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We will review in this paper several topologies of radio over fiber systems targeting low cost applications. These applications aim to extend the coverage of, or to distribute, wireless communications signals using fiber based network architectures. They are devoted to be deployed as home or office networks and will focus on affordable demonstrations.
Perfect tunneling of power through waveguides can be achieved by taking advantage of surface plasmon conditions. A few years ago, a waveguide filled by metamaterials with negative parameters was proposed in order to achieve such perfect tunneling behaviour. The aim of this communication is to both analyze and visualize in the time domain a structure presenting both a plasmonic resonance and perfect...
This article concentrates on frequency diversity techniques, considering transmit diversity schemes where there is a single transmitter antenna and a single receiver antenna. Two different carriers are generated by the transmitter and modulated by the same data signal, then the two modulated carriers are transmitted at the same time. At the receiver, the two modulated carriers are also received at...
In this paper, we achieved a very important gain improvement for a circularly polarized (CP) patch antenna using a new left handed medium (LHM) structure. To this end, a homogenization procedure of the LHM is carried out in order to design the patch antenna at a suitable frequency where the losses of the LHM are low. From the results we obtained, it is noted that in the presence of the LHM, the antenna...
Optical single side band is a format that proves to be very efficient when dispersion is present in the fiber. This paper reports the construction and optimization of a broadband optical single sideband prototype. We present our work in the implementation of optical single-sideband (OSSB) modulation and in the application of this modulation format for baseband transmission and microwave photonics...
In this paper we describe the design of a microwave receiver in which photonic components replace analog microwave circuitry. The receiver is targeted to provide a spurious free dynamic range of ~140 dBHz2/3 and a signal to noise ratio of 7 dB in the 0 to 20 GHz range with a 4 GHz bandwidth.
This paper presents a design technique for a low-noise amplifier for the 1.8–4 GHz ultra wideband (UWB) wireless receivers. The LNA uses a circuit topology consisting of one gain stage with series inductor feedback using ATF technology and it is operated at 1 V. The noise figure of this LNA varies from 3 to 1.5 dB, and its gain is very flat 10 dB throughout frequency band spanning from 1.8 to 4 GHz...
In this work, a negative-ϵ equivalent response medium is proposed in stripline technology. To achieve band rejection behaviour, Complementary Split Ring Resonators (CSRR) are placed in the central conductor strip of a conventional stripline planar transmission line. Due to strong normal electric field incidence, adequate excitation of the stripline is achieved, leading to band rejection in the quasi-static...
This paper presents an application of the planar model approach to the design of reconfigurable dipole antenna. The model of the whole antenna consists of a planar structure connected via a microstrip line which guarantees a continuous excitation. For this we have to use the commercial electromagnetic software ADS (Momentum) based on the method of moments (MoM) to investigate the electromagnetic behaviour...
In this paper, we propose a dual-band rectangular DRA using the strip-fed method for 2.4 GHz ISM and 4 GHz bands applications. The proposed antenna is composed of small ceramic dielectric (21.65 mm ?? 15 mm ?? 26.1 mm, alumina). In order to achieve our goals, we made a cylindrical perforation through the DRA. The measured bandwidth and maximum radiation gain are 2.35 - 2.48 GHz (VSWR < 1.05, 8...
In this paper, a new design of a compact T shaped microstrip antenna for multioperating bands of wireless communication systems is presented. The proposed antenna has the multiband measured performances covering 2.4 GHz band WLAN (2.4-2.484GHz), and the 5-GHz band WLAN (5.15-5.35/5.725-5.825 GHz). Several properties of the proposed compact antenna for multiband operation such as impedance bandwidth,...
Admission control of a WCDMA network is a very important task which an operator must take into account in order to avoid the instability of mobile network due to the increasing of interference level when a new mobile station appears in the cell. It is based on the target load factor value fixed in the dimensioning phase. The numerical results are obtained by Matlab and an interface is developed by...
In this paper we present the different type of laser diodes that are developed at Alcatel-Thales III-V Lab in order to fulfil different functions required for radio over fibre and radar systems. The first device that is presented is a directly modulated laser with a bandwidth exceeding 20 GHz and good linearity that is used for analog wideband link. This kind of device is precious for remote delivery...
In this article we design a novel ka band low noise amplifier with high stability. in this design Ga FET used to high gain and low noise figure and conditional and unconditional stability. We applied a low noise cost solution for various Ka band receivers such as P-to-P radio, WLAN and UWB sensors. Finally circuit layout with ADS software is presented and very low noise figure about 1.3 dB and about...
In this paper, we study the effects of the uniaxial permittivity anisotropy of the substrate, on the resonant frequency and the bandwidth of a rectangular microstrip antenna of the structure as: substrate; patch; superstrate. The problem is rigorously formulated by using the integral equation based on the dyadic spectral Green's function. To obtain the complex resonant frequency of mode TM01, the...
In this paper, the effects of a metal plate to antenna parameters (input impedance, return loss and radiation patterns) is presented when the RFID tag antenna is horizontally placed near the metal plate. The metal plate has finite size and rectangular shape. The new technique based on the moment method and RWG basis functions developed by Ghannay et al. has been used to simulate the dependency of...
In this paper, we study a planar horn antenna fed by a rectangular waveguide operating in the fundamental mode. The aim of this work is to enhance gain by periodic stacked subwavelength hole array. We applied several types of holes with different thicknesses of the metal plate and with varied distance between the periodic stacked subwavelength hole array and the antenna. We found a good improvement...
This paper presents a design technique for a low-noise amplifier for the 1.8-4 GHz ultra wideband (UWB) wireless receivers. The LNA uses a circuit topology consisting of one gain stage with series inductor feedback using ATF technology and it is operated at 1 V. The noise figure of this LNA varies from 3 to 1.5 dB, and its gain is very flat 10 dB through out frequency band spanning from 1.8 to 4 Ghz...
The analysis of surface plasmon polariton (SSP) propagation through a long nano-metallic channel by a spatio-temporal finite element model is presented in detail for the first time. Interesting results showing the evolution of the signal's temporal information together with the signal's transverse spatial distribution along the channel's axis will be reported.
This paper describes the synthesis of a microstrip linear antenna array operating at 24 GHz frequency. A linear array with 5 elements, called the 1??5 array, has been considered and Dolph-Chebyshev method has been used for synthesizing. It has investigated how the performance properties of a linear array are affected by varying some parameters such as N-element, inter-element spacing (d) on radiation...
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