Antenna apparatus

摘要

In an antenna apparatus in which n dielectric layers with epsilon r1- epsilon rn in dielectric constants are respectively stacked between a ground plate and a major radiating conductor, the thickness t1-tn of the dielectric layers are determined so as to satisfy substantially the following equations: (t1+t2+ . . . +tn)/(t1/ epsilon r1+t2/ epsilon r2+ . . . +tn/ epsilon rn)= epsilon reff, and t1+t2+ . . . tn=tminwith respect to a dielectric constant epsilon reff of the antenna defined for a desired beam width, and the minimum value tmin of the dielectric layers capable of ensuring a desired operation band and low reflection losses in this dielectric constant epsilon reff. Thus, the thinnest antenna structure which can ensure a desired radiation in directions of low elevation angles, and desired operation bands and low reflection losses can be made.