Radar test device with planar reflecting shield

Radar test apparatus for examining a test subject to be illuminated by a beam of radiation from a radar set including an antenna for emitting and receiving a radar beam into and from a path extending in a predetermined direction, comprising:

• a rotator for supporting said test subject and including platform means for mounting the test subject for rotation in the path of said beam together with a conductive turntable mounted below said test subject,
• a shield positioned behind the test subject on the side away from the radar antenna,
• said shield being inclined at an angle to the direction of said beam for reflecting those portions of the radar beam which pass the test subject out of the received path seen by the antenna,
• said shield having an opening therein surrounding said shaft and turntable,
• means forming a seal between the turntable and the shield and including a recess having a diamond shaped outer periphery formed in the shield and a thickness substantially less than one-quarter wavelength of the radar beam,
• said recess having a plurality of edges formed in the shield and generally configured-oriented so that no edge is reflective into the receive path of said antenna, and
• a foil having a peripheral shape complementary to said recess for closely fitting in the outer periphery of said recess and in making relation to the shield in the manner of a fairing to provide a continuous smooth transition therebetween essentially free from generation of reflections, and further having an inner shape for lying in touching engagement onto the upper surface of said turntable.