A novel EM concentrator with open-concentrator region based on multi-folded transformation optics

Abstract

Conventional concentrators with inhomogeneous coating materials that fully enclose the destined region pose great challenges for fabrication. In this paper, we propose to design an EM concentrator with homogeneous materials. Distinguished from conventional ones, the elaborately designed EM concentrator features a concentrator region that is open to the outer-world, which is achieved with multi-folded transformation optics method by compressing and folding the coating materials to create window(s). Based on this concept, we also investigate open-rotator and open rotational-concentrator devices, which could simultaneously rotate and store the EM waves in the central destined region. Due to the open nature of our proposed designs, we believe they will find potential applications in remote controlling with impressive new functionalities.

A bi-functional illusion device based on transformation optics

“…where J is the Jacobian tensor, and for the triangular shape only in 2D transformation, the Jacobian matrix can be found as [19]:…”

“…Similarly, directive antennas have been introduced employing the TO to achieve high-directivity from the smaller-sized antenna [36][37][38][39][40][41]. Overall, the TO technique is useful in constructing the conceptual devices, whereas the hurdle of complex constitutive parameters can be minimized by achieving homogeneous-materials using linear coordinate transformation method [19,39,42]. The human's perception of outer environment and world is due to the brain judgment based on the information of five-senses.…”

Design of open devices based on multi-folded transformation optics

“…AS an ingenious mathematical approach, transformation optics (TO) [1][2][3][4][5][6] provides a powerful and convenient way to control the electromagnetic (EM) fields arbitrarily, arousing much attentions in the past two decades. Based on this methodology, novel devices with varied functions and applications have been proposed, designed and experimented with an unprecedented prosperity, including invisible cloaks [7][8][9][10][11][12][13], concentrators [14][15][16][17][18], illusory devices [19][20][21][22][23][24][25][26][27][28] and antennas [29][30][31][32][33][34][35] etc. The most striking device among them is invisible cloak, where some properly designed materials are utilized to direct the EM waves propagates smoothly around an arbitrarily shaped object, making the entire device (including the coated object) become invisible for the outside viewers.…”

Experimental Demonstration of a Multi-Beam Antenna With Full Parameters Based on Inductor-Capacitor Networks

“…Transformation optics (TO) [1][2][3], which is based on the form invariance of Maxwell's equations, has attracted significant attention in the design of novel electromagnetic and optical devices to guild waves along predesigned routes. Many novel devices based on TO theory have been proposed and implemented, including cloaks [4][5][6][7][8], concentrators [9][10][11], illusion devices [12][13][14], and lens [15][16][17][18]. Among these devices, multi-beam antennas capable of achieving multi-beam emission show promise for many potential applications in the fields of satellite communications, smart traffic systems, and multiple-input multiple-output (MIMO) systems [19][20][21][22][23][24].…”