Abstract
Design and analysis of metasurface-based devices mainly rely on the ideal ray theory and full-wave simulation technique. However, for near-field and low-frequency applications, these idealized design and time-consuming full-wave simulation methods often suffer from inaccuracy and inefficiency, which hinders the rapid prototyping and further evolution of metasurface-based devices. Here, dipole-based wavelet superposition (DWS) is proposed and formulated to accurately and efficiently design the metasurface and analyze its diffraction field, by treating unit cell on the metasurface and every wavefront representing the target field as Hertzian dipole. We further define quantitatively an effective zone, within which the proposed DWS offers sufficiently accurate results comparable to the full-wave simulation. A series of numerical experiments on design and analysis of metasurface are then carried out to validate our DWS method. Excellent and more superior consistence with the full-wave analysis and theoretical results confirms that the DWS method provides an advanced closed-loop design and analysis tool with significantly improved accuracy and efficiency for metasurface-based devices.
Highlights
In recent years, various metasurface-based devices featuring small cubage, multi-functionality, superior capability, high dependability, and ease of integration, have received continuously growing attention [1]–[6]
It involves two field computation problems, one is to compute the phase profile on the metasurface according to the desired target field, and the other is to calculate the diffraction field generated by the metasurface
The amplitude and phase patterns of the diffraction field within three adjacent regions are computed by the dipole-based wavelet superposition (DWS) and compared with those extracted by the finite-different time-domain (FDTD) full-wave solver, the Huygens-Fresnel principle (HF), and the Huygens’ Principle (HP)
Summary
Various metasurface-based devices featuring small cubage, multi-functionality, superior capability, high dependability, and ease of integration, have received continuously growing attention [1]–[6]. Huygens-Fresnel principle (HF) and its variants have been adopted, where the diffraction wavefront is interpreted as the superposition of spherical wavelets radiating by fictitious infinitesimal point sources on the diffraction aperture (i.e., metasurface) They have been successfully applied to accurately estimate the far-field patterns diffracted by the metasurface [15]–[19], but failed to compute its diffraction field within the near-field region including the evanescent area with acceptable accuracy. How to rapidly yet accurately estimate the diffraction near-field and far-field generated by the metasurface and reversely the phase profile on the metasurface according to the desired target field becomes an issue of practical significance To tackle these issues, inspired by the Helmholtz-Kirchhoff diffraction integral theory and its pattern-propagation Eigenfactor [27], we adopt Hertzian dipole instead of point source to model the subwavelength unit cell on the metasurface and every wavefront representing the target field. The proposed method is applicable to the entire electromagnetic spectrum
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
