ANTENNA APPARATUS

摘要

Excellent electrical characteristics are obtained even when an antenna is further assembled to an antenna device provided with an antenna case having only a limited space. An antenna element (31) is formed on an antenna subst rate (30) which is arranged upright on an antenna base (20). A planar antenn a unit (35) is firmly attached to the antenna base (20) so that a planar ant enna unit is positioned directly below the antenna element (31). When the wa velength of the center frequency in the operation frequency band of the plan ar antenna unit (35) is expressed by .lambda., an interval between an upper surface of the planar antenna unit (35) and a lower end of the antenna eleme nt (31) is approximately 0.25.lambda. or more. Thus, radiation directivity o f the planar antenna unit (35) within a horizontal surface is permitted to b e nondirectional without being affected by the antenna element (31), and exc ellent gain characteristics can be obtained.