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Applied Superconductivity, IEEE Transactions on

Issue 2  Part 3 • Date June 1997

 This issue contains several parts.Go to:  Part 1  | Part 2 

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Displaying Results 1 - 25 of 364
  • The 1996 Applied Superconductivity Conference

    Publication Year: 1997 , Page(s): 0_1 - 0_27
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  • Superconducting direct digital synthesizer

    Publication Year: 1997 , Page(s): 2270 - 2273
    Cited by:  Papers (4)
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    Communications transmitters, receivers, radar applications, and related test equipment require precise control over generated frequencies which can be provided by digital synthesis. Superconductivity technology offers to greatly improve the operational frequency range at a tiny fraction of the power of present GaAs and Si digital frequency synthesizers, an important consideration for systems with multiple receiver elements and satellite applications. We designed, fabricated, and tested a digital superconducting frequency synthesizer on a 1-cm square substrate in niobium technology and tested at 4 Kelvin. The chip contains a 12-bit pipelined MVTL incremental phase accumulator (simple expansion to 32 bits achieves one part in 4.3/spl times/10/sup 9/ frequency resolution). The most significant 10-bits of the accumulated phase proceed to a Sine ROM which is based on SQUID cells and employs data compression to minimize circuit size. An 8-bit ROM output word proceeds to a superconducting D/A converter to construct the analog output waveform which updates each clock cycle. We have operated the entire superconducting synthesizer above 1 GHz. Our performance goal with present fabrication technology is /spl ges/4 GHz operation. View full abstract»

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  • Contention solver for a superconducting packet switch

    Publication Year: 1997 , Page(s): 2274 - 2277
    Cited by:  Papers (3)  |  Patents (2)
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    The paper describes the architecture of a contention solver (CS) to be used in a superconducting packet switch prototype, and the design and tests of 2/spl times/2 switching elements which compose the CS. The contention solver is based on a Batcher sorter, in which switching elements check for contention between input packets. A priority port is used to guarantee correct operation of the sorter even if a packet is invalidated during the sorting process. A 2/spl times/2 CS switching element with 2-bit data-width was designed in dual-rail logic. It was fabricated using three-junction SQUID gates by a standard Nb tri-layer process, and consists of 102 OR-equivalent gates in an area of 1.2 mm x 1.8 mm. Its correct operation was confirmed completely. View full abstract»

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  • Circuits for chip-to-chip transportation of bits from single flux quantum circuits

    Publication Year: 1997 , Page(s): 2278 - 2281
    Cited by:  Papers (5)
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    We have designed circuits to transmit and receive bits generated by Single-Flux-Quantum (SFQ) circuits. Our circuits were fabricated using shunted Nb-AlOx-Nb junctions. The transmitter is a series array of dc SQUIDs driven into the voltage state in response to an input SFQ pulse. The receiver circuit is inductively coupled to the transmitter. Current from the transmitter biases a junction race in the receiver such that a clock pulse either passes (a '1' bit) or does not (a '0' bit). We have measured a maximum peak-to-peak amplitude from the transmitter of 296 /spl mu/V at a clock rate of 2.5 GHz, and 187 /spl mu/V at 5 GHz. View full abstract»

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  • A vortex transitional memory cell for 1-Mbit/cm/sup 2/ density Josephson RAMs

    Publication Year: 1997 , Page(s): 2282 - 2287
    Cited by:  Papers (4)
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    We developed an 8.5 /spl mu/m/spl times/11.5 /spl mu/m vortex transitional (VT) memory cell. The memory cell is the smallest Josephson memory cell ever reported. The cell was fabricated by electron cyclotron resonance plasma etching and bias-sputtering planarization. This is also the first Josephson circuit fabricated with sub-micron minimum feature size. Proper nondestructive read-out operation was verified even after half-selected conditions. An operating margin of /spl plusmn/14% was obtained for control currents I/sub X/ and I/sub Y/. These results are promising for developing a 1-Mbit/cm/sup 2/ density Josephson RAM. View full abstract»

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  • New multi-flux-quantum logic family

    Publication Year: 1997 , Page(s): 2288 - 2291
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    We report on a voltage-state logic family based on shunted Josephson junctions and on the Rapid Single Flux Quantum (RSFQ) concept. Storing information in a voltage-state form makes this Multi-Flux-Quantum Logic (MFQL) easier to match to complementary metal-oxide semiconductor (CMOS) circuits. The switching of MFQL element between the voltage and zero-voltage states takes a minimum of two SFQ pulses, and the switching time of this logic is comparable to that of RSFQ logic. The key logic element is an inverter in the form of an asymmetric interferometer, and the underlying idea is to use a separate superconducting wire to supply a standard dc output voltage for the elements. The asymmetric interferometer, directly coupled to the other elements, is actually a Josephson junction based three-terminal device or transistor. Elements such as NOT, OR, NOR, XOR, XNOR, a toggle flip-flop, and an RS trigger have been simulated, and show margins better than /spl plusmn/24%. The performance of this logic with current circuit fabrication technologies is also discussed. View full abstract»

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  • High-T/sub c/ superconductor oversampled delta modulator for analog-to-digital converters

    Publication Year: 1997 , Page(s): 2292 - 2295
    Cited by:  Papers (2)
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    Based on a single-level YBCO thin film topology and seven bicrystal grain-boundary junctions, a high temperature superconductor delta modulator for analog-to-digital converters has been designed, fabricated, and tested. A single bit quantizer based on a quantum flux parametron (QFP) comparator is used for the modulator. A large superconducting inductor is used both for the signal input and for the feedback. A small resistor is chosen for connecting the comparator to the read-out section. The oversampling provides large input signal bandwidth with high dynamic range. Circuit simulations prove the concept of the design. The effective LSB and MSB of the modulator are discussed in terms of input inductance, junction critical current, and QFP noise current. The density of latched output pulses is proportional to the change of input amplitude. Au wires were employed to make crossover of bias lines. Although this modulator did not function as expected for low-speed measurements, it shows the proper latching behaviour of the output section at 4.2 K and 35 K. View full abstract»

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  • Fabrication and characterization of YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta///SrTiO/sub 3//Ag trilayer films on SrTiO/sub 3/ bicrystal substrates

    Publication Year: 1997 , Page(s): 2296 - 2299
    Cited by:  Papers (5)
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    We have fabricated YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta///SrTiO/sub 3//Ag trilayer thin films on bicrystal SrTiO/sub 3/ substrates for electric field effect three terminal devices. For the electrical transport measurements the samples were patterned using optical lithography and wet or ion beam etching. The dielectric properties of the SrTiO/sub 3/ barrier layer were analyzed by measuring the temperature and voltage dependence of the relative dielectric constant /spl epsiv//sub r/ and the resistivity /spl rho//sub iso/. By optimization of the deposition process, /spl rho//sub iso/=2/spl times/10/sup 10/ /spl Omega/m and a breakdown voltage E/sub bd/=1/spl times/10/sup 7/ V/m were obtained at 4.2 K. For /spl epsiv//sub r/ a maximum value of 460 was observed around 75 K. By the deposition of the trilayer structure on bicrystal substrates, gated grain boundary Josephson junctions (GBJs) were fabricated. High quality GBJs have been obtained covered by a SrTiO/sub 3/ gate insulator with a maximum change in the polarization of 0.08 C/m/sup 2/. View full abstract»

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  • Josephson properties of Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub y/ bicrystal junctions grown by a sequential deposition technique using molecular beam epitaxy

    Publication Year: 1997 , Page(s): 2300 - 2303
    Cited by:  Papers (1)
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    We report Josephson and crystallographic properties of the Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub y/ junctions fabricated on MgO(100) bicrystal substrates by a molecular-beam-epitaxy method incorporating co-evaporation and sequential deposition techniques. With the sequential deposition technique which has the advantage of promoting the surface diffusion of adatoms, we obtained the highly growth-controlled films without precipitation of any second impurity phases. During the film growth, the sharp reflection high-energy electron diffraction (RHEED) patterns were also observed. However, the RHEED patterns showed the a-b twin structures due to the lattice mismatch, which influenced the Josephson transport properties at the junction boundary. The normal resistance of the bicrystal junction was 1.5 /spl Omega/ and the I/sub c/R/sub n/ product was 0.75 mV at 4.2 K. The Shapiro steps under millimeter-wave irradiation were clearly observed up to 65 K. The Josephson microwave self-radiation spectra at receiving frequency f/sub REC/=22 GHz. The observed Josephson transport properties are discussed in relation to the microscopic crystallographic properties. View full abstract»

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  • Conduction mechanisms in c-axis oriented YBCO based trilayer junctions with ferromagnetic A/sub 0.7/B/sub 0.3/MnO/sub 3/ manganite barriers

    Publication Year: 1997 , Page(s): 2304 - 2307
    Cited by:  Papers (4)
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    The mixed-valence manganites (A/sub 0.7/B/sub 0.3/)MnO/sub 3/ are prospective barrier materials for high-T/sub c/ junctions. They exhibit colossal magnetoresistance (CMR) and are chemically and structurally compatible with YBa/sub 2/Cu/sub 3/O/sub 7/ (YBCO). The resistivity can be varied by an impressive 11 orders of magnitude upon substitution of the cations A and B. We have studied the magnetisation and resistivity of La/sub 0.7/Ca/sub 0.3/MnO/sub 3/ (LCMO) thin films in grown epitaxially with YBCO by pulsed-laser deposition. We report here on the fabrication of c-axis oriented YBCO trilayer junctions employing LCMO as a barrier material. The crystal structure and surface morphology of a series of heterostructures has been studied using XRD and atomic force microscopy. The current-voltage characteristics have been measured as a function of temperature and magnetic field. In contrast to previously reported results the resulting devices exhibit no supercurrents. We propose the Glazman-Matveev inelastic tunnelling via localised states as a possible conduction mechanism for quasiparticle transport through the manganite barrier. View full abstract»

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  • Edge-like planar sandwich-type junctions using a-axis oriented YBa/sub 2/Cu/sub 3/O/sub 7-x//insulator/YBa/sub 2/Cu/sub 3/O/sub 7-x/ trilayers

    Publication Year: 1997 , Page(s): 2308 - 2310
    Cited by:  Papers (1)
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    We have fabricated the in-plane aligned a-axis oriented YBa/sub 2/Cu/sub 3/O/sub 7-x//LaSrGaO/sub 4//YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO/LSGO/YBCO) heteroepitaxial trilayers on LSGO (100) substrates. A LSGO insulating barrier and top YBCO layer were grown on the ion-beam etched in-plane aligned, a-axis oriented YBCO bottom layer. Superconductor-insulator-superconductor edge-like planar sandwich-type junctions using these a-axis oriented YBCO/LSGO/YBCO trilayers had a superconducting transition temperature of 84 K and revealed flux-flow type I-V characteristics. View full abstract»

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  • Magnetic field modulation of critical currents in YBaCuO co-planar Josephson junctions using focused ion beam

    Publication Year: 1997 , Page(s): 2311 - 2314
    Cited by:  Papers (2)
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    The YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// co-planar Josephson junctions by Focused Ion Beam were fabricated by changing the width and the thickness of a YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// thin film. The magnetic properties of the junctions were measured at different temperatures. In the junction with 300 nm thickness, the magnetic field modulation of the critical current at 4.2 K was not observed. Near the critical temperature of the junction, the magnetic modulation curve was similar to that of a dc-SQUID. From the SEM observation, some microshorts were observed on the junction. In the junction with 200 nm thickness, the I-V curve was changed from flux-flow junction type to RSJ type. The magnetic modulation curve of the 7 /spl mu/m wide junction at 4.2 K was similar to a Fraunhofer pattern. Thus it is considered that the coupling region was changed from a microshort to weak coupling region, when the thickness of the YBaCuO film was decreased from 300 nm to 200 nm. View full abstract»

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  • Nondestructive detection of dislocations in steel using a SQUID gradiometer

    Publication Year: 1997 , Page(s): 2315 - 2318
    Cited by:  Papers (13)
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    We have developed a magnetic flux imaging system. The magnetic flux image (MFI) shows the distribution of magnetic flux density over a plate like specimen. The change of the pattern in the MFI by tensile deformation has been investigated in a carbon steel without applying magnetic field using the system. A clear striped pattern appeared after deformation by fine plastic strain between 0.2 and 1.0% before strain-hardening. Luders bands, which are groups of slip bands, appeared on the plate surface and were observed at the corresponding locations of the stripes in the MFIs. This shows that the fine deformation is nondestructively detected using the MFI. View full abstract»

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  • Materials issues related to the fabrication of HTS SQUIDs

    Publication Year: 1997 , Page(s): 2319 - 2322
    Cited by:  Papers (2)
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    A number of materials related problems have hindered the development of a reproducible process for the fabrication of high-quality SQUIDs and magnetometers. In this paper we discuss the use of GdBa/sub 2/Cu/sub 3/O/sub 7/ and YBa/sub 2/Cu/sub 3/O/sub 7/ thin films for the fabrication of step-edge and bicrystal magnetometers and how materials selection can influence issues such as reproducibility, yield and noise performance. Magnetometers with noise performance as low as 63 fT//spl radic/Hz have been made with variations in junction parameters (I/sub c/ and R/sub n/) that are as low as 25% on-chip and 57% from chip-to-chip. View full abstract»

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  • Wideband front end for high-frequency SQUID electronics

    Publication Year: 1997 , Page(s): 2323 - 2326
    Cited by:  Papers (5)
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    We report the development of a wide-bandwidth, low-noise front end to facilitate the high frequency operation of both LTS and HTS DC SQUIDs. A transformer of novel design non-resonantly matches the dynamic impedance of the SQUID through a twisted pair to a room-temperature amplifier. The amplifier uses active feedback techniques to flatten the response of the signal path. When operated in conjunction with the high frequency SQUID feedback electronics (developed by IBM T.J. Watson Labs) with a modulation frequency of 16 MHz, and a Quantum Design DC SQUID, the system achieved a slew rate of 1.9/spl times/10/sup 6/ /spl Phi//sub 0/ s/sup -1/, a closed-loop performance of 5 MHz and a noise level of 5.5 /spl mu//spl Phi//sub 0//(Hz)/sup 1/2/. The response from SQUID input to amplifier output was relatively flat from 2 MHz to 25 MHz, with usable signal to 45 MHz. We believe the performance is limited by cabling and expect significant improvements in miniaturized design. View full abstract»

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  • SQUID gradiometers for a fundamental study of underwater magnetic detection

    Publication Year: 1997 , Page(s): 2327 - 2330
    Cited by:  Papers (3)
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    An LTS SQUID gradiometer measuring six elements of first order magnetic gradient was produced for a fundamental study of magnetic detection and localization under water. It was installed at the sea bottom shallower than 30 m and we measured magnetic noise which might degrade its detecting performance. Noise caused by the imbalance of the gradiometer pickup coils was suppressed by using an auxiliary three-axis SQUID magnetometer output. The imbalance parameters were determined by measuring geomagnetic variations surrounding the sea bottom. A test for the trial detection of an iron boat was conducted with the use of this gradiometer. The results obtained showed a high signal-to-noise ratio for the gradiometer. View full abstract»

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  • Angular dependence of the symmetry of the order parameter in YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta//

    Publication Year: 1997 , Page(s): 2331 - 2334
    Cited by:  Papers (6)
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    Using a 4.2 K scanning SQUID microscope, we examined twinned thin-film YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO)-Ag-PbIn SQUIDs and measured the phase of the order parameter in the YBCO for 13 different tunneling angles. We have found that the order parameter in YBCO is time-reversal symmetric and shows a d(x/sup 2/-y/sup 2/)-pairing symmetry, provided the junctions are properly made. Detailed analysis of our data reveals that any time-reversal breaking component is less than 5%, which rules out states such as d(x/sup 2/-y/sup 2/)+ is or d(x/sup 2/-y/sup 2/)+ id/sub xy/. View full abstract»

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  • HTSC Josephson junctions and dc SQUIDs on SrTiO/sub 3/ bicrystal substrates grown by floating zone method

    Publication Year: 1997 , Page(s): 2335 - 2337
    Cited by:  Papers (1)
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    A new approach to the fabrication of a SrTiO/sub 3/ bicrystal substrates, based on floating zone growth of natural SrTiO/sub 3/ bicrystals with misorientation angles 24/spl deg/ and 37/spl deg/, has been developed. Thin film YBCO Josephson junctions and dc SQUIDs on SrTiO/sub 3/ bicrystal substrates were fabricated and studied at T=77 K. The critical current density j/sub c/ and I/sub c/R/sub n/ product for the junctions with misorientation angle /spl alpha/=24/spl deg/ were close to 2/spl times/10/sup 4/ A/cm/sup 2/ and 190-260 /spl mu/V, respectively, while for /spl alpha/=37/spl deg/ it was found that j/sub c//spl ap/2/spl times/10/sup 3/ A/cm/sup 2/ and I/sub c/R/sub n//spl ap/90-120 /spl mu/V. The dc SQUIDs were made with typical inductances 20-80 pH, critical currents of 20-150 /spl mu/A and resulting voltage modulation 10-40 /spl mu/V. Noise measurements performed at 77 K revealed low 1/f noise with cut-off frequency about 10 Hz. View full abstract»

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  • Tunable YBCO resonators on YIG substrates

    Publication Year: 1997 , Page(s): 2338 - 2342
    Cited by:  Papers (17)  |  Patents (3)
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    A tunable stripline resonator has been fabricated from YBa/sub 2/Cu/sub 3/O/sub 7-x/ (YBCO) films deposited on single-crystal Y/sub 3/Fe/sub 5/O/sub 12/ (YIG) substrates. The films were deposited by laser ablation and employ buffer layers for epitaxial growth. The surface resistance of the YBCO on YIG has been measured independently and is 5/spl times/10/sup -4/ /spl Omega/ at 10 GHz and 77 K. The resonator is tuned with an external field that changes the permeability of the YIG. At 77 K we have observed tunablity of the fundamental (approximately 1.7 GHz in zero applied field) and the overtone resonances of the stripline. A mode of resonance frequency of 12 GHz has demonstrated tuning of 500 MHz for 500 Oe external field without appreciable degradation of the Q which is about 1200. For 2 kOe the tuning range is approximately 1 GHz. For higher applied fields the Q of the resonance degrades significantly presumably because of degradation of the surface resistance of the YBCO due to the applied field. The measured Q in zero applied field is about a factor of two to four lower than expected from the surface resistance of the film indicating that losses in the YIG may be affecting the performance. View full abstract»

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  • Numerical characterization of impedance transformers consisting of vertically stacked superconducting transmission lines

    Publication Year: 1997 , Page(s): 2343 - 2346
    Cited by:  Papers (1)  |  Patents (1)
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    A novel coupling configuration between an SIS mixer, an antenna, and a local oscillator has been numerically characterized for an integrated receiver operated in the sub-THz region. The configuration consists of two vertically stacked superconducting striplines, where the thickness of their common electrode t/sub 2/ is of the order of its magnetic penetration depth /spl lambda//sub 2/. It has been found that the coupling efficiency between the antenna and the mixer decreases with decrease of t/sub 2///spl lambda//sub 2/, while that between the mixer and the local oscillator has a local maximum. It is also shown that the coupling efficiencies increase with decrease of Q/sub A/, the Q-factor due to the tunneling loss in the mixer. For Q/sub A/=5.0 and 16, 75-85% of the available signal power and sufficient power from the local oscillator can be absorbed in the tunnel conductance of the mixer at 1 THz. This coupling efficiency is equal to or larger than that of a conventional planar coupler. View full abstract»

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  • Superconductor ferrite phase shifters and circulators

    Publication Year: 1997 , Page(s): 2347 - 2350
    Cited by:  Papers (9)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (524 KB)  

    We have previously demonstrated high-T/sub c/ superconductor/ferrite nonreciprocal microwave phase shifters that avoid dc magnetic-flux penetration of the superconductor through a novel design of the magnetic circuit, and thus operate with very low loss. Recently, a simplified magnetic structure has been introduced, and devices with approximately 0.1 dB insertion loss with 500 degrees of phase shift (figure of merit 5000 deg/dB) at 10 GHz and 77 K using YBCO have been demonstrated. The same operating principles have been applied to the design and fabrication of circulators. By combining three low-loss phase shifters and three T junctions on a ferrite substrate in a configuration with three-fold symmetry, a three-port switching circulator has been demonstrated using niobium at 4 K. The insertion loss is less than 1 dB, the isolation greater than 20 dB, and switching time less than 1 /spl mu/s. The switching circulator can serve as a low-loss, high-speed rf switch. Extension of this design to YBCO is discussed. Higher performance, reduced weight and volume, as well as lower cost are anticipated for microwave systems that can benefit from such circulators and phase shifters. View full abstract»

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  • Full-wave modeling of HTS dual-mode patch filters and staggered coupled-line filters

    Publication Year: 1997 , Page(s): 2351 - 2354
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (444 KB)  

    In order to obtain high-power handling, dual-mode patch HTS filters have been analyzed through Green's function and desegmentation techniques. A precise circuit model has been obtained and applied to the filter design process, and useful design curves relating filter parameters and physical dimensions of the square patch have been plotted. Several designs have been made using them and then optimized with the Method of Moments in the Spectral Domain. For higher order circuits, staggered coupled-line HTS filters have been considered. The designs have been made using the method of moments to compute the coupling capacitances, and then optimized with the Method of Moments in the Spectral Domain. One dual-mode patch filter and one staggered coupled-line filter have been fabricated on a YBCO film. Measurements agree well with simulations. View full abstract»

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  • Influence and evaluation of parasitic inductance in shunted Josephson junctions

    Publication Year: 1997 , Page(s): 2355 - 2358
    Cited by:  Papers (2)
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    The shunt resistors used in many Josephson junction circuits contain an inductive component that can significantly degrade high-frequency performance. Numerical simulations reveal complex dynamical behaviour, including relaxation oscillations, period-doubling sequences, and chaos, all of which are serious problems for applications as high-frequency sources and detectors. This complex AC behaviour creates features in the simulated DC current-voltage characteristics. Since these simulations closely match experimental data, they can be used to investigate the high-frequency AC behaviour of real junctions. Thus, we are able to use simple DC measurements to observe evidence of complex high-frequency dynamics. The inductance of the shunt branch can be accurately determined by comparing simulations to measurements. Simulations also allow us to map regions of the parameter space which exhibit complicated behaviour. These regions should be avoided when a nearly sinusoidal voltage waveform is desired, as is the case for Josephson junction-based oscillators. View full abstract»

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  • 125% bandwidth superconducting chirp filters

    Publication Year: 1997 , Page(s): 2359 - 2362
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (471 KB)  

    A previously-presented synthesis procedure is employed to design ultra-wide bandwidth linear chirp (quadratic phase) filters. The synthesis procedure eliminates the harmonic responses, theoretically permitting a bandwidth close to 200% (i.e. the frequency band zero to twice centre frequency) without aliasing problems. It can also be configured so that the chirp Fresnel ripples are relegated to the time domain. (This avoids a large frequency domain ripple which in a low-loss device would create the inadmissible requirement that gain at the peak of the ripple be greater than unity.) The design procedure is equally suitable for single and dual delay line implementations. Measurements to be presented will be on superconducting single-track coplanar and microstrip filters, patterned from epitaxial YBCO films sputtered onto 2-inch diameter LaAlO/sub 3/ substrates. They have a centre frequency of 8 GHz, bandwidth of 10 GHz (125%), and a TB product of 80. View full abstract»

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  • Optimization of SrTiO/sub 3/ for applications in tunable resonant circuits

    Publication Year: 1997 , Page(s): 2363 - 2366
    Cited by:  Papers (44)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (472 KB)  

    A series of SrTiO/sub 3/ (STO) films have been grown at a wide range of deposition conditions in order to determine the optimal growth parameters to maximize ferroelectric tuning while maintaining the lowest dielectric losses. The deposition pressure of the ambient O/sub 2/ (40 mTorr

    a(bulk) at higher pressures (P(dep)>65 mTorr). The dielectric constant (/spl epsiv//sub r/) and loss tangent (tan/spl delta/) were determined as a function of applied field at room temperature (300 K) and at liquid nitrogen temperature (77 K). The low frequency dielectric properties of the STO films were found to be a weak function of the strain of the ferroelectric film. View full abstract»

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IEEE Transactions on Applied Superconductivity contains articles on the applications of superconductivity and other relevant technology.

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Editor-in-Chief
Britton L. T. Plourde
Syracuse University
bplourde@syr.edu
http://asfaculty.syr.edu/pages/phy/plourde-britton.html