Broad-band antenna array with application to radio astronomy

A broad-band antenna element and beam-forming matrix have been developed for reception of signals at 25-100 MHz. The element is a zig-zag log-periodic antenna with a nominal impedance of
430\Omega
and a VSWR of less than 1.9. The matrix utilizes time-delay gradients to obtain frequency-independent beam positions and also allows several different beam positions to be monitored simultaneously. Observations of natural radio sources using a 16-element array have verified its usefulness.