238 results found
Otter WJ, Hanham SM, Klein N, et al., 2014, W-band Laser-controlled Photonic Crystal Variable Attenuator, IEEE MTT-S International Microwave Symposium (IMS), Publisher: IEEE, ISSN: 0149-645X
Hu F, Otter WJ, Lucyszyn S, THz metal mesh filters on thick fused silica substrate, International Conference on THz and Mid Infrared Radiation and Applications to Cancer Detection using Laser Imaging, Workgroup Meetings of COST ACTIONs MP1204 and BM1205
Pinuela M, Mitcheson PD, Lucyszyn S, 2013, Ambient RF energy harvesting in urban and semi-urban environments, Transactions on Microwave Theory and Techniques, Vol: 61, Pages: 2715-2726, ISSN: 0018-9480
Pinuela M, Yates DC, Lucyszyn S, et al., 2013, Maximizing DC-to-Load Efficiency for Inductive Power Transfer, IEEE Transactions on Power Electronics, Vol: 28, Pages: 2437-2447, ISSN: 0885-8993
Inductive Power Transfer (IPT) systems for transmitting tens to hundreds of watts have been reported for almost a decade. Most of the work has concentrated on the optimization of the link efficiency and have not taken into account the efficiency of the driver. Class-E amplifiers have been identified as ideal drivers for IPT applications, but their power handling capabilityat tens of MHz has been a crucial limiting factor, since the load and inductor characteristics are set by the requirements of the resonant inductive system. The frequency limitation of the driver restricts the unloaded Q factor of the coils and thus the link efficiency. With a suitable driver, copper coilunloaded Q factors of over 1,000 can be achieved in the low MHz region, enabling a cost-effective high Q coil assembly. The system presented in this paper alleviates the use of heavy andexpensive field-shaping techniques by presenting an efficient IPT system capable of transmitting energy with a dc-to-load efficiency above 77% at 6 MHz across a distance of 30 cm. To the authorsknowledge this is the highest dc-to-load efficiency achieved for an IPT system without introducing restrictive coupling factor enhancement techniques.
Lucyszyn S, Pranonsatit S, 2013, RF MEMS for antenna applications, European Conference on Antennas and Propagation (EUCAP 2013), Pages: 1988-1992
Pinuela M, Yates DC, Mitcheson PD, et al., 2013, London RF Survey for Radiative Ambient RF Energy Harvesters and Efficient DC-load Inductive Power Transfer, 7th EurAAP European Conference on Antennas and Propagation (EUCAP 2013), Pages: 2839-2843
Huang X, Lucyszyn S, 2013, Silicon RFIC UWB bandpass filter using bulk-micromachined trench couplers, IEEE International Wireless Symposium (IWS2013), Publisher: Institute of Electrical and Electronic Engineers
Hu F, Lucyszyn S, 2013, Improved ‘THz torch’ technology for short-range wireless data transfer, IEEE International Wireless Symposium (IWS2013), Publisher: Institute of Electrical and Electronic Engineers
Otter WJ, Hanham SM, Ridler N, et al., Sub-THz photonic crystal devices, International Conference on THz and Mid Infrared Radiation and Applications to Cancer Detection using Laser Imaging, Workgroup Meetings of COST ACTIONs MP1204 and BM1205
Klein N, Shaforost O, Wang K, et al., Microwave-to-terahertz investigation of CVD graphene: towards sensor and communication applications, 39th International Conference on Micro and Nano Engineering (MNE 2013), Pages: 223-223
Lucyszyn S, Hu F, THz torch technology for low-cost security applications, NATO Conference 2013 on THz and Security Applications
Otter WJ, Hanham SM, Ridler NM, et al., 100 GHz photonic crystal devices, ARMMS RF & Microwave Society Conference
Lee RMA, Sunday A, Kapur N, et al., 3D microwave & millimetre-wave system-on-substrate using sacrificial layers for printed RF MEMS components, R2i2 Electronics Conference, Joint IMAPS-UK, ESP-KTN & IeMRC Event
Papantonis S, Ridler NM, Lucyszyn S, A new technique for vector network analyzer calibration verification using a single reconfigurable device, 82nd ARFTG Conference
Rathnayake-Arachchige D, Hutt DA, Conway PP, et al., Patterning of electroless copper deposition on low temperature co-fired ceramic, IEEE 15th Electronics Packaging Technology Conference (EPTC 2013), Pages: 630-644
Otter WJ, Hanham SM, Episkopou E, et al., 2013, Photoconductive Photonic Crystal Switch, 38th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz), Publisher: IEEE, ISSN: 2162-2027
Pinuela M, Yates DC, Lucyszyn S, et al., The New Wireless, Energy Harvesting 2013, EPSRC Energy Harvesting Network
Lucyszyn S, 2013, An Engineering Approach Towards Creating Ubiquitous THz Applications, International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves (MSMW), Publisher: IEEE, Pages: 45-45
Lucyszyn S, Hu F, Otter WJ, 2013, Technology Demonstrators for Low-cost Terahertz Engineering, 3rd Asia-Pacific Microwave Conference Proceedings (APMC), Publisher: IEEE, Pages: 518-520
Lawson J, Pinuela M, Yates DC, et al., 2013, Long range inductive power transfer system, 13th International Conference on Micro and Nano Technology for Power Generation and Energy Conversion Applications (PowerMEMS), Publisher: IOP PUBLISHING LTD, ISSN: 1742-6588
Klein N, Basey-Fisher TH, Otter WJ, et al., 2013, TOWARDS MICROWAVE AND MILLIMTER WAVE BIOSENSORS, International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves (MSMW), Publisher: IEEE, Pages: 509-+
Episkopou E, Papantonis S, Otter WJ, et al., 2012, Defining material parameters in commercial EM solvers for arbitrary metal-based THz structures, IEEE Transactions on Terahertz Science and Technology, Vol: 2, Pages: 513-524
Frequency-domain solvers are used extensivelyfor modeling arbitrary metal-based terahertz structures. Fourwell-known commercially available electromagnetic (EM) modelingsoftware packages include HFSS™, CST MicrowaveStudio®, EMPro, and RSoft. However, there are a number ofoperational issues that relate to how they can be used to obtainmore meaningful and accurate results. Even experienced usersof these and similar software packages may not fully appreciatesome of the subtle ambiguities in defining boundaries and materialparameters for use in THz applications. To this end, a detailedcomparative study has been undertaken, in consultation with allfour vendors. First, in order to avoid introducing ambiguities,frequency dispersion in materials has to be clearly defined fromfirst principles; in both intrinsic and effective forms. Differentfrequency dispersion models are then introduced for ‘metal-like’materials. To act as benchmark structures, conventional air-filledmetal-pipe rectangular waveguides, associated cavity resonatorsand a spoof surface plasmon waveguide have been simulated,using a raft of different approaches; with a view to illustratingquantifiable weaknesses in commercial software packages forsimulating arbitrary metal-based THz structures. This paperhighlights intuitive and logical approaches that give incorrectresults and, where possible, makes recommendations for themost appropriate solutions that have hitherto not been given inTechnical Notes.
Pinuela M, Yates DC, Mitcheson PD, et al., 2012, Current State of Research at Imperial College London in RF Harvesting and Inductive Power Transfer, 2nd International Workshop on Wireless Energy Transport and Harvesting, Pages: 1-4
This paper presents simulation and experimental results for ambient RF energy harvesting and Inductive Power Transfer systems. End-to-end and dc-load efficiency measurements and calculations were performed to demonstrate the capabilities of both systems, respectively. An RF spectral survey was conducted across all the 270 underground stations in London. DTV, GSM900, GSM1800 and 3G were selected as the highest contributors and single banded rectennas were fabricated for all frequencies. Ground level measurements demonstrate that more than 50 stations have suitable channel power levels per band to allow ambient RF energy harvesting. Efficiencies of up to 40% were achieved with a single banded rectenna operating at GSM 900, and efficiencies higher than 20% were achieved for TV and 3G. Furthermore a high frequency, semi-resonant Class-E driver was used to transfer 60 W of power across a 30 cm distance with a dc-load efficiency of 66%.
Episkopou E, Papantonis S, Holmes AS, et al., Optically-controlled plasma switch for integrated terahertz applications, 39th IEEE International Conference on Plasma Science (ICOPS2012)
Hu F, Lucyszyn S, THz torch technologies for 21st century applications, IoP Photon12
Hu F, Lucyszyn S, 2011, Ultra-low cost ubiquitous THz security systems, 25th Asia-Pacific Microwave Conference (APMC2011), Publisher: Engineers Australia, Pages: 60-62
Lucyszyn S, Larsson MP, 2011, Mechanical bend testing of fullerene nanowhiskers, Fullerene Nanowhiskers, Editors: Miyazawa, Publisher: Pan Stanford Publishing, Pages: 117-136, ISBN: 9789814241854
Pranonsatit S, Holmes AS, Lucyszyn S, 2011, Microwave modelling of radio frequency microelectromechanical rotary switches, IET Microwaves, Antennas & Propagation, Vol: 5, Pages: 255-261
In this study, both full 3D electromagnetic and equivalent circuit modelling of a radio frequencymicroelectromechanical systems (RF MEMS) single-pole eight-throw rotary switch are reported for the first time. Excellentagreement has been achieved between measurements and modelled performance for frequencies up to 12 GHz. In order tovalidate the effectiveness of the modelling, a 2-bit true time delay phase shifter having a centre frequency of 2 GHz has beendemonstrated. The traditional topology of the switched delay line was adopted with two rotary switches employed for signalrouting. This phase shifter represents the first ever application of any RF MEMS rotary switch. It is shown that the switchmodel can accurately predict the measured performance of the phase shifter, without the need for adding new circuit elementsor tweaking of model parameters. The low measured root mean square deviations of insertion phase from the predictedresponses increase as 1.3o, 1.9o, 2.5o and 3.4o when the phase states are stepped through 0o, 90o, 180o and 270o, respectively.
Lucyszyn S, Zhou Y, 2011, Engineering approach to modelling metal THz structures, Online Journal of Terahertz Science and Technology (JTST), Vol: 4, Pages: 1-8, ISSN: 1941-7411
Lucyszyn S, Lu H, Hu F, 2011, Ultra-low Cost THz Short-range Wireless Link, IEEE-MTT-S International Microwave Workshop Series on Millimeter Wave Integrated Technologies, Publisher: IEEE, Pages: 49-52
This paper demonstrates an ultra-low cost THz system for implementing a short-range wireless communications link in the far/mid-infrared parts of the electromagnetic spectrum. The basic prototype front-end hardware is deliberately kept very simple; based around miniature incandescent light bulbs, THz filters and pyroelectric infrared sensors. While only a low data rate has been experimentally demonstrated so far, this does not represent a fundamental limitation, as a number of technological enhancements are possible. It is believed that this “THz torch” technology has its niche in ubiquitous security applications that do not require high data rates or large distance operation (e.g. secure RFID, smart key fobs and remote controls).
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