The Study on Stealth Design Technology
Abstract—In this report we study some basic ideas on stealth technology. Loosely speaking, the stealth technology can be divided into two categories: the study on target shape design and the study on radar absorbing materials. In this report, we explain the basic principles of these two categories, and give some simulations by CST Microwave Studio and Feko to show the effects of stealth technology.
I. I NTRODUCTION The purpose of stealth design is to protect the target from being detected by the enemy’s radar and to increase the target survivability. Ideally, for an object to be ”stealth”, it needs to have a low optical visibility in addition to ...view middle of the document...
Some typical examples of the stealth design include F-22 stealth ﬁghter plane, F-117 stealth ﬁghter planes, B-2 stealth bomber, sea shadow stealth vehicle, etc. Fig. 1 Fig. 3 are pictures of F22, F117 and sea shadow, respectively. Generally speaking, the research on stealth design can be divided into two categories: the target shape design and the research on radar absorbing materials. Each of these two categories includes a board range. The low-reﬂection shaping requirements have strong negative inﬂuence on the aircraft’s aerodynamic properties. There are two distinctly different approaches to establishing the overall shape of a stealth object: 1) by adopting a compact, smooth blended external geometry. This technique is exempliﬁed by the Northrop B-2. 2) By
employing a faceted conﬁguration, using ﬂat surfaces arranged to minimize normal reﬂections back toward the illuminating radar and eliminate glint. The Lockheed-Martin F-117A adopted this design. The design of radar absorber materials also has two major distinct ways: 1) by admitting the signal and then attenuating its intensity. This type has a wide range of radar frequencies but is usually heavy and expensive. 2) By generating internal reﬂections which interfere with the waves reﬂected from the outer surface. It is called resonant radar absorber material because it is only effective at a number of discrete frequencies. The remainder of the paper is organized as follows. The scatter mechanism is brieﬂy discussed in Section II. Section III presents some discussion on the effect of faceted design. Section IV discusses the resonant radar absorber material; and
Fig. 3: Sea Shadow
in Section V, we offer some concluding remarks. II. S CATTER M ECHANISM We focus the microwave bandwidth radar, at which frequency, the wave length is usually much smaller than the target; therefore, the RCS of the target can be discussed under the optical region. When the EM wave that hits on the target are scattered by a variety of mechanisms: 1) Specular: Specular wave scattering is essentially a reﬂection of the incoming wave. The main contribution arises when the Poynting vector of the incoming wave vector is perpendicular to the local surface. 2) Diffraction: Diffraction occurs when there is a discontinuity in the target geometry or a discontinuity in the electromagnetic material properties of the object. 3) Diffracted surface waves: A surface wave may result when the incoming wave is more or less aligned along the length of a long thin coated body. The scattering arises when the surface wave encounters surface discontinuities, the end of the body or changes in the electromagnetic properties of the surface of the body. 4) Radiation from creeping waves: When the surface which supports a surface wave makes a gentle bend in the longitudinal plane of the surface wave, the surface wave will convert into an attenuated creeping wave that continues to follow the surface and space waves that radiate away from...