Beam-switched planar array antenna for mobile communications

Reduction or elimination of interfering waves is important for preventing degradation of communication quality in mobile communications. A directivity switched antenna, based on the concept of four antennas beam-switched by four linear magnetic currents and using 90 degrees phase-lag hybrid junctions, has been proposed as a means to eliminate interfering waves. In this paper, a wide-band planar antenna element suitable for a magnetic current antenna and improved placement of array antennas are proposed. It is confirmed that directivity of four-directional type is achieved by the four-element array antennae. The eigenvalue of the antenna is obtained by the finite element method in the two-dimensional approximation and the unloaded quality factor Q is examined. The antenna directivity was evaluated and tested by the magnetic current model, neglecting the mutual coupling of elements, and good agreement was obtained. Correlations between directional branches and the directivity of antennas loaded by dielectric materials are studied. (C) 1998 Scripta Technica.