Patent ID: 8115690

Claim:
A free space antenna structure comprising: a first radiating element having a first fundamental frequency with a wavelength of λ longer , an electrical length of the first radiating element being λ longer /4; a second radiating element having a second fundamental frequency with a wavelength of λ shorter , which is shorter than λ longer , the first and second fundamental frequencies being unrelated, an electrical length of the second radiating element being 3λ longer /4, the second radiating element having a monopole of electrical length of λ shorter /4 and a dipole of electrical length λ shorter /2, the monopole and dipole laterally overlapping such that the monopole and dipole are electrically, but not physically, coupled to each other and the monopole drives the dipole at the second fundamental frequency; and a non-conductive cover surrounding the first and second radiating elements.