We fabricated a two-stage LCLC low-pass filter using a 100-nm-thick NbTi thin film on a sapphire substrate and investigated its microwave transmission characteristics as functions of temperature and magnetic field applied parallel to the substrate plane. At T = 1.8 K, the fabricated filter exhibited a cutoff frequency of approximately 1 GHz and an attenuation of approximately 20 dB in the stopband. By analyzing the measured ∣S21∣ characteristics using an ABCD-matrix model, we extracted an effective inductance of Lmea = 46.1 nH and an interdigitated-capacitor capacitance of CIDC = 1.59 pF for each LC cell. Temperature-dependent measurements enabled the effective inductance to be separated into temperature-independent and kinetic-inductance contributions, yielding a sheet kinetic inductance of 1.61 pH/□. Under parallel magnetic fields, the cutoff frequency shifted toward lower frequencies because of an increase in the effective inductance, while the low-pass response was maintained up to B|| = 9 T. These results demonstrate that NbTi-based LCLC filters can serve as on-chip bias-line components for suppressing high-frequency noise and microwave leakage in cryogenic, high-magnetic-field environments.
목차
Abstract 1. 서론 2. 소자 설계 3. 소자 제작 및 측정 4. 실험 결과 및 토의 5. 결론 ACKNOWLEDGMENT REFERENCES
Bongkeon Kim [ Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Jeonnam-Gwangju, 61005, Republic of Korea. ]
Yong-Joo Doh [ Department of Physics and Photon Science, Gwangju Institute of Science and Technology, Jeonnam-Gwangju, 61005, Republic of Korea. ]
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