High Gain Conical Beam Antenna Array Exploiting Grating Lobes

The alternative solution is presented for single- and multi-ring arrays with a high-gain and wide elevation coverage conical beam. Effects of ring radii, number of elements, beam switching and multi-ring operation are analyzed using array theory. Gain enhancement at the large flare angle is obtained by using grating lobes of the array factor with conical pattern elements. The switching technology is employed to improve pattern ripple in azimuthal plane and to exploit the grating lobes for achieving high gain. Excitations of all the elements are in phase. A prototype of a single-ring array with 13 elements has been fabricated and measured. Three sub-arrays each composed of four elements are arranged on the ring and the other single element is located at the center. Measured results show that elevation beam coverage is from 20° to 55° and the maximum radiation gain is 9 dBi at 48° elevation at 12.5 GHz.