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.

Design of bowtie-slot on-chip antenna backed with E-shaped FSS at 94 GHz

Abstract: To meet the growing demand for miniaturization and compactness, antennas are being designed over CMOS chips. On-chip antennas (OCAs) suffer from low gains and radiation efficiency due to high dielectric constant and low resistivity of Silicon. Artificial magnetic conductors (AMC) are used in OCAs to increase gain and reduce power confinement in the substrate. In this paper, a bowtie slot antenna is presented whose gain is enhanced by an array of back-to-back E-shaped (B2BE) frequency selective surface (FSS). The operating frequency of antenna is 94 GHz where its gain is boosted from −2.71 dBi to −1.94 dBi. Designed in a standard IHP 130nm BiCMOS process without any extra post-processing step, the S11 is below −10dB from 90 GHz to 105 GHz with an antenna size of 710×310×650 µm3

The stabilisation of phased array antennas

Abstract: A method of stabilizing the action of a phased array antenna system in which the amplitudes and phases of signals applied to, or produced by, elements of the antenna are monitored, differences are detected and suitable weighting factors are determined and applied to remove the differences between the amplitudes and phases of the said signals. Transmitting and receiving antenna systems are described.

Metamaterials Applied to ESPAR Antenna for Mutual Coupling Reduction

Abstract: Phased array smart antennas are becoming the primary choice for wireless communication solutions. Along with the increased usage of this technology, the problems related to mutual electromagnetic coupling between elements become evident. On arrays consisting of only one active element and multiple parasite elements (which steer the radiation pattern), as is the case of the electronically steerable passive array radiator (ESPAR) antenna, it is desirable to have maximum mutual coupling between each parasite element and the active one. However, the mutual coupling between parasite elements decreases the overall efficiency of the adaptive algorithm used to optimize the radiating pattern of the array. This letter explores the use of metamaterial as a near-field electromagnetic insulator. A novel ESPAR antenna structure, composed by metamaterial between parasite elements, has been proposed. The metamaterial structure transforms the conventional behavior of electromagnetic waves. The wave–metamaterial interaction behaves as a high-impedance area, which attenuates electromagnetic waves that move across it. The results show an effective minimization of the mutual coupling between the passive elements, with no significant impact to the mutual coupling between the active element and each passive one.

The phase-only shaping and adaptive nulling of an amplitude pattern

Abstract: An efficient phase-only control method is reported for shaping a given antenna array amplitude pattern and simultaneously placing adaptive nulls in unknown interference directions. The method iteratively minimizes a functional (that incorporates constraints imposed on the desired pattern shape and power measured at the array output) with respect to phases of the array element excitations and to the phase of the given amplitude pattern by a coordinate-by-coordinate (single-coordinate) method that finds the minimum along each coordinate by a closed-form formula using three power measurements per one iteration. The method shows fast convergence, is stable to phase shifter errors, and complies with the digital phase control. Results of computer modeling are provided.

Full-wave simulation of frequency diverse array antenna using the FDTD method

Abstract: This paper describes 2-D analysis of a frequency diverse transmit array antenna with a periodic modulated pattern in range using the finite difference time domain methods. The elements of applied linear array are equally spaced and have same phase but operated at different frequencies. The result pattern of frequency diverse array forms range-dependent beam patterns whereas conventional array pattern forms same beam patterns in far field range. This range-dependent beam pattern provides more flexible beam scan options and lessens undesirable interferences such as multipath. The simulation results for radiation patterns of open-ended waveguide (OEG) antenna array are presented. The characteristics of radiation pattern were investigated by the each different simulation for frequency offset change, radiation element space change and array number change.