Broadband active differential array for the mid-frequency SKA band Articles uri icon

publication date

  • April 2014

start page

  • 27

end page

  • 38


  • 2


  • 56

International Standard Serial Number (ISSN)

  • 1045-9243

Electronic International Standard Serial Number (EISSN)

  • 1558-4143


  • This paper presents the design and characterization process of an active array demonstrator for the mid-frequency range (i.e., 300 MHz-1000 MHz) of the future Square Kilometre Array (SKA) radio telescope. This demonstrator, called FIDA3 (FG-IGN: Fundacion General Instituto Geografico Nacional - Differential Active Antenna Array), is part of the Spanish contribution for the SKA project. The main advantages provided by this design include the use of a dielectric-free structure, and the use of a fully-differential receiver in which differential low-noise amplifiers (LNAs) are directly connected to the balanced tapered-slot antennas (TSAs). First, the radiating structure and the differential low-noise amplifiers were separately designed and measured, obtaining good results (antenna elements with low voltage standing-wave ratios, array scanning capabilities up to 45 degrees, and noise temperatures better than 52 K with low-noise amplifiers at room temperature). The potential problems due to the differential nature of the proposed solution are discussed, so some effective methods to overcome such limitations are proposed. Second, the complete active antenna array receiving system was assembled, and a 1 m(2) active antenna array tile was characterized.


  • antenna array; mutual coupling; phased arrays; radio astronomy; receiving antennas; ultra wideband antennas; simulation; antenna