in addition here the maximum gain of the vertical polarization is a low value of u2212 28 13 dbi in addition fig5 shows the result of measuring a horizontal radiation pattern of substrate 2 for the case in which the ground connection component 6 is provided at the distant position 6 b far from the power feed point 1 as can be understood from this result the principal polarization of the radiation pattern is vertical polarization and thus the principal polarization changes in comparison to the case in which the ground connection component 6 is provided at the proximate position 6 a note that the horizontal polarization having a toroidal directionality remains as is but the maximum gain becomes u2212 19 28 dbi in addition in contrast the maximum gain of a vertical polarization which is the principal polarization is u2212 15 01 dbi and a high gain of 13 db is obtained in comparison to the case in which the ground connection component 6 is provided at the proximate position 6 a in addition fig6 shows the result of measuring the radiation pattern for the case in which the ground connection component 6 is provided at the intermediate position 6 c of the boundary 7 as can be understood from this result the vertical polarization and the horizontal polarization of the radiation pattern are both substantially identical and a directionality of u2212 17 dbi is obtained at the maximum gain in this manner for the same antenna element 3 simply by changing only the connection position of the ground areas 5 a and 5 b the polarization can be improved by adjusting the gain of the vertical polarization the horizontal polarization or both polarizations note that fig7 shows the results.