A Foldable Tightly Coupled Crossed Rings Antenna Array of Ultrawide Bandwidth and Dual Polarization

Abstract

Low-profile foldable array antennas are becoming increasingly more important for a wide range of applications such as satellite communications and wearable electronic devices. The conventional arrays formed by patch-like antennas have been extensively studied on surfaces with a curvature but they have exhibited limited bandwidth and polarization performance. This study investigates a coupling enhanced crossed rings antenna array with two typical configurations for dual polarization, which inherently produces ultrawide bandwidth, dipole-like polarization characteristics and a fully curved array (FCA) eventually. The fractional bandwidth of the array is over 100% on a planar surface and expanded to approximately 140% on the curved surface. For the bent array of slant polarization, the beamwidth increases by over 20 • compared to the planar array and cross polarization discrimination (XPD) maintains above 15 dB. The effects of curvature on the impedance matching and polarized radiation patterns for such arrays are investigated by measuring the performance of the fabricated prototype arrays. The results revealed that the tightly coupled crossed rings antenna array on a curved surface has a potential to form multiple beams on a limited aperture size through smaller subarrays which can yield ultrawide bandwidth due to concentrated mutual coupling mechanism. This characteristic is promising in applications where traditional flat panel arrays are difficult to implement such as in mobile stations, moving platforms and for satellite communication on-the-move.

Multibeam Cylindrical Conformal Array in the Presence of Enhanced Mutual Coupling

“…The spacing between the elements and the geometry of the array influence the mutual coupling [29]. Mutual coupling may be utilized to increase the bandwidth of the antenna arrays [30]. The characteristics of mutual coupling in an array are complex, particularly for non-planar arrays, for instance, cylindrical conformal arrays.…”

“…Unlike a planar antenna array, a cylindrical conformal array (CCA) can provide omnidirectional coverage around the antenna array [30][31][32]. This feature is especially desired for scientific applications, for example, Cylindrical Polarimetric Phased Array Radar (CPPAR) is capable of maintaining broadside polarimetric purity at all azimuthal directions [33].…”

Multibeam Cylindrical Conformal Array in the Presence of Enhanced Mutual Coupling

“…The spacing between the elements and the geometry of the array influence the mutual coupling [19]. Mutual coupling may be utilized to increase the bandwidth of the antenna arrays [20]. The characteristics of mutual coupling in an array are complex, in particularly, for non-planar arrays, for instance, cylindrical conformal arrays.…”

“…Unlike a planar antenna array, a cylindrical conformal array (CCA) can provide omnidirectional coverage around the antenna array [19][20][21]. This feature is not typically required for tracking or detecting services.…”

A Sector Ring Shape UWB Antenna by Tightly Coupling

“…It is more easily integrated into key systems such as automobiles and unmanned aerial vehicles. [8] In this research, a novel design of a lowprofile broadband antenna is presented. Several fan-ring microstrip patches are placed on the upper and lower sides of a ring-shaped dielectric substrate.…”