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Observation of tunable nonlinear effects in an analogue of superconducting composite right/left hand filter.

Liu H, Lei J, Jiang H, Guan X, Ji L, Ma Z - Sci Rep (2015)

Bottom Line: 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.However, any future effort in creating tunable structures would require knowledge of nonlinear properties.Its nonlinear effects on temperature and power are studied by theoretical analysis and experiments.

View Article: PubMed Central - PubMed

Affiliation: Department of Information Engineering, East China Jiaotong University, Nanchang, 330013, China.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Measured IMD3 of the HTS filter for two different frequencies at 77 K.1.58 GHz is at a left-hand frequency, and 1.9 GHz is at a right-hand frequency. IMD3 stands for the third-order intermodulation distortion. IP3 is the third-order intercept point.
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f8: Measured IMD3 of the HTS filter for two different frequencies at 77 K.1.58 GHz is at a left-hand frequency, and 1.9 GHz is at a right-hand frequency. IMD3 stands for the third-order intermodulation distortion. IP3 is the third-order intercept point.

Mentions: For high reliable communication systems, such as digital telecommunication systems, nonlinear responses are an outstanding problem38. In the nonlinear regime, spurious signals are generated within passband, undermining device performance. Thus, evaluation of this characteristic is very important for HTS CRLH filter. To investigate nonlinearity of this filter, third-order intermodulation distortion (IMD3) is analyzed and measured. As a significant measurement of power handling capability, the third-order intercept point (IP3) is computed, which is defined as input power at which extrapolations of the fundamental and generated signal curves intersect. Figure 8 exhibits the input power versus output power at 77 K. Two-tone fundamental signals (1.57985 GHz and 1.58015 GHz signals for the left-hand frequency @1.58 GHz while 1.89985 GHz and 1.90015 GHz for the right-hand frequency @1.9 GHz) are input to the measured passband. IP3 of the left-hand and right-hand frequency are 42 and 33 dBm, respectively. It shows a good power handling capability. Based on the experiment results39, it can be found that the higher the frequency goes, the bigger the value of IP3 becomes. However in this experiment, it is interestingly found that IP3 at 1.58 GHz (left-hand frequency) is 9 dB more than that at 1.9 GHz (right-hand frequency). This means that the former can handle 8 times power as that of the latter. This experimental result reveals that the proposed HTS CRLH filter at left-hand frequency has better power handling capability. The mechanism at left-hand frequencies (ε < 0 and μ < 0) can slow electromagnetic wave, thereby increasing the interaction time with nonlinear medium embedded in it. Or they can help by concentrating the local field and thus enhancing a nonlinear response30.


Observation of tunable nonlinear effects in an analogue of superconducting composite right/left hand filter.

Liu H, Lei J, Jiang H, Guan X, Ji L, Ma Z - Sci Rep (2015)

Measured IMD3 of the HTS filter for two different frequencies at 77 K.1.58 GHz is at a left-hand frequency, and 1.9 GHz is at a right-hand frequency. IMD3 stands for the third-order intermodulation distortion. IP3 is the third-order intercept point.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4595847&req=5

f8: Measured IMD3 of the HTS filter for two different frequencies at 77 K.1.58 GHz is at a left-hand frequency, and 1.9 GHz is at a right-hand frequency. IMD3 stands for the third-order intermodulation distortion. IP3 is the third-order intercept point.
Mentions: For high reliable communication systems, such as digital telecommunication systems, nonlinear responses are an outstanding problem38. In the nonlinear regime, spurious signals are generated within passband, undermining device performance. Thus, evaluation of this characteristic is very important for HTS CRLH filter. To investigate nonlinearity of this filter, third-order intermodulation distortion (IMD3) is analyzed and measured. As a significant measurement of power handling capability, the third-order intercept point (IP3) is computed, which is defined as input power at which extrapolations of the fundamental and generated signal curves intersect. Figure 8 exhibits the input power versus output power at 77 K. Two-tone fundamental signals (1.57985 GHz and 1.58015 GHz signals for the left-hand frequency @1.58 GHz while 1.89985 GHz and 1.90015 GHz for the right-hand frequency @1.9 GHz) are input to the measured passband. IP3 of the left-hand and right-hand frequency are 42 and 33 dBm, respectively. It shows a good power handling capability. Based on the experiment results39, it can be found that the higher the frequency goes, the bigger the value of IP3 becomes. However in this experiment, it is interestingly found that IP3 at 1.58 GHz (left-hand frequency) is 9 dB more than that at 1.9 GHz (right-hand frequency). This means that the former can handle 8 times power as that of the latter. This experimental result reveals that the proposed HTS CRLH filter at left-hand frequency has better power handling capability. The mechanism at left-hand frequencies (ε < 0 and μ < 0) can slow electromagnetic wave, thereby increasing the interaction time with nonlinear medium embedded in it. Or they can help by concentrating the local field and thus enhancing a nonlinear response30.

Bottom Line: 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.However, any future effort in creating tunable structures would require knowledge of nonlinear properties.Its nonlinear effects on temperature and power are studied by theoretical analysis and experiments.

View Article: PubMed Central - PubMed

Affiliation: Department of Information Engineering, East China Jiaotong University, Nanchang, 330013, China.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus