Plane antenna, and portable radio using same

摘要

A microstrip plane antenna is disclosed which comprises a plate-like dielectric substance (1c), a patch conductor (1b) provided on one side of the dielectric substance (1c), and a ground conductor (4) provided on the other side of the dielectric substance (1c) and which feeds electric power to the patch conductor (1b) by means of a back feeding method, wherein the patch conductor (1b) has a square shape; and at least three different-sized sides.