Electric and Magnetic Mode-Switchable Dual Antenna for Null Compensation

A novel dual antenna is proposed for null compensation. The primary antenna is a rectangular loop antenna that generates an electric-loop mode. A zeroth-order resonant (ZOR) antenna is used as the auxiliary antenna, which produces a magnetic-loop mode and reduces the overall antenna size. Since the auxiliary antenna can be placed inside the primary antenna, the overall occupied space is the same as the size of the single primary loop antenna. The electric- and magnetic-loop current distributions are orthogonal to each other, so their nulls are effectively compensated. The performances of the proposed antennas are demonstrated in both a full-wave simulation and experiments at 2.3 GHz.