Probe movement system for spherical near-field antenna testing

A probe movement apparatus for use in spherical near-field testing of antennas comprising:

• a. an azimuth rotary positioner mounted on a base,
• b. a bent cantilevered azimuth arm supported and rotated by said azimuth rotary positioner,
• c. a bearing mounted on said bent cantilevered azimuth arm, said bearing supports an antenna being tested and allows rotation of said antenna independent of rotation of said bent cantilevered azimuth arm, said bearing located such that said bearing and said azimuth rotary positioner have coincident rotation axes,
• d. a means for keeping the portion of said bearing that supports said antenna stationary relative to said base while said bent cantilevered azimuth arm is rotated,
• e. an elevation rotary positioner mounted on tip of said bent cantilevered azimuth arm such that axes of rotation of said azimuth rotary positioner and said elevation rotary positioner intersect and are orthogonal,
• f. an bent cantilevered elevation arm supported and rotated by said elevation rotary positioner,
• g. a probe attached to the tip of said bent cantilevered elevation arm,
• h. the azimuth and elevation arms shaped such that appropriate rotation of the arms by the rotary positioners move said probe to any point on a spherical surface which encloses said antenna except those points or areas blocked by apparatus components,
• i. a means to command the positioner's movement.