7 research outputs found
Analysis of a Waveguide-Fed Metasurface Antenna
The metasurface concept has emerged as an advantageous reconfigurable antenna
architecture for beam forming and wavefront shaping, with applications that
include satellite and terrestrial communications, radar, imaging, and wireless
power transfer. The metasurface antenna consists of an array of metamaterial
elements distributed over an electrically large structure, each subwavelength
in dimension and with subwavelength separation between elements. In the antenna
configuration we consider here, the metasurface is excited by the fields from
an attached waveguide. Each metamaterial element can be modeled as a
polarizable dipole that couples the waveguide mode to radiation modes. Distinct
from the phased array and electronically scanned antenna (ESA) architectures, a
dynamic metasurface antenna does not require active phase shifters and
amplifiers, but rather achieves reconfigurability by shifting the resonance
frequency of each individual metamaterial element. Here we derive the basic
properties of a one-dimensional waveguide-fed metasurface antenna in the
approximation that the metamaterial elements do not perturb the waveguide mode
and are non-interacting. We derive analytical approximations for the array
factors of the 1D antenna, including the effective polarizabilities needed for
amplitude-only, phase-only, and binary constraints. Using full-wave numerical
simulations, we confirm the analysis, modeling waveguides with slots or
complementary metamaterial elements patterned into one of the surfaces.Comment: Original manuscript as submitted to Physical Review Applied (2017).
14 pages, 14 figure