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Liu H.,East China Jiaotong University | Lei J.,East China Jiaotong University | Zhan X.,East China Jiaotong University | Guan X.,East China Jiaotong University | And 2 more authors.
Applied Physics Letters | Year: 2014

In this Letter, a multi-resonant split ring resonator (SRR) is proposed for multi-band application. Its equivalent circuit model and even/odd-mode analysis are investigated. To verify this design methodology, a quad-band high-temperature superconducting (HTS) metamaterial structure is designed and fabricated with a compact size of 11.1 mm × 14.95 mm (about 0.149 λg by 0.2 λg). The insertion losses at each passband are 0.13, 0.07, 0.135, and 0.2 dB, respectively. The temperature effects and power handling capability of the quad-band HTS filter are also studied and the results show that the device has both perfect quad-band bandpass performance (temperature < 77 K) and perfect bandstop performance (temperature > 100 K) for the multi-band communication and superconductor switch applications. © 2014 AIP Publishing LLC.


PubMed | Tianjin Hi Technology Superconducting Electronic Technologies Co., Saitama University and East China Jiaotong University
Type: | Journal: Scientific reports | Year: 2015

Artificial structures with negative permittivity or permeability have attracted significant attention in the science community because they provide a pathway for obtaining exotic electromagnetic properties not found in natural materials. At the moment, the great challenge of these artificial structures in microwave frequency exhibits a relatively large loss. It is well-known that superconducting thin films have extremely low surface resistance. Hence, it is a good candidate to resolve this constraint. Besides, the reported artificial structures with negative permittivity or permeability are mainly focusing on linear regime of wave propagation. However, any future effort in creating tunable structures would require knowledge of nonlinear properties. In this work, a tunable superconducting filter with composite right/left-hand transmission property is proposed and fabricated. Its nonlinear effects on temperature and power are studied by theoretical analysis and experiments.


Ji L.Y.,Tianjin Hi Technology Superconducting Electronic Technologies Co. | Ma J.,Tianjin Hi Technology Superconducting Electronic Technologies Co. | Ma J.,Hebei University of Technology | Sun J.,Tianjin Hi Technology Superconducting Electronic Technologies Co. | And 5 more authors.
Science in China, Series F: Information Sciences | Year: 2010

A high temperature superconducting (HTS) filter with a linear phase is designed for CDMA2000 communication systems. The principle and equivalent model of the filter have been presented. The theoretical result, coupling matrix, and the simulated result with Sonnet software have also been demonstrated. The desired filter with 12-pole and 2 cross couplings has a center frequency of 830 MHz. The measurement results show that the response of practical filters is in good agreement with that of simulated results and theoretical analysis, the group delay variation is less than ±10 ns over 60% of the filter bandwidth, and the skit slope of the filter is about 37 dB/MHz. © 2010 Science China Press and Springer-Verlag Berlin Heidelberg.

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