CN110502864A - A kind of airframe and its electromagnet shield effect appraisal procedure - Google Patents

A kind of airframe and its electromagnet shield effect appraisal procedure Download PDF

Info

Publication number
CN110502864A
CN110502864A CN201910809451.2A CN201910809451A CN110502864A CN 110502864 A CN110502864 A CN 110502864A CN 201910809451 A CN201910809451 A CN 201910809451A CN 110502864 A CN110502864 A CN 110502864A
Authority
CN
China
Prior art keywords
airframe
gap structure
shield effect
electromagnet shield
model
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN201910809451.2A
Other languages
Chinese (zh)
Inventor
甄国帅
臧家左
吕朝晖
祈雪峰
毛宇
张文杰
王焱
张涛
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenyang Aircraft Design and Research Institute Aviation Industry of China AVIC
Original Assignee
Shenyang Aircraft Design and Research Institute Aviation Industry of China AVIC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shenyang Aircraft Design and Research Institute Aviation Industry of China AVIC filed Critical Shenyang Aircraft Design and Research Institute Aviation Industry of China AVIC
Priority to CN201910809451.2A priority Critical patent/CN110502864A/en
Publication of CN110502864A publication Critical patent/CN110502864A/en
Pending legal-status Critical Current

Links

Abstract

This application involves a kind of airframe electromagnet shield effect appraisal procedure, appraisal procedure includes: to establish the true gap structure model of gap structure respectively according to gap structure feature and electromagnet shield effect building and simplify gap structure model;Two models are emulated, and at least one structural parameters in gap structure model are simplified in variation, keep the simulation result of two models consistent, the structural parameters for simplifying gap structure model are obtained with this;Airframe model is constructed, and keeps the gap structure parameter in airframe model consistent with the structural parameters for simplifying gap structure model;It is arranged inside and outside electric field monitor and electromagnetic radiation source in airframe model, and emulates and obtains the first electromagnetism numerical value with airframe and the second electromagnetism numerical value except airframe, thus can get the electromagnet shield effect of airframe.

Description

A kind of airframe and its electromagnet shield effect appraisal procedure
Technical field
The application belongs to aircraft electromangnetic spectrum field, in particular to a kind of airframe electromagnet shield effect assessment side Method and device.
Background technique
With the development of electronic technology, modern aircraft has been equipped with a large amount of electronic equipment, in addition, High power radar, electronics The equipment of the high power radiation sources such as Jamming pod, High-Power Microwave equipment and electromagnetic pulse equipment and use, so that aircraft is flat Stronger, more complicated electromagnetic environment is formed around platform.
The electromagnet shield effect of airframe is the important indicator parameter that aircraft adapts to external forceful electric power magnetic environment.Airframe Electromagnet shield effect should be assessed at airplane design initial stage, to find the problem and to solve in time, evade design risk.
Existing airframe electromagnet shield effect means of testing and test scope are limited, and measuring accuracy is difficult to assess, and It needs prototype to test, disconnects with airplane design process.
Summary of the invention
There is provided a kind of airframe electromagnet shield effect appraisal procedures for the purpose of the application, to solve or mitigate background At least one problem in technology.
The technical solution of the application is: a kind of airframe electromagnet shield effect appraisal procedure, the appraisal procedure include:
True gap structure model and the institute of the gap structure are constructed according to gap structure feature and electromagnet shield effect State that true gap structure model is corresponding to simplify gap structure model;
Emulate the true gap structure model and it is described simplify gap structure model, and simplify gap structure described in changing At least one structural parameters in model, so that the emulation for simplifying gap structure model Yu the true gap structure model As a result consistent, and the structural parameters of gap structure model are simplified described in acquisition;
The airframe model with the gap structure is constructed, and joins the gap structure in the airframe model Number is consistent with the structural parameters for simplifying gap structure model;
Electric field monitor and electromagnetic radiation source are respectively set inside and outside the airframe model, the electromagnetic radiation source is released The electromagnetic wave of preset frequency is put, and emulates the aircraft body structure model to obtain the first electromagnetism by the electric field monitor Numerical value, and only remove the aircraft body structure model and simplify gap structure model to obtain the second electromagnetism numerical value, it is described The difference of first electromagnetism numerical value and the second electromagnetism numerical value is the electromagnet shield effect of the airframe.
In one embodiment of the application, the gap structure includes airplane hatch cover and hatch door.
In one embodiment of the application, the structural parameters for simplifying fissures model include gap depth and slit width Degree.
In one embodiment of the application, the gap depth is determined according to the gap actual depth;The slit width Degree is set as variable, for matching the electromagnet shield effect characteristic of true gap structure.
In one embodiment of the application, the airframe model is according to the bay section distribution inside airframe, baffle Distribution and device distribution building.
In one embodiment of the application, when airframe model construction, ignores cable complicated inside airframe Harness, frame, hole and small device.
In one embodiment of the application, the electromagnetic radiation source load is plane wave.
In one embodiment of the application, minimum range of the plane wave away from airframe surface is greater than simulation frequency pair Ten times for answering electromagnetic wavelength.
In one embodiment of the application, the difference includes that the first electromagnetism numerical value subtracts the second electromagnetism numerical value And/or the second electromagnetism numerical value subtracts the first electromagnetism numerical value.
In addition, the airframe has electromagnet shield effect, the electromagnetism present invention also provides a kind of airframe Shield effectiveness is determined according to as above any airframe electromagnet shield effect appraisal procedure.
The airframe electromagnet shield effect appraisal procedure of the application provides a kind of with true gap structure model Equivalent method substitutes true fissures model using fissures model is simplified, had both remained the electromagnet shield effect of true fissures model Characteristic, in turn avoids true fissures model generally existing flood tide mesh generation in simulations, substantially save computing resource and when Between, in addition, the application can also quick and precisely assess the electromagnet shield effect of airframe at airplane design initial stage, set for aircraft Meter is provided with reference to amendment foundation, gives the modeling method of airframe internal structure.
Detailed description of the invention
In order to illustrate more clearly of technical solution provided by the present application, attached drawing will be briefly described below.It is aobvious and easy Insight, drawings discussed below are only some embodiments of the present application.
Fig. 1 is the present processes flow diagram.
Fig. 2 is the true gap structure model (left side) at certain hatch door in one embodiment of the application and simplifies gap structure model (right side) schematic diagram.
Fig. 3 is the true gap structure model (left side) at certain lid in one embodiment of the application and simplifies gap structure model (right side) schematic diagram.
Fig. 4 is the electromagnet shield effect simulation result comparison diagram in gap at certain hatch door in above-described embodiment.
Fig. 5 is the electromagnet shield effect simulation result comparison diagram in gap at certain lid in above-described embodiment.
Fig. 6 is the hatch door (at forebody) of airframe and the position distribution of lid (at wing) in one embodiment of the application Schematic diagram.
Fig. 7 is that schematic diagram is arranged in the electric field monitor in above-described embodiment inside airframe.
Fig. 8 is the electromagnet shield effect schematic diagram of noselanding gear well near zone in above-described embodiment.
Fig. 9 is the electromagnet shield effect schematic diagram of wing oil filler lid near zone in above-described embodiment.
Specific embodiment
To keep the purposes, technical schemes and advantages of the application implementation clearer, below in conjunction in the embodiment of the present application Attached drawing, technical solutions in the embodiments of the present application is further described in more detail.
The application proposes that a kind of airframe electromagnet shield effect appraisal procedure based on numerical simulation, this method are suitable for Airframe surface is equipped with all aircraft platforms that lid and hatch door etc. form gap structure, is the electromagnetic shielding of airframe Measures of effectiveness provides foundation.
As shown in Figure 1, the application airframe electromagnet shield effect appraisal procedure includes the following steps:
S1, according to the true gap structure model of gap structure feature and electromagnet shield effect building gap structure and true Gap structure model is corresponding to simplify gap structure model.
In this application, have apertured structure and generally include lid and hatch door etc..Simplify the structure of gap structure model Parameter mainly includes gap depth and gap width, wherein gap depth is determining according to the actual (real) thickness in airframe, generally It is chosen for 1 millimeter.The gap width for simplifying gap structure model is set as variable, can be used for matching the electromagnetism of true gap structure Shield effectiveness characteristic.
Such as the true fissures model at the nose gear door of Fig. 1 left figure illustrated embodiment, it is corresponding to simplify gap For model as shown in Fig. 1 right figure, the gap width after optimization is 0.2 millimeter (10-1000MHz frequency range) and 0.6 millimeter of (1000- 2000MHz frequency range), wherein simplifying gap is to blacken shown in straight line in Fig. 1 right figure.
True fissures model at the wing oil filler lid of Fig. 2 left figure illustrated embodiment, it is corresponding to simplify gap knot For structure model as shown in Fig. 2 right figure, the gap width after optimization is 0.06 millimeter (100-200MHz frequency range), simplifies gap as figure It is blackened shown in straight line in 2 right figures.
S2, it to true gap structure model and simplifies gap structure model and carries out electromagnet shield effect emulation, change simplifies At least one structural parameters in gap structure model, so that simplifying the emulation of gap structure model Yu true gap structure model As a result consistent, when result is consistent, obtains and record the structural parameters for simplifying gap structure model.
Since gap depth is usually varied less or is held essentially constant in true gap structure, and gap width is due to system Making the reasons such as tolerance will cause variation, therefore in modeling and simulation, and it is logical to change the structural parameters simplified in gap structure model It is often gap width, simplify gap structure model when emulation keeps simulation result consistent with true gap structure model, the essence of record The structural parameters of simple gap structure model are gap width.
True fissures model is tied with the electromagnet shield effect emulation for simplifying fissures model in embodiment as shown in Figure 3 and Figure 4 Fruit comparison diagram, when simulation comparison result is more consistent, it was demonstrated that the slit width degree for simplifying fissures model chosen in above-mentioned steps It is worth relatively reasonable.
S3, building have the airframe model of the gap structure, and join the gap structure in airframe model Number is consistent with the structural parameters for simplifying gap structure model.
According to true distribution of the gap structure on airframe, chooses slot edge setting and simplify fissures model, simplify The gap depth of gap structure model is traditionally arranged to be 1 millimeter, and gap width is the knot of the gap width recorded in above-mentioned steps Fruit.
Be distributed when simulation model inside airframe constructs according to the main bay section distribution inside airframe, baffle, Biggish device distribution of shape etc. is constructed.In addition, ignoring complexity inside airframe in airframe model construction The factors such as cable harness, frame, hole and small device, these factors will increase dramatically simulation time, and simulation accuracy is not Controllably.
The position distribution of nose gear door and wing oil filler lid in airframe, figure in embodiment as shown in Figure 6 Middle frame is the slot edge place of hatch door or lid.According to the slit width for simplifying gap structure model chosen in above-mentioned steps Gap is simplified on degree, setting airframe surface.
Have when the organism internal structure of nose gear door region A1 is arranged, before and after landing gear compartment baffle carry out every It is disconnected, be cockpit above landing gear compartment, separated between cockpit and landing gear compartment, ignore cable harness inside landing gear compartment, Frame and the small device of installation etc..When the organism internal structure of wing oil filler lid region A2 is arranged, referring to above-mentioned The organism internal structure of nose gear door region A1 is arranged, this place repeats no more.
S4, electric field monitor and electromagnetic radiation source are respectively set inside and outside airframe model, electromagnetic radiation source release is pre- Determine the electromagnetic wave of frequency, and emulates aircraft body structure model to obtain the first electromagnetism numerical value by electric field monitor, and only Removal aircraft body structure model and simplify gap structure model and other settings are constant to obtain the second electromagnetism numerical value, first is electric Magnetic number value and the difference of the second electromagnetism numerical value are the electromagnet shield effect of airframe.
In this application, electric field monitor need to be arranged near the gap of internal body, to improve monitoring accuracy.In body The electromagnetic radiation source of outside setting can be realized by loaded antenna or loaded planar wave.Wherein, when loaded planar wave, plane The minimum range on pitch of waves airframe surface should be greater than ten times that simulation frequency corresponds to electromagnetic wavelength.
In the embodiment of the present application, in emulation twice, the numerical value that electric field monitor obtains is converted into dB value, passes through dB The difference of value can get the electromagnet shield effect of lid or hatch door.Wherein, difference can be electric field monitor in second of emulation The numerical value of acquisition subtracts the numerical value that electric field monitor obtains in emulation for the first time, or electric field monitor in emulation for the first time The numerical value of acquisition subtracts the numerical value that electric field monitor obtains in second of emulation.
It is monitored in embodiment as shown in Figure 7 in nose gear door region and wing oil filler lid region setting electric field Device successively carries out electromagnet shield effect emulation twice, calculates electromagnet shield effect, electromagnetism by the result of electric field monitor twice Shield effectiveness simulation result is as shown in Figure 7 and Figure 8.Pass through the electricity for making the difference available corresponding site of attached drawing upper and lower in Fig. 7 or Fig. 8 Magnetic screen efficiency.
Finally, the airframe has electromagnet shield effect, the electromagnetism present invention also provides a kind of airframe Shield effectiveness is determined according to above-mentioned airframe electromagnet shield effect appraisal procedure.
The airframe electromagnet shield effect appraisal procedure of the application has the advantages that
1) the present processes provide the equivalent method of lid or the true fissures model of hatch door, using simplifying fissures model True fissures model is substituted, the electromagnet shield effect characteristic of true fissures model has both been remained, has in turn avoided true fissures model Generally existing flood tide mesh generation in simulations substantially saves computing resource and time.
2) the present processes can quick and precisely assess the electromagnet shield effect of airframe at airplane design initial stage, be Airplane design is provided with reference to amendment foundation, gives the modeling method of airframe internal structure.
The above, the only specific embodiment of the application, but the protection scope of the application is not limited thereto, it is any Within the technical scope of the present application, any changes or substitutions that can be easily thought of by those familiar with the art, all answers Cover within the scope of protection of this application.Therefore, the protection scope of the application should be with the scope of protection of the claims It is quasi-.

Claims (10)

1. a kind of airframe electromagnet shield effect appraisal procedure, which is characterized in that the appraisal procedure includes
The true gap structure model of the gap structure and described true is constructed according to gap structure feature and electromagnet shield effect Real gap structure model is corresponding to simplify gap structure model;
Emulate the true gap structure model and it is described simplify gap structure model, and simplify gap structure model described in changing In at least one structural parameters so that the simulation result for simplifying gap structure model Yu the true gap structure model Unanimously, and described in acquisition the structural parameters of gap structure model are simplified;
Construct the airframe model with the gap structure, and make gap structure parameter in the airframe model with The structural parameters for simplifying gap structure model are consistent;
Electric field monitor and electromagnetic radiation source are respectively set inside and outside the airframe model, the electromagnetic radiation source release is pre- Determine the electromagnetic wave of frequency, and emulates the aircraft body structure model to obtain the first electromagnetism number by the electric field monitor Value, and only remove the aircraft body structure model and simplify gap structure model to obtain the second electromagnetism numerical value, described the The difference of one electromagnetism numerical value and the second electromagnetism numerical value is the electromagnet shield effect of the airframe.
2. airframe electromagnet shield effect appraisal procedure as described in claim 1, which is characterized in that the gap structure packet Include airplane hatch cover and hatch door.
3. airframe electromagnet shield effect appraisal procedure as described in claim 1, which is characterized in that described to simplify slit die The structural parameters of type include gap depth and gap width.
4. airframe electromagnet shield effect appraisal procedure as claimed in claim 3, which is characterized in that the gap depth root It is determined according to the gap actual depth;
The gap width is set as variable, for matching the electromagnet shield effect characteristic of true gap structure.
5. airframe electromagnet shield effect appraisal procedure as described in claim 1, which is characterized in that the airframe mould Type is constructed according to bay section distribution, baffle distribution and the device distribution inside airframe.
6. airframe electromagnet shield effect appraisal procedure as claimed in claim 5, which is characterized in that the airframe mould Type ignores cable harness, frame, hole and small device complicated inside airframe when constructing.
7. airframe electromagnet shield effect appraisal procedure as described in claim 1, which is characterized in that the electromagnetic radiation source It is realized by loaded planar wave or antenna.
8. airframe electromagnet shield effect appraisal procedure as claimed in claim 7, which is characterized in that the plane wave is away from winged The minimum range of machine body surface is greater than ten times that simulation frequency corresponds to electromagnetic wavelength.
9. airframe electromagnet shield effect appraisal procedure as described in claim 1, which is characterized in that the difference includes institute State that the first electromagnetism numerical value subtracts the second electromagnetism numerical value and/or the second electromagnetism numerical value subtracts the first electromagnetism numerical value.
10. a kind of airframe, which is characterized in that the airframe has electromagnet shield effect, the electromagnet shield effect It is determined according to airframe electromagnet shield effect appraisal procedure as described in any one of claim 1 to 9.
CN201910809451.2A 2019-08-29 2019-08-29 A kind of airframe and its electromagnet shield effect appraisal procedure Pending CN110502864A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201910809451.2A CN110502864A (en) 2019-08-29 2019-08-29 A kind of airframe and its electromagnet shield effect appraisal procedure

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201910809451.2A CN110502864A (en) 2019-08-29 2019-08-29 A kind of airframe and its electromagnet shield effect appraisal procedure

Publications (1)

Publication Number Publication Date
CN110502864A true CN110502864A (en) 2019-11-26

Family

ID=68590553

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201910809451.2A Pending CN110502864A (en) 2019-08-29 2019-08-29 A kind of airframe and its electromagnet shield effect appraisal procedure

Country Status (1)

Country Link
CN (1) CN110502864A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112329154A (en) * 2020-11-26 2021-02-05 中国航空工业集团公司沈阳飞机设计研究所 Electromagnetic environment simulation method
CN113056184A (en) * 2021-03-15 2021-06-29 上海应用技术大学 Shielding net simulation design method based on optimized interference signal and whole framework
CN113311250A (en) * 2020-02-26 2021-08-27 上海飞机制造有限公司 Cable braided shielding layer shielding effectiveness evaluation method, device, equipment and medium
CN116187109A (en) * 2023-04-27 2023-05-30 北京航天天美科技有限公司 Radio frequency interface window structure simulation optimization method

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8039763B1 (en) * 2005-03-15 2011-10-18 Stealthdrive, Inc. EMI-shielding solutions for computer enclosures using combinations of two and three-dimensional shapes formed in sheet metal
RU2523422C1 (en) * 2013-04-26 2014-07-20 Негосударственное образовательное учреждение высшего профессионального образования "Российский новый университет" (НОУ ВПО "РосНОУ") Test method isolated objects (aircrafts) for corona effect on and device for its implementation
CN104573244A (en) * 2015-01-14 2015-04-29 西安电子科技大学 PEEC-based electromagnetic screen effect simulation method of case with coupling
CN105183939A (en) * 2015-07-21 2015-12-23 电子科技大学 Equivalent circuit-based method for calculating shielding efficiency of cavity with hole arrays
CN106777536A (en) * 2016-11-26 2017-05-31 山东省计算中心(国家超级计算济南中心) Electro-magnetic far-field two, three-dimensional visual processing method based on fine Electromagnetic Simulation
CN108051668A (en) * 2017-12-05 2018-05-18 上海无线电设备研究所 The radiation-emitting interference simulation of PEDs and the test method of calibration in aircraft cabin

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8039763B1 (en) * 2005-03-15 2011-10-18 Stealthdrive, Inc. EMI-shielding solutions for computer enclosures using combinations of two and three-dimensional shapes formed in sheet metal
RU2523422C1 (en) * 2013-04-26 2014-07-20 Негосударственное образовательное учреждение высшего профессионального образования "Российский новый университет" (НОУ ВПО "РосНОУ") Test method isolated objects (aircrafts) for corona effect on and device for its implementation
CN104573244A (en) * 2015-01-14 2015-04-29 西安电子科技大学 PEEC-based electromagnetic screen effect simulation method of case with coupling
CN105183939A (en) * 2015-07-21 2015-12-23 电子科技大学 Equivalent circuit-based method for calculating shielding efficiency of cavity with hole arrays
CN106777536A (en) * 2016-11-26 2017-05-31 山东省计算中心(国家超级计算济南中心) Electro-magnetic far-field two, three-dimensional visual processing method based on fine Electromagnetic Simulation
CN108051668A (en) * 2017-12-05 2018-05-18 上海无线电设备研究所 The radiation-emitting interference simulation of PEDs and the test method of calibration in aircraft cabin

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
何秋仙: "电子设备电磁兼容仿真关键技术研究", 《中国优秀硕士学位论文全文数据库(电子期刊) 信息科技辑》 *
张奕: "隐身飞机口盖衬垫屏蔽效能仿真及测试装置的研制", 《中国优秀硕士学位论文全文数据库(电子期刊) 工程科技Ⅱ辑》 *
王辉;张建斌;俞斌;: "空间电磁辐射的缝隙仿真建模技术研究", 电子测试 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113311250A (en) * 2020-02-26 2021-08-27 上海飞机制造有限公司 Cable braided shielding layer shielding effectiveness evaluation method, device, equipment and medium
CN113311250B (en) * 2020-02-26 2024-04-05 上海飞机制造有限公司 Method, device, equipment and medium for evaluating shielding effectiveness of cable braided shielding layer
CN112329154A (en) * 2020-11-26 2021-02-05 中国航空工业集团公司沈阳飞机设计研究所 Electromagnetic environment simulation method
CN113056184A (en) * 2021-03-15 2021-06-29 上海应用技术大学 Shielding net simulation design method based on optimized interference signal and whole framework
CN116187109A (en) * 2023-04-27 2023-05-30 北京航天天美科技有限公司 Radio frequency interface window structure simulation optimization method

Similar Documents

Publication Publication Date Title
CN110502864A (en) A kind of airframe and its electromagnet shield effect appraisal procedure
CN104462713A (en) Electromagnetic compatibility modeling method and system for rail transit vehicle
Gutierrez et al. HIRF virtual testing on the C-295 aircraft: On the application of a pass/fail criterion and the FSV method
CN110516397B (en) Method and system for simulating thunder electromagnetic environment
CN104778151B (en) Target with open cavity Analysis of Electromagnetic Scattering method based on moment method and parabolic equation
CN110502863A (en) A kind of gap structure and its electromagnet shield effect appraisal procedure
CN111707875A (en) Electric control pry shielding effectiveness testing device and method for gas gathering station field
Munteanu et al. It's about time
Wendt et al. A macromodeling-based hybrid method for the computation of transient electromagnetic fields scattered by nonlinearly loaded metal structures
CN100593966C (en) Electromagnetic wave shielding method and electromagnetic wave shielding cover
Toyota et al. Stopband analysis using dispersion diagram for two-dimensional electromagnetic bandgap structures in printed circuit boards
Xiao et al. Simulation analysis of electromagnetic shielding of electronic device chassis
He et al. Numerical investigation on interference and absorption of electromagnetic waves in the plasma-covered cavity using FDTD method
Wu et al. Progress of electromagnetic compatibility design for unmanned aerial vehicles
CN104573244B (en) A kind of electromagnetic screen effect emulation mode of the annex cabinet containing connection based on PEEC
CN207457374U (en) A kind of armored vehicle vehicle Electromagnetic Simulation system
Danoon et al. On the integration of lightning protection with stealth coated wind turbine blades
CN115236411A (en) Radiation source modeling method for electronic device in shielding case
Cordill et al. Shielding effectiveness of composite and aluminum aircraft, model and measurement comparison
Gutierrez et al. Influence of geometric simplifications on high-intensity radiated field simulations
Ding et al. A Novel EMC Simulation Analysis Method for Ship-Borne Phased Array Radar System
CN103869198A (en) Approximate simplifying method for reducing electromagnetic environmental simulation complexity in airplane
Yan et al. Simulation analysis of complex electromagnetic environment effect of helicopter engine
CN108170954A (en) A kind of simulating analysis of signal equipment electric field radiation transmitting
Arık et al. Reducing emi by multiple slits shielding

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
RJ01 Rejection of invention patent application after publication
RJ01 Rejection of invention patent application after publication

Application publication date: 20191126