Planar antenna

Claim 1

A planar antenna for receiving polarized waves of a wavelength λg transmitted as carried on SHF band from a satellite, the antenna comprising a power-supply circuit pattern including power-supply terminals and additional power-supply terminals respectively formed by a conductive material, said additional power-supply terminals are provided as optional power-supply terminals connected as extensions of said power-supply terminals and have a mutual phase difference of an integer multiple of wavelength λg, a radiation circuit pattern including radiation elements and additional radiation elements respectively formed by a conductive material, said radiation elements corresponding respectively to each of said power-supply terminals and said additional radiation elements corresponding respectively to each of said additional power-supply terminals, and a ground conductor layer disposed with respect to said power-supply circuit pattern and radiation circuit pattern with a dielectric layer interposed between the power-supply circuit pattern and the ground conductor layer wherein a further dielectric layer is interposed between said power-supply circuit pattern and said radiation circuit pattern, whereby said power-supply and radiation circuit patterns and said ground conductor layer form a mutually spaced parallel relationship.