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In the present paper the state of the art, possibilities, advantages and disadvantages of the patented corrugated horn antennas that combine horizontal and vertical corrugations is being covered. These rather new type and probably not very well known yet, corrugated horn profiles; combine in the same horn antenna both horizontal and vertical corrugations. This horn antenna produces with reasonable...
In this overview paper we have studied different options for implementing antennas in multi-system mobile terminals that are becoming more and more common. The presented recent results included broadband antenna elements with multi-frequency matching circuits and the use of tunable or selectable centre frequency. All the solutions are based on the idea of shifting complexity from the 3D antenna element...
Extensions of traditional Single-Input Single-Output (SISO) UWB systems to Multiple Elements Antennas (MEA) at both ends of the links (MIMO: Multiple-Input Multiple-Output) are investigated. The mutual coupling in arrays of UWB biconical antennas and the radiation patterns are analyzed in time domain from measurement data in frequency domain. The contribution of MEA in UWB communications is evaluated...
This paper deals with a new concept of filtering antenna. We present here, the design of combined functions: we show how to combine a filter and an antenna in order to integrate the filter in the radiation diagram and the antenna in the filtering function. The association of the two functions presents an acceptable return loss and a selective radiated power. We offer the possibility to realize system...
Time domain computation combined with the Skulkin and Turchin approach appears to be efficient and informative to study the behaviour of a reflector antenna fed with pulses. The knowledge of the impulse response allows to calculate the response of the antenna to any input signal like a generalized gaussian pulse meaningful of ultra wide band signals. As the classical radiation pattern or gain concepts...
In this paper, we propose a new formulation of the CNS-FDTD method to treat dispersive media by using complex electric susceptibility directly. To clarify the characteristics of the method, we derived numerical dispersion equations and stability conditions, and made the propagation analysis in cold plasma. Furthermore, applying the method to cold plasma slab, Debye slab, and Lorentz slab analyses,...
A novel compact planar inverted-F antenna (PIFA) for laptop computers is presented. The proposed antenna is a multi-band single-feed PIFA operating in the IEEE 802.11a (5150–5350 MHz, 5725–5825MHz), IEEE 802.11b,g (2400–2484 MHz) and HIPERLAN2 (5470–5725MHz) frequency bands. The broad impedance bandwidth is achieved by combining a trapezoidal feed plate with two different resonance paths in the radiating...
Application of wavelet signal processing techniques to radar target cross section (RCS) identification is a very promising strategy to achieve high recognition level for any type of complex target. Capabilities and limitations of wavelet techniques have to be taken into account when applied to these recognition problems and these major issues are addressed in this paper using practical targets.
Design procedures (analysis, synthesis and optimization), technologies (materials and fabrication issues) and applications of millimetre-wave dielectric lens antennas are reviewed. In particular a detailed state of the art of mm-wave shaped-beam applications is given. Future trends are also proposed.
We present the terahertz performance of integrated lens antennas consisting of a double-slot planar feed antenna and a synthesized elliptical lens. The radiation pattern and the impedance of the planar feed are computed using the method of moments; the collimating action of the lens is modeled using the physical-optics approach based on the Huygens principle. In the frequency range from 1.5 to 3 THz...
We present a numerical study of resonant negative refractive index metamaterials (NRI) in which their effective parameters are calculated. For a finite and infinite periodic media consisting of Split Ring Resonators (SRR) and metallic wires the effective refractive index is compared by means of two different methods. A significant difference between the two cases is highlighted in the frequency interval...
Active integrated antenna (AIA) has been extended into the push pull power amplifier designs, where the power of two anti-phase driven class-B power amplifiers are directly combined through a dual feed planar antenna [1]. In the AIA approach, active devices are directly integrated with the antenna, allowing the antenna to serve as a power combiner and a harmonically tuned load, in addition to its...
A novel approach to designing antenna systems, based on the preeminence of the fabrication technology, is discussed. In view of creating the basis for developing ubiquitous radio-channel applications, the use of a technologies that are adequate to mass-production, namely lithographic ones, is advocated. For demonstrating the concept, a helix antenna, implemented in a stratified, printed technology,...
This paper presents a novel structure with dual polarisation and orthogonal feeding. The radiating element is a dielectric resonator antenna (DRA). It constitutes a very compact source suitable for active arrays. The simulated results are presented at 4.5 GHz. At that step, a large bandwidth, a low cross-polarisation and a high isolation between polarisations are demonstrated.
A simple method to evaluate the mutual coupling matrix in an antenna array is presented here. This global mutual coupling correction procedure is independent of the type of antenna. The method is firstly validated for a dipole array and then for a microstrip patch antenna array. Very good agreement between this mutual coupling correction and the reference solution is observed in both cases.
This paper describes the basic design, the optimization, and the overall performance of the balanced-fed dual-band built-in antenna. The four major key structural parameters of this antenna including the additional parameter h3 were optimized for the dual-band operation in Japan using the efficient parallel Method of Moment based on the 16 parallel PC cluster system. The bandwidth of 340 MHz for 2...
The study that is done in this paper compares the physical phenomena observed when placing a 50Ω microstrip line on respectively a periodic lattice of SRRs and a SSRRs defected ground plane. In both cases, a band-stop phenomenon is observed, but the coupling with the microstrip line is completely different. When using SRRs, there is a weak magnetic coupling since the magnetic field of the line does...
The purpose of this study was to determine whether millimeter waves exposure at 60GHz, upcoming to use for indoor high rate communications in local area networks, could lead to a stress response in human brain cells. U-251 MG cell line was sham-exposed or exposed to low power density millimeter radiation for different duration, from 1h to 33h. Using the transfection technique, we analyzed the gene...
Future centimetre-wavelength radio telescopes will use low-noise phased arrays as feed antennas. Two key reasons for developing this technology is that it enables the radio telescope to have several simultaneous beams on the sky, increasing the speed of the instrument, and because it allows the properties of the feed to be optimised. However, to date only two experimental demonstrations of phased-array...
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