抄録
It had been widely accepted that a dipole located close to a reflector does not radiate radio wave due to the cancellation with the wave from its image dipole. We proved this prejudice false by studying its physics theoretically and experimentally. Eventually, we proposed a novel Ultra Low Profile Dipole (ULPD), which has a built-in balun and impedance matching capability to realize excellent antenna characteristics. This paper describes the history and way of thinking as for ULPD. A basic ULPD with two inputs shows to have a peculiar quadruple mode instead of two dipole modes, and the antenna gain is 8.4 dBi or more. Then, a practical ULPD with a single input is proposed, and is shown to have almost the same characteristics as the basic ULPD.
