TABLE OF CONTENTS A number of phased array radar systems have been built, and a representative selection is briefly reviewed below.
This S-band phased array radar is part of the Navy Aegis weapon system and was developed by RCA. It has four phased array apertures to give unobstructed hemispherical coverage (Fig. 7.1). In its early configuration it used a simple feed system with, on receive, 68 subarrays, each containing 64 waveguide-type radiators, for a total of 4352 elements. On transmit, subarrays were combined in pairs, and 32 such pairs gave a transmit aperture of 4096 radiators. The phase shifters fed directly into waveguide radiators, had 5 bits, and were of the nonreciprocal, flux-drive, latching garnet configuration. A later version was designed for low sidelobes. The subarray size had to be reduced to 2 elements to avoid quantization lobes, and, similarly, the phase shifter had to be refined by driving it with 7-bit accuracy. The resulting phased array has an aperture with a constrained-feed structure and 4350 waveguide-type radiators. Monopulse sum and difference receive patterns and the transmit pattern are separately optimized.
Figure 7.45 shows the antenna being tested in a near-field facility16 where the field near the aperture is measured with a probe for far-field pattern calculation.
Thomson CSF has developed an S-band multifunction phased array radar, the TRS...
