| Artificial electromagnetic material is a very hot research topic in microwave filed over the past 10 years.Metamaterial and metasurface,which developed from it,has excellent performance to enhance the traditional antenna's characteristic.This thesis mainly concerns the design of portable high gain antenna and the realization of beam deflection and beam scanning.Traditional high-gain antennas such as microstrip array antennas,aperture antennas,although able to achieve high gain,but bulky,the bandwidth is not wide.The traditional broadband antenna such as L-shaped probe fed microstrip antennas,microstrip slot antennas,although can achieve very wide bandwidth but has lower gain,unstable radiation pattern over operation frequency,sometimes the main lobe direction will occur with a deflection.And this thesis designs a broadband microstrip antenna,based on zero-index metamaterial,working at 10 GHz not only to achieve 19.5% relative bandwidth,but also has quite stable radiation pattern over the operation frequency range,final has average gain of 11 dB.On the other hand,there are two main developing stage in beam deflection and beam scanning technology in the past,the first generation is parabolic antenna,widely used in satellite communications microwave band,which is composed of a parabolic reflector and its feed source located at the focal point,rotating parabolic reflector to be achieved by mechanical beam scanning,but generally parabolic is made by metal,so the mechanical rotation power is relatively large,and the scanning speed is relatively slow.The second generation is active phased array antenna,active phased array antenna uses a large number of transmit/receive modules,each radiator has a transmitter/receiver module,which makes the active phased array antenna expensive.To solve the above problems,this thesis uses the design principle of the Huygens metasurface,simulation implements a 30 degree deflection metamaterial radome with high transmittance. |
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