A LOOP-LOADED PIFA FOR SWITCHABLE BEAM PATTERNS

Abstract

A switchable beam pattern antenna composed of electric and magnetic radiators, i.e., a monopole and a loop, is proposed. The proposed antenna is designed to operate at 2 GHz for wireless communications. By controlling the state of the switch located at the junction between the dipole and the loop, the antenna can select one between two beam patterns. The simulated 10 dB frequency bandwidths are observed to be approximately 9.5% (1.87-2.06 GHz) and 10.0% (1.93-2.13 GHz) for on and off states, respectively. The simulated and measured results indicate that the proposed antenna operates at approximately the same frequencies, whereas it is clearly observed that the antenna's maximum beam direction is alternated depending on the switching states.