Broadband high efficiency full wave open coaxial stub loop antenna

摘要

A broadband, high-efficiency loop radiator is characterized by a coaxial loop one wavelength in circumference with a continuous center conductor fed through a coaxial T feed and a discontinuity of the outer shield next to the feed point of 50 ohms input impedance. Radiation occurs as a result of this transmission line discontinuity resulting in a reflected wave back down the shield. The one wavelength dimension of the loop generates two in phase electric dipoles spaced one diameter apart resulting in a bidirectional radiation pattern of 3 dBil and a 30% operational bandwidth due to the frequency compensation of the open stub. The open stub loop antenna acts as a low loss parallel tuned circuit appearing across a generator and the series impedance of the loop antenna resulting in increased bandwidth.