Precision radar measurements using a novel compact test range

A compact radar test range is reported. The range is capable of coupling a fully operational W-band, dual-axis, dual polarised seeker system to a transponder which generates simulated target and clutter returns while allowing full seeker antenna movement. The range is considerably more compact, less complex and less expensive than currently used techniques. Its operation relies on the close coupling of the seeker antenna to a transponder antenna with a similar sized aperture. Both antennas face into a single 4 foot diameter ellipsoidal reflector. With one antenna at each of the reflectors foci, whichever direction the radar beam is directed it will always be incident on the transponder antenna. The beam of the transponder antenna is directed by a flat scanning plate in order to obtain constant coupling loss. Less than +or-0.5 dB variation in coupling loss is achieved over scanning angles of at least +or-30 degrees in both the azimuth and elevation axes, thus allowing accurate sensitivity measurements to be made. Minimum distortion occurs to the seeker antenna radiation patterns which means that the monopulse discriminator performance is maintained and the ground detection and target tracking performance can be evaluated.<>