Objective The objective of SUPACT is to develop high-frequency active superconducting components that operate at liquid nitrogen temperatures and make use of the special properties of superconducting circuits (very high magnetic field sensitivity, inherent quantisation and counting mechanisms, low dispersion and loss in high-frequency operation).The main achievements during the first year have been: Establishment of common test structures and procedures by specifying and defining the important parameters of films, junctions and superconducting quantum interference devices (SQUIDs). A common mask for patterning of test structures has been designed and circulated to all participants. Development of complete simulation and modelling programmes to allow circuit parameters to be calculated from device geometries, individual junction characteristics to be understood, and device performance to be simulated as a function of frequency and device parameters. A careful treatment of noise has been included to provide an accurate description of realistic structures. Fabrication of reproducible bicrystal and N-YBCO superconductor normal metal supercondutor (SNS) junctions, although further development is needed in order to obtain a manufacturable process. It is likely that different junction technologies will be appropriate in different applications. Detailed modelling of electron beam irradiated (EBI) junctions to show the almost ideal uniform behaviour of these junctions. These EBI junctions allow considerable flexibility in device fabrication. A survey of analogue to digital conversion (ADC) technologies has been carried out, comparing silicon, gallium arsenide (GaAs), niobium (Nb) and high-Tec technologies. The survey indicates clear advantages for a superconducting technology in a number of applications. A prototype ADC test structure has been designed and simulated to show the limitations of the frequency response. Preliminary microwave measurements have been made on a closely related structure. Coupling schemes for the input and output of a broad band SQUID have been designed and simulated. The input coils can operate up to several hundred megahertz, and the output is designed to give broad band coupling to semiconductor electronics. The photoresponse of a range of ramp and trilayer junctions, and a superconducting field effect transistor (FET) has been measured, and shown to be sufficiently large for array applications.The fundamental building-block of these components is the Josephson Junction (JJ), and the first part of the project will concentrate on the fabrication and characterisation of reproducible and reliable JJs, using HTS materials from the YBCO family and step, step edge and bi-epitaxial designs. The junctions will be used as the basis for three demonstrators; a broad-band SQUID, and infrared detector, and ADC demonstration circuits. Fields of science natural scienceschemical sciencesinorganic chemistrytransition metalsnatural scienceschemical sciencesinorganic chemistrypost-transition metalsnatural sciencesphysical scienceselectromagnetism and electronicssemiconductivitynatural scienceschemical sciencesinorganic chemistrymetalloidsnatural sciencesphysical scienceselectromagnetism and electronicssuperconductivity Programme(s) FP3-ESPRIT 3 - Specific research and technological development programme (EEC) in the field of information technologies, 1990-1994 Topic(s) Data not available Call for proposal Data not available Funding Scheme Data not available Coordinator GEC Marconi Ltd EU contribution No data Address Elstree Way WD6 1RX Borehamwood United Kingdom See on map Total cost No data Participants (4) Sort alphabetically Sort by EU Contribution Expand all Collapse all Commissariat à l'Energie Atomique (CEA) France EU contribution No data Address Centre d'Études de Grenoble 17 avenue des Martyrs 38041 Grenoble See on map Total cost No data Siemens AG Germany EU contribution No data Address Otto-Hahn-Ring 6 81739 München See on map Total cost No data Technische Hochschule Ilmenau Germany EU contribution No data Address Am Ehrenberg 98693 Ilmenau See on map Total cost No data University of Cambridge United Kingdom EU contribution No data Address Free School Lane CB2 3RF Cambridge See on map Total cost No data