A monopolar patch antenna with a V-shaped slot for car-to-car (C2C) and wireless local area network (WLAN) communications is presented in this paper. To widen the impedance bandwidth of antenna, techniques adding shorting pin are applied to an equilateral triangular patch. By properly placing pins on patch, two operating modes, i.e., TM10 TM20, obtained. The presence can generate additional TM11 mode. These three resonances found frequency resulted wideband characteristic. proposed operate...

Abstract Distributed optical fibre sensors deliver a map of physical quantity along an fibre, providing unique solution for health monitoring targeted structures. Considerable developments over recent years have pushed conventional distributed towards their ultimate performance, while any significant improvement demands substantial hardware overhead. Here, technique is proposed, encoding the interrogating light signal by single-sequence aperiodic code and spatially resolving information...

A broadband low profile dual polarized patch antenna for fourth generation long term evolution (4G LTE) is presented in this communication. By employing two wideband feeding mechanisms the input ports, a element with characteristics of high port isolation and wide impedance bandwidth successfully designed. meandering probe (M-probe) pair twin-L-probes are proposed to feed polarization. The design balun has bandwidths over 47% at ports as well 37 dB within entire operating band. Over 8 dBi...

Noise models for both single-pulse and coded Brillouin optical time-domain analyzers (BOTDA) are established to quantify the actual signal-to-noise ratio (SNR) enhancement provided by pulse coding at any fiber position in operating condition. Simulation experimental results show that polarization noise spontaneous scattering (SpBS) signal beating could highly penalize performance of coded-BOTDA, depending on code type interrogated position. The also serve as a useful tool optimize SNR...

When studying the spatial resolution and Brillouin frequency shift (BFS) uncertainty in optical time domain analysis (BOTDA) system with a hotspot, people usually focuses on point best performance hotspot neglect huge error around it. The is caused by gain spectrum (BGS) contributed both ambient segment, which distorted from standard Lorentzian curve. Due to distortion of BGS, estimated BFS near shifted actual value results along fiber. BGS can be double-peak or single-peak curve that...

A dual band-notched ultra-wideband (UWB) slot antenna fed by coplanar waveguide (CPW) is presented in this paper. The CPW feed designed for 50 ohms, and notched bands are centered at 5.8GHz WLAN 8.0GHz X inserting a pair of slots the radiation patch. proposed has small size 25×24×0.787mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , relatively stable omnidirectional pattern over entire frequency have been obtained.

Most development of cellular communications technology has been focused on providing services to the wealthiest 20% world's population - top economic pyramid. We discuss motivation for serving bottom pyramid (BoP), loosely defined as 4 billion people earning less that US$2000/year. consider design requirements a rural wireless telecommunications system BoP, and how they differ from traditional WLL requirements. alternative technologies architectures meeting these requirements, ranging...

A wideband and low profile dual-polarized antenna element for LTE base stations is presented in this paper. The operates from 1.89GHz to 2.66GHz S <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> <;-10dB has gains of around 9dBi within its operating bandwidth at both input ports. This dual polarized a very high isolation 40dB between the two Besides, height proposed about 0.16λ xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> , which...

Symmetrical apodization technique of the chirped fiber Bragg grating has advantages suppressing sidelobes reflection spectra and smoothing curves group delay. However, it shortens bandwidth spectrum markedly. Compared with symmetrical method, asymmetric method can increase 3dB by 64.08% without change delay curves. The simulation is implemented using a rised cosine function different length ratios at both ends grating. There compromise between ripple. result shows that 30% long wavelength...

An optimized fitting function is studied to restore the BFS in BOTDA system when double-peak Brillouin gain spectrum appears. Based on this technique, frequency accuracy and spatial position improved greatly around hotspot.

Design rules for minimizing the measurement time of frequency-scanned phase-sensitive optical time-domain reflectometry (Φ-OTDR) are addressed, enabling to achieve shortest possible without large errors nor systematical errors.

The loop configuration consisting of a lead fiber and sensing is common approach to realize Brillouin Optical Time-Domain Analysis (BOTDA), which however impractical implement for some field scenarios where only single physically available. In this paper, novel single-fiber-based BOTDA with far-end modulation proposed experimentally demonstrated, in an auxiliary light pulse are injected from the near-end fiber, counter-propagating probe generated by modulating far-end. By dedicatedly...

A multi-channel tunable mechanically induced long-period fiber gratings (LPFGs) scheme is presented, which can induce several LPFGs with different resonance wavelengths simultaneously. spectra characteristics are simulated to find the influence of these parameters such as grating length, tilt angle and pressure on fiber. The simulation results show that transmission loss peak mainly depends both length pressure, while factor dominates resonant wavelength. infuence angles experimentally...

A novel BOTDA method for narrowing the BGS with adjustable spatial resolution is proposed. The simulation and experiment shows that higher Brillouin gain 19 MHz linewidth are realized different resolution.

We propose a spontaneous Brillouin scattering threshold estimation model based on n-FSK modulation. The relationship between and number of tone is investigated. validity the proved through experiments.

A single code sequence designed by a genetic searching algorithm is proposed to enhance the signal-to-noise ratio of Brillouin distributed sensors without hardware modification, enabling high-performance and cost-effective sensing over 200-km-loop setup.

A new single-ended BOTDA technique based on far-end modulation is proposed and demonstrated. 80-km-long sensing range 1.8 MHz frequency accuracy are achieved with 2 m spatial resolution.

The impact of optical noises on the performance coded Brillouin time-domain analyzers is modelled and experimentally demonstrated. This enables quantitatively evaluating actual coding gain at any point along sensing fiber.