Journal ArticleDOI
Metamaterial-based electronically controlled transmission-line structure as a novel leaky-wave antenna with tunable radiation angle and beamwidth
Sungjoon Lim,Christophe Caloz,Tatsuo Itoh +2 more
- Vol. 53, Iss: 1, pp 161-173
Reads0
Chats0
TLDR
In this article, a metamaterial-based electronically controlled transmission line structure is presented and demonstrated as a novel leaky-wave (LW) antenna with tunable radiation angle and beamwidth functionalities.Abstract:
A metamaterial-based electronically controlled transmission-line structure is presented and demonstrated as a novel leaky-wave (LW) antenna with tunable radiation angle and beamwidth functionalities. This structure is, in essence, a composite right/left-handed (CRLH) microstrip structure incorporating varactor diodes for fixed-frequency voltage-controlled operation. Angle scanning at a fixed frequency is achieved by modulating the capacitances of the structure by adjusting the (uniform) bias voltage applied to the varactors. Beamwidth tuning is obtained by making the structure nonuniform by application of a nonuniform bias voltage distribution of the varactors. A rigorous analysis based on an extension of the CRLH concept is proposed and the corresponding dispersion curves, obtained by equivalent-circuit formulas with LC parameters extracted from full-wave simulation, are shown. A 30-cell LW antenna structure, incorporating both series and shunt varactors for optimal impedance matching and maximal tuning range, is designed. This prototype exhibits continuous scanning capability from 50/spl deg/ to -49/spl deg/ by tuning the bias voltages from 0 to 21 V at 3.33 GHz. A maximum gain of 18 dBi at broadside is also achieved. In addition, it provides half-power beamwidth variation of up to 200% with comparison to the case of uniform biasing. The effect of intermodulation due to the nonlinearity of the varactors is shown to be negligible for antenna applications. The antenna is tested in a 10-Mb/s binary phase-shift keying transmission link and successful recovery of the baseband data is demonstrated.read more
Citations
More filters
Journal ArticleDOI
Composite right/left-handed transmission line metamaterials
TL;DR: In this paper, the fundamental electromagnetic properties of left-handed metamaterials and the physical realization of these materials are reviewed based on a general transmission line (TL) approach.
Journal ArticleDOI
Transformation optics and metamaterials
TL;DR: The potential of transformation optics to create functionalities in which the optical properties can be designed almost at will is reviewed, which can be used to engineer various optical illusion effects, such as the invisibility cloak.
Journal ArticleDOI
Experimental demonstration of frequency-agile terahertz metamaterials
Hou-Tong Chen,John F. O'Hara,Abul Kalam Azad,Antoinette J. Taylor,Richard D. Averitt,David Shrekenhamer,Willie J. Padilla +6 more
TL;DR: In this paper, the authors demonstrate frequency-agile terahertz metamaterials operating in the far-infrared by incorporating semiconductors in critical regions of metallic split-ring resonators.
Journal ArticleDOI
Reconfigurable scan-beam single-arm spiral antenna integrated with RF-MEMS switches
TL;DR: In this paper, a reconfigurable rectangular spiral antenna with a set of micro electro mechanical system (MEMS) switches, which are monolithically integrated and packaged onto the same substrate, is presented.
Patent
Metamaterial antenna arrays with radiation pattern shaping and beam switching
TL;DR: In this article, the authors present an approach for using composite left and right handed (CRLH) metamaterial (MTM) structure antenna elements and arrays to provide radiation pattern shaping and beam switching.
References
More filters
Journal ArticleDOI
The Electrodynamics of Substances with Simultaneously Negative Values of ∊ and μ
Journal ArticleDOI
Experimental Verification of a Negative Index of Refraction
TL;DR: These experiments directly confirm the predictions of Maxwell's equations that n is given by the negative square root ofɛ·μ for the frequencies where both the permittivity and the permeability are negative.
Journal ArticleDOI
Magnetism from conductors and enhanced nonlinear phenomena
TL;DR: In this paper, it was shown that microstructures built from nonmagnetic conducting sheets exhibit an effective magnetic permeability /spl mu/sub eff/, which can be tuned to values not accessible in naturally occurring materials.
Journal ArticleDOI
Composite Medium with Simultaneously Negative Permeability and Permittivity
TL;DR: A composite medium, based on a periodic array of interspaced conducting nonmagnetic split ring resonators and continuous wires, that exhibits a frequency region in the microwave regime with simultaneously negative values of effective permeability and permittivity varepsilon(eff)(omega).
Journal ArticleDOI
Extremely Low Frequency Plasmons in Metallic Mesostructures
TL;DR: A mechanism for depression of the plasma frequency into the far infrared or even GHz band is proposed: Periodic structures built of very thin wires dilute the average concentration of electrons and considerably enhance the effective electron mass through self-inductance.
Related Papers (5)
Composite right/left-handed transmission line metamaterials
Electromagnetic metamaterials : transmission line theory and microwave applications : the engineering approach
Christophe Caloz,Tatsuo Itoh +1 more