Abstract
Mode-converting metasurfaces are passive, lossless devices that can be designed to transform a set of incident modes to a desired set of transmitted modes. In this paper, mode-converting metasurfaces are utilized to synthesize arbitrary, azimuthally-invariant TM apertures. The methods presented in this work can be used to design antennas that can meet specific near-field and far-field criteria unlike most metasurfaces which solely manipulate the far field. The proposed antennas consist of a coaxially-excited, radial cavity topped by the mode-converting metasurface. The main role of the mode-converting metasurface is to establish the desired aperture by converting the modal distribution of the excitation to that of desired aperture. Its secondary role is to impedance match the coaxial feed to the radial cavity. Using modal network theory, an optimization-based design procedure is developed to synthesize the proposed metasurface antennas. The admittance profiles of the electric sheets that comprise the metasurface are optimized to establish the desired aperture profile. To illustrate the design procedure, a radial Gaussian beam antenna is synthesized at 10 GHz and its performance is verified using a full wave electromagnetic solver. The proposed antenna has a height and weight advantage over Gaussian beam horn antennas.
Highlights
D UE TO their negligible thickness compared to the wavelength, metasurfaces have enabled the design of numerous low-profile microwave and optical devices [1], [2]
As explained in [3], the cascaded electric sheet model is better than the generalized sheet transition conditions (GSTCs) model for two main reasons
A general method to synthesize azimuthally-invariant, TM apertures using low-profile, simple-to-feed, cascaded-sheet metasurface antennas was proposed in this paper
Summary
D UE TO their negligible thickness compared to the wavelength, metasurfaces have enabled the design of numerous low-profile microwave and optical devices [1], [2]. GSTCs relate the magnetic and electric surface currents on a sheet to the average fields at a sheet [7], [8] Both models are used to design metasurface-based devices for a variety of applications. Metasurface antennas can serve as a low-profile, simple-to-feed alternative to conventional antenna arrays, reflectors, or reflectarrays They are typically designed using a single electric sheet above a grounded dielectric substrate. A lossless, passive, and reflectionless bianisotropic sheet cannot be synthesized to reshape the incident normal power profile, unless auxiliary surface waves are added to the solution. The spatial dispersion resulting from the finite thickness of the three-sheet cascade, and the transverse propagation of the fields between the three sheets are neglected in the design procedure All these factors deteriorate the realized metasurface performance. The analysis presented here can be modified for cylindrical TE apertures
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
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
