Dual-polarization Reflectarray Research Articles

Ka/W Dual-Band Reflectarray Antenna for Dual Linear Polarization

In this letter, a dual-layer dual-band dual linear polarization reflectarray is proposed, which consists of three different types of dual-layer elements: cross-dipole element for the Ka-band, modified phoenix square loop, and square patch for the W-band operation. A new unit choice strategy based on the characteristic of the proposed unit is presented to eliminate the coupling effect and improve the local periodic condition. The proposed reflectarray is fabricated on a dual-layer Taconic substrate, which covers an area of 600 × 600 mm2. Its measured peak gain is 44.1 and 49.6 dB at 35.5 and 94.05 GHz, respectively, and maximum sidelobe level is –22 dB. The proposed reflectarray architecture may find applications in missions requiring dual-frequency operations with these types of separations.

DESIGN OF X/KU DUAL-BAND DUAL-LINEAR POLARIZATION REFLECTARRAY USING DOUBLE PARALLEL DIPOLE ELEMENTS

Two single-layer X/Ku dual-band dual-polarization reflectarray antennas of different sizes with double parallel dipole elements are presented. Elements of the two bands are set to two orthogonal linear polarizations and placed in interlaced grid. The proposed reflectarrays operate in two frequency- bands within X-band centered at 10 GHz and Ku-band centered at 13.58 GHz. The smaller size reflectarray with elements arranged in a 13 × 13 grid for X-band and in a 12 × 12 grid for Ku- band is designed and simulated first. Based on the excellent dual-band performance of the small size reflectarray, then a larger size prototype has been designed, manufactured and measured. Measured results demonstrate the maximum gain of 28.54 dB with 50.93% aperture efficiency at 10 GHz and 31.06 dB with 51.34% aperture efficiency at 13.58 GHz, which show desirable dual-band dual-polarization radiation performance.

Complex Reflection Coefficient Synthesis Applied to Dual-Polarized Reflectarrays With Cross-Polar Requirements

An extended formulation of the intersection approach (IA) algorithm is presented to synthesize matrices of complex reflection coefficients for dual-polarized reflectarrays. The synthesis of complex reflection coefficients allows to impose copolar as well as cross-polar specifications, since these coefficients fully characterize the behavior of the unit cell. The implementation of the algorithm is based on the use of the fast Fourier transform (FFT) in both the forward and backward projectors of the IA, allowing for a highly efficient and fast synthesis process of dual-polarized reflectarrays. Although arbitrary restrictions can be enforced in the reflection coefficients, they might not be feasible for passive antennas. Hence, the unit cell is analyzed as a lossless and lossy passive two-port network and the restriction equations are derived for both cases involving amplitudes and phases of the reflection coefficients. The lossless constraints proved to be too restrictive so lossy restrictions should be applied to achieve feasible reflection coefficients for passive array design. Test cases are provided, which confirm that the algorithm is able to synthesize with success radiation patterns with copolar and cross-polar requirements with restrictions applied to the reflection coefficients.

INVESTIGATION ON USING CPSS ELEMENTS IN DUAL CIRCULAR POLARIZATION REFLECTARRAY ANTENNAS

In this paper, properties of three types of Circular Polarization Selective Surface (CPSS) cells including Pierrot, Morin, and Tilston, for using in dual circular polarization reflectarray antenna design are investigated. First they are designed for a center frequency about 10GHz, and circular polarization properties including Reflection Loss, Transmission Loss, Reflected Axial Ratio, and Transmitted Axial Ratio are calculated and presented. Finally, reflection phase curves are presented, and the comparison between simulated properties is accomplished. Simulations show that Tilston cell is more optimum in dual circular polarization reflectarray antennas.

Comparison of Synthesis Strategies for a Dual-Polarized Reflectarray

This paper presents and compares four optimization strategies for printed reflectarrays. They are applied to synthesize a dual-polarized reflectarray using two kinds of slot-loaded patches. They provide objective criteria to deal with the numerous geometrical parameters available to tune the phase. The study relies on the comparative measurements of four different prototypes for the same reflectarray (with the wavelength at GHz).