ANTENNA DEVICE, AND RADIO MODULE AND RADIO COMMUNICATION APPARATUS USING THE SAME

PROBLEM TO BE SOLVED: To improve a high frequency radiation characteristic by reducing the number of turns of a low frequency antenna element even when an interval between low frequency side and high frequency side resonance frequencies is large.SOLUTION: An antenna block 10 mounted on a printed board includes: first and second radiation electrodes 12, 13 formed on surfaces of an antenna carrier 11; and a first switch for electrically connecting end portions of the first radiation electrode 12 and second radiation electrode 13. The first and second radiation electrodes 12, 13 comprise turned strip patterns, and especially, the first radiation electrode 12 has a length of about a quarter of a resonance wavelength of a high frequency antenna. An antenna device 1 provides a high frequency antenna element configured by the first radiation electrode 12 when the first switch is off, and a low frequency antenna element configured by the first radiation electrode 12 and the second radiation electrode 13 connected together when the first switch is on.