| The research of micro-antenna has gradually become a hot filed. And if the traditional antenna is enough small to react to TeraHertz wave, optical wave and electromagnetic wave close to the infrared wave band, then it could be called as micro-antenna, which is in the size of Nanometer to micrometer. Under irradiation of electromagnetic wave in the same order as wavelength of the antenna, local surface plasmon resonance will appear in the surface of the micro-antenna, and the result is that plasmon will occur in the antenna, which could scatter electromagnetic wave. The characteristics of these scattered waves are determined by the size, shape and materials of the micro-antenna, therefore the amplitude, phase, polarization and energy of scattered light could be controlled by designing micro-antenna at different shapes and sizes, and accordingly realizing the manipulation of the far-field wavefront. In this way, the micro-antennas could be widely applied into fields including deflection light, Subwavelength focus, multi-functional ultrathin plane lens, Nano half wave plate, stealth materials, photovoltaic conversion, Solar energy efficiency enhancement, Raman enhancement, fluorescence enhancement, quantum communication, cell detection, Surface Plasmon Resonance enhancement, nano communication and arithmetical operation. Even with a bright application prospect, however the micro-antenna theory development is pretty immature at present, and from antenna theoretical analysis and modeling, to material selection, and to processing technology, all of them are still in the research phase, especially in the link of the verification of the established antenna model, since it typically adopts Surface Plasmon Resonance(FDTD) algorithm, which generally consumes large amount of time and has convergence difficulty, greatly reducing the R&D efficiency. In this paper, I try to introduce the RWG-Moment of Method(RWG-MOM) algorithm used for calculating electromagnetic wave in the classical microwave band into solving the micro-antenna, so as to quickly solve the scattering field of the antenna model. And in comparison with the computation of FDTD algorithm, RWG-MOM algorithm realized 30 times speed boosting at minimum and 100 times at maximum when used to solve the Ultra-thin lens parameters of three manipulation light wave consisted of C-shape antenna. On the other hand, I also designed a Silver nano antenna in this paper, which can cause random mutations to phase of the circularly polarized light ranging from 0 to 2π, so as to realize the light free bending and focusing. The paper continues with discussions on the factors influencing the focusing and refracting power of Nano antenna array. In the end, this paper addresses the feasibility of micro-antenna in microorganism detection, analyzes the impact of the size, relative position and experimental environment of the microorganism on the antenna resonant frequency, furthermore, the paper also analyzes changes of resonant frequency of antennas in different shapes when loading same kind of microorganism. |
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