Propagation on Modulated Corrugated Rods (Correspondence)

In reviewing the literature on the subject of modulated surface wave antennas, we came across the paper "Propagation on Modulated Corrugated Rods" by C. C. Wang and E. T. Kornhauser in which the authors study, both theoretically and experimentally, slow-wave propagation on modulated corrugated rod structures excited in the circularly symmetric TM mode.