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Browsing by Author "Alharbi, Khalid H."

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  • Resonant tunneling diode photodetectors for optical communications
    Publication . Rodrigues, Gil C.; Rei, João F.; Foot, James A.; Alharbi, Khalid H.; Al-Khalidi, Abdullah; Wang, Jue; Wasige, Edward; Figueiredo, José; Costa, M. F. M.
    Resonant tunneling diodes (RTDs) have been extensively studied due to their potential applications in very high speed electronics, optical communications, and terahertz generation. In this work, we report the latest results on the characterization of the resonant tunneling diode photo-detectors (RTD-PDs), incorporating InGaAlAs light sensitive layers for sensing at the telecommunication wavelength of lambda = 1310 nm. We have measured responsivities up to 28.8 A/W and light induced voltage shift of 204.8 V/W for light injection powers around 0.25 mW.
    2017Conference object Open access Show more
  • Resonant tunnelling diode terahertz sources for broadband wireless communications
    Publication . Wasige, Edward; Alharbi, Khalid H.; Al-Khalidi, Abdullah; Wang, Jue; Khalid, Ata; Rodrigues, Gil; Figueiredo, José; Sadwick, L. P.; Yang, T.
    This paper will discuss resonant tunnelling diode (RTD) sources being developed on a European project iBROW (ibrow. project. eu) to enable short-range multi-gigabit wireless links and microwave-photonic interfaces for seamless links to the optical fibre backbone network. The practically relevant output powers are at least 10 mW at 90 GHz, 5 mW at 160 GHz and 1 mW at 300 GHz and simulation and some experimental results show that these are feasible in RTD technology. To date, 75 - 315 GHz indium phosphide (InP) based RTD oscillators with relatively high output powers in the 0.5 - 1.1 mW range have been demonstrated on the project. They are realised in various circuit topologies including those that use a single RTD device, 2 RTD devices and up to 4 RTD devices for increasingly higher output power. The oscillators are realised using only photolithography by taking advantage of the large micron-sized but broadband RTD devices. The paper will also describe properties of RTD devices as photo-detectors which makes this a unified technology that can be integrated into both ends of a wireless link, namely consumer portable devices and fibre-optic supported base-stations (since integration with laser diodes is also possible).
    2017Conference object Open access Show more