Design of the low-profile inverted-F antenna with multi-parasitic elements

In this paper, an improved low-profile inverted-F antenna is presented. Compared with conventional inverted-F antenna, this antenna can produce wider frequency bandwidth by adding parasitic elements on two sides and in the bottom simultaneously. The influence of primary structure parameters on the input impedance and resonance frequency is analyzed. Based on the study above, an improved low-profile inverted-F antenna with three parasitic elements at 1.2 GHz is designed, simulated and analyzed. It can be concluded from the results that the frequency bandwidth can reach 33% for a VSWR=2, which is more than four times as wide as that of a conventional inverted-F antenna. This antenna has great potential in practical application.