A design of annular ring microstrip antenna with finite ground structure is proposed in this paper. The proposed geometry offers impedance bandwidth of 2.362 GHz and has stable radiation patterns for all resonant frequencies in the operational band. It is also found that shape and dimension of the finite ground plane is a key factor in improving the bandwidth of the proposed geometry. The geometry is low profile and has simple structure, therefore can be used for lower band of ultra-wideband applications.
