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.

On Conditions for Constant Radiation Characteristics for Log-Periodic Array Antennas

Abstract: Wide frequency band antenna systems are required for many now and future applications, such as in radio astronomy and ultrawideband (UWB) technology. Constant radiation characteristics over a decade bandwidth are required for some of wide band applications, for example, feeds for reflector antennas in radio telescope. The log-periodic array antenna is one of the technologies for wideband antennas. In the present paper, an analysis on condition for constant radiation characteristics over wide bandwidth for a log-periodic array antenna is presented. From this condition, a guide rule for designing a wideband log-periodic array antenna is obtained. The Eleven antenna, a decade bandwidth log-periodic array antenna, is selected to illustrate the condition and verify the analysis in the paper.

Multi-layer array antenna

Abstract: A multi-layer array antenna having high frequency band microstrip antennas formed on a surface of a first dielectric substrate, comb-shaped low frequency band microstrip antennas formed on a surface of a second dielectric substrate which is disposed on the first dielectric substrate, and through-holes for supplying microwave power to the comb-shaped low frequency band microstrip antennas through the first and the second dielectric substrates.

Improvements relating to antenna isolation and diversity in relation to dielectric antennas

Abstract: There are disclosed various techniques for improving isolation between dielectric antennas mounted on a small substrate, for example a PCB in a mobile communications device or WLAN access point or the like. The techniques include arranging the antennas in various orthogonal configurations so that nulls in their radiation patterns coincide and optionally making use of polarisation diversity. Further techniques include the provision of conductive barriers between the antennas and feeding one antenna with part of a signal from another antenna in anti-phase. The present invention allows a number of antennas to be provided in a small area so as to provide good operational diversity.

A 900 MHz Beam Steering Parasitic Antenna Array for Wearable Wireless Applications

Abstract: A 900 MHz wearable beam steering antenna array is proposed. A wideband driven dipole when assisted by several varactor diode controlled parasitic dipoles allows the array beam to be steered in the azimuth. Antenna array prototypes fabricated using copper, conductive fabrics and conductive threads show good bandwidth and radiation performance. The array when placed against an anatomically correct human body model shows that the array beam can be steered along 3 distinct angles, 0, 45, and 315 degrees with 5.9 dBi peak gain.

Dual Subwavelength Fabry–Perot Cavities for Broadband Highly Directive Antennas

Abstract: A new concept for designing broadband and subwavelength profile Fabry-Perot-type antennas is introduced. A novel multilayer periodic array design is proposed, yielding two subwavelength-profile Fabry-Perot cavities that significantly enhance the bandwidth performance of the resulting highly directive antenna. The design is based on two optimized double-layer periodic arrays of dissimilar dimensions, each double-layer array consisting of a capacitive artificial magnetic conductor (AMC) layer and an inductive partially reflective surface (PRS) layer printed on either side of a dielectric substrate. They are placed at about a quarter-wavelength distance from a ground plane and from each other. Thus, two air cavities are created with a total profile of less than λ/2. The proposed antenna has been simulated in CST Microwave Studio, achieving 18.3 dBi directivity with 8% bandwidth.