Low profile small antenna and constructing method therefor

摘要

A built-in antenna applied to sending and reception of radio waves of a few giga cycles is improved and made smaller, and is made suitable for industrial production and has its tuning bandwidth widened. "An antenna pattern (6) which resonates at lambd/4" is formed on a substrate (5) and a zigzag portion (6a) is provided on a portion of the antenna pattern (6) which resonates at lambd/4. On the other hand, the substrate (5) and a bobbin (8) are supported by a metallic frame (7), and "a helical coil (9) which resonates at lambd/4" is wound and formed upon the bobbin (8). Capacitance (c) is provided between the antenna pattern (6) which resonates at lambd/4 and the helical coil (9) to electrically couple them.