The Circular Eleven Antenna: A New Decade-Bandwidth Feed for Reflector Antennas With High Aperture Efficiency

Abstract

Future ultra-wideband (UWB) radio telescopes require UWB feeds for reflector antennas, and many new UWB feed technologies have gained substantial progress to satisfy the tough specifications for future radio telescope projects, such as the square kilometer array (SKA). It has been noticed that, different from traditional narrow-band horn feeds, all UWB feeds are non-BOR (Body of Revolution) antennas. Therefore, BOR1 efficiency becomes an important characterization for the modern UWB feed technologies. We present a novel circular Eleven feed, constructed of "circularly" curved folded dipoles printed on flat circuit boards, in order to have high BOR1 efficiency at a low manufacture cost. The Genetic Algorithm (GA) optimization scheme has been applied to the design for achieving a low reflection coefficient. Simulated and measured results show that the circular Eleven feed has a reflection coefficient below-6 dB over 1.6-14 GHz and below-10 dB over 78% of the band, and an aperture efficiency higher than 60% over 1-10 GHz and 50% up to 14 GHz.

Macros programming in modern electromagnetics software packages by the application example of log-periodic dipole array antennas designing

“…Similar macros seem to be especially useful for de signing fully parameterized models of LPDAs with a large number of dipoles or more complicated log periodic antennas such as, for example, eleven feed with circular dipoles [3]. In addition, usage of such macros frees us from the necessity of manually adding or remov ing dipoles from the whole LPDA model when a number of dipoles is determined during optimization.…”

Two new types of compact ultra-wideband antennas for EMC measurements

“…The eleven antenna is a cascaded log-periodic duallypolarized folded dipole array [3]- [6], as shown in Figs. 1-5. In theory, the antenna can have an infinite large bandwidth when the antenna has an infinite large size.…”

“…Therefore, the polarization can be linear or circular; 5) compact size. The design theory and procedure have been reported in [3]- [6]. Here we present the typical performance of several eleven feed.…”

Arrangements and applications of self-grounded antennas

“…Many UWB antennas have been developed [2]- [5]. We presented a new type of UWB antennas -the self-grounded antennas in the paper [6]- [9].…”