Antenna device, radar device, and transfer device

A radar device comprising:

• an antenna device;
• and
• a radar transmission/reception circuit that causes the antenna device to transmit or receive a radar wave, wherein
• the antenna device includes
• a board including
• a conductor layer,
• a first conductor pattern arranged on a surface of the board,
• a connecting section that connects the first conductor pattern to the conductor layer,
• a second conductor pattern that has one end side connected to one end side of the first conductor pattern and has a length which is equal to or longer than approximately ¼ of an operating wavelength,
• multiple first electromagnetic bandgap elements arranged on both sides of the first conductor pattern in a longitudinal direction on the board,
• multiple second electromagnetic bandgap elements arranged on both sides of the second conductor pattern in a longitudinal direction on the board,
• a conductor plate that faces the first conductor pattern, and
• a third conductor pattern that has one end side connected to another end side of the second conductor pattern and is arranged on the surface of the board;
• wherein the second conductor pattern has a first portion located on a side of the second conductor pattern closer to the first conductor pattern, and a second portion located on a side opposite to the first portion, and the first portion faces the conductor plate, and the second portion and the third conductor pattern do not face the conductor plate.

A transfer device comprising:

• a board including a conductor layer;
• a first conductor pattern arranged on a surface of the board;
• a connecting section that connects the first conductor pattern to the conductor layer;
• a second conductor pattern that has one end side connected to one end side of the first conductor pattern, has a length which is equal to or longer than approximately ¼ of an operating wavelength, and is arranged on the surface of the board;
• multiple first electromagnetic bandgap elements arranged on both sides of the first conductor pattern in a longitudinal direction on the board;
• multiple second electromagnetic bandgap elements arranged on both sides of the second conductor pattern in a longitudinal direction on the board;
• a conductor plate that faces the first conductor pattern;
• and
• a third conductor pattern that has one end side connected to another end side of the second conductor pattern and is arranged on the surface of the board;
• wherein the second conductor pattern has a first portion located on a side of the second conductor pattern closer to the first conductor pattern, and a second portion located on a side opposite to the first portion, and the first portion faces the conductor plate, and the second portion and the third conductor pattern do not face the conductor plate.