Film Applications

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Film Applications
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Introduction

• Superconducting film

• nmµm scale superconductor

Materials

• HTS YBCO, BSCCO

• LTS Nb,MgB2

Applications
Coated conductor
SQUID
Pulsed laser deposition (PLD)
RSFQ
Filter
Voltage regulator
Fault current limiter
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Josephson effect

• The Josephson effect is the phenomenon of current
  flow across two weakly coupled superconductors

Josephson Junction (JJ)
SIS
Micro-bridge
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Magnetic flux quantum

• Magnetic flux passing through a superconducting
  ring

Total magnetic flux through the ring is quantized
in units of F0
F0Magnetic flux quantum
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SQUID (Superconducting Quantum Interference
Device)

• Consists of a superconducting loop with two (or
  one) Josephson Junctions
• Very sensitive detector of magnetic flux

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SQUID (Superconducting Quantum Interference
Device)

• Consists of a superconducting loop with two (or
  one) Josephson Junctions
• Very sensitive detector of magnetic flux

Applications
Magneto Cardio Graphy (MCG)
Magneto Encephalo Graphy (MEG)
Non destructive Testing (NDT)
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RSFQ (Rapid Single Flux Quantum)

• Josephson junction-based circuits
• Based on superconductivity and quantized magnetic
  flux

Trapped magnet quantum
High-speed ten times faster than CMOS
JJ
Low-power nW scale
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Superconducting Filter
Superconductor
Resonators

• Low-loss
• Sharpskirt characteristics

Applications
mobile-telecommunication base stations
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Bandwidth tunable high-Tc superconducting filter

• F. Aiga , Y. Terashima, M. Yamazaki, H. Fuke, H.
  Kayano,
• R. Kato, T. Hashimoto
• Advanced Materials and Devices Laboratory,
  Corporate Research and Development Center,
  Toshiba Corporation,
• 1 Komukai Toshiba-cho, Saiwai-ku, Kawasaki
  212-8582, Japan
• Received 17 October 2001 received in revised
  form 11 January 2002 accepted 20 February 2002

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1. Introduction

• Low-loss and highly selective high-Tc
  superconducting (HTS) microwave filters can
  enhance performance of mobile communication
  systems

It is often necessary to tune the filter
characteristics (the center frequency and the
bandwidth)

• A novel tuning method (The center frequency
  tuning)

Additional dielectric plate is stacked above the
microstrip line filter with an air gap
Controlling the distance between the substrate
and the dielectric plate
In this paper

• Present new development of the HTS band-pass
  filter, whose center frequency and bandwidth can
  be tuned independently

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2. Design

• Substrate
• 0.5-mm-thick LaAlO3 (LAO)

• Composed of two different band-pass filters

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2. Design

• Composed of two different band-pass filters

Center frequency1.93 GHz
3 dB bandwidth20 MHz
Attenuation of 30 dB1.0 MHz
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2. Design

• Composed of two different band-pass filters

Center frequency1.93 GHz
3 dB bandwidth20 MHz
Attenuation of 30 dB1.0 MHz
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2. Design

• Prepare two dielectric plates

0.5-mm-thick sapphire plates
Set them above filter 1-part and filter 2-part
Tuning can be obtained by adjusting the distances
between the dielectric plates and the substrate
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3. Results and discussion

• The center frequency tuning

The sapphire plates set above both filter 1-part
and filter 2-part
Distance0.25 mm

• Simulated frequency response

The center frequency
Original 1.93 GHz
no degradation
f0 tuning 1.92 GHz

• Measured frequency response

The center frequency
Original 1.941 GHz
The center frequency tuning of 10MHz is also
obtained
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3. Results and discussion

• The bandwidth tuning

The sapphire plate was set only above the filter
2-part
Distance0.35 mm

• Simulated frequency response

The bandwidth
Original 20 MHz
no degradation
BW tuning 15 MHz

• Measured frequency response

The bandwidth
Original 20 MHz
BW tuning 15 MHz
The bandwidth tuning of 5 MHz is also obtained in
the measurement
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3. Results and discussion

• The other type of bandwidth tuning

The center frequency is kept unchanged
Tuning can be obtained by adjusting two distances
independently (d1,d2)

• Measured frequency response

The bandwidth
Tuned from 20 to 15 MHz
The bandwidth tuning of 5 MHz is obtained
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4. Conclusion

• Developed a novel HTS band-pass filter, whose
  center frequency and bandwidth can be tuned
  independently

• The tuning characteristics of the entire filter
  can be controlled by adjusting the distances
  between the dielectric plates and the substrate.

• A center frequency tuning of 10 MHz and a
  bandwidth tuning of 5 MHz were obtained with no
  degradation of the low-loss and sharp-skirt
  characteristics.

• This tunable filter is expected to be useful in
  the application to mobile-telecommunication base
  stations