Figure 3
From: A novel EM concentrator with open-concentrator region based on multi-folded transformation optics
Scheme illustration of the proposed open rotation-coating device that rotates the EM field while the rotation region is not fully enclosed with the rotation-coating. A linear homogeneous coordinate transformation is used to design the rotator by constructing several triangle regions in virtual space. At the first step, the mapping of rotation-coating is defined as the dashed lines’ regions in virtual space labeled by \(1,2,3\,\mathrm{....}\,8\) are transformed into a conventional rotator with eight different regions (here labeled \(1^{\prime} ,2^{\prime} ,3^{\prime} \mathrm{....}8^{\prime} \)). In easy words, the \({\rm{\Delta }}ABC\) is mapped into \({\rm{\Delta }}A^{\prime} B^{\prime} C^{\prime} \) and so on. The material parameters of the proposed rotator designed from this method are homogeneous and easy to fabricate. In the second step, bigger dashed lines circle is compressed into region I and region II (contained mapped medium of \(6^{\prime} \) and \(7^{\prime} \) regions), and then isotropic folded material is used to coat the compressed region.
