A Compact planar antenna for modern microwave communication systems

This paper presents the development of a compact antenna suitable for a range of frequency bands which are widely used in modern microwave communication systems. The proposed antenna incorporates a modified Finite Ground CPW (FGCPW) fed strip monopole with a flaring and an embedded sleeve to implement dual band operation. Software simulations are carried out using FEM based commercial simulation package, Ansoft HFSS to investigate the effect of each antenna element over the antenna characteristics. Finally, the optimized antenna is prototyped and the experimental results are observed to be in good agreement with the simulated ones. Experimental results shows a 2:1 VSWR bandwidth of 24 % at the centre frequency of 2 GHz for the first resonant band and 56.3 % bandwidth at the centre frequency of 4.5 GHz in the second resonant band. The surface current in the antenna is computed in order to identify the contribution of each antenna elements at the resonant bands and to identify the frequency determining element at each resonant band. The proposed antenna is then simulated to verify frequency tuning by varying appropriate element in each operating band. Measured radiation patterns reveal nearly omnidirectional behavior with average gain of better than 3.5dBi and 2.5 dBi and efficiency of 79 % and 68 % in the first and second resonant bands respectively