Evaluation of compact range using a diagonal flat plate

The authors present a method which uses a diagonal flat plate to develop a stray signal criterion based on a tolerable RCS (radar cross section) measurement error. The scattered cross section of a 1.25 ft by 1.25 ft diagonal flat plate has been measured in a compact range with a blended rolled-edge reflector and with a knife-edge reflector. The measured RCS pattern of the plate at 6 GHz is shown, with the ideal plate RCS pattern plotted for comparison. The stray signal from one of the junctions between the rolled edge and the parabolic section is about 6.2 degrees from the axis of the plate. As a result, there should be an error in the plate RCS pattern at approximately=3.1 degrees . It is found that this error is about 0.88 dB for the blended rolled-edge reflector. The knife edge of the modified reflector is located about 12 degrees from the plate axis and, as a result, there is a significant error (5.17 dB) in the plate RCS pattern at theta =6 degrees .<>