Wideband Array-Fed Fabry-Perot Cavity Antenna for 2-D Beam Steering

Abstract

We propose the design and test of a 2-D Fabry-Perot structure based on a multilayer slab arrangement fed by a circular array of simple sources. Such a class of planar leakywave antenna can be made by low-loss commercial laminates and it is bounded on top by a sub-wavelength partially-reflecting surface. The antenna is designed to suppress undesired radiation from the quasi-TEM mode while leaking power by the excitation of a fast TM1 leaky mode, which is a perturbed version of the guided-wave supported by the corresponding parallel-plate waveguide. An accurate dispersive analysis for the multilayer structure is developed and an original feeding system is designed and optimized to provide the needed wideband impedance matching. Thanks to translational invariance enabled by the homogenized nature of the partially reflecting screen, the antenna is used as a radiating element in the design of a leaky-waveenhanced phased array, constituted by an arrangement of vertical probes to generate directive pencil beams steerable at a single frequency in azimuth and by changing frequency in elevation.

Twisted Beams With Variable OAM Order and Consistent Beam Angle via Single Uniform Circular Arrays

“…As a consequence of the lateral truncation, endfire radiation is no longer zero, mainly due to edge diffraction by the quasi-TEM mode supported by the FPCA, whose excitation coefficient is not exactly zero. Similar spurious radiative effects have been observed in [53], [54], where they have This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/.…”

“…The indicated value of the relative permittivity is sufficiently larger than one so as to make the undesired quasi-TEM mode supported by the cavity a slow wave and hence reduce its spurious radiative effects on the antenna pattern at the operating frequency [49], [53]. However, since that value does not correspond to any commercial material, a multilayer design for the cavity has been adopted, in order to synthesize an effective permittivity approximately equal to the desired one by employing commercially available laminates [54]. In particular, a three-layer configuration has been selected, constituted by two sheets of RT Duroid 5880 with relative permittivity 2.2 and thickness 1.57 mm, separated by a thick foam layer with relative permittivity 1.04 and thickness 9 mm; the resulting multilayered cavity has thus a total thickness of 12.14 mm.…”

Pattern Reconfigurable Antennas at Millimeter-Wave Frequencies: A Comprehensive Survey

“…al. go one step further in [64], combining a multilayer design of Fabry-Pérot cavity antennas (FPCAs) with a multisource feeding network, forming thus a phased-array capable of steering the beam. VOLUME 4, 2016 Despite of the low-cost and high-gain performance RCAs and FPCAs, they can easily suffer from narrow-bandwidth.…”

High Gain Periodic 2-D Leaky-Wave Antenna With Backward Radiation for Millimeter-Wave Band

“…However, the model is not practical as small slots are used to maintain the plane wave mode inside the phased array area and, accordingly, there is no amplitude attenuation as in practical leaky wave antennas. In [25], the radial waveguide was utilized as Fabry-Perot cavity to illuminate partially reflected surface (PRS) to steer the beam in two dimensions. Six probes in circular constellation were used to feed PRS.…”