Ground Reflection Effect Reduction in RCS Measurement Using Resistive Tapered Fences

Concealment and hiding of military equipment from the enemy is one of the most important issues in the design of this equipment. This hiding generally performed against microwave frequencies, and the quantity that minimized is the radar cross section (RCS). In order to measure the mentioned quantity, it is necessary to expose the target in an environment without reflection to electromagnetic waves and then to measure the reflected waves from it and thus determine the RCS. In most cases, RCS of an object is the desired in the absence of the ground effect. However, the object is exposed to the ground effect due to its position on the pylon, and in addition to measuring the real object, its image also be seen. One way to reduce the ground effect is to use metal fences. However, the edges diffraction and the large side lobe level of the reflected wave from these fences has made their use difficult. As shown, the use of resistive tapered fences solves both of the above problems. In this paper, for the first time, using 7 fences with tapered resistance and designing a desired arrangement for them, this effect has been removed in the form of five examples. Since the length of the fences is several meters and several tens of wavelengths, here the whole structure considered two-dimensional and therefore a two-dimensional moment code (2D-MoM), in addition to the asymptotic solution of CST software, used to analyze the structure.