A diffusion solder position between two parts has intermetallic phases formed by two solder components. This backlight device includes; fluorescent tubes that emit light when power is supplied to the fluorescent tube electrodes; and a light guide plate that guides the light emitted from the fluorescent tubes to a liquid crystal panel. A pair of beacon receivers receives the two downconverted signals and a controller communicates with the first beacon receiver and the second beacon receiver through a first connection and a second connection. The controller, when in the reflecting mode, may cause back-to-back pairs of first antenna elements from the arrays to define a feed-through zone for the first antenna beam, and cause second antenna elements in the first array to define a first active zone for the first antenna beam.