3.1.1.2
Main Reflector Design
The main reflector is one of the core components of the antenna system. Its theoretical curved
surface is formed by synthetic curve rotating around the axis of the antenna. The antenna
reflector is divided into multiple plates because of cumulative materials, manufacturing
engineering, final assembly adjustment, etc. The reflector is divided into two rings. Inner ring
reflector is divided into 20 same sector unit plates and the outer ring is divided into 20 sector
unit plates. So the main reflector of antenna is composed of 40 reflector units.
The stretched and shaped 2A12-O aluminum board with thickness of δ=2mm is used as
individual sector plate after quenching, stretching and shaping. Z type aluminum casting
material is used as back rib after quenching, stretching and shaping in order to perform
positioning with rivet the die table for riveting rib and reflector. Each sector plate is supported
at backups via 6 stretching bolts. In order to ensure the process precision, such process
technology as first bonding and second riveting is adopted to improve the strength of
individual plate and reduce the number of rivets and thus decrease the local deformation of
plate caused by riveting points. The high precision mould and tool set up process are used for
all procedures, such as stretching, stretch bending, riveting. The accuracy of the individual
plate is ≤0.25mm (R.M.S). The reassembly precision of whole main reflector is ≤0.45mm
(R.M.S).
3.1.1.3
Subreflector and Its Supporting Mechanism Design
The subreflector is made of aluminum casting material and adopts the integral structure. It is
manufactured with the numerically controlled machine tool to ensure its precision, which is
not more than 0.15mm (R.M.S). The subreflector supporting mechanism is composed of four
support rods and one adjustment mechanism. In order to reduce its shadow to the main
reflector and ensure the supporting rigidity, the subreflector support rod adopts the flat oval
steel tube, of which one end is supported at the main backups and the other is connected with
the subreflector through adjusting mechanism. The four adjusting bolts of adjusting
mechanism are used to implement the adjustment of subreflector axial movement, lateral
movement and drift angle. The three-dimensional forming diagram of subreflector and its
supporting mechanism is shown in Fig.3.1-4.
