ARRAY ANTENNA

Japanese Patent JP3791331

B2

PROBLEM TO BE SOLVED: To obtain an array antenna in structure for spreading the beam width of an array element pattern by solving the problem that the beam width of the array element pattern becomes narrow for adversely affecting wide-angle beam scanning characteristics in the conventional array antenna. SOLUTION: In the array antenna, a dipole 2 operating at frequency f1 is arranged at an element position that is determined from conditions for preventing grating lobe from being generated even if scanning is made at a wide angle by beams at the frequency f1. A plurality of poles 3 with a specific length are arranged nearly vertically to a conductor bottom board 1 near each dipole 2, thus expanding the beam width of the array element pattern due to the influence of re-radiation from an induced current being distributed on the poles 3.