Antenna device and radio communication apparatus

A radio communication apparatus comprising:

• an antenna device including:
• an antenna having a single feed;
• a shunt circuit including:
• a first shunt matching circuit configured to cause impedance, viewed from a main path connecting the antenna and a radio frequency circuit, to be substantially infinite with respect to all frequency ranges handled by the antenna;
• and
• a second shunt matching circuit configured to provide a predetermined impedance characteristic with respect to a first subset of the frequency ranges handled by the antenna,
• wherein a first end of each of the first and second shunt matching circuits are connected to ground, and a second end of each of the first and second shunt matching circuits are selectively connected to the main path;
• and
• a selection controller configured to control selection of which of the first and second shunt matching circuits are connected to the main path.

An antenna device comprising:

• an antenna having a single feed;
• a shunt circuit including:
• means for causing impedance, viewed from a main path connecting the antenna and a radio frequency circuit, to be substantially infinite with respect to all frequency ranges handled by the antenna;
• and
• means for providing a predetermined impedance characteristic with respect to a first subset of the frequency ranges handled by the antenna,
• wherein the means for causing and means for providing are selectively connected to the main path;
• and
• means for controlling selection of which of the means for providing and means for causing are connected to the main path.