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A low cost radio over fiber (RoF) systems using vertical cavity surface emitting lasers (VCSEL) and multimode fiber (MMF) were studied. The system concept was designed and investigated by simulation. The electrical circuits were designed and fabricated. The simulation results were verified by measurement. The result of the simulations and measurements of(More)
The effect of mechanochemical activation upon the intercalation of formamide into a high-defect kaolinite has been studied using a combination of X-ray diffraction, thermal analysis, and DRIFT spectroscopy. X-ray diffraction shows that the intensity of the d(001) spacing decreases with grinding time and that the intercalated high-defect kaolinite expands to(More)
Adsorption and desorption of Aroclor 1254 (a mixture of polychlorinated biphenyls [PCBs]) from 0.25% (wt/vol) aqueous solutions of Triton X-100 on polymeric materials common in laboratories (red vacuum rubber, latex, Tygon, Norprene, manosil, polyethylene, polypropylene, phenoxy resin, nylon, and Teflon) is described. Teflon, nylon, and phenoxy resins(More)
VCSELs (Vertical-cavity surface-emitting lasers) offer a number of unique advantages: a threshold current that is low and stable with temperature so that electricity is converted to light with a very high efficiency; the ability to be modulated at very high frequencies; a circular output beam with low divergence, simplifying the optical system. Lifetime(More)
Multimode fiber links can offer a useful approach for low cost and short Radio over Fiber (RoF) systems. However, in these connections the distortion effects are higher than in a singlemode fiber system. These effects can be compensated by a suitable optical receiver. In this paper an improved receiver structure is investigated for Radio over Multimode(More)
For interconnections between the stations of mobile networks optical links are frequently used. The mobile networks require new modulation methods to achieve higher transmission capacity. For that purpose the m-QAM modulation method is a proper approach. On the other hand, the signal transmission in the mobile network is strongly affected by multipath wave(More)
In this paper, the combination of radio over multimode fibre and radio over free space optical systems are experimentally investigated. A mode filtering technique is adopted in order to deal with the modal effects in such hybrid systems. Considering mode filtering effect, we have determined transfer function and performed link budget analysis. Measurement(More)
In this paper, we propose a new scheme for the integration between the outdoor and indoor 4G long term evolution networks employing the radio-over free space optics technology for the rural environments applications to reduce the deployment cost. We experimentally characterise the system performance under the atmospheric fading effects including thick fog(More)
Multimode fibers (MMFs) can be a cost effective solution for Radio over Fiber links. Compared to single mode fibers (SMF) the larger core of the MMF reduces the installation cost, however, MMFs have higher linear distortion effect. The impact of the modal dispersion limits the quality of communications. By applying mode filters, the effect of the modal(More)