A new electronically steerable 1056 dipole array at 327 MHz for the Ooty radio telescope

Abstract

The electronically steerable 1056-element linear dipole array installed on the Ooty radio telescope in 1982 is described. The colinear dipole array consists of 22 subarrays of 48 dipole each and employs a low loss (about 0.6 dB) 4-bit PIN diode phase-shifter, after each dipole, for steering the telescope beam in declination. The phase-shifters are controlled by a computer and transistor drivers. The maximum VSWR at the input of any dipole is not above 2 over a scan range of + or - 40 deg, and the frequency range of + or - 6 MHz.