Figure 2 shown.

[0072] (6) In the design method of the present invention, the inflation gas is in addition to SF 6 , or N 2 It can also be filled with inert gases or directly with positive pressure air.

[0073] Example 2

[0074] The required horn antenna parameters are as follows: gain 15dBi, working frequency band L band, power capacity 10MW.

[0075] (1) Calculate the field strength distribution inside the antenna based on the antenna model

[0076] Use commercial electromagnetic software to simulate the antenna model and set the antenna feed input power P 0 =0.5W, calculate the field strength distribution inside the antenna, the maximum field strength value E max =477.3V / m, E max The location is inside the horn antenna feed waveguide, and the minimum field strength value is E min =50V / m.

[0077] (2) Calculate the antenna power capacity

[0078] According to formula (2), substitute the input power P 0 =0.5W, maximum field strength value E max =477.3V / m and air breakdown field strength E air =1.5MV / m, vacuum breakdown field strength E va =35MV / m, SF 6 Breakdown field strength E SF6_1 =3MV / m (1 atmosphere), E SF6_2 =4.5MV / m (1.5 atmospheres), E SF6_3=6MV / m (2 atmospheres), note that the actual engineering margin is taken into account here, and all dielectric breakdown field strengths are reduced by half. According to the above calculation, the power capacity of the antenna under different dielectric conditions is P cair =5MW, P cva =220MW, P Csf6_1 =20MW, P csf6_2 =44.5MW, P csf6_3 =79MW.

[0079] (3) Design of multi-stage sealing scheme based on field distribution and power capacity

[0080] By comparison, we can see that the actual input power P in =20MW at the antenna air power capacity P cair and vacuum power capacity P cva Therefore, a sealing scheme design can be carried out.

[0081] According to formula (2), substitute it into the simulation to calculate the input power P 0 =0.5W, air breakdown field strength E air =1.5MV / m and input power P in =10MW, the corresponding field strength of the antenna is calculated to be E=335V / m. min <E<E max , so there is a position where E is located. Find the position in the antenna cavity where the field strength is just equal to E, which is where the sealing window is located. The sealing solution at this time is Figure 4 As shown, the sealing window divides the interior of the antenna into two parts. The space near the feed port is evacuated, and the space near the antenna surface is not processed. An ordinary antenna cover is added to the antenna surface to prevent dust.

[0082] Example 3

[0083] The required horn antenna parameters are as follows: gain 10dBi, working frequency band L band, power capacity 200MW.

[0084] (1) Calculate the field strength distribution inside the antenna based on the antenna model

[0085] Use commercial electromagnetic software to simulate the antenna model and set the antenna feed input power P 0 =0.5W, calculate the field strength distribution inside the antenna, the maximum field strength value E max =477.3V / m, E max The location is inside the horn antenna feed waveguide, and the minimum field strength value is E min =253V / m.

[0086] (2) Calculate the antenna power capacity

[0087] According to formula (2), substitute the input power P 0 =0.5W, maximum field strength value E max =477.3V / m and air breakdown field strength E air =1.5MV / m, vacuum breakdown field strength E va =35MV / m, SF 6 Breakdown field strength E SF6_1 =3MV / m (1 atmosphere), E SF6_2 =4.5MV / m (1.5 atmospheres), E SF6_3 =6MV / m (2 atmospheres), note that the actual engineering margin is taken into account here, and all dielectric breakdown field strengths are reduced by half. According to the above calculation, the power capacity of the antenna under different dielectric conditions is P cair =5MW, P cva =220MW, P Csf6_1 =20MW, P csf6_2 =44.5MW, P csf6_3 =79MW.

[0088] (3) Design of multi-stage sealing scheme based on field distribution and power capacity

[0089] By comparison, we can see that the actual input power P in = 200MW at the antenna air power capacity P cair and vacuum power capacity P cva Therefore, a sealing scheme design can be carried out.

[0090] According to formula (2), substitute it into the simulation to calculate the input power P 0 =0.5W, air breakdown field strength E air =1.5MV / m and input power P in =200MW, the calculated field strength of the antenna is E = 237V / m. Since E < E min , so there is no position where E is located.

[0091] According to formula (2), substitute it into the simulation to calculate the input power P 0 =0.5W, sulfur hexafluoride breakdown field strength E SF6_1 =3MV / m (1 atmosphere), E SF6_2 =4.5MV / m (1.5 atmospheres), E SF6_3 =6MV / m (2 atmospheres) and input power P in =200MW, calculate the field strength E corresponding to the antenna SF6_1 '=150V / m、E SF6_2 '=225V / m、E SF6_3 '=300V / m,where E min <ESF6_3 '<E max , therefore, we find that the field strength inside the antenna cavity is exactly equal to E SF6_3 ', which is where the sealing window is located. The sealing solution at this time is Figure 5 As shown in the figure, the sealing window divides the interior of the antenna into two parts. The space near the feed port is evacuated, and the space near the antenna port is filled with SF at 2 atmospheres. 6 Gas, a sealed antenna cover is added at the antenna surface to prevent dust and ensure airtightness.

[0092] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0093] It should be understood that those skilled in the art can make improvements or changes based on the above description, and all these improvements and changes should fall within the scope of protection of the appended claims of the present invention.

Claims

1. A design method for a multi-segment sealed high power capacity antenna, characterized in that: The method comprises the following steps: Step 1. Calculate the field strength distribution inside the antenna according to the antenna model: Use electromagnetic software to simulate the antenna model, set the antenna feed input power, calculate the field strength distribution inside the antenna, and obtain the maximum and minimum field strength values; Step 2, calculate the power capacity of the antenna: according to the input power, maximum field strength value and breakdown field strength under different medium conditions calculated by simulation, calculate the power capacity of the antenna under different medium conditions; Step 3: Design multi-stage sealing according to field strength distribution and power capacity, including: If the input power during actual use is between the antenna's air power capacity and vacuum power capacity, a sealed design can be performed; calculate the corresponding air breakdown field strength E in the antenna, and find the position in the antenna cavity where the field strength is just equal to E; If the position of E can be found, a sealing window is set at this position. The sealing window divides the inside of the antenna into two parts. The space near the feed port is evacuated, and the space near the antenna aperture is not processed. An ordinary radome is added to the antenna aperture. If the position of E cannot be found, the breakdown field strength E' of the special gas corresponding to the antenna is calculated according to the gas actually used, and a sealing window is set at this position. The sealing window divides the inside of the antenna into two parts. The space near the feed port is evacuated, and the space near the antenna surface is filled with special gas. A sealed antenna cover is added at the antenna surface. The calculation method of input power in this method is: The formula between input power and field strength in the waveguide cavity is as follows: in, Ec is the maximum field strength at the input power, the long side a of the waveguide cavity, the wide side b of the waveguide cavity, the wavelength λ, and the dielectric constant ε r .

2. The method for designing a multi-segment sealed high power capacity antenna according to claim 1, characterized in that: Different medium conditions in this method include: air, vacuum, special gas; the special gas adopts inert gas or directly filled with positive pressure air; the inert gas includes SF6 and N2.

3. The method for designing a multi-segment sealed high power capacity antenna according to claim 2, characterized in that: In this method, the formula for calculating the power capacity of the antenna in three medium conditions: air, vacuum, and special gas is: Among them, the input power P0 and the simulated maximum field strength value E max , air breakdown field strength E air , vacuum breakdown field strength E va 、Special gas breakdown field strength E S , air power capacity P cair , Vacuum power capacity P cva 、Special gas power capacity P cS .

4. The method for designing a multi-segment sealed high power capacity antenna according to claim 3, characterized in that: In this method, the maximum breakdown field strength is selected as 1 / 3 of the theoretical value as the actual breakdown field strength to retain the engineering margin.

5. The method for designing a multi-segment sealed high power capacity antenna according to claim 3, characterized in that: The method for calculating the corresponding air breakdown field strength E in the antenna in this method is: The relationship between power capacity and field strength satisfies the following formula: Wherein, E1 is the maximum field intensity in the waveguide cavity when the input power is P1, and E2 is the maximum field intensity in the waveguide cavity when the input power is P2; Substitute the simulation to calculate the input power P0 and the air breakdown field strength E air And input power P in From the formula of the relationship between power capacity and field strength, the air breakdown field strength E corresponding to the antenna can be calculated; The method for calculating the breakdown field strength E' of the corresponding special gas in the antenna is: Substitute the input power P0 and the special gas breakdown field strength E into the simulation calculation S And input power P in From the formula of the relationship between power capacity and field strength, calculate the breakdown field strength E' of the special gas corresponding to the antenna.

6. The method for designing a multi-segment sealed high power capacity antenna according to claim 1, characterized in that: The structure of the sealing window in the method includes: a ceramic sheet, a waveguide matching structure, and a rectangular waveguide wall.

7. The method for designing a multi-segment sealed high power capacity antenna according to claim 1, characterized in that: The antenna in the method is an antenna with high power capacity, including: a horn antenna, a waveguide slot array antenna, and a parabolic antenna.

8. The method for designing a multi-segment sealed high power capacity antenna according to claim 1, characterized in that: If the input power in the actual use process is not satisfied in this method, it is necessary to continue to judge: If the input power is greater than the vacuum power capacity during actual use, the antenna cannot meet the required power capacity requirements; If the input power is less than the antenna's air power capacity during actual use, the antenna can directly meet the power capacity requirement in the air state.

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