Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Realization of Flattened Structural Luneburg Lens Based on
  Quasi-Conformal Transformation   Conventional structural Luneburg lens is a symmetric circular gradient-index
lens with refractive indices decreasing from the centre along the radial
direction. In this paper, a flattened structural Luneburg lens (FSLL) based on
structural thickness variations is designed by using the quasi-conformal
transformation (QCT) technique. Through numerical simulations and experimental
studies, the FSLL is demonstrated to have excellent beam steering performance
for the manipulation of flexural wave propagation at desired angles.

20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
9
The categories of this paper are: nlin
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat
26
The categories of this paper are: bayes-an
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
12
The categories of this paper are: nucl-th
34
The categories of this paper are: chem-ph
33
The categories of this paper are: plasm-ph