Sidelobe performance can be improved cost-effectively.

Progress has been made in a continuing effort to develop low-geometricprofile, wide-frequency-band microwave antennas intended for incorporation into wide-band aperiodic arrays for use in high-speed communications. The effort has produced improved designs for canted sector antennas, cost-effective approximations of random arrays of such antennas, and software for simulating the performances of such antennas and arrays.

The effort began with an examination of simple canted sector antennas, which consist mainly of triangular radiating elements canted above ground planes. The limits of the operational frequency bands of these antennas and arrays thereof are determined by limits on acceptable variations in their radiation patterns. Simple canted sector antennas offer advantages of simplicity and wide impedance bandwidths. The disadvantage of simple canted sector antennas is that they exhibit close-tobroadside radiation-pattern depressions that are unacceptable for the purpose of adequate scanning of arrays.

Figure 1. The Modified Canted Sector Antenna exhibits better sidelobe performance than does the corresponding simple canted sector antenna, which lacks the corner tapers and bends shown here.