SMALL ANTENNA APPARATUS OPERABLE IN MULTIPLE BANDS INCLUDING LOW-BAND FREQUENCY AND HIGH-BAND FREQUENCY AND SHIFTING LOW-BAND FREQUENCY TO LOWER FREQUENCY

摘要

A radiator is provided with a looped radiation conductor, a capacitor, an inductor, a feed point on the radiation conductor, and a magnetic block provided at at least a part of the inside of a loop of the radiation conductor. When the radiator is excited at a low-band resonance frequency, a first current flows through a first path extending along an inner perimeter of the loop of the radiation conductor and including the inductor and the capacitor. Magnetic flux produced by the first current passes through the magnetic block, thus increasing the inductance of the radiation conductor. When the radiator is excited at a high-band resonance frequency, a second current flows through a second path including a section extending along an outer perimeter of the loop of the radiation conductor, the section including the capacitor but not including the inductor, the section extending between the feed point and the inductor.