Abstract: A circuit-board antenna has a standing wave resonance which is utilized to extend the radiation end of a dipole antenna as its radiation length, e.g. (n+¼) times the wavelength. Half the wavelength in the radiation direction of the dipole antenna is designed to be twisted, the radiation from which cancels with itself, resulting in a radiation gain in the radiation direction. A circuit board is used to make such a dipole antenna. It can conveniently achieve the goal of self cancellation for radiation from the twisty part. The radiation orientation of the antenna can be adjusted to be upward or downward by modifying the extension length between the radiation end and the ground end of the dipole antenna.