Patent ID: 6683575
Filing Date: 2004-01-27
Classification: H01Q

Abstract:
An antenna apparatus comprising:a feed point; a first linear antenna element which has one end connected to the feed point; a second linear antenna element which has one end connected to the other end of the first linear antenna element; a third linear antenna element which has one end connected to the other end of the first linear antenna element; a fourth linear antenna element which has one end connected to the other end of the second linear antenna element; and a connection element which connects the other end of the second linear antenna element and a ground terminal, wherein a sum of lengths of the first, second, and fourth linear antenna elements is Â¼ a wavelength corresponding to a series-resonance frequency of the first, second, and fourth linear antenna elements, a sum of lengths of the second, third, and fourth linear antenna elements is Â½ a wavelength corresponding to a parallel-resonance frequency of the second, third, and fourth linear antenna elements, a sum of lengths of the first and third linear antenna elements is Â¼ a wavelength corresponding to a series-resonance frequency of the first and third linear antenna elements, and the parallel-resonance frequency is higher than a frequency of the series-resonance frequency of the first, second, and fourth linear antenna elements and lower than the series-resonance frequency of the first and third linear antenna elements.