ANTENNA DEVICE AND COMMUNICATIONS APPARATUS USING THE SAME FOR INCREASED BANDWIDTH AND AVERAGE GAIN BY REDUCING GAIN LOSS AT PLURAL FREQUENCY BANDS

摘要

PURPOSE: An antenna device and a communications apparatus using same are provided to increase a bandwidth and an average gain of the antenna device by preventing gain loss at plural frequency bands. CONSTITUTION: An antenna device includes a mounting substrate(20) having a ground portion and a non-ground portion, a chip antenna(10), and at least one second radiation electrode(40). The chip antenna is mounted onto the non-ground portion and includes a substrate, the first radiation electrode(12) formed on the substrate, a power-supplying electrode(13) connected or not connected to the other end of the first radiation electrode, and a terminal electrode(14) connected or not connected to one end of the first radiation electrode. The second radiation electrode is formed in a conductor pattern on the non-ground portion. An end of the second radiation electrode is connected or not connected to the terminal electrode while the other end is an open end. A cavity is provided between the chip antenna and/or the second radiation electrode and the ground portion.