Bessel Beam Radial Slot Antenna

The resonance type radial slot antenna as a high efficiency Bessel beam launcher was designed and investigated in wide band of operation frequencies. The analytical method to determine resonant frequencies of short-circuit radial line was evaluated and applied to calculation of the resonant frequencies of the radial resonators with different modes number, dielectric permittivity and sizes. The experimental results are in good agreement with calculation once. The expression for E and H are obtained and applied to the calculation of both electric and magnetic fields distributions. The impedance, voltage and current of radial line are investigated and related diagrams of intended modes are plotted. The circular slots are located on the top plate of radial line and are excited by the radialy inward traveling transverse electromagnetic (TEM) mode in the upper part of line. The slots are arrayed on top plate which they can couple with the radial current flowing over the line to produce a radially polarized broadside beam. The position of these radiating slots is estimated from the maximum values of current distribution of line. It was founded that the observe at the distance up to 70λ.