出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：A novel low frequency dual polarized feed with symmetric pattern is presented for use in big reflector antennas. In this paper we describes the design, construction and characterization of a low frequency feed for GMRT antennas covering the frequency range 30- 90 MHz as an example for the proposed feed. Two main goals of our design are, 1) to get a feed system in which the sky noise dominates the system temperature in the frequency range of interest, with reasonable aperture efficiency and symmetrical E & H plane patterns with the constraint that 2) its physical dimension is suitable for mounting it along with one of the existing feeds on the GMRT antenna turret, with minimum interference to its operation. In the first phase of this project, receiver systems consisting of V-dipole feeds and front-ends have been installed on four of the thirty GMRT antennas. Test observations were carried out on a number of bright 3C sources. The initial results are encouraging.
