Array antenna apparatus having at least two feeding elements and operable in multiple frequency bands

An array antenna apparatus comprising:

• a first feeding element having a first feed point;
• a second feeding element having a second feed point;
• a third feeding element having a third feed point;
• and
• a parasitic element electrically connected to the respective first, second and third feeding elements, wherein
• in a first frequency band, respective resonances in at least two feeding elements of the first, second and third feeding elements substantially occur independent of each other, by eliminating electromagnetic mutual coupling between the at least two feeding elements, and exciting one of the at least two feeding elements through the feed point thereof as well as exciting another of the at least two feeding elements through the feed point thereof, and
• in a second frequency band lower than the first frequency band, a loop antenna having a certain electrical length is formed by the first feeding element, the parasitic element, and one of the second and third feeding elements, and a resonance of the loop antenna substantially occurs by exciting the first feeding element through the first feed point.

An array antenna apparatus comprising:

• a first feeding element having a first feed point;
• a second feeding element having a second feed point;
• a third feeding element having a third feed point;
• a first parasitic element electrically connected to the respective first and second feeding elements;
• and
• a second parasitic element electrically connected to the respective second and third feeding elements, wherein
• in a first frequency band, respective resonances in at least two feeding elements of the first, second and third feeding elements substantially occur independent of each other, by eliminating electromagnetic mutual coupling between the at least two feeding elements, and exciting one of the at least two feeding elements through the feed point thereof as well as exciting another of the at least two feeding elements through the feed point thereof,
• at a first frequency in a second frequency band lower than the first frequency band, a first loop antenna having a first electrical length is formed by the first and second feeding elements and the first parasitic element, and a resonance of the first loop antenna substantially occurs by exciting the first feeding element through the first feed point, and
• at a second frequency different from the first frequency in the second frequency band, a second loop antenna having a second electrical length different from the first electrical length is formed by the second and third feeding elements and the second parasitic element, and a resonance of the second loop antenna substantially occurs by exciting the third feeding element through the third feed point.

A wireless communication apparatus comprising an array antenna apparatus, the array antenna apparatus including:

• a first feeding element having a first feed point;
• a second feeding element having a second feed point;
• and
• a first parasitic element electrically connected to the respective first and second feeding elements, wherein
• in a first frequency band, respective resonances in the first and second feeding elements substantially occur independent of each other, by eliminating electromagnetic mutual coupling between the first and second feeding elements, and exciting the first feeding element through the first feed point as well as exciting the second feeding element through the second feed point, and
• in a second frequency band lower than the first frequency band, a loop antenna having a certain electrical length is formed by the first and second feeding elements and the first parasitic element, and a resonance of the loop antenna substantially occurs by exciting the first feeding element through the first feed point.