IET Microwaves Antennas & Propagation · 2015 · 69 citations · 11 references
EngineeringElectrical EngineeringAntennasElectromagneticsMicrowave EngineeringAntenna DesignAntenna RadiationMicrostrip AntennasMicrowave AntennasPlanar AntennasSmall AntennasAntenna Bandwidth EnhancementMetamaterial Antenna DesignMetamaterial AntennasMetamaterial Transmission LinesMetamaterial-based AntennasMicrowave Antenna DesignRadio Frequency TransceiversResonance Frequencies
This study presents a metamaterial‐based antenna using the concept of composite right–left‐handed transmission‐lines. The radiation‐cells layouts are based on L/F‐shaped slits, so these slits are engraved on the radiation‐patches for establishing a series‐capacitor effect. Moreover, the radiation cells including the spirals and via‐holes for the shunt‐inductors implementation. By cascading the proper number of cells, the desired antennas for very/ultra‐high frequency‐bands are designed. The first‐antenna with four L‐shaped cells isconstructed on the Rogers_RO4003 substrate with thickness of 0.8 mm, so that each of cells occupies the size of 2.3 mm × 4.9 mm. This antenna covers the experimental‐bandwidth of 0.2–1.8 GHz, which corresponds to 160% feasible‐bandwidth. This antenna resonates at frequencies of 600–850–1200–1550 MHz, so highest gain and efficiency, happened at 1550 MHz, are 3.4 dBi and 88%. For improving the antenna performances, the second‐antenna is modelled with one‐cell more than first‐antenna and with changing in the slit configuration to F‐shape and increasing in the same substrate thickness to 1.6 mm. F‐shaped antenna has size of 14.5 mm × 4.4 mm × 1.6 mm, covering a measured‐bandwidth of 0.11–2.1 GHz with five resonance frequencies at 450–725–1150–1670–1900 MHz, which corresponds to 180.1% practical‐bandwidth. Maximum of the measured gain and efficiency of antenna are 4.5 dBi and 95%, which occur at 1900 MHz.
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Experimental Verification of a Negative Index of Refraction
R. A. Shelby, David R. Smith, S. Schultz · Science · 2001 · 9.2K citations