Antenna system and an in-vehicle communication apparatus

摘要

An antenna system for use in a wide frequency band has a reflection board that has a board shape with an outer edge and an inner edge. The antenna system connects the reflection board and an antenna module in a manner that does not allow a flow of a direct current. Further, a dimension of the reflection board along a polarization direction of the antenna module has a value that is equal to or greater than a product of a maximum wavelength of a usable frequency band multiplied by a wavelength reduction rate of a dielectric material.