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.

T/R module architecture tradeoffs for phased array antennas

Abstract: Active phased array radars typically require solid state T/R modules with high output power, low noise figure, high third order intercept (TOI), and sufficient gain in both transmit and receive. Since the T/R module cost is 40-60% of the antenna cost, it is imperative to use an architecture that meets all requirements with a minimum number of MMIC chips. In this paper we examine several T/R module architectures, analyze their performance, provide a tradeoff between different performance parameters, and recommend an architecture for a given set of requirements.

Space-time coding for distributed antenna arrays

Abstract: Recently, there has been significant interest in employing space-time codes in a distributed fashion, where a codeword is spread across antennas at large geographical separations. In such situations, the differences in path delays between disparate transmit antennas and the receiver often requires the consideration of space-time codes that are robust to such offsets. In this paper, this problem is motivated from the application of public safety radio. The optimal receiver is derived, and a number of codes are obtained. Finally, a matched filter bound analysis and numerical results are presented to demonstrate the performance gains of the derived codes relative to other approaches.

Waveguide Fed Broadband Millimeter Wave Short Backfire Antenna

Abstract: A broadband millimeter-wave short backfire antenna (SBA), excited by a bowtie dipole and fed by an E-band rectangular waveguide, is presented in this paper. Its subreflector is replaced by two simple strips printed on the opposite sides of the same supporting substrate of the bowtie exciter for ease and accuracy of fabrication. For reference of practical designs, detailed parametric studies are performed in this paper. Measurements and simulations show that the proposed antenna can feature an improved operating bandwidth and broadside gain compared to the previously reported conventional SBAs. The measured impedance bandwidth for SWR $\leq$ 2 is 57%, from 55.7 to 100 GHz, in which the measured broadside gain is from 13.8 to 18.5 dBi with the peak gain at 85 GHz. Finally, high illumination efficiency of the bowtie exciter is highlighted by comparisons with a straight dipole excited SBA.

Miniaturized Array Antenna Using Artificial Magnetic Materials for Satellite-Based AIS System

Abstract: The ground-based automatic identification system (AIS) is a coastal tracking and messaging system used by vessels for maritime traffic monitoring. The European SAT-AIS initiative aims at providing a space-based complementary system to extend the range of the existing AIS to high seas via very high frequency (VHF) satellite constellation. The AIS Miniaturized Antenna (AISMAN) activity concentrates on the development of a VHF array antenna for minisatellite platforms in low Earth orbit. Array element volume minimization and mass reduction are considered performance drivers due to the in-orbit array deployment and satellite mass requirements. Artificial magnetic materials (AMMs) have been chosen as design concept of the baseline array element due to the significant size reduction they can offer. Further technical solutions, such as slotted ground plane, combined with AMM, have allowed for an outstanding profile reduction, while preserving high radiation efficiency and low back radiation. Innovative testing methodologies have been specifically developed to handle truncation errors and echo signals while performing radiation pattern measurement of the array on a full-scale mockup platform in a hemispherical automotive near field (NF) range. This paper discusses the design of array elements, from breadboard to engineering model (TRL4), manufacturing and validation campaigns at single element and array level.

Miniature phased array antenna system

Abstract: A miniature phased array antenna system employs a substrate having a high dielectric constant. A plurality of antenna elements are located on a surface of the substrate, and a superstrate having a high dielectric constant covers the antenna elements. The dielectric constant, thickness, and shape of the superstrate enable it to act as a dielectric lens for controlling the phase relationship of a signal received by the antenna elements. The design of the superstrate dielectric lens permits a reduction in the physical spacing between the antenna elements while maintaining spatial diversity in phase between signals arriving from different directions. Thus, the antenna array may be significantly smaller than conventional phased array antennas while maintaining a similar phase relationship to that achieved using conventional phased array antennas. Electronic circuitry coupled to each of the plurality of antenna elements applies complex weights to received signals prior to a summation thereof in order to reconstruct a desired signal and to deconstruct an undesired signal. SAW filters employed in the electronic circuitry are temperature controlled to maintain group-delay and phase-offset stability.