Antenna Measurement Techniques: Catr with Different Serrated Reflectors

Microwave antennas are to be tested necessarily to assure the customer that they perform as per the design specifications. The performance of a microwave antenna can be adjudged by measurements employing open test range, microwave anechoic chamber, Near Field ?Far Field (NF-FF) techniques and Compact Antenna Test Ranges. Real estate can represent a significant investment for far field ranges, and the only tangible accomplishment of the size is to flatten the amplitude. One of these can serve as a source, offering the possibility of ?compact? range. The primary limitation on field flatness is the diffraction level from the edge of the reflector. Three methods of reflector edge treatment for reducing the ripples are in use, serrating the edge, which scatters the diffracted signal in directions away from the quiet zone; rolling the edge, which directs the scattered signal to the wall, and resistive tapering, which absorbs the excess edge illumination. The major improvement comes from serrating the edge.