Abstract. In the present paper we describe the methods and results of the
modeling and performance optimization of the imaging millimeter wave Cassegrain
radiotelescope for solar research. We propose to use the 2-row densely
packed array feed as a receiver, aligned with one image coordinate, and active
beam scanning along the other one in order to maximize the number of pixels and
achieve the best image quality with a feed of minimal size and weight. To solve
the problem, conventional methods of antenna engineering and radioastronomy, as
well as millimeter-wave imaging approaches were employed. Beam scanning optical
systems with tertiary and secondary optics were considered. Two kinds of
systems using tertiary mirror were studied, with an elliptic tertiary, and with
a hyperbolic one, for the case of a magnification Ě = 10. The auxiliary swinging flat mirror is used for the
beam scanning in those systems. In the system with a secondary optics, the beam
is scanned using the subreflector, the case of M = 3 is
considered. An optical design using secondary optics is shown to be more
appropriate for the beam scanning.
Key words: solar radioastronomy, multibeam radiotelescope, secondary and
tertiary optics, ray tracing, multibeam pattern modeling.
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