Tutorial: Phased array antennas for radio astronomy

This tutorial presentation will provide a basic introduction to recent applications of phased array antennas for radio frequency astronomical observations. Antenna arrays of four basic types are used for astronomical observations: (1) synthesis imaging arrays, (2) horn cluster feeds, (3) phased array feeds, and (4) aperture arrays. Synthesis imaging arrays are highly sparse arrays of dish antennas with extremely large separation between antennas relative to the electromagnetic wavelength. These kinds of arrays have been used for many decades and are routinely used at various RF and microwave bands at sites around the world. The focus of this presentation is on more recent research and development work on the third and fourth types of array antennas, which involve dense phased arrays combined with digital beamforming for astronomical observations.