Patent ID: 6452560
Filing Date: 2002-09-17
Classification: G03F,H01P,H01Q

Abstract:
An antenna, suitable for transmitting and receiving electromagnetic signals of wavelength &lgr;, said antenna comprising:a nonconductive substantially planar substrate having front and rear surfaces bounded by a common peripheral edge, said peripheral edge enclosing an antenna axis orthogonal to said front surface; a transmission line disposed on said rear surface; a conductive layer disposed on said front surface, said conductive layer including i. a plurality of slotted openings arrayed about said antenna axis, and ii. a surface-wave suppression region enclosing said array of slotted openings and attenuating surface waves propagating along said front surface from said slotted openings toward said peripheral edge; and a plurality of peripheral openings disposed between said surface-wave suppression region and said peripheral edge, said peripheral openings extending through said conductive layer and said substrate and attenuating surface waves propagating within said substrate by diffraction; such that an electromagnetic signal fed into said transmission line is coupled sequentially into respective said slotted openings and transmitted from said slotted openings substantially in the direction of said antenna axis.