Low-Profile and High-Gain Linear Polarized Loop Antenna

A loop antenna on top of a metal plate can provide a higher gain than that of a dipole antenna. A low depth profile multi-loop antenna geometry is proposed with a thickness of 0.02 wavelength to the back metal plate. The designed loop antenna is self-matched to the 50-ohm impedance of a source and provides a high directional gain of 8.2 dBi. The antenna gain is increased to 10.0 dBi by using a dual multi-loop geometry. Sample antennas are designed and manufactured for operating at 2250 MHz. The antennas are measured and characterized for the return loss, radiation pattern and gain. The proposed antenna can be used as a wearable antenna in wireless body area network (WBAN), in which the backside radiation is reduced and the antenna impedance characteristics are not affected by the background tissues.