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Weak Link Array Junctions in EuBa_2Cu_3O_<7-x> Films for Microwave Detection (Special Section on Superconducting Devices)

Koji Tsuru, Osamu Michikami

IEICE Transactions on ElectronicsAug 25, 19940 citations

Microwave detection using weak link Josephson junctions

Koji Tsuru, Osamu Michikami

Springer eBooksJan 1, 19941 citation

Millimeter Wave Mixing Properties of EuBa 2Cu 3O 7-δ Bicrystal Grain Boundary Junction Arrays

Koji Tsuru, Kazunori Miyahara, Minoru Suzuki

We report the millimeter wave mixing properties of high-T c superconductor Josephson junction arrays using a waveguide-to-microstrip converter in the 100 GHz frequency range. The junction arrays consist of 3 weak links fabricated from EuBa2Cu3O7-δ thin films grown on an MgO bicrystal substrate. In these junction arrays, Shapiro steps are observed in the presence of 100 GHz irradiation at intervals of 3 times the fundamental step voltage. Millimeter wave mixing with an input local oscillator frequency of 99.142 GHz and an input signal frequency of 99.880 GHz is detected as the IF output at 738 MHz. The IF output power peaks at voltages corresponding to those of the dynamic resistance dV/ dI. A mixing conversion efficiency of -24.1 dB is obtained for a 3-junction array.We report the millimeter wave mixing properties of high-T c superconductor Josephson junction arrays using a waveguide-to-microstrip converter in the 100 GHz frequency range. The junction arrays consist of 3 weak links fabricated from EuBa2Cu3O7-δ thin films grown on an MgO bicrystal substrate. In these junction arrays, Shapiro steps are observed in the presence of 100 GHz irradiation at intervals of 3 times the fundamental step voltage. Millimeter wave mixing with an input local oscillator frequency of 99.142 GHz and an input signal frequency of 99.880 GHz is detected as the IF output at 738 MHz. The IF output power peaks at voltages corresponding to those of the dynamic resistance dV/ dI. A mixing conversion efficiency of -24.1 dB is obtained for a 3-junction array.

Japanese Journal of Applied PhysicsDec 1, 19961 citation

Coherent Effects in Array Junctions Using Eu1Ba2Cu3O7-x Thin Films

Koji Tsuru, Kazunori Miyahara, Minoru Suzuki +2 more

Springer eBooksJan 1, 19950 citations

Broadband detection properties of EuBa/sub 2/Cu/sub 3/O/sub 7-δ/ array junctions

Koji Tsuru, Mineharu Suzuki, Osamu Michikami

We have fabricated EuBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// Josephson junction arrays of two different sizes to improve detection output and microwave coupling between junctions and an rf source. The arrays contain three weak link grain boundary junctions made on an MgO bicrystal substrate. It is demonstrated that both the junction array configuration and smaller junction size are effective in improving microwave coupling and hence in increasing the responsivity. The best responsivity obtained is 1085 V/W for broadband detection at 11.9 GHz.>We have fabricated EuBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// Josephson junction arrays of two different sizes to improve detection output and microwave coupling between junctions and an rf source. The arrays contain three weak link grain boundary junctions made on an MgO bicrystal substrate. It is demonstrated that both the junction array configuration and smaller junction size are effective in improving microwave coupling and hence in increasing the responsivity. The best responsivity obtained is 1085 V/W for broadband detection at 11.9 GHz.>

IEEE Transactions on Applied SuperconductivityJun 1, 19952 citations

Planar superconducting YBCO microwave mixer employing an engineered grain boundary weak link junction

R. Seed, Paul C. Dorsey, Hoton How +2 more

A microstrip transmission line was patterned from a superconducting YBa/sub 2/Cu/sub 3/O/sub 7-x/ film which was laser deposited on a SrTiO/sub 3/ bicrystal substrate. A microbridge in the microstrip was then patterned at the bicrystal interface to fabricate a superconducting grain boundary junction. Microwave mixing was observed with an input local oscillator frequency of 9.000 GHz, and an input signal frequency of 9.941 GHz. The output signal at 941 MHz was detected as a transmitted signal. The junction was current biased slightly above the critical current I/sub c/. The measured conversion loss was compared to the calculated value based upon a numerical solution of the equation for a superconducting weak link junction.>A microstrip transmission line was patterned from a superconducting YBa/sub 2/Cu/sub 3/O/sub 7-x/ film which was laser deposited on a SrTiO/sub 3/ bicrystal substrate. A microbridge in the microstrip was then patterned at the bicrystal interface to fabricate a superconducting grain boundary junction. Microwave mixing was observed with an input local oscillator frequency of 9.000 GHz, and an input signal frequency of 9.941 GHz. The output signal at 941 MHz was detected as a transmitted signal. The junction was current biased slightly above the critical current I/sub c/. The measured conversion loss was compared to the calculated value based upon a numerical solution of the equation for a superconducting weak link junction.>

IEEE Transactions on Applied SuperconductivityJan 1, 19946 citations

Weak link array junctions in EuBa2Cu3O7-x films for microwave detection

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Weak link array junctions in EuBa2Cu3O7-x films for microwave detection

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