Design of Coplanar waveguide fed Crossed Slot Reconfigurable Antenna for Wireless Applications

Abstract

This paper reports the design analysis of a compact reconfigurable CPW fed crossed slot antenna with radiation pattern and frequency diversity with multi-band characteristics. The main antenna consists of CPW fed rectangular patch with dimensions $22\times 20 \text{mm}^{2}$ which operates at 4.2GHz. The frequency and pattern reconfigurability is obtained by inserting two crossed slots along the diagonals of the rectangle and inserting four switches at all the four corners. The switches realised in this design are PIN diodes. By switching operation, the designed antenna can be operated at four operating modes exhibiting multi-band reconfiguration in three modes and single resonant frequency in last mode. Triple band and dual band characteristics are obtained in three operating modes. The three operating frequencies the antenna can operate are 3.1GHz, 3.8GHz, 4.4GHz which are suitable for WiMAX, and other C-band wireless applications. The compact aperture volume of the antenna is 50mm X 50mm X 1.6mm and it is designed on a low cost FR4 substrate with $\varepsilon_{\mathrm{r}}=4.4$ . The effect of gap width between coplanar ground and the centre strip conductor is analysed carefully and obtained good radiation pattern in elevation plane, gain, and efficiency. Ansys HFSS CAD tool has been used for simulations and the results are presented.