Design of a Polarization-Diverse Planar Leaky-Wave Antenna for Broadside Radiation

Abstract

The design of a K-band radial leaky-wave antenna is presented for polarization diversity applications. The antenna structure is constituted by an annular, radially periodic, and metallic strip grating printed on top of a single-layer grounded dielectric slab. The integrated feeding system is defined by a 2 × 2 array of planar slot sources for cylindrical surface-wave excitation. By the addition of the grating, the surface wave is perturbed and enables cylindrical leaky-wave radiation by means of a fast n = −1 space harmonic, whose behavior is characterized through a full-wave dispersive analysis. By proper phasing and spacing of the four independent TM feeds, positioned close to the center of the annular grating and on the ground plane, we demonstrate the possibility of radiating directive broadside beams offering linear, left-or right-handed circularly polarized radiation, and sum and delta patterns. Thus, we propose an original solution to flexibly control the polarization of a high-gain beam by means of a simple and low-cost feeding system, made by the minimum number of integrated array sources. To accurately assess the antenna features and performance, the role of a zeroth-and first-order cylindrical leaky waves propagating along the antenna aperture is also discussed. The proposed antenna design may be of interest for direction-of-arrival estimation by means of monopulse radars, as well as for a wide class of applications where flexible control of the polarization is desired, such as satellite and terrestrial point-to-point communication systems and earth observation.

Dual-Polarized Aperture-Coupled Patch Antennas With Application to Retrodirective and Monopulse Arrays

“…Utility for beam steering in both the elevation and azimuth is reported, and, thanks to the achieved isolation between the input and output ports, a DCP retrodirective antenna array (RDA) is measured as an application example as well as sum and difference patterns. In this respect, similar investigations have been reported in [3]- [7] and [21], [22], respectively, but with different antenna designs. The key element of our proposed isolation approach in this paper consists of the integration of a hybrid feed system for the radiating patches in conjunction with additional slots enabling cancellation of the relevant currents, both at the patch aperture level and within the feed system itself.…”

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

“…Fabry-Perot cavity antennas (FPCAs) exploit PRSs for the top aperture (made by a homogenizable, quasi-uniform metal screen) and can be defined as a class of 2-D planar LWA. Contrasted with alternative bull-eye designs (see, e.g., [18], [23] and refs. therein), which are made by non-homogenizable gratings, FPCAs offer translation invariance, which is convenient to embed an array of sources below the PRS for beam steering [17], [19].…”

Directive 2-D Beam Steering by Means of a Multiport Radially Periodic Leaky-Wave Antenna

“…Metasurface antennas excited by multiple feeds to achieve multibeam and beam-scanning capabilities have been proposed in [19], [20]. Finally, some of the present authors proposed in [21] a 2-D LWA fed by four surfacewave launchers placed in the antenna center to provide full polarization reconfigurability.…”