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In this paper, a metasurface (MS) is designed based on the hybrid array pattern synthesis and particle swarm optimization method for wideband monostatic and multistatic radar stealth. The non-absorptive MS is composed of two kinds of electronic band gap structures with the reflection phase difference of 180° (±37°) over a wide frequency range. Far field scattering pattern of the MS can be quickly and accurately synthetized by the method of moments and array pattern synthesis. A new strategy is proposed for realizing the diffusion reflection of electromagnetic waves by redirecting electromagnetic energies to more directions through optimizing the reflected phase arrangement for the MS by hybrid array pattern synthesis and particle swarm optimization algorithm. Due to the non-uniform distributions of phase gradient between neighboring lattices, numerous scattering lobes are produced in the upper half-space, leading to a great reduction of bistatic radar cross section (RCS). The -10 dB RCS reduction bandwidth of 80.2% is achieved for both monostatic and bistatic at normal incidence. The specular reflection and bistatic scattering for oblique incidence with TE and TM polarizations are also considered in detail. The measured results are in good agreement with the corresponding simulations. [ABSTRACT FROM AUTHOR]

The theory of traveling-wave scattering and two kinds of methods for restraining the traveling-wave scattering are represented in the paper. The traveling-wave scattering could be declined by shaping and radar absorbing material (RAM). The experimental results prove that inhibition effect of traveling-wave scattering using the above methods is prominent. A traveling-wave current comes into being, when a long, thin body is illuminated by grazing incident electromagnetic wave. The flowing traveling-wave current is reflected when it encounters the end of the truncation, and the traveling-wave scattering contributes a lot to the radar cross section (RCS) of the target. The traveling-wave scattering can be researched by making use of the existed concepts of antenna theory. In this paper, a sample of traveling-wave broad was manufactured. Firstly, we restrained the traveling-wave scattering by shaping. The end edge of traveling-wave broad was transformed into saw-tooth or circular arc shape, and measured results proved the shaping method could reduce the RCS of the traveling-wave broad by 10 dB at X-band. Moreover, we restrained the traveling-wave scattering by coating radar absorbing material on the surface of the broad. And the measured results showed that the method of radar absorbing material could reduce the RCS of the traveling-wave broad by more than 10 dB at X-band. [ABSTRACT FROM AUTHOR]

The detection and recognition of moving target is focused by lots of research scholars greatly. However, the algorithms for detection and recognition have to be tested and verified by a great deal of radar echo data. Efficient electromagnetic scattering simulation becomes an effective and economic method for achieving it. The design of appropriate moving target electromagnetic scattering simulation for computer-generated bots poses serious challenges as they have to satisfy stringent requirements that include computation and execution efficiency. This paper discusses a novel efficient high-frequency electromagnetic scattering simulation approach of the rotating moving complex targets. Based on the wide-adopted high-frequency asymptotic methods, such as Physical Optics (PO), Equivalent Edge Current (EEC) and Shooting Bouncing Ray (SBR), a novel efficient approach is proposed by employing the adaptable NVIDIA OptiX ray-tracing engine to solve scattering problems of rotating moving complex targets. High accuracy and efficiency of the hidden-surface-removal (HSR) in PO/EEC and the ray-tracing in SBR are realized at the same time with the state-of-art GPU computation technology. The precise scattering modulation effects of rotating moving target are therefore achieved. Experiments show the effectiveness of the approach. [ABSTRACT FROM AUTHOR]

A novel microwave absorber is presented in this paper. The absorber is a single layer structure based on the topology of a Salisbury screen, but in which the conventional resistive layer is replaced by an active frequency selective surface (AFSS) controlled by PIN diodes. The reflectivity response of the tunable microwave absorber can be controlling by adjusting the current in PIN diodes. Experimental results are presented and prove the working mechanism of the new absorber, which show that the reflectivity response can be modulated over the frequency band from 10GHz to 12GHz. [ABSTRACT FROM AUTHOR]