Defence radar antennas at Thomson-CSF planar arrays and recent studies

The present investigation is concerned with developments related to defense radar antennas. One of the three principal areas in which the evolution of antennas occurs is related to the increasing use of electronic scanning. This trend is based on the constant progress in rapid-switching phase shifters (ferrite or diode). Electronic scanning makes rapid movement of the beam possible, and provides adaptability (variable width, possibility of creating zeros in the pattern for protection against jamming). Another area of rapid progress involves the increasing use of planar arrays providing flat antennas, while the third area is concerned with digital beam-forming (DBF) antennas. DBF involves the use of a computer, and it is expected that DBF antennas will probably revolutionize radar by the end of the century. A description is given of examples of studies conducted in the various areas of antenna evolution.