By Topic

Applied Superconductivity, IEEE Transactions on

Issue 4 • Date Dec. 1997

Filter Results

Displaying Results 1 - 11 of 11
  • A 4 X 4 superconducting Batcher-Banyan switch

    Publication Year: 1997 , Page(s): 3817 - 3823
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (492 KB)  

    The paper describes a Batcher sorter and a Banyan network which together form a nonblocking and self-routing switch. The Batcher sorter sorts input packets in the order of their address values. This sorting operation guarantees no blocking in the succeeding Banyan network and presents an efficient way to check contention. The Banyan network distributes contention-free packets to their final destinations. The Batcher and Banyan switches were designed by using a three-junction SQUID gate family driven by three-phase powering clocks. The Batcher sorter is composed of 2/spl times/2 Batcher switching elements. Each Batcher switching element sorts two input packets in the order of their address values. A 4/spl times/4 Batcher sorter with 2-b data width, which is composed of six 2/spl times/2 Batcher switching elements, was fabricated by an Nb tri-layer process. Its correct operation was confirmed. The Banyan network consists of 2/spl times/2 Banyan switching elements. A 2/spl times/2 Banyan switching element with 2-b data width was also fabricated. The correct operation was confirmed up to 4 GHz by using a test pattern generator integrated on-chip. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design and operation of data switching circuits for a superconductive three-node parallel processor interconnection system

    Publication Year: 1997 , Page(s): 3824 - 3829
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (155 KB)  

    We have proposed a superconductive packet switching interconnection circuit for a three-node parallel processor system. At each node, the processor unit communicates with the others through a ring interface circuit (called RIF circuit). In this paper, we report the design of the switching protocols of the RIF circuit and the result of an operation experiment on each protocol. The protocols operate successfully at 20 kHz. Additionally, the functions of checking validity and setting validity of the packet operate successfully at over 1 GHz. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Data-driven self-timed RSFQ high-speed test system

    Publication Year: 1997 , Page(s): 3830 - 3833
    Cited by:  Papers (14)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (127 KB)  

    Functional testing of rapid single-flux-quantum (RSFQ) logic circuits at high speed is necessary to further optimize circuit design, but it is not easy to do off-chip testing because of the high speed and small amplitude of SFQ pulses. This paper will present the design and test results of an 20 Gb/s bit-by-bit on-chip high-speed digital test system based on data-driven self-timed (DDST) circuits. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A novel planarization technique for a high-T/sub c/ multilevel IC process

    Publication Year: 1997 , Page(s): 3834 - 3839
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (281 KB)  

    A novel technique has been developed to planarize insulating layers which may be used in a YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) IC process. The technique, called complementary mask planarization (CoMP), has been successfully implemented to planarize line gratings etched in an SrTiO/sub 3/ insulator. The average surface roughness of the line gratings as measured by an atomic force microscope (AFM) was reduced from 3000 to 250 /spl Aring/ after planarization. Films of YBCO were the posited and patterned in the form of narrow strips over the line gratings to simulate insulated crossovers in IC structures. The I-V characteristics of the YBCO strips over planarized line gratings showed that the critical current density is higher by two orders of magnitude than those over unplanarized gratings. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Full-wave analysis of the image hybrid dielectric/HTS resonator

    Publication Year: 1997 , Page(s): 3840 - 3843
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (126 KB)  

    An analysis of the image hybrid dielectric/high-temperature superconductor (HTS) resonator is carried out. A full-wave radial mode-matching method is used to obtain the electromagnetic fields inside the resonator for single TE/sub 01/ and dual HE/sub 11/ modes. Measured resonant frequencies and quality factors of these modes are compared with numerical results of the analysis. The resonator power-handling capability is estimated from the field at the surface of the HTS film, assuming a certain value for the critical field of the HTS film. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A high-temperature superconducting receiver for low-frequency radio waves

    Publication Year: 1997 , Page(s): 3845 - 3849
    Cited by:  Papers (4)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (67 KB)  

    We have developed a receiver for low-frequency radio waves using high-temperature superconducting quantum interference devices (SQUIDs). The primary application of such a receiver is to communicate in underground areas where the overburden results in significant losses at the usual radio frequencies. The receiver constructed consists of a SQUID, a small dewar, control electronics, and a battery pack. The SQUID was fabricated in our laboratory using an edge junction technology, discussed in previous publications. For this work we increased the effective area by including a standard galvanically coupled pickup loop. We have investigated background noise spectra and found that the low noise door of the SQUIDs can be fully utilized in the receiver, provided that the signals be encoded with a bandwidth narrower than the 60 Hz spacing between powerline harmonics. The most significant advantage of SQUIDs for this application is that they allow the compact construction of three-axis receivers that are necessary to overcome a dominant source of vibrational or motional noise. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A 100-GHz fixed-tuned waveguide SIS mixer exhibiting broad bandwidth and very low noise temperature

    Publication Year: 1997 , Page(s): 3850 - 3857
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (239 KB)  

    This paper presents design and performance data for a 100-GHz waveguide superconductor-insulator-superconductor (SIS) mixer, which is incorporated with a twin-junction device (i.e., two identical junctions connected in parallel through a tuning inductance) and a fixed-tuned broad-band waveguide mixer mount. The 100-GHz mixer is actually developed as a prototype of the 500-GHz one. The constructed 100-GHz SIS receiver results in an overall receiver noise temperature (DSB) of less than 40 K over the frequency range from 80-120 GHz, with a minimum value of just 20 K that is four times as large as the quantum limit (i.e., 4/spl planck//spl omega//k). Such a performance is comparable or even superior to those of the best mechanically tunable waveguide SIS receivers at the same frequency band. In addition, some interesting mixing behaviors related to this two-junction device are described in detail. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Conceptual design of an electrical machine with both low and high T/sub c/ superconductors

    Publication Year: 1997 , Page(s): 3858 - 3865
    Cited by:  Papers (6)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (155 KB)  

    The emergence of high T/sub c/ superconducting (HTS) wires with large critical current densities allows the design and construction of many applications, for example, rotating electrical machines. Nevertheless, the current "state of the art" of Bi "powder in tube" wires, the most advanced HTS conductor, is not adequate for an ac operation. We thus propose a fully superconducting synchronous machine with an NbTi stationary 4 K armature and a rotating Bi-2223 field winding at 20 or 40 K. Thanks to the armature cryogenic environment, the cooling of the Bi coils is very simple. The conceptual design of a typical machine is suggested and several electromagnetic designs are presented. The first one deals with a Bi field winding adapted to an existing NbTi armature of a tenth of kYA. Afterwards, large torque motors are theoretically designed comparing the high (at 20 and 40 K) and low T/sub c/ field winding solutions. The results are comparable for NbTi and Bi at 20 K. But with a Bi field winding operating at 40 K, the performances are degraded. Otherwise, at 4 or 20 K fully superconducting motors show high performances in terms of weight, volume, and efficiency. Nevertheless, the Bi field windings require a large amount of material indicating that improvements in critical current density are needed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of critical-state problems in type-II superconductivity

    Publication Year: 1997 , Page(s): 3866 - 3873
    Cited by:  Papers (54)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (430 KB)  

    An efficient numerical scheme is proposed for modeling the hysteretic magnetization of type-II superconductors. Numerical examples are presented for the Bean and Kim critical state models. It is shown that Bean's model is a Hele-Shaw type problem. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Superconducting cylinder in a static transverse magnetic field

    Publication Year: 1997 , Page(s): 3874 - 3879
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (200 KB)  

    A piecewise continuous distribution of the critical currents is proposed to make compatible the Maxwell equations and constitutive equations of superconducting media. A magnetic moment of the infinite superconducting cylinder is calculated on the base of the proposed shell model. Some generalizations of the calculation method are given for superconductors of more complicated shapes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 1997 Index IEEE Transactions on Applied Superconductivity Vol. 7

    Publication Year: 1997 , Page(s): 1 - 129
    Save to Project icon | Request Permissions | PDF file iconPDF (5895 KB)  
    Freely Available from IEEE

Aims & Scope

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

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Britton L. T. Plourde
Syracuse University
bplourde@syr.edu
http://www.phy.syr.edu/~bplourde