Imperial College London

ProfessorNeilAlford

Central FacultyOffice of the Provost

Associate Provost (Academic Planning)
 
 
 
//

Contact

 

+44 (0)20 7594 6724n.alford

 
 
//

Assistant

 

Miss Catherine Graham +44 (0)20 7594 3330

 
//

Location

 

2..05 (in RSM) or 3.09 (in the Faculty Building)Royal School of MinesSouth Kensington Campus

//

Summary

 

Publications

Publication Type
Year
to

406 results found

Button TW, Smith PA, Alford NM, Greed RB, Adams MJ, Nicholson BFet al., 1997, HTS cavities for low phase noise oscillator applications, 1996 Applied Superconductivity Conference, Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Pages: 3064-3066, ISSN: 1051-8223

Conference paper

Penn SJ, Alford NM, Button TW, 1997, High Q dielectric resonators using YBa2Cu3Ox thick films and polycrystalline dielectrics, 1996 Applied Superconductivity Conference, Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Pages: 3500-3503, ISSN: 1051-8223

Conference paper

Zuccaro C, Ghosh I, Urban K, Klein N, Penn S, Alford NMet al., 1997, Materials for HTS-shielded dielectric resonators, 1996 Applied Superconductivity Conference, Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Pages: 3715-3718, ISSN: 1051-8223

Conference paper

Alford NM, Penn SJ, Button TW, 1997, High-temperature superconducting thick films, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, Vol: 10, Pages: 169-185, ISSN: 0953-2048

Journal article

Alford NM, Penn SJ, Button TW, 1997, High temperature superconducting thick films and bulk materials, Cyril Hilsum Symposium on Functional Materials in New Millennium Systems - From Science into Applications, Publisher: INST MATERIALS, Pages: 105-137

Conference paper

Zuccaro C, Winter M, Penn S, Alford NM, Filhol P, Forterre G, Klein Net al., 1997, Microwave properties of dielectrics for HTS devices, 3rd European Conference on Applied Superconductivity (EUCAS 1997), Publisher: IOP PUBLISHING LTD, Pages: 69-72, ISSN: 0951-3248

Conference paper

Button TW, Smith PA, McN Alford N, Greed RB, Adams MJ, Nicholson BFet al., 1997, HTS cavities for low phase noise oscillator applications, IEEE Transactions on Applied Superconductivity, Vol: 7, Pages: 3064-3066, ISSN: 1051-8223

The origins of phase noise in oscillator systems are reviewed. A simple self-excited 7. 5Ghz oscillator incorporating either a conventional metal cavity resonator or a high temperature superconducting (HTS) cavity has been produced. Comparative measurements made at 77K demonstrate significant improvements in the close-to-carrier noise performance of the oscillator incorporating the HTS cavity; lOdB at a 10kHz offset rising to more than 25dB at a lOHz offset. The unloaded Q of the HTS cavity doubled to >ltf on cooling from 77K to 64K suggesting that further improvements in noise performance could be achieved. © 1997 IEEE.

Journal article

Penn SJ, Templeton A, Wang X, Alford NMet al., 1997, HTS shielded sintered dielectric microwave resonators, 3rd European Conference on Applied Superconductivity (EUCAS 1997), Publisher: IOP PUBLISHING LTD, Pages: 355-358, ISSN: 0951-3248

Conference paper

Penn SJ, Alford NMN, Button TW, 1997, High Q dielectric resonators using ybaicuaox thick films and polycrystalline dielectrics, IEEE Transactions on Applied Superconductivity, Vol: 7, Pages: 3500-3503, ISSN: 1051-8223

The combination of high Q dielectric resonators and high temperature superconducting (HTS) films offer many advantages in the area of cellular and satellite communications. The high cost of single crystal dielectrics and HTS thin films may be unattractive in certain applications. Superconducting thick films and polycrystalline ceramic dielectrics offer a high performance low cost alternative to high Q thin film/single crystal dielectric resonators. Results on polycrystalline dielectrics show that g's well in excess of 10s at 10 GHz and 77 K can be achieved in a design made compact by the use of a HTS thick film shield. © 1997 IEEE.

Journal article

Alford NM, Penn SJ, 1996, Sintered alumina with low dielectric loss, JOURNAL OF APPLIED PHYSICS, Vol: 80, Pages: 5895-5898, ISSN: 0021-8979

Journal article

Button TW, Smith PA, Dolman G, Meggs C, Remillard SK, Hodge JD, Penn SJ, Alford NMet al., 1996, Properties and applications of thick film high temperature superconductors, IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, Vol: 44, Pages: 1356-1360, ISSN: 0018-9480

Journal article

WELLHOFER FANMBTW, 1996, Superconductor production for processing electromagnetic signals by blending partially reacted starting materials with solvent, forming layer and heating to peritectic temperature of superconducting material or above for specified period, US6119025-A

Patent

WELLHOFER FANMBTW, 1996, Forming high temperature superconducting materials|by sintering a layer of unreacted blended starting material above its peritectic temperature, US5789347-A

Patent

DANTSKER E, LUDWIG F, KLEINER R, CLARKE J, TEEPE M, LEE LP, ALFORD NM, BUTTON Tet al., 1995, LOW-NOISE YBA2CU3O7-X-SRTIO3-YBA2CU3O7-X MULTILAYERS FOR IMPROVED SUPERCONDUCTING MAGNETOMETERS (VOL 66, PG 373, 1995), APPLIED PHYSICS LETTERS, Vol: 67, Pages: 725-726, ISSN: 0003-6951

Journal article

IVRISSIMTZIS LP, LANCASTER MJ, ALFORD NM, 1995, A HIGH-GAIN YBCO ANTENNA-ARRAY WITH INTEGRATED FEED AND BALUN, 1994 Applied Superconductivity Conference, Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Pages: 3199-3202, ISSN: 1051-8223

Conference paper

HOSKING MW, PROYKOVA YG, HEWITT A, ALFORD NM, BUTTON TWet al., 1995, A SUPERCONDUCTING AND INTEGRATED MICROWAVE TRANSMITTER AND RECEIVER IN MICROSTRIP USING THICK-FILM YBCO, 1994 Applied Superconductivity Conference, Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Pages: 2287-2290, ISSN: 1051-8223

Conference paper

PHILLIPS WA, JEDAMZIK D, LAMACRAFT K, ZAMMATTIO S, GREED RB, HEDGES SJ, WHITEHEAD PR, NICHOLSON BF, BUTTON TW, SMITH PA, ALFORD NM, PETERS N, GRIER Jet al., 1995, AN INTEGRATED 11GHZ CRYOGENIC DOWNCONVERTER, 1994 Applied Superconductivity Conference, Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Pages: 2283-2286, ISSN: 1051-8223

Conference paper

ALFORD NM, BUTTON TW, PENN SJ, SMITH PAet al., 1995, YBA2CU3OX LOW-LOSS CURRENT LEADS, 1994 Applied Superconductivity Conference, Publisher: IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Pages: 809-812, ISSN: 1051-8223

Conference paper

DEWHURST CD, CARDWELL DA, ALFORD NM, 1995, INVESTIGATION OF THE TEMPERATURE-DEPENDENCE OF THE CRITICAL-STATE IN MELT-PROCESSED YBA2CU3O7-DELTA THICK-FILMS, JOURNAL OF APPLIED PHYSICS, Vol: 77, Pages: 2607-2612, ISSN: 0021-8979

Journal article

LUDWIG F, DANTSKER E, KLEINER R, KOELLE D, CLARKE J, KNAPPE S, DRUNG D, KOCH H, ALFORD NM, BUTTON TWet al., 1995, INTEGRATED HIGH-T-C MULTILOOP MAGNETOMETER, APPLIED PHYSICS LETTERS, Vol: 66, Pages: 1418-1420, ISSN: 0003-6951

Journal article

DEWHURST CD, CARDWELL DA, ALFORD NM, 1995, INVESTIGATION OF THE TEMPERATURE-DEPENDENCE OF THE CRITICAL-STATE IN MELT-PROCESSED YBA2CU3O7-PARTIAL-DERIVATIVE THICK-FILMS, JOURNAL OF APPLIED PHYSICS, Vol: 77, Pages: 2067-2072, ISSN: 0021-8979

Journal article

CENTENO AER, EXCELL PS, BUTTON TW, ALFORD NMet al., 1995, INVESTIGATION OF SUPERCONDUCTING THICK-FILM HELICAL RESONATOR, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, Vol: 5, Pages: 19-21, ISSN: 1051-8223

Journal article

Phillips WA, Greed RB, Jedamzik D, Lamacraft K, Zammattio S, Hedges SJ, Whitehead PR, Nicholson BF, Smith PA, Alford NMN, Grier J, Button TW, Peters Net al., 1995, An Integrated 11GHz Cryogenic Downconverter, Pages: 2283-2286, ISSN: 1051-8223

A cryogenic downconverter has been designed and built to demonstrate the integration of semiconducting and superconducting components in a complete subsystem cooled by a closed cycle Stirling cryocooler. The frequency selective receiver converts 11GHz (X-band) signals to an IF of 1000MHz using a high temperature superconducting (HTS) microstrip input filter with a 1% bandwidth, a silicon diode mixer and a local oscillator stabilized by means of a 10GHz HTS cavity and driven by a GaAs HEMT. The components are packaged into a cryogenic unit cooled to 60K. Details of the system integration are presented, together with microwave and thermal test results. © 1995 IEEE

Conference paper

Alford N, Penn SJ, Button TW, Smith PAet al., 1995, Thick film applications of high temperature superconductors, ISSN: 0963-3308

High temperature superconductors (HTS) are described with particular reference to three promising applications. The first is the use of HTS thick film resonators in coupled cavity resonators for use as filters at 0.9 and 1.8 GHz. The second is the combination of superconductors and dielectric resonators to provide high Q devices for frequency standards and filters. The third is the use of HTS in the receiver coils used in magnetic resonance imaging machines where a key goal is enhanced signal to noise.

Conference paper

Ivrissimtzis LP, Lancaster MJ, Alford NMN, 1995, A High Gain YBCO Antenna Array with Integrated Feed and Balun, Pages: 3199-3202, ISSN: 1051-8223

A supergain antenna array of closely spaced printed dipoles made of thick film YBCO was designed and experimentally tested. An optimization of the directive gain with respect to interelement spacing, dipole length, and other circuit parameters, subject to constraints in array size, was performed by combining the spectral domain Method of Moments and transmission line theory. The design procedure accounts for losses associated with the strip material, both at the feed and the radiating dipoles, and power dissipation in the substrate. A practical design of a sixteen element array is demonstrated, with an integrated feeding network and a balun, also made of high-Tc superconductors (HTS). Performance is compared against simulated data. The superconducting array has gain significantly higher than that of a similar supercooled silver array, albeit at the expense of transmission bandwidth. It is shown that supergain is practically achievable by miniature, printed HTS dipole arrays. © 1995 IEEE

Conference paper

Penn SJ, Button TW, Smith PA, Alford NMet al., 1995, Radio-frequency and low noise performance of YBCO thick films, 2nd European Conference on Applied Superconductivity (EUCAS 1995), Publisher: IOP PUBLISHING LTD, Pages: 1051-1054, ISSN: 0951-3248

Conference paper

Wu Z, Davis LE, Alford NM, Button Tet al., 1994, Tuneable Electrically Small HTS Thick-Film Loop Antenna and Two-Element Array with Increased Bandwidth at VHF, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, Vol: 235-40, Pages: 3373-3374, ISSN: 0921-4534

Journal article

Miklich AH, Koelle D, Shaw TJ, Ludwig F, Nemeth DT, Dantsker E, Clarke J, Alford NM, Button TW, Colclough MSet al., 1994, Low-frequency excess noise in YBa<inf>2</inf>Cu<inf>3</inf>O<inf>7-x</inf> dc superconducting quantum interference devices cooled in static magnetic fields, Applied Physics Letters, Vol: 64, Pages: 3494-3496, ISSN: 0003-6951

We have investigated the performance of YBa2Cu3O 7-x dc superconducting quantum interference devices (SQUIDs) cooled in static magnetic fields, B0, of 0.01-1 mT. For fields less than the earth's ambient field, about 0.05 mT, the white noise of the devices at 77 K is not materially affected. However, at a frequency f of 1 Hz the spectral density of the 1/f noise, SΦ (1 Hz), at 0.05 mT increases by an order of magnitude over that for zero field. Furthermore, SΦ (1 Hz) scales approximately linearly with B0, suggesting strongly that the noise originates in the motion of vortices in the YBCO film. This increase in noise is likely to be an issue for SQUIDs operated in the earth's field.

Journal article

IVRISSIMTZIS LP, LANCASTER MJ, MCLEAN TSM, ALFORD NMet al., 1994, HIGH-GAIN SERIES FED PRINTED DIPOLE ARRAYS MADE OF HIGH-T(C) SUPERCONDUCTORS, IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, Vol: 42, Pages: 1419-1429, ISSN: 0018-926X

Journal article

JONES AR, CARDWELL DA, INGLE NJC, ASHWORTH SP, CAMPBELL AM, ALFORD NM, BUTTON TW, WELLHOFER F, ABELL JSet al., 1994, CORRELATION OF TRANSPORT AND MAGNETIC CRITICAL CURRENTS IN MELT-PROCESSED YBA2CU3O7-DELTA THICK-FILMS, JOURNAL OF APPLIED PHYSICS, Vol: 76, Pages: 1720-1725, ISSN: 0021-8979

Journal article

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://wlsprd.imperial.ac.uk:80/respub/WEB-INF/jsp/search-html.jsp Request URI: /respub/WEB-INF/jsp/search-html.jsp Query String: id=00506609&limit=30&person=true&page=9&respub-action=search.html