Stabilizing a missile radar antenna Using Axiomatic Design

Abstract:

This thesis work describes a brand new concept of how to, from a mechanical perspective,

stabilize/mount a radar antenna. The antenna must be able to rotate ±60 degrees around pitch

and yaw without disturbing the radar characteristics. At the same time the antenna diameter

must be as large as possible to enhance radar quality.

Axiomatic Design was applied as the work method which helped developing a brand new

concept of how to mount the antenna. This concept study was made for Saab Bofors Dynamics

at Massachusetts Institute of Technology in the lab ”Park Centre for Complex Systems” under

supervision of Prof. Nam P. Suh (MIT) and Jan-Gunnar Persson (KTH).

The invention process using Axiomatic Design resulted in a brand new concept. A fixed

sphere, in which the antenna can slide, eliminates the translational degrees of freedom. Two

linkages actuate the antenna by means of linear motors. A careful selection of joints eliminates

the last unwanted degree of freedom. Left are two rotational DOF, one around pitch and one

around yaw. Only the thickness of the sphere and the missile inner diameter limit the size of the

antenna diameter.

The radar disturbance is remaining low, since the additional disturbance is very low and the

same in every angle in the ±60 degree of freedom that the antenna has. That is achieved by

letting the antenna slide inside a sphere where the walls are equally thick all around the

required work space. The material of the sphere could preferably be the same as in the radome.

Oversteering is minimized since direct drive is possible. No transmission is needed.

The antenna has physical restrictions at 90 degrees. Since that is outside the work space it does

not affect the rotation mechanism.