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Title: (YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}},Au)/SrTiO{sub 3}/LaAlO{sub 3} thin film conductor/ferroelectric coupled microstripline phase shifters for phased array applications

Abstract

We report on the design, fabrication, and testing of novel YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}/SrTiO{sub 3}/LaAlO{sub 3} (YBCO/STO/LAO) and Au/SrTiO{sub 3}/LaAlO{sub 3} (Au/STO/LAO) coupled microstrip line phase shifters (CMPS). These CMPS were tested at frequencies within the Ku and K bands (12{endash}20 GHz), at temperatures from 24 to 77 K, and at dc voltages (V{sub dc}) from zero to 350 V. A relative insertion phase shift ({Delta}{phi}) of 390{degree} was measured for an eight-element YBCO/STO/LAO CMPS at V{sub dc}=350V, 16 GHz, and 40 K. At 77 K, a {Delta}{phi}{approximately}260{degree} was obtained for the CMPS at the same bias and frequency. Both results correspond to an effective coupling length of 0.33 cm. At both temperatures, the phase shifter exhibits a figure of merit of {approximately}30{degree}/dB. To our knowledge, these are the best results published so far at these frequencies where miniaturization, insertion loss, and phase delay are key considerations. {copyright} {ital 1997 American Institute of Physics.}

Authors:
; ; ; ;  [1]; ; ; ;  [2]
  1. National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio 44135 (United States)
  2. SCT, Golden, Colorado 80401 (United States)
Publication Date:
OSTI Identifier:
552935
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 71; Journal Issue: 21; Other Information: PBD: Nov 1997
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; 36 MATERIALS SCIENCE; SUPERCONDUCTING DEVICES; MICROWAVE POWER TRANSMISSION; HIGH-TC SUPERCONDUCTORS; PHASE SHIFT; LANTHANUM COMPOUNDS; STRONTIUM COMPOUNDS; GOLD; YTTRIUM COMPOUNDS; BARIUM COMPOUNDS; SUPERCONDUCTING FILMS; YTTRIUM OXIDES; BARIUM OXIDES; COPPER OXIDES; STRONTIUM OXIDES; TITANIUM OXIDES; LANTHANUM OXIDES; FERROELECTRIC MATERIALS; TEMPERATURE DEPENDENCE; GHZ RANGE 01-100

Citation Formats

Van Keuls, F.W., Romanofsky, R.R., Bohman, D.Y., Winters, M.D., Miranda, F.A., Mueller, C.H., Treece, R.E., Rivkin, T.V., and Galt, D. (YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}},Au)/SrTiO{sub 3}/LaAlO{sub 3} thin film conductor/ferroelectric coupled microstripline phase shifters for phased array applications. United States: N. p., 1997. Web. doi:10.1063/1.120251.
Van Keuls, F.W., Romanofsky, R.R., Bohman, D.Y., Winters, M.D., Miranda, F.A., Mueller, C.H., Treece, R.E., Rivkin, T.V., & Galt, D. (YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}},Au)/SrTiO{sub 3}/LaAlO{sub 3} thin film conductor/ferroelectric coupled microstripline phase shifters for phased array applications. United States. doi:10.1063/1.120251.
Van Keuls, F.W., Romanofsky, R.R., Bohman, D.Y., Winters, M.D., Miranda, F.A., Mueller, C.H., Treece, R.E., Rivkin, T.V., and Galt, D. Sat . "(YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}},Au)/SrTiO{sub 3}/LaAlO{sub 3} thin film conductor/ferroelectric coupled microstripline phase shifters for phased array applications". United States. doi:10.1063/1.120251.
@article{osti_552935,
title = {(YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}},Au)/SrTiO{sub 3}/LaAlO{sub 3} thin film conductor/ferroelectric coupled microstripline phase shifters for phased array applications},
author = {Van Keuls, F.W. and Romanofsky, R.R. and Bohman, D.Y. and Winters, M.D. and Miranda, F.A. and Mueller, C.H. and Treece, R.E. and Rivkin, T.V. and Galt, D.},
abstractNote = {We report on the design, fabrication, and testing of novel YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}/SrTiO{sub 3}/LaAlO{sub 3} (YBCO/STO/LAO) and Au/SrTiO{sub 3}/LaAlO{sub 3} (Au/STO/LAO) coupled microstrip line phase shifters (CMPS). These CMPS were tested at frequencies within the Ku and K bands (12{endash}20 GHz), at temperatures from 24 to 77 K, and at dc voltages (V{sub dc}) from zero to 350 V. A relative insertion phase shift ({Delta}{phi}) of 390{degree} was measured for an eight-element YBCO/STO/LAO CMPS at V{sub dc}=350V, 16 GHz, and 40 K. At 77 K, a {Delta}{phi}{approximately}260{degree} was obtained for the CMPS at the same bias and frequency. Both results correspond to an effective coupling length of 0.33 cm. At both temperatures, the phase shifter exhibits a figure of merit of {approximately}30{degree}/dB. To our knowledge, these are the best results published so far at these frequencies where miniaturization, insertion loss, and phase delay are key considerations. {copyright} {ital 1997 American Institute of Physics.}},
doi = {10.1063/1.120251},
journal = {Applied Physics Letters},
number = 21,
volume = 71,
place = {United States},
year = {Sat Nov 01 00:00:00 EST 1997},
month = {Sat Nov 01 00:00:00 EST 1997}
}
  • A characteristic feature of epitaxial (110) thin films of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} and PrBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} on (110)SrTiO{sub 3} substrates is that the films have a tendency to crack along the (001) planes. We have studied the crack spacing as a function of deposition temperature and film thickness. The experimental data have been found to be in excellent agreement with a theoretical analysis of the crack spacings in brittle films. The study has allowed us to determine the critical thickness below which no cracks are expected to form as a function of temperature for (110) films ofmore » YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}, PrBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}}, and YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}/ PrBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} bilayers.« less
  • Epitaxial YBa[sub 2]Cu[sub 3]O[sub 7[minus][delta]] thin films irradiated with swift heavy ions under different directions showed a strongly changed angular dependence of the critical current density [ital J][sub [ital c]]([ital B],[ital T],[var theta]) in the mixed state. Additional peaks, which dominate the angular dependence of [ital J][sub [ital c]], appear at angles where the magnetic field is parallel to the irradiation direction, due to the strong pinning of the introduced linear defects. Irradiated YBa[sub 2]Cu[sub 3]O[sub 7[minus][delta]]/PrBa[sub 2]Cu[sub 3]O[sub 7[minus][delta]] superlattices, however, reveal no additional [ital J][sub [ital c]] peaks but an isotropic [ital J][sub [ital c]] enhancement in amore » wide angular range. This contrary behavior could be explained by flux lines of different dimensionality.« less
  • A trilayer YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}/LaAlO{sub 3}/YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} transmission line was fabricated to measure the penetration depth of the high-temperature superconducting layers, to determine the microwave losses, and to demonstrate the potential for practical high-temperature superconductor multilayer microwave circuits. All layers were deposited onto a (100) MgO substrate by pulsed laser deposition. The superconducting films are {ital c}-axis oriented with critical temperatures of 89 K. From the phase velocity measurements, the penetration depth was found to be consistent with weak-coupled BCS theory in the local limit with a zero-temperature value of 135 nm. A simple phenomenological temperature dependencemore » for the penetration depth is also presented. This successful trilayer fabrication process, besides allowing the determination of the penetration depth and microwave loss, also expands the possible applications of the high-temperature superconductors.« less
  • Ferroelectric and superconductor bilayers of Ba{sub 0.1}Sr{sub 0.9}TiO{sub 3} (BSTO)/YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} (YBCO), with different YBCO film thicknesses, have been fabricated in situ by pulsed-laser deposition on 1.2 deg. vicinal LaAlO{sub 3} substrates. The dielectric properties of BSTO thin films were measured with a parallel-plate capacitor configuration in the temperature range of 77-300 K. We observed a strong dependence of the dielectric properties of BSTO thin films on the thickness of the YBCO layer. As the YBCO-film thickness increases, the temperature of the dielectric permittivity maximum of BSTO thin films shifts to higher values, and the leakage current andmore » dielectric loss increase drastically, while the dielectric constant and dielectric tunability decrease remarkably. The results are explained in terms of the transformation in the growth mode of the YBCO layer from two-dimensional step flow to three-dimensional island that leads to significant deterioration in the dielectric properties of BSTO thin films. We propose that improved dielectric properties could be obtained by reasonably manipulating the growth mode of the YBCO layer in the multilayer structures.« less
  • The growth process of an YBCO/LaAlO{sub 3}/YBCO trilayered film made by pulsed laser deposition has been studied by high resolution transmission electron microscopy (HRTEM). The high resolution images of the cross-section samples have shown that a 7 nm layer of LaAlO{sub 3} has been grown epitaxially between {ital c}-axis oriented YBCO layers having the nominal thickness of 250 nm. A stacking fault in the LaAlO{sub 3} layer may introduce a stacking fault into the YBCO layer, which may form nucleation sites for {ital a}-axis oriented grains. A second phase had been formed at the interface between the LaAlO{sub 3} layermore » and the lower YBCO layer, which has been identified by image simulation and energy dispersive x-ray (EDX) analysis as a new tetragonal La{endash}Al{endash}Cu{endash}O phase based on LaAlO{sub 3} in which some of Al atoms have been replaced by Cu. The approximate lattice parameters of the new phase are {ital a}=0.38 nm and {ital c}=0.76 nm. However, no second phase was found at the interface between the lower YBCO layer and the LaAlO{sub 3} substrate. {copyright} {ital 1996 Materials Research Society.}« less