Miniature Antennas

There has been much interest in producing platform tolerant antennas which can be used on automobile, aircraft, etc. Integrating numerous antennas into these platform can be challenging, because of limited space, cost and electromagnetic interference issues. Therefore, to reduce the conventional antenna size and provide the platform tolerance property become an important object for such applications.

Proposed SRR antenna over miniaturised EBG surface, and the combined structure on a large metal plat

In this project, we propose an Electrically Small Antenna (78mm×36mm×0.8mm) which uses a Split Ring Resonator as main radiating element and in addition uses lumped elements to realize further miniaturisation of the antenna. The antenna itself is tunable by simply varying the loaded capacitance value. Here we have demonstrated a possible resonant frequency tuning range of 300-600MHz.

Measured |S11| of the proposed antenna/EBG structure

Miniaturised AMC/EBG surfaces were also developed by using lumped elements components. In this research, we found out that the AMC/EBG unit cell size can be reduced to a minimum scale of λ/140.

To integrate the antenna and the AMC/EBG surface, the antenna performance can be significantly improved. A 14×10 array of 10mm unit cell EBG (ka=0.62) can provide 300% of fractional bandwidth and 3dB gain enhancement of the antenna. In addition, the combined structure is platform tolerable to work on a large metal surface.