Antenna structure and communication apparatus including the same

摘要

An antenna structure (1) includes a surface-mounted antenna (2) which has a base member (7). A radiating electrode (8) and an antenna-side control electrode (11) are disposed on the base member (7). A capacitance is generated between the antenna-side control electrode (11) and an open end (8a) of the radiating electrode (8), and the antenna-side control electrode (11) electrically floats. A board-side control electrode (4) which is electrically connected with the antenna-side control electrode (11) and which electrically floats is disposed on a mounting board (3). The board-side control electrode (4) is connected with a ground conductor (6) at high frequencies through a resonant frequency adjuster (15). The resonant frequency adjuster (15) has a capacitance or an inductance. By changing the capacitance or the inductance, the resonant frequency of the radiating electrode (8) can be changed without changing the surface-mounted antenna (2).