Ideally Hard Struts to Achieve Invisibility

Fernández-González, José-Manuel; Rajo‐Iglesias, Eva; Silva, Manuel

doi:10.2528/pier09102603

Cited by 6 publications

(3 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using our design method, we can find the approximate effective circuit for the structure, which is the parallel combination of L s = 15.15 nH and C s = 0.73 pF, and we set the non-Foster circuit elements to be close to these values according to equation (5). We use 24 unit cells of the non-Foster based wideband hard surface to coat the PEC blockage, with 6 unit cells on each edge.…”

Section: Resultsmentioning

confidence: 99%

“…That means if we want to realize a wideband TE surface wave mode which is close to the light line, we should load the surface with a parallel non-Foster inductor and capacitor which are given by equation (5). Considering the stability conditions [31] for non-Foster circuits, we must ensure that |L neg | > L s and |C neg | < C s .…”

Section: Methodsmentioning

confidence: 99%

“…Both TE and TM surface waves can smoothly pass around an obstacle coated with the hard surface, as illustrated in figure 1(a). Thus, the hard surface is usually used to reduce the electromagnetic blockage due to obstacles [3][4][5], such as the struts of a reflector antenna, which is shown in figure 1(b).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Theoretical design and analysis of wideband active hard electromagnetic surfaces using non-Foster circuit loaded anisotropic metasurfaces

Sievenpiper

2018

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The electromagnetic (EM) hard surface which can both support transverse electric and transverse magnetic surface wave modes has the important ability to reduce the EM blockage of metallic obstacles. We propose a method to design an electrically thin hard surface with wide bandwidth by loading with non-Foster elements. The wideband hard surface composed of an anisotropic impedance coating can be considered as a kind of active metasurface. We develop a method to determine the values of the loading non-Foster circuit which can minimize the dispersion of the unit cells. For this method, we derive accurate values for the loading non-Foster elements through theoretical analysis. We also determine the fundamental limitations on the bandwidth due to stability requirements. To verify our theoretical design, we simulate the transmission performance between the two ports on opposite sides of a metallic rhombus-shaped obstacle coated with the non-Foster based metasurface. The simulated results show that the blockage has been largely reduced over a broad bandwidth from 0.2 GHz to 1.5 GHz. Finally, we provide a discussion on how the resistive part of the non-Foster circuit can affect the performance of the wideband hard surface coating.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Theoretical design and analysis of wideband active hard electromagnetic surfaces using non-Foster circuit loaded anisotropic metasurfaces

Sievenpiper

2018

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

Improvement in side-lobe performance of prime focal reflector antenna

Tyagi

Singh

Chakrabarthy

et al. 2016

Microw. Opt. Technol. Lett.

View full text Add to dashboard Cite

This paper presents a simple and elegant solution to improve the degradation of side lobe level (SLL) caused by strut and feed system blockage in prime focal reflector antenna system. This is accomplished by numerical optimization of reflecting wedges, which may be integrated with conventional rectangular cross‐sectional struts. Design, optimization and analysis of metallic sheet feed cover have been carried out to reduce diffraction caused by the feed system. Quadrilateral meshing is used to analyze non‐standard scatterers. Comprehensive analysis results showing frequency response of SLL of antenna system have been discussed, for different antenna component assemblies. A novel method has been implemented to understand the effect of wedged struts and feed cover for SLL improvement. Experimental data have also been presented to validate the simulated antenna parameters. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1304–1311, 2016

show abstract

Omnidirectional surface wave cloak using an isotropic homogeneous dielectric coating

Mitchell‐Thomas

Quevedo–Teruel

Sambles

et al. 2016

Sci Rep

View full text Add to dashboard Cite

The field of transformation optics owes a lot of its fame to the concept of cloaking. While some experimental progress has been made towards free-space cloaking in three dimensions, the material properties required are inherently extremely difficult to achieve. The approximations that then have to be made to allow fabrication produce unsatisfactory device performance. In contrast, when surface wave systems are the focus, it has been shown that a route distinct from those used to design free-space cloaks can be taken. This results in very simple solutions that take advantage of the ability to incorporate surface curvature. Here, we provide a demonstration in the microwave regime of cloaking a bump in a surface. The distortion of the shape of the surface wave fronts due to the curvature is corrected with a suitable refractive index profile. The surface wave cloak is fabricated from a metallic backed homogeneous dielectric waveguide of varying thickness, and exhibits omnidirectional operation.

show abstract

Ideally Hard Struts to Achieve Invisibility

Cited by 6 publications

References 16 publications

Theoretical design and analysis of wideband active hard electromagnetic surfaces using non-Foster circuit loaded anisotropic metasurfaces

Theoretical design and analysis of wideband active hard electromagnetic surfaces using non-Foster circuit loaded anisotropic metasurfaces

Improvement in side-lobe performance of prime focal reflector antenna

Omnidirectional surface wave cloak using an isotropic homogeneous dielectric coating

Contact Info

Product

Resources

About