The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Yagi-Uda antennas are commonly used for data communications. Link budgets are calculated to ensure adequate fade margin. The presence of adjacent conducting material can affect antenna gain and impedance matching. Numerical modeling demonstrates that the gain of a 12 element Yagi-Uda is degraded by more than 2 dB when a human model is located in close proximity to the rear of the antenna. There are...
This paper develops and applies a complete channel model for MIMO in aircraft that includes the effects of noise, interference and channel correlation. Clarke's, hyper-Rayleigh, IEEE TGn and an advanced ray-tracing model were used to predict the channel effects. Gaussian noise, thermal noise (at the transmitter and the receiver), non-Gaussian noise, and the aircraft system noise were included as well...
An X-band conformal array antenna designed for the use of unmanned aerial vehicles with polarimetric radars/sensors is presented. The array antennas mounted on the cylinder with various curvature radii are experimentally studied. The array can be easily placed on the aircraft fuselage or payload due to its ultra-thin and ultra-lightweight characteristics. It should have potential applications in radar...
The paper describes the enclosure model and show that performance is sensitive to the radome and back wall position for a given cavity size. For the isolated horns the initial radome position is established by using a fixture to allow accurate positioning of the radome in front of the horn and select the position that minimizes the measured VSWR at the desired frequency, constructed a mockup of the...
In this paper, we demonstrated that hallway propagation is driven by multiple wall reflections leading to high received field in both LoS case and non-LoS case at hallway junctions due to multiple corner diffraction. The result was verified by T-shaped hallway measurements. Based on the simulation results, it was shown that a repeater system with 30 dB total gain can enhance propagation around hallway...
In order to characterize channel dynamics accurately, antennae with high gain and high efficiency is required. This is the reason why in this work we propose the design of a high-gain antenna array with beamforming capabilities.
Increasing consumer demand for additional and more capable wireless and high-speed data services has led to many new wideband and multiband communications devices. Multiple-input multiple-output (MIMO) antenna systems are one such technology that can increase data rates, provide robustness and reduce interference. However, mutual coupling issues can arise from having multiple antennas in compact and...
Two different substrate integrated waveguide fed dielectric resonator antenna (SIW- fed DRA), series and corporate feed, have been proposed for high efficiency antenna applications.
The lateral radiation millimeter-wave antenna using post-wall waveguide was proposed and the two type of prototype antenna was estimated. As a result, the measured directivity and gain of prototype antenna agree with the simulated data using simply-modeled HFSS reasonably. It was confirmed that the proposed antenna characteristics was able to estimate by simple model simulation. And the feasibility...
The wireless interconnection has attracted much attention recently as an alternative to the conventional wired interconnection in the ultra large scale integration (ULSI) technology. In this paper, a wireless interconnection operating at 25 GHz, which utilizes novel antenna in the form of a tapered slot structure, is described. The design takes into account an environment similar to the one used in...
We find that using metamaterial antenna radome made by 90 degree rotational symmetric unit cell structure can enhance the gain of dual-polarized antenna. The Jerusalem cross structure is proposed for dual-polarized antenna radome and its refraction index is designed to be near zero. This radome is designed for the WiMAX applications. Simulation results show that this antenna radome can improve the...
Two new AP-GA techniques that minimize calls to CEM solvers have been developed. They extract as much information as possible from a single CEM solver run, to serve in the assessment of multiple design candidates, instead of just one. The proposed schemes leverage multilevel (inner-outer) Pareto GAs, along with approximate objective function evaluations to reduce the cost of forward CEM analysis without...
This paper presents a novel high gain rectifying antenna for 8 GHz wireless power transmission. A reflectarray is combined with the rectifying antenna to achieve high gain. An 8times1 rectenna array is also designed as a feed antenna of the reflectarray. The rectenna array has a return loss of 29 dB at 8 GHz. The rectenna array and the reflectarray have a gain of 15.07 dBi and 18.6 dBi, respectively...
This paper investigates the performance of the single slot ring element for Ka-band reflectarray designs. Using the element rotation technique, two Ka-band circularly polarized reflectarray prototypes are designed and implemented, with different thicknesses of the substrate. The bandwidth is significantly enhanced when a thick substrate is used.
The requirements, design, and performance of the Juno Microwave Radiometer patch array antennas were discussed. The antennas meet both the electrical performance and environmental requirements. There is generally good agreement between measurements and calculations.
In this paper, the authors investigate the use of carbon-fiber composite material for the radiating element for an radiofrequency identification antenna, the T-match folded bow-tie antenna. We consider two kinds of composites that have relatively high electrical conductivity for the radiating element: (1) a braided tissue of carbon fibers embedded in epoxy resin, and (2) reinforced long carbon-fibers...
This paper presents the design of a multi-band, closed spaced Yagi antenna which consists of a folded driver and multiple helical-shaped directors. If one or more straight directors are added to the folded driver, more than one resonant frequency is observed. However, the maximum realized gain and the front-to-back ratio at each resonant frequency are not good because radiation from directors interfere...
In this paper, we present the design of an ultra-wideband Vivaldi array for a reconfigurable STW application utilizing an imaging radar system to view images through walls comprised of various types of materials. The proposed Vivaldi array, fed by four-section Wilkinson power dividers, demonstrates a frequency band of 1-10 GHz and acceptable radiation patterns over the entire operation band.
In conclusion, a novel planar PCB multiband antenna with parasitic element is proposed in this paper. Using only two simple radiating elements, the antenna operates with three separate resonant modes, covering six popular communication bands. The antenna area only occupies a small physical space (18 times 37 times 0.6 mm3). This simple planar PCB structure makes the antenna fabrication very cost effective...
Left-handed (LH) loading has been applied to printed wire antennas, such as dipole antennas and the loop antenna. These antennas are based on periodic LH cells. The resonant frequency depends on the components of the LH cells, which can be used to develop small antennas. Moreover, LH loading provides new capabilities in the design of wire antennas. For example, a meandered dipole with LH loading provides...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.