Patent ID: 7755545
Filing Date: 2010-07-13
Classification: H01Q

Abstract:
1. An antenna comprising: a ground conductor having a ground potential; a single feeding point whose one end is formed by a part of the ground conductor; and a plurality of transmission lines to which RF power supplied to the feeding point is input, for radiating electromagnetic waves of a plurality of frequencies into space, wherein the plurality of transmission lines include a specific transmission line that consists of a single element without being separated by space to radiate electromagnetic waves of the plurality of frequencies into space commonly to the plurality of frequencies, wherein the number of the plurality of transmission lines is equal to or more than four, wherein impedance matching is performed at the feeding point with respect to the plurality of frequencies, and wherein the plurality of frequencies are composed of n frequencies of first, second, third and fourth to n-th frequencies, where n is a positive integer of two or more, and wherein the total length of the plurality of transmission lines is shorter than the sum of a quarter wavelength of an electromagnetic wave of the first frequency and half wavelengths of electromagnetic waves of the second, third and fourth to n-th frequencies, the second, third and fourth to n-th frequencies being higher than the first frequency.