ANTENNA DEVICE

摘要

Good electric characteristics are obtained even after an antenna being further incorporated into an antenna apparatus including an antenna case having a limited space.
An antenna device 31 is formed on an antenna substrate 30 installed upright in an antenna base 20. A flat antenna unit 35 is fastened to the antenna base 20 so that the flat antenna unit 35 is immediately below the antenna device 31. If the wavelength of a center frequency in an operating frequency band of the flat antenna unit 35 is », an interval between an upper surface of the flat antenna unit 35 and a lower end of the antenna device 31 is set to about 0.25» or more. Accordingly, it becomes possible to make directional characteristics of radiation in a horizontal plane of the flat antenna unit 35 non-directive without being affected by the antenna device 31 and also to achieve good gain characteristics.