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- Kim, Jang-Yong, et al.
(författare)
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Magnetically and electrically tunable devices using ferromagnetic/ferroelectric ceramics
- 2004
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Ingår i: Physica status solidi. B, Basic research. - : Wiley. - 0370-1972 .- 1521-3951. ; 241:7, s. 1714-1717
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Tidskriftsartikel (refereegranskat)abstract
- There has been a growing interest in tunable devices applications such as filters, phase shifters, and resonators. Both of ferromagnetic and ferroelectric materials have strong advantages in the high tunability and stability. Therefore many reports have been published by employing ferrite or dielectric materials for high frequency devices applications. Both of controllable dielectric permittivity and magnetic permeability were considered one of the solutions for impedance matching in tunable devices. In this experiment ferromagnetic/ferroelectric composite ceramics were successfully fabricated without any cracking or shrinkage. Fabricated ferromagnetic/ferroelectric composite ceramic showed ferroelectric properties of P-E hysteresis and magnetic properties of B-H hysteresis loops.
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| 2. |
- Kim, Jang-Yong, et al.
(författare)
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Na0.5K0.5NbO3 film microwave varactors
- 2004
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Ingår i: Integrated Ferroelectrics. - : Informa UK Limited. - 1058-4587 .- 1607-8489. ; 66, s. 291-300
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Tidskriftsartikel (refereegranskat)abstract
- Na0.5K0.5NbO3 (NKN) and Pb(Zr 0.53Ti0.47)O3 (PZT) films have been grown by rf-magnetron sputtering and pulsed laser deposition techniques, correspondingly, on sapphire (Al2O3-0112, r-cut), quartz (Y + 36°-cut) and YAlO3 + 1%Nd(Nd:YAlO3-001) single crystal substrates with Interdigital Capacitor (IDC) of Coplanar Waveguide (CPW) structure. Photolithography and metal lift-off technique was used for processing of the tunable microwave capacitor. Microwave network analyzer with G-S-G Picoprobe and probe station performed microsvave measurement with external DC bias. NKN film interdigital capacitors on Nd:YAlO3 show superior performance in the microwave range from 1 to 40 GHz. Within this range, the voltage tunability (40 V, 200 kV/cm) was about 29%, loss tangent ∼0.13, K-factor from 152% @10 GHz to 46% @40 GHz, voltage independent Cp was about 230 fF, tan δp changes from 0.14 @ 10 GHz to 0.36 @40 GHz, real and imaginary part of interconnect impedance increases with frequency from 0.13 Ω@ 10 GHz to 0.50 Ω @40 GHz and from 1.9 Ω@10 GHz to 5.9 Ω @40 GHz respectively.
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