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Capacitive-coupled Series Spoof Surface Plasmon Polaritons.

Yin JY, Ren J, Zhang HC, Zhang Q, Cui TJ - Sci Rep (2016)

Bottom Line: Two conventional H-shaped unit cells are proposed to construct a new unit cell, and every two new unit cells are separated by a gap with certain distance, which is designed to implement capacitive coupling.It is shown that the proposed structure exhibits a stopband in 9-9.5 GHz while the band-pass feature maintains in 5-9 GHz and 9.5-11 GHz.The compact size, easy fabrication and good band-pass and band-stop features make the proposed structure a promising plasmonic device in SPP communication systems.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China.

ABSTRACT
A novel method to realize stopband within the operating frequency of spoof surface plasmon polaritons (SPPs) is presented. The stopband is introduced by a new kind of capacitive-coupled series spoof SPPs. Two conventional H-shaped unit cells are proposed to construct a new unit cell, and every two new unit cells are separated by a gap with certain distance, which is designed to implement capacitive coupling. The original surface impedance matching is disturbed by the capacitive coupling, leading to the stopband during the transmission of SPPs. The proposed method is verified by both numerical simulations and experiments, and the simulated and measured results have good agreements. It is shown that the proposed structure exhibits a stopband in 9-9.5 GHz while the band-pass feature maintains in 5-9 GHz and 9.5-11 GHz. In the passband, the reflection coefficient is less than -10 dB, and the transmission loss is around 3 dB; in the stopband, the reflection coefficient is -2 dB, and the transmission coefficient is less than -30 dB. The compact size, easy fabrication and good band-pass and band-stop features make the proposed structure a promising plasmonic device in SPP communication systems.

No MeSH data available.


Related in: MedlinePlus

Simulated S-parameters with different values of gap distance g between two unit cells.(a) Reflection coefficients. (b) Transmission coefficients.
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f6: Simulated S-parameters with different values of gap distance g between two unit cells.(a) Reflection coefficients. (b) Transmission coefficients.

Mentions: To get a better understanding on the influence of the capacitance between new unit cells, the reflection and transmission coefficients are simulated under different gap distances. With reference to Fig. 6, it can be observed that when the gap distance between new unit cells increases, the frequency range of stopband becomes wider, owing to the larger mismatch of the surface impedance. This is consistent to the predictions before. It is worth noting that the cutoff frequency of the first passband agrees well with the dispersion curve in Fig. 2. However the big mismatch will also lead to the bad performance of the structure. We note that the reflection coefficient is above −10 dB during the passband, and the transmission loss becomes larger in both passbands for wider gap at the same time, especially in the second passband. On the basis of the definition of the bandstop filter, the energy can be transmitted under majority frequencies but reflected under some appoint frequencies, so here the performances of passband and stopband are both taken into account when measure the performance of the whole structure. According to the general relationship between the performance and the gap distance among unit cells, a narrower stopband and better performance in passband can be realized by a smaller distance than 0.1 mm. Nevertheless, due to the processing condition, the gap cannot be smaller than 0.1 mm, and hence we set the final gap as 0.1 mm. Other ways to increase the capacitance between unit cells (e.g. the interdigital capacitive structure) can also be considered in the future work.


Capacitive-coupled Series Spoof Surface Plasmon Polaritons.

Yin JY, Ren J, Zhang HC, Zhang Q, Cui TJ - Sci Rep (2016)

Simulated S-parameters with different values of gap distance g between two unit cells.(a) Reflection coefficients. (b) Transmission coefficients.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4835726&req=5

f6: Simulated S-parameters with different values of gap distance g between two unit cells.(a) Reflection coefficients. (b) Transmission coefficients.
Mentions: To get a better understanding on the influence of the capacitance between new unit cells, the reflection and transmission coefficients are simulated under different gap distances. With reference to Fig. 6, it can be observed that when the gap distance between new unit cells increases, the frequency range of stopband becomes wider, owing to the larger mismatch of the surface impedance. This is consistent to the predictions before. It is worth noting that the cutoff frequency of the first passband agrees well with the dispersion curve in Fig. 2. However the big mismatch will also lead to the bad performance of the structure. We note that the reflection coefficient is above −10 dB during the passband, and the transmission loss becomes larger in both passbands for wider gap at the same time, especially in the second passband. On the basis of the definition of the bandstop filter, the energy can be transmitted under majority frequencies but reflected under some appoint frequencies, so here the performances of passband and stopband are both taken into account when measure the performance of the whole structure. According to the general relationship between the performance and the gap distance among unit cells, a narrower stopband and better performance in passband can be realized by a smaller distance than 0.1 mm. Nevertheless, due to the processing condition, the gap cannot be smaller than 0.1 mm, and hence we set the final gap as 0.1 mm. Other ways to increase the capacitance between unit cells (e.g. the interdigital capacitive structure) can also be considered in the future work.

Bottom Line: Two conventional H-shaped unit cells are proposed to construct a new unit cell, and every two new unit cells are separated by a gap with certain distance, which is designed to implement capacitive coupling.It is shown that the proposed structure exhibits a stopband in 9-9.5 GHz while the band-pass feature maintains in 5-9 GHz and 9.5-11 GHz.The compact size, easy fabrication and good band-pass and band-stop features make the proposed structure a promising plasmonic device in SPP communication systems.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Millimeter Waves, Southeast University, Nanjing 210096, China.

ABSTRACT
A novel method to realize stopband within the operating frequency of spoof surface plasmon polaritons (SPPs) is presented. The stopband is introduced by a new kind of capacitive-coupled series spoof SPPs. Two conventional H-shaped unit cells are proposed to construct a new unit cell, and every two new unit cells are separated by a gap with certain distance, which is designed to implement capacitive coupling. The original surface impedance matching is disturbed by the capacitive coupling, leading to the stopband during the transmission of SPPs. The proposed method is verified by both numerical simulations and experiments, and the simulated and measured results have good agreements. It is shown that the proposed structure exhibits a stopband in 9-9.5 GHz while the band-pass feature maintains in 5-9 GHz and 9.5-11 GHz. In the passband, the reflection coefficient is less than -10 dB, and the transmission loss is around 3 dB; in the stopband, the reflection coefficient is -2 dB, and the transmission coefficient is less than -30 dB. The compact size, easy fabrication and good band-pass and band-stop features make the proposed structure a promising plasmonic device in SPP communication systems.

No MeSH data available.


Related in: MedlinePlus