Study On The Forming Process Of Curved FSS Radome And Its Error On Electromagnetic Characteristics

Frequency selection surface radome(FSS radome)is a new type of stealth radome which combines the selective transmission of frequency selection surface with traditional dielectric radome.The radome can greatly reduce the radar cross section of the target.It has been widely used in stealth technology field.In practical engineering applications,radome often have more complex curved surface shape,which greatly increases the difficulty of theoretical design and manufacturing of curved FSS radome.Based on this,starting with the theoretical design of curved FSS radome,this paper explored the technological scheme of preparing curved FSS radome by means of secondary solidification method,and carried out electromagnetic simulation analysis for various technological errors in the process of forming.And a folded FSS radome with strong design ability is innovatively proposed.Firstly,the theoretical design of the curved FSS radome was carried out,which included two parts: the design of the radome wall structure and the design of the frequency selective surface.Based on the conventional A sandwich wall structure,a frequency selection surface A sandwich wall structure is designed.Based on the traditional annular FSS units structure,a frequency selection surface of a square annular FSS unit periodic array with rectangular arrangement was designed.At the same time,the electromagnetic simulation analysis of the double-layer square annular FSS unit was carried out by HFSS software.The results showed that the electromagnetic transmission characteristics of the double-layer square annular FSS unit structure show good double-band characteristics in the frequency band of 2~20 GHz.Secondly,the curved FSS radome was fabricated by the combination of two forming processes: the mold pressing process and the vacuum bag-autoclave process.In other words,the second solidification process.The intermediate FRP dielectric layer was fabricated by mold pressing process with glass fiber/epoxy resin composite preprepreg as raw material.After the above preparation,the final product of curved FSS radome was fabricated by precisely compounding the upper and lower layers of frequency selective surface flexible screen and the molded intermediate FRP dielectric layer by vacuum bag-autoclave process.At the same time,aiming at some quality problems in the fabrication process of curved FSS radome,the corresponding process quality control measures were put forward,and the process was optimized and improved.Thirdly,aiming at the various technological errors in the fabrication of curved FSS radome,such as the electromagnetic parameter errors of the intermediate layer,the thickness errors of the intermediate layer,the displacement errors of the double-screen dislocation,the stretching and folding errors of the frequency selective surface and the air gap errors,based on the electromagnetic simulation software HFSS,the effects of different technological errors on the curved FSS radome were studied in detail,and the necessary tolerance margin in the actual preparation process was given.Finally,based on the exploratory research of curved FSS radome,a folded FSS radome with strong design ability was innovatively proposed,and the theoretical design,forming process and radar scattering performance of folded FSS radome were deeply studied.The results showed that the folded FSS radome can greatly reduce the radar cross section of the target and has good radar scattering performance.