Research On The Property Of Artificial Magnetic Conductor And Its Application In Antenna

Artificial magnetic conductor (AMC) is the metamaterial that could exhibit areflection coefficient of unity with the zero-degree phases over a limited frequencyrange. The traditional antenna mounts on a perfect electric conductor (PEC) plane asthe reflection plane to improve the antenna gain and decrease the radiation angle;however the distance between the horizontal antenna and the ground plane is at leastquarter of λ, which is the free-space wavelength at working frequency. Nevertheless,AMC has the property of fully reflection with zero-phase at resonance frequency. Thehorizontal antenna could be pressed close to the AMC and can be designed thelow-profile antenna and show the attractive prospect.This dissertation introduces briefly the surface wave band-gap and reflection phaseband-gap of AMC, and analyzes the reflection phase band-gap and of different typesof AMC. The angular stabilization of resonant frequency for both TE and TMpolarization are discussed. The effects of some structure parameters on the bandwidthare also simulated. The plum-shaped unit, composed of four circular patches, isproposed in this paper to be fully symmetrical, and the periodic array can be used asthe reflection plane for various antennas. The numerical results show that itsbandwidth reaches about22.22%.This paper proposes a novel antenna with a low profile and high gain, which adoptsan AMC reflection surface. The optimized antenna has the center frequency2.58GHz,the bandwidth11.63%, which covers the LTE band. The composite antenna has aheight about9.5mm and is just one-twelfth of the wavelength in the free space atworking frequency. Moreover, the peak gain is closed to9.7dBi, which proves thefeasibility and validable of the theory in this paper. Finally, the measured resultsshow that this antenna has a good VSWR, and the gain is9.13dBi, which agrees withthe simulation result.The antenna broadband and multiband technique is also discussed in this paper.The resonance bandwidth of AMC unit improved more than10%by increasing the patches and slots. Finally, this paper presents a modified H-shaped AMC, theimproved structure has a performance of dual-band.