可控的人工结构材料及其在天线中的应用
|
摘要
本论文围绕着可控人工结构材料及其在天线中的应用进行了系统的研究。主要研究了加载变容二极管的变容型可控表面结构人工材料和体结构人工材料两种材料的电磁可控特性。并将变容型可控的人工结构材料应用到天线设计上，分别实现了频率可重构天线和方向图可重构天线。此外，针对石墨烯新型材料在微波高频段可控的人工结构材料中的应用进行积极探索，为设计高频可控的人工结构材料提供了思路。论文的主要内容和结论如下：
（1）变容型可控的表面结构和体结构人工材料电磁特性研究。分别提出在高阻抗表面上和体结构人工材料上加载变容二极管来实现谐振频率和电磁性质大范围连续可调的可控人工结构材料。分别研究了变容型可控的表面结构和体结构人工结构材料的电磁性质随变容二极管电容的调节规律。研究结果表明可控的表面结构人工材料的带隙在1.8GHz-3.2GHz范围内连续可调。可控的体结构人工材料的谐振频率及其电磁参数在较大范围内实现连续的调控。
（2）变容型可控的人工结构材料在可重构天线中的应用。将变容型可控的表面结构人工材料和体结构人工材料分别应用于设计频率可重构天线和方向图可重构天线。建立了基于变容型可控的频率可重构天线和方向图可重构天线的物理模型。研究结果表明：频率可重构天线的工作频率可在较大的频率范围内连续可调，方向可重构天线的方向图可实现在34范围内连续可变。进一步证实了变容型可控的人工结构材料的大范围连续可调特性。
（3）基于石墨烯的高频可控的人工结构材料研究。针对传统可控器件在微波高频上存在的问题，提出利用石墨烯来构造高频段快速连续可控的人工结构材料。实验证实了石墨烯FET的电导率和载流子浓度的可调性能。在高频设计了基于石墨烯的可控的人工结构材料，仿真结果表明材料的电磁特性能实现较大频率范围内连续可调，初步证实了基于石墨烯的可控人工结构材料的电磁可调特性。
In this thesis, we mainly focus on the tunable metamaterials and its tunableelectromagnetic properties. By loading variable capacitance into metamaterials, Tunablesurface and bulk metamaterial can be realized and their tunable EM properties werestudied and validated by the theory and experiments results. Based on the tunablesurface and bulk metamaterials, frequency reconfigurable and radiation reconfigurableantenna were constructed. Besides，graphene which is a novel artificial material and itsapplication in constructing tunable metamaterials in the high frequency were studied.The main work and conclusion are listed as following:
(1) Studies on the properties of tunable surface metamaterial and bulk metamaterialby loading variable capacitance. Tunable surface metamaterial and tunable bulkmetamaterial was proposed by loading varactor diode into structure. The capacitanceof the varactor diode can dynamically change the resonance frequency continuously inlarge scale, which resulted tunable electromagnetic properties. Our results indicated thatthe band gap of the surface metamaterial can be tuned continuously in the range of1.8GHz to3.2GHz. And the tunable resonance frequency and electromagneticproperties in large range for the bulk metamaterial is also validated.
(2) The applications of tunable metamaterials in reconfigurable antenna. Dealingwith the requirements of reconfigurable antenna, tunable surface metamaterial and bulkmetamaterials were proposed to design frequency reconfigurable and radiation patternreconfigurable antenna, respectively. We have built the theory model for thereconfigurable antenna based on the tunable metamaterials by loading variable antenna.The results indicated that the working frequency of the frequency reconfigurableantenna can be changed continuously in the range of2.36GHz3.34GHz. And mainlobe of the radiation pattern can be tuned within34by properly arranging thedistribution of the capacitance of the varactor diode. It provides a way for us to designreconfigurable antenna.
(3) Research on a novel tunable metamaterial in high frequency of microwave.Based on the inability of tunable microwave device in high frequency, we proposed toconstruct tunable metamaterials in high frequency by employing graphene. Themeasured results shown the conductivity of graphene FET and the density of the carriercan be tuned dynamically. More importantly, the tunable metamaterial in high frequencybased on graphene formed, and the simulation results demonstrated that theelectromagnetic properties of graphene tunable metamaterial could be modulateddynamically and continuously in a wide frequency range. It lays a foundation for ourfuture works on graphene tunable metamaterial.
（1）变容型可控的表面结构和体结构人工材料电磁特性研究。分别提出在高阻抗表面上和体结构人工材料上加载变容二极管来实现谐振频率和电磁性质大范围连续可调的可控人工结构材料。分别研究了变容型可控的表面结构和体结构人工结构材料的电磁性质随变容二极管电容的调节规律。研究结果表明可控的表面结构人工材料的带隙在1.8GHz-3.2GHz范围内连续可调。可控的体结构人工材料的谐振频率及其电磁参数在较大范围内实现连续的调控。
（2）变容型可控的人工结构材料在可重构天线中的应用。将变容型可控的表面结构人工材料和体结构人工材料分别应用于设计频率可重构天线和方向图可重构天线。建立了基于变容型可控的频率可重构天线和方向图可重构天线的物理模型。研究结果表明：频率可重构天线的工作频率可在较大的频率范围内连续可调，方向可重构天线的方向图可实现在34范围内连续可变。进一步证实了变容型可控的人工结构材料的大范围连续可调特性。
（3）基于石墨烯的高频可控的人工结构材料研究。针对传统可控器件在微波高频上存在的问题，提出利用石墨烯来构造高频段快速连续可控的人工结构材料。实验证实了石墨烯FET的电导率和载流子浓度的可调性能。在高频设计了基于石墨烯的可控的人工结构材料，仿真结果表明材料的电磁特性能实现较大频率范围内连续可调，初步证实了基于石墨烯的可控人工结构材料的电磁可调特性。
In this thesis, we mainly focus on the tunable metamaterials and its tunableelectromagnetic properties. By loading variable capacitance into metamaterials, Tunablesurface and bulk metamaterial can be realized and their tunable EM properties werestudied and validated by the theory and experiments results. Based on the tunablesurface and bulk metamaterials, frequency reconfigurable and radiation reconfigurableantenna were constructed. Besides，graphene which is a novel artificial material and itsapplication in constructing tunable metamaterials in the high frequency were studied.The main work and conclusion are listed as following:
(1) Studies on the properties of tunable surface metamaterial and bulk metamaterialby loading variable capacitance. Tunable surface metamaterial and tunable bulkmetamaterial was proposed by loading varactor diode into structure. The capacitanceof the varactor diode can dynamically change the resonance frequency continuously inlarge scale, which resulted tunable electromagnetic properties. Our results indicated thatthe band gap of the surface metamaterial can be tuned continuously in the range of1.8GHz to3.2GHz. And the tunable resonance frequency and electromagneticproperties in large range for the bulk metamaterial is also validated.
(2) The applications of tunable metamaterials in reconfigurable antenna. Dealingwith the requirements of reconfigurable antenna, tunable surface metamaterial and bulkmetamaterials were proposed to design frequency reconfigurable and radiation patternreconfigurable antenna, respectively. We have built the theory model for thereconfigurable antenna based on the tunable metamaterials by loading variable antenna.The results indicated that the working frequency of the frequency reconfigurableantenna can be changed continuously in the range of2.36GHz3.34GHz. And mainlobe of the radiation pattern can be tuned within34by properly arranging thedistribution of the capacitance of the varactor diode. It provides a way for us to designreconfigurable antenna.
(3) Research on a novel tunable metamaterial in high frequency of microwave.Based on the inability of tunable microwave device in high frequency, we proposed toconstruct tunable metamaterials in high frequency by employing graphene. Themeasured results shown the conductivity of graphene FET and the density of the carriercan be tuned dynamically. More importantly, the tunable metamaterial in high frequencybased on graphene formed, and the simulation results demonstrated that theelectromagnetic properties of graphene tunable metamaterial could be modulateddynamically and continuously in a wide frequency range. It lays a foundation for ourfuture works on graphene tunable metamaterial.
引文
[1] Pendry, J.B., Negative refraction makes a perfect lens. Physical review letters,2000.85(18):p.3966-3969.
[2] Fang, N., et al., Sub-diffraction-liffraction-limited optical imaging with a silver superlens.Science,2005.308(5721): p.534-537.
[3] Liu, Z., et al., Far-field optical hyperlens magnifying sub-diffraction-limited objects.Science,2007.315(5819): p.1686-1686.far-field optical hyperlens magnifyingsub-diffraction limited objects
[4] Thevenot, M., et al., Directive photonic-bandgap antennas. Microwave Theory andTechniques, IEEE Transactions on,1999.47(11): p.2115-2122.A metamaterial for directiveemission
[5] Enoch, S., et al., A metamaterial for directive emission. Physical review letters,2002.89(21):p.213902.
[6] Schurig, D., et al., Metamaterial electromagnetic cloak at microwave frequencies. Science,2006.314(5801): p.977-980.
[7] Cai, W., et al., Optical cloaking with metamaterials. Nature photonics,2007.1(4): p.224-227.
[8] Liu, R., et al., Broadband ground-plane cloak. Science,2009.323(5912): p.366-369.
[9] Han, J., A. Lakhtakia, and C.-W. Qiu, Terahertz metamaterials with semiconductorsplit-ring resonators for magnetostatic tunability. arXiv preprint arXiv:0807.2495,2008.
[10]Hand, T.H. and S.A. Cummer, Frequency tunable electromagnetic metamaterial usingferroelectric loaded split rings. Journal of Applied Physics,2008.103(6): p.066105-066105-3.
[11]Kang, L., et al., Ferrite-based magnetically tunable left-handed metamaterial composed ofSRRs and wires. Optics express,2008.16(22): p.17269-17275.
[12]Zhao, Q., et al., Electrically tunable negative permeability metamaterials based on nematicliquid crystals. Applied Physics Letters,2007.90(1): p.011112-011112-3.
[13]Q. Zhao, L. Kang, B. Du, B. Li, J. Zhou, Electrically tunable negative permeabilitymetamaterials based on nematic liquid crystals, Appl. Phys. Lett.90,011112(2007).
[14]Ekmekci, E., et al., A tunable multi-band metamaterial design using micro-split SRRstructures. Opt. Express,2009.17(18): p.16046-16058.
[15]He, P., et al., A microstrip tunable negative refractive index metamaterial and phase shifter.Applied Physics Letters,2008.93(19): p.193505-193505-3.
[16]He, P., et al., Tunable negative refractive index metamaterial phase shifter. ElectronicsLetters,2007.43(25): p.1440-1441.
[17]Sievenpiper, D., et al., A steerable leaky-wave antenna using a tunable impedance groundplane. Antennas and Wireless Propagation Letters, IEEE,2002.1(1): p.179-182.
[18]Sievenpiper, D., et al., A tunable impedance surface performing as a reconfigurable beamsteering reflector. Antennas and Propagation, IEEE Transactions on,2002.50(3): p.384-390.
[19] V. G. Veselago, The electrodynamics of substances with simultaneously negative valuesof and μ, Sov. Phys. Usp.,1968,10:509~514.
[20]J. B. Pendry, A. J. Holden, W. J. Stewart, and I. Youngs, Extremely low frequency plasmonsin metallic mesostructures, Phys. Rev. Lett.,1996,76:4773~4776.
[21]J.B. Pendry, A.J. Holden, D.J. Robbins, and W.J. Stewart, Low frequency plasmons inthin-wire structues, J. Phys. Condens. Matter,1998,10(7):4785~4809.
[22]J. B. Pendry, A. J. Holden, D. J. Robbins, and W. J. Stewart, Magnetism from conductorsand enhanced nonlinear phenomena, IEEE Trans. Microwave Theory Tech.,1999,47(11):2075~2084.
[23] R. A. Shelby, D. R. Smith, and S. Schultz, Experimental verification of a negative indexof refraction, Science,2001,292:77~79.
[24] D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S, Schultz, Compositemedium with simultaneously negative permeability and permittivity, Phys. Rev. Lett.,2000,84(18):4184~4187.
[25]Shau–Gang Mao, Min–Sou Wu, A novel3–dB directional coupler with broad band widthand compact size using composite right/left-handed coplanar waveguides. IEEE Microwaveand wireless components letters.2007,17(5):331-333.
[26] Caloz C, Sannada A, Itoh T. A novel composite right/left-handed coupled-line directionalcoupler with arbitrary coupling level and broad bandwidth. IEEE Transactions onmicrowave Theory and Techniques.2004,52(3):980-992.
[27] Hoang Van Nguyen, Christophe Caloz. Generalized coupled-mode approach ofmetamaterial coupled-line couplers: coupling theory, phenomenological explanation, andexperimental demonstration. IEEE Transactions on microwave Theory and Techniques.2007,55(5):1029-1039.
[28] Liao Shaowei, Yan Ping, Xu Jianhua, Wang Ya. Coaxial waveguide based left-handedtransmission line. IEEE Microwave and wireless components letters.2007,17(8):568-570.
[29] Kim H, Kozyrev A B, Kar A, et al. Compact left-handed transmission lines as a linearphase-voltage modulator and efficient harmonic generator. IEEE Transactions onmicrowave Theory and Techniques.2003,51(12):2306-2314.
[30]]S. John, Strong localization of photons in certain disordered dielectric superlattices, Phys.Rev. Lett.,1987,58(23):2486~2489.
[31] E. Yablonovitch, Inhibited spontaneous emission in solid-state physics and electronics,Phys. Rev. Lett.,1987,58(20):2059~2062.
[32]D. Sievenpiper, L. Zhang, F. J. Broas, N. G. Alexopolous, and E. Yablonovitch,High-impedance electromagnetic surfaces with a forbidden frequency band, IEEE Trans.Microw. Theory Tech.,1999,47(11):2059-2074.
[33] V. Radisic et al., Novel2-D photonic bandgap structure for microstrip lines, IEEEMicrowave and Guided Wave Letters,1998,8(2):69~71.
[34] Y. Fei-Ran et al., A uniplanar compact photonic-bandgap (UC-PBG) structure and itsapplications for microwave circuit, IEEE Transactions on Microwave Theory andTechniques,1999,47(8):1509-1514.
[35] B. A. Munk, Finite antenna arrays and FSS, New-York: IEEE Press, Wiley-Interscience,2003.
[36]K. Chul-Soo et al., A novel1-D periodic defected ground structure for planar circuits, IEEEMicrowave and Guided Wave Letters,2000,10(4):131~133.
[37]周济.“超材料（metamaterials）”：超越材料性能的自然极限.2005,四川大学学报（自然科学版）,42(2):15-16.
[38]崔万照，马伟，邱乐得，张洪太.电磁超介质及其应用.北京：国防工业出版社，2008，1-3.
[39]徐慧良，EBG结构和低折射率特性材料应用于天线设计中的应用，博士论文，中科院光电技术研究所，2008.
[40]Padilla, W.J., D.N. Basov, and D.R. Smith, Negative refractive index metamaterials.Materials today,2006.9(7): p.28-35.
[41] R. Shelby, D. Smith, S. Nemat-Nasser, and S. Schultz, Microwave transmission through atwo-dimensional, isotropic, left-handed metamaterial, Applied Physics Letters,2001,78:4892001.
[42]Russell, P., Photonic crystal fibers. Science,2003.299(5605): p.358-362.
[43]Fan, S., et al., High extraction efficiency of spontaneous emission from slabs of photoniccrystals. Physical Review Letters,1997.78(17): p.3294-3297.
[44]H. Altug and J. Vujkovic, Photonic crystal nanocavity array laser, Opt. Express,2005,13:8819-8828.
[45]I. Rumsey, M. P. May, and P. K. Kelly, Photonic band-gap structure used as filters inmicrostrip circuits, IEEE Microwave Guided Wave Letters,1998,8(10):336~339.
[46]M. J. Hill, R. W. Ziolkowski, and J. Papapolymerou, A high-Q reconfigurable planar EBGcavity resonator, IEEE Microwave Wireless Compo. Lett.,2001,6:255~257.
[47]V. Radisic, Y. Qian, and T. Itoh, Broadband power amplifier using band-gap structure,IEEE Microwave Guided Wave Lett.,1998,8(1):13~14.
[48]Y. Horri, and M. Tsutsumi, Suppression of the harmonic radiation from the PBG microstripantenna,1999IEEE MTT-S,724-727.
[49]R. Gonzalo, P. de Maagt, and M. Sorolla, Enhanced patch-antenna performance bysuppressing surface waves using photonic-bandgap structures, IEEE Trans. MicrowaveTheory Tech.,1999,47(11):2131-2138.
[50] P. de Maagt, R. Gonzalo, Y. C. Vardaxoglou, and J. M. Baracco, Electromagneticbandgap antennas and components for microwave and (sub)millimeter wave applications,IEEE Trans Antennas Propagat.,200351(10):2667–2677.
[51]F. Yang and Y.Rahmat-Samii, A low profile circularly polarized curl antenna overelectromagnetic band-gap (EBG) surface, Microwave Opt. Technol. Lett.,2001,31(3):264~267.
[52]F. Yang and Y.Rahmat-Samii, Reflection phase characterizations of the EBG ground planefor low profile wire antenna applications, IEEE Trans. Antennas Propagation,2003,51(10):2691~2703.
[53]Cheype, C., et al., An electromagnetic bandgap resonator antenna. Antennas andPropagation, IEEE Transactions on,2002.50(9): p.1285-1290.
[54]Zhang, X. and Z. Liu, Superlenses to overcome the diffraction limit. Nature materials,2008.7(6): p.435-441.
[55]Liu, Z., et al., Experimental studies of far-field superlens for sub-diffractional opticalimaging. Opt. Express,2007.15(11): p.6947-6954.
[56]Hand, T. and S. Cummer, Characterization of tunable metamaterial elements using MEMSswitches. Antennas and Wireless Propagation Letters, IEEE,2007.6: p.401-404.
[57]Gil, I., et al., Tunable metamaterial transmission lines based on varactor-loaded split-ringresonators. Microwave Theory and Techniques, IEEE Transactions on,2006.54(6): p.2665-2674.
[58]Wang, Y., C. Du, and X. Dong, Creating a simplified, frequency-tunable metamaterial.SPIE Newsroom,2011.
[59]Wang, Y., et al. Frequency tunable electromagnetic metamaterial based on mechanicalmovement method. in Photonics Asia2010.2010: International Society for Optics andPhotonics.
[60]Wang, J., et al., A tunable left-handed metamaterial based on modified broadside-coupledsplit-ring resonators. Progress In Electromagnetics Research Letters,2009.6: p.35-45.
[61]Liu, L., S. Matitsine, and P. Tan, Electromagnetic smart screen for tunable transmissionapplications. Microwave and Optical Technology Letters,2008.50(6): p.1510-1514.
[62]Chen, H.-T., et al., Experimental demonstration of frequency-agile terahertz metamaterials.Nature photonics,2008.2(5): p.295-298.
[63]Han, J. and A. Lakhtakia, Semiconductor split-ring resonators for thermally tunableterahertz metamaterials. Journal of Modern Optics,2009.56(4): p.554-557.
[64]Hand, T.H. and S.A. Cummer, Controllable magnetic metamaterial using digitallyaddressable split-ring resonators. Antennas and Wireless Propagation Letters, IEEE,2009.8: p.262-265.
[65]Xiao, S., et al., Tunable magnetic response of metamaterials. Applied Physics Letters,2009.95(3): p.033115-033115-3.
[66]Zhang, F., et al., Magnetically tunable left handed metamaterials by liquid crystalorientation. Optics express,2009.17(6): p.4360-4366.
[67]Wang, X., et al., Tunable optical negative-index metamaterials employing anisotropic liquidcrystals. Applied Physics Letters,2007.91(14): p.143122-143122-3.
[68]Reynet, O. and O. Acher, Voltage controlled metamaterial. Applied Physics Letters,2004.84(7): p.1198-1200.
[69]Elamaran, B., et al. A beam-steerer using reconfigurable PBG ground plane. in MicrowaveSymposium Digest.2000IEEE MTT-S International.2000: IEEE.
[70]Chang, T., R. Langley, and E. Parker, An active square loop frequency selective surface.Microwave and Guided Wave Letters, IEEE,1993.3(10): p.387-388.
[71]Wang, J., et al., A tunable left-handed metamaterial based on modified broadside-coupledsplit-ring resonators. Progress In Electromagnetics Research Letters,2009.6: p.35-45.
[72]Sheng, Z. and V.V. Varadan, Tuning the effective properties of metamaterials by changingthe substrate properties. Journal of applied physics,2007.101(1): p.014909-014909-7.
[73]Balandin, A.A., et al., Superior thermal conductivity of single-layer graphene. Nano letters,2008.8(3): p.902-907.
[74]Lee, C., et al., Measurement of the elastic properties and intrinsic strength of monolayergraphene. Science,2008.321(5887): p.385-388.
[75]Du, X., et al., Approaching ballistic transport in suspended graphene. NatureNanotechnology,2008.3(8): p.491-495.
[76]Novoselov, K., et al., Electric field effect in atomically thin carbon films. Science,2004.306(5696): p.666-669.
[77]Wang, H., et al., Graphene frequency multipliers. Electron Device Letters, IEEE,2009.30(5): p.547-549.
[78]Wang, H., et al., BN/Graphene/BN transistors for RF applications. Electron Device Letters,IEEE,2011.32(9): p.1209-1211.
[79]Moon, J., et al., Low-phase-noise graphene FETs in ambipolar RF applications. ElectronDevice Letters, IEEE,2011.32(3): p.270-272.
[80]Lin, Y.-M., et al., Wafer-scale graphene integrated circuit. Science,2011.332(6035): p.1294-1297.
[81]Tamagnone, M., et al., Analysis and design of terahertz antennas based on plasmonicresonant graphene sheets. Journal of Applied Physics,2012.112(11): p.114915-114915-4.
[82]Burke, J.E., Analytical Study of Tunable Bilayered-Graphene Dipole Antenna.2011, DTICDocument.
[83]Perruisseau-Carrier, J. Graphene for antenna applications: Opportunities and challengesfrom microwaves to THz. in Antennas and Propagation Conference (LAPC),2012Loughborough.2012: IEEE.
[84]Tamagnone, M., et al., Reconfigurable terahertz plasmonic antenna concept using agraphene stack. Applied Physics Letters,2012.101: p.214102.
[85]Carrasco, E., M. Tamagnone, and J. Perruisseau-Carrier, Tunable Graphene Reflective Cellsfor THz Reflectarrays and Generalized Law of Reflection. arXiv preprint arXiv:1212.3158,2012.
[86]Ju, L., et al., Graphene plasmonics for tunable terahertz metamaterials. NatureNanotechnology,2011.6(10): p.630-634.
[87]Vakil, A. and N. Engheta, Transformation optics using graphene. Science,2011.332(6035):p.1291-1294.
[88]Tennant, A. and B. Chambers, A single-layer tuneable microwave absorber using an activeFSS. Microwave and Wireless Components Letters, IEEE,2004.14(1): p.46-47.
[89]Gil, I., et al., Varactor-loaded split ring resonators for tunable notch filters at microwavefrequencies. Electronics Letters,2004.40(21): p.1347-1348.
[90]Liang, J. and H.D. Yang, Microstrip patch antennas on tunable electromagnetic band-gapsubstrates. Antennas and Propagation, IEEE Transactions on,2009.57(6): p.1612-1617.
[91]Yang, L., et al., A novel compact electromagnetic-bandgap (EBG) structure and itsapplications for microwave circuits. Microwave Theory and Techniques, IEEE Transactionson,2005.53(1): p.183-190.
[92]杨雪松，微带可重构天线研究，博士论文，电子科技大学，2006。
[93]魏文博，可重构天线研究，博士论文，西安电子科技大学，2008。
[94]Aydin, K. and E. Ozbay, Capacitor-loaded split ring resonators as tunable metamaterialcomponents. Journal of applied physics,2007.101(2): p.024911-024911-5.
[95]Munk, B.A., Frequency selective surfaces: theory and design.2005:Wiley-Interscience.
[96]Brown J. Articial dielectrics. Progress in dielectrics.1960,2:195-225.
[97]Smith, D.R., et al., Calculation and measurement of bianisotropy in a split ring resonatormetamaterial. Journal of applied physics,2006.100(2): p.024507-024507-9.
[98]Smith, D., et al., Determination of effective permittivity and permeability of metamaterialsfrom reflection and transmission coefficients. Physical Review B,2002.65(19): p.195104.
[99]Koschny, T., et al., Effective medium theory of left-handed materials. Physical review letters,2004.93(10): p.107402.
[100] F. R. Yang, K. P. Ma, Y. Qian, and T. Itoh, A uniplanar compact photonic-bandgap(UC-PBG) structure and its applications for microwave circuits, IEEE Trans. Microwave.Theory Tech.,1999,47(8):1509-1514.
[101] Sha, Y., et al., Experimental investigations of microwave absorber with FSS embedded incarbon fiber composite. Microwave and Optical Technology Letters,2002.32(4): p.245-249.
[102] Costa, F., A. Monorchio, and G. Manara, Analysis and design of ultra thin electromagneticabsorbers comprising resistively loaded high impedance surfaces. Antennas and Propagation,IEEE Transactions on.58(5): p.1551-1558.
[103] Fan, S., et al., Channel drop tunneling through localized states. Physical Review Letters,1998.80(5): p.960-963.
[104] Ozbay, E., et al., Micromachined millimeter‐wave photonic band‐gap crystals. AppliedPhysics Letters,1994.64(16): p.2059-2061.
[105] Tretyakov, S., Analytical modeling in applied electromagnetics.2003: Artech HousePublishers.
[106] Xiao, S. and B. Wang, Preliminary research on microstrip reconfigurable antenna. ChineseJournal of Radio Science,2002.17(4): p.386-390.
[107] Nikolaou, S., et al., Pattern and frequency reconfigurable annular slot antenna using PINdiodes. Antennas and Propagation, IEEE Transactions on,2006.54(2): p.439-448.
[108] Huff, G., et al., A novel radiation pattern and frequency reconfigurable single turn squarespiral microstrip antenna. Microwave and Wireless Components Letters, IEEE,2003.13(2):p.57-59.
[109] Gupta, K., et al. Design of frequency-reconfigurable rectangular slot ring antennas. inAntennas and Propagation Society International Symposium,2000. IEEE.2000: IEEE.
[110] Cetiner, B.A., et al., RF MEMS integrated frequency reconfigurable annular slot antenna.Antennas and Propagation, IEEE Transactions on.58(3): p.626-632.
[111] Schaubert, D.H., et al., Frequency-agile, polarization diverse microstrip antennas andfrequency scanned arrays.1983, Google Patents.
[112] Zhang, S., et al., A pattern reconfigurable microstrip parasitic array. Antennas andPropagation, IEEE Transactions on,2004.52(10): p.2773-2776.
[113] Dolfi, D., et al., Experimental demonstration of a phased-array antenna optically controlledwith phase and time delays. Applied optics,1996.35(26): p.5293-5300.
[114] Bray, M. and D. Werner. A broadband open-sleeve dipole antenna mounted above a tunableEBG AMC ground plane. in Antennas and Propagation Society International Symposium,2004. IEEE.2004: IEEE.
[115] Wang, X., et al., Room-temperature all-semiconducting sub-10-nm graphene nanoribbonfield-effect transistors. Physical Review Letters,2008.100(20): p.206803.
[116] Xia, F., Farmer, D. B., Lin, Y.-M.&Avouris, Ph. Graphene field-effect transistors with highon/off current ratio and large transport band gap at room temperature. Nano Lett.10,715–718,2010.
[117] Martins, T., et al., Electronic and transport properties of boron-doped graphenenanoribbons. Physical Review Letters,2007.98(19): p.196803.
[118] Son, Y.-W., M.L. Cohen, and S.G. Louie, Energy gaps in graphene nanoribbons. PhysicalReview Letters,2006.97(21): p.216803.
[119] Lin, Y.-M., et al.,100-GHz transistors from wafer-scale epitaxial graphene. Science,2010.327(5966): p.662-662.
[120] Wu, Y., et al., High-frequency, scaled graphene transistors on diamond-like carbon. Nature,2011.472(7341): p.74-78.
[121] Rebeiz, G.M., G.-L. Tan, and J.S. Hayden, RF MEMS phase shifters: design andapplications. Microwave Magazine, IEEE,2002.3(2): p.72-81.
[122] Schwierz, F., Graphene transistors. Nature Nanotechnology,2010.5(7): p.487-496.
[123] Liang, G., et al., Performance projections for ballistic graphene nanoribbon field-effecttransistors. Electron Devices, IEEE Transactions on,2007.54(4): p.677-682.
[124] Neto, A.C., et al., The electronic properties of graphene. Reviews of modern physics,2009.81(1): p.109.
[125] X. Liang, Z. Fu and S. Y. Chou, Graphene transistors fabricated via transfer-printing Indevice active-areas on large wafer, Nano Letters,2007,7(12):3840-3844.
[2] Fang, N., et al., Sub-diffraction-liffraction-limited optical imaging with a silver superlens.Science,2005.308(5721): p.534-537.
[3] Liu, Z., et al., Far-field optical hyperlens magnifying sub-diffraction-limited objects.Science,2007.315(5819): p.1686-1686.far-field optical hyperlens magnifyingsub-diffraction limited objects
[4] Thevenot, M., et al., Directive photonic-bandgap antennas. Microwave Theory andTechniques, IEEE Transactions on,1999.47(11): p.2115-2122.A metamaterial for directiveemission
[5] Enoch, S., et al., A metamaterial for directive emission. Physical review letters,2002.89(21):p.213902.
[6] Schurig, D., et al., Metamaterial electromagnetic cloak at microwave frequencies. Science,2006.314(5801): p.977-980.
[7] Cai, W., et al., Optical cloaking with metamaterials. Nature photonics,2007.1(4): p.224-227.
[8] Liu, R., et al., Broadband ground-plane cloak. Science,2009.323(5912): p.366-369.
[9] Han, J., A. Lakhtakia, and C.-W. Qiu, Terahertz metamaterials with semiconductorsplit-ring resonators for magnetostatic tunability. arXiv preprint arXiv:0807.2495,2008.
[10]Hand, T.H. and S.A. Cummer, Frequency tunable electromagnetic metamaterial usingferroelectric loaded split rings. Journal of Applied Physics,2008.103(6): p.066105-066105-3.
[11]Kang, L., et al., Ferrite-based magnetically tunable left-handed metamaterial composed ofSRRs and wires. Optics express,2008.16(22): p.17269-17275.
[12]Zhao, Q., et al., Electrically tunable negative permeability metamaterials based on nematicliquid crystals. Applied Physics Letters,2007.90(1): p.011112-011112-3.
[13]Q. Zhao, L. Kang, B. Du, B. Li, J. Zhou, Electrically tunable negative permeabilitymetamaterials based on nematic liquid crystals, Appl. Phys. Lett.90,011112(2007).
[14]Ekmekci, E., et al., A tunable multi-band metamaterial design using micro-split SRRstructures. Opt. Express,2009.17(18): p.16046-16058.
[15]He, P., et al., A microstrip tunable negative refractive index metamaterial and phase shifter.Applied Physics Letters,2008.93(19): p.193505-193505-3.
[16]He, P., et al., Tunable negative refractive index metamaterial phase shifter. ElectronicsLetters,2007.43(25): p.1440-1441.
[17]Sievenpiper, D., et al., A steerable leaky-wave antenna using a tunable impedance groundplane. Antennas and Wireless Propagation Letters, IEEE,2002.1(1): p.179-182.
[18]Sievenpiper, D., et al., A tunable impedance surface performing as a reconfigurable beamsteering reflector. Antennas and Propagation, IEEE Transactions on,2002.50(3): p.384-390.
[19] V. G. Veselago, The electrodynamics of substances with simultaneously negative valuesof and μ, Sov. Phys. Usp.,1968,10:509~514.
[20]J. B. Pendry, A. J. Holden, W. J. Stewart, and I. Youngs, Extremely low frequency plasmonsin metallic mesostructures, Phys. Rev. Lett.,1996,76:4773~4776.
[21]J.B. Pendry, A.J. Holden, D.J. Robbins, and W.J. Stewart, Low frequency plasmons inthin-wire structues, J. Phys. Condens. Matter,1998,10(7):4785~4809.
[22]J. B. Pendry, A. J. Holden, D. J. Robbins, and W. J. Stewart, Magnetism from conductorsand enhanced nonlinear phenomena, IEEE Trans. Microwave Theory Tech.,1999,47(11):2075~2084.
[23] R. A. Shelby, D. R. Smith, and S. Schultz, Experimental verification of a negative indexof refraction, Science,2001,292:77~79.
[24] D. R. Smith, W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S, Schultz, Compositemedium with simultaneously negative permeability and permittivity, Phys. Rev. Lett.,2000,84(18):4184~4187.
[25]Shau–Gang Mao, Min–Sou Wu, A novel3–dB directional coupler with broad band widthand compact size using composite right/left-handed coplanar waveguides. IEEE Microwaveand wireless components letters.2007,17(5):331-333.
[26] Caloz C, Sannada A, Itoh T. A novel composite right/left-handed coupled-line directionalcoupler with arbitrary coupling level and broad bandwidth. IEEE Transactions onmicrowave Theory and Techniques.2004,52(3):980-992.
[27] Hoang Van Nguyen, Christophe Caloz. Generalized coupled-mode approach ofmetamaterial coupled-line couplers: coupling theory, phenomenological explanation, andexperimental demonstration. IEEE Transactions on microwave Theory and Techniques.2007,55(5):1029-1039.
[28] Liao Shaowei, Yan Ping, Xu Jianhua, Wang Ya. Coaxial waveguide based left-handedtransmission line. IEEE Microwave and wireless components letters.2007,17(8):568-570.
[29] Kim H, Kozyrev A B, Kar A, et al. Compact left-handed transmission lines as a linearphase-voltage modulator and efficient harmonic generator. IEEE Transactions onmicrowave Theory and Techniques.2003,51(12):2306-2314.
[30]]S. John, Strong localization of photons in certain disordered dielectric superlattices, Phys.Rev. Lett.,1987,58(23):2486~2489.
[31] E. Yablonovitch, Inhibited spontaneous emission in solid-state physics and electronics,Phys. Rev. Lett.,1987,58(20):2059~2062.
[32]D. Sievenpiper, L. Zhang, F. J. Broas, N. G. Alexopolous, and E. Yablonovitch,High-impedance electromagnetic surfaces with a forbidden frequency band, IEEE Trans.Microw. Theory Tech.,1999,47(11):2059-2074.
[33] V. Radisic et al., Novel2-D photonic bandgap structure for microstrip lines, IEEEMicrowave and Guided Wave Letters,1998,8(2):69~71.
[34] Y. Fei-Ran et al., A uniplanar compact photonic-bandgap (UC-PBG) structure and itsapplications for microwave circuit, IEEE Transactions on Microwave Theory andTechniques,1999,47(8):1509-1514.
[35] B. A. Munk, Finite antenna arrays and FSS, New-York: IEEE Press, Wiley-Interscience,2003.
[36]K. Chul-Soo et al., A novel1-D periodic defected ground structure for planar circuits, IEEEMicrowave and Guided Wave Letters,2000,10(4):131~133.
[37]周济.“超材料（metamaterials）”：超越材料性能的自然极限.2005,四川大学学报（自然科学版）,42(2):15-16.
[38]崔万照，马伟，邱乐得，张洪太.电磁超介质及其应用.北京：国防工业出版社，2008，1-3.
[39]徐慧良，EBG结构和低折射率特性材料应用于天线设计中的应用，博士论文，中科院光电技术研究所，2008.
[40]Padilla, W.J., D.N. Basov, and D.R. Smith, Negative refractive index metamaterials.Materials today,2006.9(7): p.28-35.
[41] R. Shelby, D. Smith, S. Nemat-Nasser, and S. Schultz, Microwave transmission through atwo-dimensional, isotropic, left-handed metamaterial, Applied Physics Letters,2001,78:4892001.
[42]Russell, P., Photonic crystal fibers. Science,2003.299(5605): p.358-362.
[43]Fan, S., et al., High extraction efficiency of spontaneous emission from slabs of photoniccrystals. Physical Review Letters,1997.78(17): p.3294-3297.
[44]H. Altug and J. Vujkovic, Photonic crystal nanocavity array laser, Opt. Express,2005,13:8819-8828.
[45]I. Rumsey, M. P. May, and P. K. Kelly, Photonic band-gap structure used as filters inmicrostrip circuits, IEEE Microwave Guided Wave Letters,1998,8(10):336~339.
[46]M. J. Hill, R. W. Ziolkowski, and J. Papapolymerou, A high-Q reconfigurable planar EBGcavity resonator, IEEE Microwave Wireless Compo. Lett.,2001,6:255~257.
[47]V. Radisic, Y. Qian, and T. Itoh, Broadband power amplifier using band-gap structure,IEEE Microwave Guided Wave Lett.,1998,8(1):13~14.
[48]Y. Horri, and M. Tsutsumi, Suppression of the harmonic radiation from the PBG microstripantenna,1999IEEE MTT-S,724-727.
[49]R. Gonzalo, P. de Maagt, and M. Sorolla, Enhanced patch-antenna performance bysuppressing surface waves using photonic-bandgap structures, IEEE Trans. MicrowaveTheory Tech.,1999,47(11):2131-2138.
[50] P. de Maagt, R. Gonzalo, Y. C. Vardaxoglou, and J. M. Baracco, Electromagneticbandgap antennas and components for microwave and (sub)millimeter wave applications,IEEE Trans Antennas Propagat.,200351(10):2667–2677.
[51]F. Yang and Y.Rahmat-Samii, A low profile circularly polarized curl antenna overelectromagnetic band-gap (EBG) surface, Microwave Opt. Technol. Lett.,2001,31(3):264~267.
[52]F. Yang and Y.Rahmat-Samii, Reflection phase characterizations of the EBG ground planefor low profile wire antenna applications, IEEE Trans. Antennas Propagation,2003,51(10):2691~2703.
[53]Cheype, C., et al., An electromagnetic bandgap resonator antenna. Antennas andPropagation, IEEE Transactions on,2002.50(9): p.1285-1290.
[54]Zhang, X. and Z. Liu, Superlenses to overcome the diffraction limit. Nature materials,2008.7(6): p.435-441.
[55]Liu, Z., et al., Experimental studies of far-field superlens for sub-diffractional opticalimaging. Opt. Express,2007.15(11): p.6947-6954.
[56]Hand, T. and S. Cummer, Characterization of tunable metamaterial elements using MEMSswitches. Antennas and Wireless Propagation Letters, IEEE,2007.6: p.401-404.
[57]Gil, I., et al., Tunable metamaterial transmission lines based on varactor-loaded split-ringresonators. Microwave Theory and Techniques, IEEE Transactions on,2006.54(6): p.2665-2674.
[58]Wang, Y., C. Du, and X. Dong, Creating a simplified, frequency-tunable metamaterial.SPIE Newsroom,2011.
[59]Wang, Y., et al. Frequency tunable electromagnetic metamaterial based on mechanicalmovement method. in Photonics Asia2010.2010: International Society for Optics andPhotonics.
[60]Wang, J., et al., A tunable left-handed metamaterial based on modified broadside-coupledsplit-ring resonators. Progress In Electromagnetics Research Letters,2009.6: p.35-45.
[61]Liu, L., S. Matitsine, and P. Tan, Electromagnetic smart screen for tunable transmissionapplications. Microwave and Optical Technology Letters,2008.50(6): p.1510-1514.
[62]Chen, H.-T., et al., Experimental demonstration of frequency-agile terahertz metamaterials.Nature photonics,2008.2(5): p.295-298.
[63]Han, J. and A. Lakhtakia, Semiconductor split-ring resonators for thermally tunableterahertz metamaterials. Journal of Modern Optics,2009.56(4): p.554-557.
[64]Hand, T.H. and S.A. Cummer, Controllable magnetic metamaterial using digitallyaddressable split-ring resonators. Antennas and Wireless Propagation Letters, IEEE,2009.8: p.262-265.
[65]Xiao, S., et al., Tunable magnetic response of metamaterials. Applied Physics Letters,2009.95(3): p.033115-033115-3.
[66]Zhang, F., et al., Magnetically tunable left handed metamaterials by liquid crystalorientation. Optics express,2009.17(6): p.4360-4366.
[67]Wang, X., et al., Tunable optical negative-index metamaterials employing anisotropic liquidcrystals. Applied Physics Letters,2007.91(14): p.143122-143122-3.
[68]Reynet, O. and O. Acher, Voltage controlled metamaterial. Applied Physics Letters,2004.84(7): p.1198-1200.
[69]Elamaran, B., et al. A beam-steerer using reconfigurable PBG ground plane. in MicrowaveSymposium Digest.2000IEEE MTT-S International.2000: IEEE.
[70]Chang, T., R. Langley, and E. Parker, An active square loop frequency selective surface.Microwave and Guided Wave Letters, IEEE,1993.3(10): p.387-388.
[71]Wang, J., et al., A tunable left-handed metamaterial based on modified broadside-coupledsplit-ring resonators. Progress In Electromagnetics Research Letters,2009.6: p.35-45.
[72]Sheng, Z. and V.V. Varadan, Tuning the effective properties of metamaterials by changingthe substrate properties. Journal of applied physics,2007.101(1): p.014909-014909-7.
[73]Balandin, A.A., et al., Superior thermal conductivity of single-layer graphene. Nano letters,2008.8(3): p.902-907.
[74]Lee, C., et al., Measurement of the elastic properties and intrinsic strength of monolayergraphene. Science,2008.321(5887): p.385-388.
[75]Du, X., et al., Approaching ballistic transport in suspended graphene. NatureNanotechnology,2008.3(8): p.491-495.
[76]Novoselov, K., et al., Electric field effect in atomically thin carbon films. Science,2004.306(5696): p.666-669.
[77]Wang, H., et al., Graphene frequency multipliers. Electron Device Letters, IEEE,2009.30(5): p.547-549.
[78]Wang, H., et al., BN/Graphene/BN transistors for RF applications. Electron Device Letters,IEEE,2011.32(9): p.1209-1211.
[79]Moon, J., et al., Low-phase-noise graphene FETs in ambipolar RF applications. ElectronDevice Letters, IEEE,2011.32(3): p.270-272.
[80]Lin, Y.-M., et al., Wafer-scale graphene integrated circuit. Science,2011.332(6035): p.1294-1297.
[81]Tamagnone, M., et al., Analysis and design of terahertz antennas based on plasmonicresonant graphene sheets. Journal of Applied Physics,2012.112(11): p.114915-114915-4.
[82]Burke, J.E., Analytical Study of Tunable Bilayered-Graphene Dipole Antenna.2011, DTICDocument.
[83]Perruisseau-Carrier, J. Graphene for antenna applications: Opportunities and challengesfrom microwaves to THz. in Antennas and Propagation Conference (LAPC),2012Loughborough.2012: IEEE.
[84]Tamagnone, M., et al., Reconfigurable terahertz plasmonic antenna concept using agraphene stack. Applied Physics Letters,2012.101: p.214102.
[85]Carrasco, E., M. Tamagnone, and J. Perruisseau-Carrier, Tunable Graphene Reflective Cellsfor THz Reflectarrays and Generalized Law of Reflection. arXiv preprint arXiv:1212.3158,2012.
[86]Ju, L., et al., Graphene plasmonics for tunable terahertz metamaterials. NatureNanotechnology,2011.6(10): p.630-634.
[87]Vakil, A. and N. Engheta, Transformation optics using graphene. Science,2011.332(6035):p.1291-1294.
[88]Tennant, A. and B. Chambers, A single-layer tuneable microwave absorber using an activeFSS. Microwave and Wireless Components Letters, IEEE,2004.14(1): p.46-47.
[89]Gil, I., et al., Varactor-loaded split ring resonators for tunable notch filters at microwavefrequencies. Electronics Letters,2004.40(21): p.1347-1348.
[90]Liang, J. and H.D. Yang, Microstrip patch antennas on tunable electromagnetic band-gapsubstrates. Antennas and Propagation, IEEE Transactions on,2009.57(6): p.1612-1617.
[91]Yang, L., et al., A novel compact electromagnetic-bandgap (EBG) structure and itsapplications for microwave circuits. Microwave Theory and Techniques, IEEE Transactionson,2005.53(1): p.183-190.
[92]杨雪松，微带可重构天线研究，博士论文，电子科技大学，2006。
[93]魏文博，可重构天线研究，博士论文，西安电子科技大学，2008。
[94]Aydin, K. and E. Ozbay, Capacitor-loaded split ring resonators as tunable metamaterialcomponents. Journal of applied physics,2007.101(2): p.024911-024911-5.
[95]Munk, B.A., Frequency selective surfaces: theory and design.2005:Wiley-Interscience.
[96]Brown J. Articial dielectrics. Progress in dielectrics.1960,2:195-225.
[97]Smith, D.R., et al., Calculation and measurement of bianisotropy in a split ring resonatormetamaterial. Journal of applied physics,2006.100(2): p.024507-024507-9.
[98]Smith, D., et al., Determination of effective permittivity and permeability of metamaterialsfrom reflection and transmission coefficients. Physical Review B,2002.65(19): p.195104.
[99]Koschny, T., et al., Effective medium theory of left-handed materials. Physical review letters,2004.93(10): p.107402.
[100] F. R. Yang, K. P. Ma, Y. Qian, and T. Itoh, A uniplanar compact photonic-bandgap(UC-PBG) structure and its applications for microwave circuits, IEEE Trans. Microwave.Theory Tech.,1999,47(8):1509-1514.
[101] Sha, Y., et al., Experimental investigations of microwave absorber with FSS embedded incarbon fiber composite. Microwave and Optical Technology Letters,2002.32(4): p.245-249.
[102] Costa, F., A. Monorchio, and G. Manara, Analysis and design of ultra thin electromagneticabsorbers comprising resistively loaded high impedance surfaces. Antennas and Propagation,IEEE Transactions on.58(5): p.1551-1558.
[103] Fan, S., et al., Channel drop tunneling through localized states. Physical Review Letters,1998.80(5): p.960-963.
[104] Ozbay, E., et al., Micromachined millimeter‐wave photonic band‐gap crystals. AppliedPhysics Letters,1994.64(16): p.2059-2061.
[105] Tretyakov, S., Analytical modeling in applied electromagnetics.2003: Artech HousePublishers.
[106] Xiao, S. and B. Wang, Preliminary research on microstrip reconfigurable antenna. ChineseJournal of Radio Science,2002.17(4): p.386-390.
[107] Nikolaou, S., et al., Pattern and frequency reconfigurable annular slot antenna using PINdiodes. Antennas and Propagation, IEEE Transactions on,2006.54(2): p.439-448.
[108] Huff, G., et al., A novel radiation pattern and frequency reconfigurable single turn squarespiral microstrip antenna. Microwave and Wireless Components Letters, IEEE,2003.13(2):p.57-59.
[109] Gupta, K., et al. Design of frequency-reconfigurable rectangular slot ring antennas. inAntennas and Propagation Society International Symposium,2000. IEEE.2000: IEEE.
[110] Cetiner, B.A., et al., RF MEMS integrated frequency reconfigurable annular slot antenna.Antennas and Propagation, IEEE Transactions on.58(3): p.626-632.
[111] Schaubert, D.H., et al., Frequency-agile, polarization diverse microstrip antennas andfrequency scanned arrays.1983, Google Patents.
[112] Zhang, S., et al., A pattern reconfigurable microstrip parasitic array. Antennas andPropagation, IEEE Transactions on,2004.52(10): p.2773-2776.
[113] Dolfi, D., et al., Experimental demonstration of a phased-array antenna optically controlledwith phase and time delays. Applied optics,1996.35(26): p.5293-5300.
[114] Bray, M. and D. Werner. A broadband open-sleeve dipole antenna mounted above a tunableEBG AMC ground plane. in Antennas and Propagation Society International Symposium,2004. IEEE.2004: IEEE.
[115] Wang, X., et al., Room-temperature all-semiconducting sub-10-nm graphene nanoribbonfield-effect transistors. Physical Review Letters,2008.100(20): p.206803.
[116] Xia, F., Farmer, D. B., Lin, Y.-M.&Avouris, Ph. Graphene field-effect transistors with highon/off current ratio and large transport band gap at room temperature. Nano Lett.10,715–718,2010.
[117] Martins, T., et al., Electronic and transport properties of boron-doped graphenenanoribbons. Physical Review Letters,2007.98(19): p.196803.
[118] Son, Y.-W., M.L. Cohen, and S.G. Louie, Energy gaps in graphene nanoribbons. PhysicalReview Letters,2006.97(21): p.216803.
[119] Lin, Y.-M., et al.,100-GHz transistors from wafer-scale epitaxial graphene. Science,2010.327(5966): p.662-662.
[120] Wu, Y., et al., High-frequency, scaled graphene transistors on diamond-like carbon. Nature,2011.472(7341): p.74-78.
[121] Rebeiz, G.M., G.-L. Tan, and J.S. Hayden, RF MEMS phase shifters: design andapplications. Microwave Magazine, IEEE,2002.3(2): p.72-81.
[122] Schwierz, F., Graphene transistors. Nature Nanotechnology,2010.5(7): p.487-496.
[123] Liang, G., et al., Performance projections for ballistic graphene nanoribbon field-effecttransistors. Electron Devices, IEEE Transactions on,2007.54(4): p.677-682.
[124] Neto, A.C., et al., The electronic properties of graphene. Reviews of modern physics,2009.81(1): p.109.
[125] X. Liang, Z. Fu and S. Y. Chou, Graphene transistors fabricated via transfer-printing Indevice active-areas on large wafer, Nano Letters,2007,7(12):3840-3844.