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Array antenna has been utilized in many radio telescope systems, especially for low frequency transient observation, to increase their resolving power. In this paper, a new method to determine the maximum resolving power of an array radio telescope based on the single antenna beamwidth is proposed. The method is derived from theoretical calculations combined with simulations. Statistical result shows...
This paper introduces a real-time multiple input and multiple output (MIMO) channel sounder to measure the vehicle-to-vehicle (V2V) propagation channel at 5.9 GHz. Compared to the existing V2V channel sounders, our design emphasizes on improving the stability of the setup and increasing the MIMO snapshot rate. The system stability allows us to develop a high resolution parameter extraction algorithm...
The uncertainty on the far field, obtained from antenna planar near field measurements, due to position errors is investigated by means of numerical analysis. These errors include periodic and random errors in both transverse and longitudinal directions. The errors' behavior was established and the most critical mechanical errors were determined.
In an array of antennas, the inter-antenna electromagnetic mutual coupling, unless properly corrected, would degrade an antenna array's performance in direction finding. In the special case of a uniformly spaced linear array of identical antennas, Azarbar, Dadashzadeh & Bakshi have suggested discarding the antennas' collected data at both ends of the linear array, on the assumption that all middle...
The effect of mutual coupling on the direction-of-arrival (DOA) estimation using sparse arrays of dipole antennas is investigated. The open circuit method is used to model the mutual coupling. DOA estimation performance in the presence of mutual coupling is compared and contrasted for different array configurations, namely, uniform linear arrays, minimum redundancy arrays, nested arrays, and co-prime...
In this paper, an S-band dual circular polarized (CP) spherical conformal phased array antenna (SPAA) is designed. It has the ability to scan a beam within the hemisphere coverage. There are 23 elements uniformly arranged on the hemispherical dome. The design process of the SPAA is presented in detail. Three different kinds of antenna elements are compared. The gain of the SPAA is more than 13 dBi...
In this study, a low cost highly directive 1×4 end-fire dipole antenna array is designed and presented, providing 9.3dB gain. This array is going to be mounted on the wings of a Remotely Piloted Aircraft System (RPAS) to ensure reliable and secured links with the Ground Control Station (GCS) over large distances. Moreover a 2×4 low cost multi-layer patch antenna array with 14dB gain, placed on the...
Abstract—Radio Frequency Identification (RFID) tag and sensor combination has become increasingly popular in green projects. Artificial Magnetic Conductor (AMC) is commonly used to enhance the performance of an antenna. In this paper, a new dipole AMC is proposed for 0.92 GHz Radio Frequency Identification tag application. The new square AMC structure optimized with multiple slots produced a bandwidth...
Analysis of the accuracy of EM simulations of antenna arrays and arrays in vicinity of complex structures, where array elements are modeled by using far field sources, is presented in this paper. Antenna arrays with strong mutual coupling between the elements are the main problem under consideration. It is shown that if the antenna elements are minimum scattering antennas fed by current generators,...
This paper presents a three-axis decoupling stubloaded parallel dipole array antenna with tri-orthogonal polarization directivity. The decoupling characteristics are realized using the phase shifter composed of a quarter-wavelength stub placed at two sides of three parallel dipole array antenna for creating the opposite phase of the current distribution. Further, the quarter-wavelength stub is operated...
This paper describes the design and analysis of a compact and efficient ultra-wideband unidirectional printed Array antenna for indoor applications. A 12cm∗12cm∗1cm array antenna is capable of covering an ultra-wide frequency band starting from LTE up to WI-MAX with an average gain exceeding 5dBi over the entire bandwidth. In comparison with the already existing antenna systems in the wireless market...
We investigate the design of Yagi-array made of parasitic dielectric spheres excited by a simple dipole to operate in the infrared range of wavelengths. Each dielectric sphere acts as a magnetic dipole near to the resonant frequency of the TE01 mode. The idea is also extended to the microwave range of frequencies utilizing an array of dielectric resonators on a microstrip structure. Analytical as...
A patent-pending 16 channel adaptive antenna based on active frequency selective surface is proposed. A Zigbee system built with this antenna is realized and tested in the real world. And serial experiments are taken. The results show that this antenna has a better performance than a pair of dipoles. At some places, this antenna can offer a stable link when the dipoles based system loses many packages...
The paper investigates the feeding structures for printed antenna arrays with parallel reflector and their influences on antenna parameters. Two printed antenna arrays are presented. The first consists of ten series fed symmetrical dipoles with tapered impedances. The second is the array of eight symmetrical dipoles that are fed by a tapered distribution. The feeding structures for both antennas are...
Recently the wireless power transmission (WPT) technology is a priority research direction in the world. The WPT can be divided into two main orientations: firstly WPT using inductive coupling, resonant coupling, and secondly WPT using the beam power technologies by microwave power beam and laser power beam. The WPT system with the beam power technology consists of a solar power satellite and rectenna...
In mobile base station antennas, linear array antennas are employed to achieve shaped beams in the vertical plane. Also, antennas are designed to achieve multi-frequency use. In the case of expanding multi-frequency range, conventional equal element spacing configuration shows a defect of producing grating lobes. In order to suppress grating lobes, unequal element spacing is promising. In this paper,...
Gaseous plasma antenna arrays (PAA) constitute a promising alternative to conventional metallic antennas for applications in which fast reconfigurability with respect to some property (e.g., the gain, the frequency band) is desired. In STARLET (plaSma anTennA foR satelLitE navigaTion) project, reconfigurable capabilities of plasma antennas will be exploited in the design and development of a PAA for...
As the world's first 10.5T whole body human MRI scanner is ready for discoveries on new research frontiers, RF challenges need to be overcome to fully realize the benefits of the ultra-high MRI system. Dipole antennas were investigated with the Finite-Difference Time-Domain (FDTD) method. For best head MRI at 10.5T, results showed that dipole arrays should be long and conformal to the head geometry...
We study the generation of thermoelectricity by arrays of antenna-coupled nanothermocouples (ACNTCs) in response to long-wave infrared radiation. An ACNTC is constructed from a dipole antenna and a nanoscale thermocouple (NTC). The NTCs are based on a newly discovered thermoelectric effect in single-metal nanostructures with cross-sectional discontinuity. Dependences on antenna array size and polarization...
Through two different applications (a MIMO system and a superdirective antenna array), we will show in this paper that a complete surface current optimization on an antenna allows the design of an optimal antenna system. For example, this surface current optimization can be applied to a MIMO system through a minimization of the cross-correlation coefficient or a superdirective antenna array with a...
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