Reflective array antenna

About: Reflective array antenna is a research topic. Over the lifetime, 4366 publications have been published within this topic receiving 57884 citations.

System and method for efficient transmit and receive beamforming protocol with heterogeneous antenna configuration

Abstract: A system and method of training antennas for two devices having heterogeneous antenna configurations in a wireless network is disclosed. The method includes communicating one or more estimation training sequences between two devices via a phased array antenna and a switched array antenna, wherein a beamforming vector of the phased array antenna is switched between phase vectors within a set of weight vectors while the switched array antenna is switched within a plurality of antenna sectors. The method further includes tuning at least one of the phase array and switched array antennas with an antenna parameter selected based at least in part on the one or more estimation training sequences. The method further includes communicating data messages via at least one of the phase array and switched array antennas so tuned.

Airborne multi-mode radiating and receiving system

Abstract: An improved directional antenna for use in an airborne vehicle is shown. The contemplated antenna includes a planar phased array of antenna elements mechanically rotatable about an axis of rotation, the plane of such array making an acute angle with such axis. The beam from such array may be electronically scanned, within wide limits, regardless of the orientation of the phased array. Also shown is an improved constrained centerfeed for the antenna elements in each row thereof in such array, the disclosed feed incorporating a double ladder arrangement, including wideband couplers, to permit the extensive use of stripline and at the same time to allow practically independent adjustment of azimuth and elevation difference patterns when the phased array is used as an element in a monopulse system.

Certain Factors Affecting the Gain of Directive Antennas

Abstract: This paper analyzes the performance of antenna arrays as influenced by certain variables within the control of the designing engineer. It starts with an extremely simple analysis of the interfering effects produced by two sources of waves of the same amplitude. This is followed by a short discussion of a paper by Ronald Foster, which considers two antennas and also 16 antennas when arranged in linear array. Two antennas separated in space by ¼ wavelength and in phase by ¼ period give sensibly more radiation in one direction than in the opposite. This, for convenience, has been called a unidirectional couplet. A number of these couplets may be arranged in linear array, thereby giving an extremely useful directive system. Diagrams are shown for such arrays as affected by the number and spacings of the individual couplets. The gains from such arrays are calculated and data are given showing fair agreement between calculation and observation. Directional diagrams for arrays of coaxial antennas indicate that somewhat less gain may be expected from this form than when the elements are spaced laterally. Combinations of these two types of arrays give marked directional properties in both their horizontal and vertical planes of reference. This principle has been used rather generally in short-wave communication. This paper also discusses effects resulting from combining two or more arrays. In one case the space between two arrays tends to emphasize spurious lobes.

A Low-Cost Wideband Circularly Polarized Slot Array With Integrated Feeding Network and Reduced Height

Abstract: This letter proposes a wideband unidirectional circularly polarized (CP) slot array with a truly planar structure, which integrates the feeding network on a single substrate. The height of the array is reduced by half compared to traditional arrays with a reflector. Four parasitic slots are etched at the edges of the ground plane to improve the gain performance when the height is reduced. The measured results show that the bandwidths (BWs) for impedance, axial ratio (AR), and gain are all more than 23%, and these three bandwidths almost cover the same frequency band. The proposed array has a good unidirectional pattern and can be used in base-station applications.

Digital computer analysis of aperture antennas

Abstract: Digital computer predictions of aperture antenna patterns are shown to be far more complete, in terms of information concerning the field vectors over virtually unrestricted angular sectors and even at short distances, when vector rather than scalar diffraction theory is applied.