Title :
Beam Focusing Using Backward-Radiating Waves on Conformal Leaky-Wave Antennas Based on a Metal Strip Grating
Author :
Foroozesh, Alireza ; Paknys, Robert ; Jackson, David R. ; Laurin, Jean-Jacques
Author_Institution :
Dept. of Electr. & Comput. Eng., Concordia Univ., Montreal, QC, Canada
Abstract :
In this paper, several conformal leaky-wave antennas (CLWAs) are designed, which utilize backward radiating waves to focus the beam. They employ a metal strip grating (MSG) in order to introduce the required phase constant (β) on a curved aperture to compensate for the defocusing due to the curvature. The required β is obtained by modulating the distance between adjacent strips/slots to scan the beam toward broadside. Using backward waves with a modulated MSG on a smoothly curved CLWA is a novel design. Using a backward wave allows for a doubling of the aperture size as compared to the forward-wave case. This, in turn, leads to a doubling of the directivity. A simple two-dimensional (2-D) Fourier-series model is used to explain the radiation physics. Full-wave analyses using the FEKO and HFSS software packages are carried out to design and analyze these CLWAs in 2-D and three-dimensional (3-D), and to verify the concept. A CLWA with a focused backward wave, supported by a modulated MSG, is fabricated and tested. The calculations and experimental results confirm that directive beaming is possible with a backward wave on a curved, modulated MSG.
Keywords :
Fourier series; conformal antennas; leaky wave antennas; metamaterial antennas; periodic structures; backward-radiating waves; beam focusing; conformal leaky-wave antennas; curved aperture; directive beaming; full-wave analyses; metal strip grating; phase constant; two-dimensional Fourier-series model; Antenna radiation patterns; Apertures; Harmonic analysis; Modulation; Strips; Surface waves; Broadside; Conformal antennas; conformal antennas; leaky-wave antennas; periodic structures; stopband;
Journal_Title :
Antennas and Propagation, IEEE Transactions on
DOI :
10.1109/TAP.2015.2478913