This seems possible even now when MMIC amplifiers are far from being perfect and cannot be widely used in high sensitive radio astronomical receivers. An attempt to improve a radiating pattern and decrease side lobe level will extend more the feed size. We can instead consider the dipol type feed which has smaller size and is almost free from spillover effects. The field of view of a radio telescope is limitted by aberrations as a receiver element is moved to off-axis positions.
Aberrations lead to an efficiency loss and a distorted beamshape.
The both field of view and sensitivity of a large radio telescope in MM band strongly depends on a number of independent receiver elements which give undistorted elements of a sky picture - pixels. Some ways also exist to expand the available focal zone in cross direction by using more narrow illumination angles and optimal turn of the plane from which the Secondary mirror may be illuminated but this would decrease aperture efficiency almost twice. Power aberration curves for Schmidt and Zenith modes are shown in Fig.1. Full identity of characteristics for MMIC LNAs made from one wafer. Cascaded MMIC LNAs do not require additional isolation.