Antenna device and manufacturing method for antenna device

An antenna device comprising:

• a first antenna element and a second antenna element which transmit and receive a radio wave;
• a housing which stores a processor configured to process a signal in response to the radio wave;
• a first element cover configured to store the first antenna element;
• and
• a second element cover configured to store the second antenna element,
• wherein the first element cover includes
• a first rotary cylinder, which is held by the housing and rotatable around a first rotational axis, and
• a first protruding cylinder, which protrudes from the first rotary cylinder and encloses the first antenna element, the first rotary cylinder protruding from the housing along the first rotational axis,
• the second element cover includes
• a second rotary cylinder, which is held by the housing and rotatable around a second rotational axis, and
• a second protruding cylinder, which protrudes from the second rotary cylinder and encloses the second antenna element,
• the second rotary cylinder protruding from the housing along the second rotational axis, and
• a first included angle defined between the first protruding cylinder and the second protruding cylinder is changed by rotation of at least one of the first and second rotary cylinders
• wherein the first rotary cylinder includes a first distal end which protrudes from a joint portion between the first rotary cylinder and the first protruding cylinder along the first rotational axis, and
• the second rotary cylinder includes a second distal end which protrudes from a joint portion between the second rotary cylinder and the second protruding cylinder along the second rotational axis.