A gate antenna device has a plurality of loop antennas which supplies
power and transmission data to an IC-integrated medium through
electromagnetic induction and acquires reception data in the form of a
fluctuation of a load from the IC-integrated medium. The plurality of
loop antennas include a power-fed loop antenna to which a signal current
is supplied and a non-power-fed loop antenna to which no signal current
is supplied. The gate antenna device expands the distance and range of
communication with an IC-integrated medium and improves the accuracy of
communication while suppressing power consumption and leakage electric
fields.