A novel compact microstrip slot antenna with spirals

A novel compact slot patch antenna with two spirals on single thin substrate is introduced, which is 66% smaller than the conventional half-wave patch antenna. The four parallel slots on surface can enhance the length of current path and reduce the size of patch, the two spirals used can decrease the height of antenna at the same time. Good agreement between the theoretical and experimental results is obtained. The measured return loss curve and radiation patterns are all presented.