Generation of microwave orbital angular momentum states using hemispherical dielectric resonator antenna

A hemispherical dielectric resonator antenna (DRA) generating two orbital angular momentum (OAM) states of l = +1 and −1 is studied theoretically and experimentally. The DRA is fed with two orthogonal signals, exciting two degenerate higher-order TE221 modes that generate the two OAM states. It was simulated with full-wave simulation software to verify the design method. A prototype operating in the microwave band (5.8 GHz) was fabricated and measured. Its S-parameters, intensity profile, and phase pattern are simulated, and the results are compared with measurements. Also, its far-field radiation pattern, realized antenna gain, and total antenna efficiency are shown for a complete study of the antenna.