Radio astronomy instrumentation in the XXI century

Institute of Radio Astronomy, National Institute for Astrophysics, Bologna, Italy

Abstract

Progress in design tools and technology development improve the basic instrument used by radio astronomers, composed by an antenna and a receiver. This paper will review some design methods now available in different areas and widely used in order to optimize radio telescope performances. Steps toward increased sensitivity are then obtained by means of complex systems such as active antenna surfaces or receiver phased arrays.