Abstract: First and second hot elements are formed on the front surface of a long and thin substrate. First and second earth elements are formed on the rear surface of the substrate. First and second parasitic elements are disposed adjacent to the hot elements and the earth elements, thereby forming a first-stage element. A second-stage element has a corresponding structure. A first branch line and a second branch line are formed on the front surface. The hot elements of the first-stage and second-stage elements are fed from a feeding point through the first and second branch lines. An earth line is formed on the rear surface. The earth elements of the first-stage and second-stage elements are fed from the feeding point through the earth line. The hot element and the earth element form a dipole antenna. The parasitic element is disposed adjacent to the dipole antenna to broaden a frequency band.

Abstract: First and second hot elements are formed on the front surface of a long and thin substrate. First and second earth elements are formed on the rear surface of the substrate. First and second parasitic elements are disposed adjacent to the hot elements and the earth elements, thereby forming a first-stage element. A second-stage element has a corresponding structure. A first branch line and a second branch line are formed on the front surface. The hot elements of the first-stage and second-stage elements are fed from a feeding point through the first and second branch lines. An earth line is formed on the rear surface. The earth elements of the first-stage and second-stage elements are fed from the feeding point through the earth line. The hot element and the earth element form a dipole antenna. The parasitic element is disposed adjacent to the dipole antenna to broaden a frequency band.