Radiation and bandwidth characteristics of two planar multistrip antennas for mobile communication systems

The measured radiation and bandwidth characteristics of two slightly different short-circuited microstrip patch antennas are reported. The bandwidth of the studied antennas bag been enhanced by dividing one wider patch into separate narrower patches which are tuned to different resonant frequencies. One of the patches is fed and the others are parasitically coupled. The results indicate that without increasing the volume occupied by the antenna its impedance bandwidth can be more than doubled with this method. In addition, the study shows that the use of parasitic elements may cause the polarization of the antenna to become frequency dependent.