Fatemeh Muhammadi- Monavar

  Abstract

 An invasive weed optimization ( IWO) algorithm design methodology is presented for improving the bandwidth of a microstrip patch antenna using jerusalem cross-shaped frequency selective surfaces (JC-FSSs). The IWO is employed to obtain optimal dimensions of the patch antenna and JC-FSS element in order for the whole structure to work at 5.8GHz with consideration of the gain. It is shown that choosing an appropriate particular shape like jerusalem cross, for the FSS element rather than a pixelized grid geo metry, allows for a superior antenna design in term of computational efficiency. Simulation results show that for this novel design, return loss bandwidths of about 10.44% have been achieved. However, considering the gain to be greater than 5 dB reduces the bandwidth to 8.41%. In general by introducing this novel jerusalem cross artificial magnetic conductor (JC-AMC) in lieu of the conventional perfect electric conductor (PEC) ground plane, the bandwidth enhancement of about 60% has been obtained. In order to check the competence of the design, the antenna-AMC structure is also synthesized. This antenna shows measured relative bandwidth of BW = 10.41%.

  Keywords : Artificial magnetic conductor (AMC), invasive weed optimization (IWO) algorithm, wideband patch antenna, jerusalem cross-shaped frequency selective surfaces (JC-FSSs)

  Defense Date: October 18, 2010 (Monday)

  Defense Time: 17:30

  Location: Room No. 305 ( Electrical Engineering Department)