II. ANTENNA STRUCTURE
The antenna structure is composed of three metallic plates
as shown in Fig.1. The top plate is cut as the elliptical
geometry with the major and minor axes of ux and uy,
respectively. The middle plate is rectangular configuration
with two opposite truncated corners whereas the remained two
corners are not truncated. The length and the width of the
rectangular one are vx and vy, respectively. The radius of the
truncated corner is cut by two radii of r1.and r2, respectively.
At the non-truncated corner, there are two square holes of the
size sh. The distance between the center of the hole and the
corner is d. The bottom plate acts as the ground with the