Simulation Of Shielding Effectiveness Of Conductive Gaskets In Stealth Aircraft's Cover And Development Of A Stripline Fixture

The electromagnetic shielding performance of the stealth aircraft sawtooth-shaped cover is an important factor affecting the overall electromagnetic compatibility of the aircraft.Due to the great challenge of practical testing,simulation of electromagnetic shielding has become a key breakthrough to study on.In order to improve the electromagnetic shielding performance of stealth aircraft,the installation of conductive gaskets is indispensable,which makes the electromagnetic simulation tougher with complex simulation model and unknown electrical parameters of gaskets.Therefore,the development of the simulation and test device for shielding effectiveness of conductive gaskets is of great significance.In this paper,a stripline device for measuring the shielding effectiveness(SE)of conductive gaskets with an upper frequency of 18 GHz has been developed.It is quite applicable for measuring conductive gaskets with a width no more than 5 mm.And an equivalent model based on the transfer impedance of conductive gaskets was constructed and the corresponding optimization method was introduced,which combined the theory of electromagnetic field and transmission line theory,and the equivalent electrical parameters of conductive gaskets can be achieved.In order to verify the correctness of the equivalent model,a 10 GHz transfer impedance testing device was successfully improved.Finally,the SE of sawtooth gaps of an enclosure is studied by simulation using HFSS.Combined with the cover structure of the stealth aircraft,a typical sample was produced and SE of sawtooth gaps of the cover of the stealth aircraft was evaluated through practical tests.The measurement shows that the stripline fixture have a voltage standing wave ratio(VSWR)lower than 2 in the frequency range of 500 MHz up to 18 GHz.The full-band dynamic range of the fixture can reach to 34 dB.The upper frequency limit of the transfer impedance testing device is promoted from 7GHz to 10 GHz and the VSWR is lower than 2.1.The correctness of the equivalent model based on the transfer impedance of conductive gaskets was verified by comparing the measuring SE of a conductive gasket using the stripline fixture with the simulated SE of the same material based on equivalent transfer impedance model using the stripline fixture model in HFSS.The characteristics of SE of sawtooth gaps are summarized through simulation and practical tests.