Font Size: a A A

The Basic Characteristics Of The Left-handed Materials And Its Applied Research In The Microstrip Antenna

Posted on:2007-01-10Degree:MasterType:Thesis
Country:ChinaCandidate:Y H LiuFull Text:PDF
GTID:2208360182978874Subject:Condensed matter physics
Abstract/Summary:PDF Full Text Request
Left-handed metamaterial (LHMs) is a periodic medium in which both the permittivity and permeability are simultaneously negative. Because their group velocity and phase velocity are in the opposite directions, they have many strange properties, such as reversed Doppler shift, reversed Cherenkov radiation, reversed Goos-Hanchen shift, negative refraction and perfect lens. The discovery of left-handed material has been regarded as one of the ten most significant discoveries in science community in 2003, and has been the front and focus area in physics and electromagnetics research.In this paper, we investigate the electromagnetic resonance of negative permittivitymetamaterial, the stopband in left-handed passband, electromagnetic resonance ofLHMs in free space, determination of the refractive index, permeability, permittivityand application of Left-handed metamaterial in microstrip patched antenna. The originalworks and results of this paper are as follows:1 A periodic array wires are designed and fabricated by shadow mask/etching technique. We numerically and experimentally studied the influences of the structure parameters, such as the thickness, width, lattice constant of the wires.2 LHMs consisting of a periodic array of interspaced copper SRRs and wires are designed and fabricated by shadow mask/etching technique. When changing the symmetry of the LHMs, we can find the stopband in the passband of LHMs, furthermore, stopband is connected with the parameter 5 which is the relative deviation of the centre of two layers of SRRs from the wire centre.3 Electromagnetic resonance of microwave LHMs in free space(1). Electromagnetic resonance of a periodic array SRRs are studied in free space and negative permeability are realized in a certain frequency range.and then, the structure parameter of SRRs which influence the behavior of the electomagnetic resonance are researched.(2). Electromagnetic resonance of a periodic array wires are studied in free space and negative permittivity are realized in a certain frequency range.(3). Electromagnetic resonance of LHMs consisting of a periodic array ofinterspaced copper SRRs and wires are investigated in free space, and the negative refraction in the designed LHMs and left-handed transmission peaks are observed, and that the location and the magnitude of left-handed transmission peaks are tunable.4 A method is suggested to calculate refractive index, permeability, permittivity of LHMs, and numerically calculate S parameter using CST software, and negative refractive index is got.5 The applications of left-handed metamaterial in microstrip patched antenna is studied. Making use of the strange properties of LHMs, the performance of the new type antenna are better improved,such as bandwidth increase, matching capability improved, forword radiation becoming stronger, side radiation becoming weaker. The efficiency and the directive of the antenna are improved.
Keywords/Search Tags:left-handed metamaterial, negative permittivity, stopband, negative refractive index, microstrip patched antenna
PDF Full Text Request
Related items