Patent ID: 8199057

Claim:
An antenna device comprising: a radiation electrode including a proximal end portion to which power is to be capacitively fed through a first capacitor portion and a distal end portion which is grounded to a ground region; and a plurality of additional radiation electrodes, each of the plurality of additional radiation electrodes being branched from the radiation electrode through a switch element and a distal end portion thereof being grounded; wherein the proximal end portion of the radiation electrode is provided with a second capacitor portion that includes opposing electrode portions, at which a maximum voltage is obtained when power is fed, and a variable capacitance element is connected to the second capacitor portion and is grounded; a respective reactance circuit is provided in each of the plurality of additional radiation electrodes; and the radiation electrode includes a first portion that extends from the first capacitor portion away from the ground region and a second portion that extends towards the ground region in an area of the distal end portion.