Broadband exterior cloaking

Abstract

Abstract:It is shown how a recently proposed method of cloaking is effective over a broad range of frequencies. The method is based on three or more active devices. The devices, while not radiating significantly, create a "quiet zone" between the devices where the wave amplitude is small. Objects placed within this region are virtually invisible. The cloaking is demonstrated by simulations with a broadband incident pulse. B 49(12), 8479-8482 (1994). 23. J. B. Pendry, "Negative refraction makes a perfect lens," Phys. Rev. Lett. 85, 3966-3969 (2000). 24. O. P. Bruno and S. Lintner, "Superlens-cloaking of small dielectric bodies in the quasistatic regime," J. Appl. Phys. 102, 124,502 (2007)

Realization of Radar Illusion Using Active Devices

“…The drawback of the former one is that signals from outside have been blocked, leading to poor communication for the target, while the latter does not affect the information transmission. Compared to the previous works [14][15][16][17][18], our scheme can not only make an object invisible to the outsider but also mimic a totally different object at a different place. It is thus a direct extension of the original work.…”

“…Generally speaking, EM invisibility, or illusion in general, can be roughly divided into four categories: (1) rendering the object transparent or invisible by controlling the parameters of metamaterials based on the scattering cancellation theory [7,9]; (2) making the object invisible or illusory by exploiting the abnormal EM properties and the special ability to control EM waves of metamaterials based on the transformation optics theory [10,11]; (3) invisibility using anomalous localized resonance method [12,13]; (4) realizing invisibility or illusion using the surface integral equation of the EM field based on active devices [14][15][16][17][18]. So far, realization of radar illusion for an EM target is mainly based on the method of transformation optics [19][20][21][22][23][24][25][26].…”

“…Hence the method has important applications in military sectors. We remark that the method has its weakness, and a serious drawback is that the probing wave must be known in advance [14][15][16].…”

An External Cloak With Arbitrary Cross Section Based on Complementary Medium

“…Recent proposals for electromagnetic cloaking techniques include plasmonic cloaking due to scattering cancelation [7,8], transformation based cloaking [1,2], active cloaking [9], broadband exterior cloaking [10], transmission-line based cloaking [11], cloaking due to anomalous resonance [12,13], etc. The scattering cancelation technique can be achieved for example by canceling radiation from the induced dipole moments of the scatter by introducing another object, in which dipole moments of the opposite direction are induced.…”

TRANSPARENT SHELLs --- INVISIBLE TO ELECTROMAGNETIC WAVES

“…Anomalous localized resonance has also been utilized to conceal small objects, and the cloaking can be achieved in the region external to the cloak [40]. Very recently, a broadband exterior cloaking mechanism, which is based on destructive interference using active cloaking devices, is also proposed by Milton and coworkers [41,42]. In contrast to these methods, Tretyakov et al theoretically and experimentally realized broadband cloaking devices by using transmission-line networks [43,44].…”