Publications [#332911] of David R. Smith

Papers Published
  1. Marks, DL; Smith, DR, Mode diversity of weakly modulated cavity antennas, Journal of the Optical Society of America A, vol. 35 no. 1 (January, 2018), pp. 135-147 [doi] .

    © 2017 Optical Society of America. The radiating mode of a cavity antenna at a particular frequency is fixed. However, by actively modulating the permittivity inside the cavity, the radiating mode may be changed. Using time-independent perturbation theory, we derive the modes of a cavity perturbed by many modulating elements. It is found that with a sufficient number of modulators of sufficient strength, the number of unique fields radiated by the cavity may reach a limit determined by the number of unperturbed cavity modes. The number of addressable radiated fields increases exponentially with the number of modulators; however, perturbations involving the interaction of several modulators become progressively weaker. For antennas at millimeter and terahertz frequencies, such cavity antennas can realize a great diversity of radiation patterns using fewer active devices, better exploiting the diversity achieved by each added modulator.