Whistler Wave Radiation From Phased Loop Antennas in a Magnetoplasma

A study is made of the radiation characteristics of phased circular loop antennas in a cold homogeneous magnetoplasma in the whistler frequency range. The antennas are assumed to have a common geometric center and the symmetry axes making a certain angle to one another, while being orthogonal to a static magnetic field superimposed on the plasma. With the use of an eigenfunction expansion representation of the excited field, conditions are determined under which such a loop antenna array is capable of launching whistler waves with the desired azimuthal index into the plasma medium. The results obtained show that the proposed phased array can be used as a source of twisted whistler waves with moderate azimuthal indices in a magnetoplasma modeled upon the Earth's ionosphere. The application of such arrays for increasing the power going to circularly polarized waves propagating along an external magnetic field is also discussed.