Antenna device and communication method

A communication method comprising:

• a step of performing one of transmission and reception by using a first directional antenna provided with a first feeding point and a second directional antenna provided with a second feeding point;
• a step of performing another one of transmission and reception by using a third directional antenna provided with a third feeding point and a fourth directional antenna provided with a fourth feeding point;
• and
• wherein the first directional antenna and the second directional antenna transmit and receive a signal with a first polarization,
• the third directional antenna and the fourth directional antenna transmit and receive a signal with a second polarization orthogonal to the first polarization,
• the first directional antenna is oriented in a first direction,
• the second directional antenna is oriented in a second direction opposite to the first direction,
• the third directional antenna is oriented in a third direction obtained by horizontally rotating the second direction by 90° or 180°,
• the fourth directional antenna is oriented in a fourth direction opposite to the third direction,
• the first feeding point and the second feeding point are placed in phase with each other, and
• the third feeding point and the fourth feeding point are placed in opposite phase to each other.