Whistler wave radiation from a circular phased array of loop antennas with the axes oriented across an external magnetic field in a magnetoplasma

Whistler wave radiation from a circular phased array of filamentary loop antennas immersed in a homogeneous cold collisionless magnetoplasma is studied. The array axis is aligned with an external static magnetic field superimposed on the plasma, and the loop axes are assumed to be tangential to the array circumference. An exact solution is obtained for the field excited by the array. Its total radiated power and partial powers going to different azimuthal field harmonics are determined. Numerical results are presented for these radiation characteristics in the whistler frequency range under conditions of the Earth's ionosphere. The results for such an array are compared with those obtained earlier in the case where the axes of the loop antennas are parallel to the external magnetic field. It is concluded that the considered phased array is capable of selectively exciting twisted whistler waves with the desired azimuthal indices and can be used as an efficient source of such waves in a magnetoplasma.