Investigation into the Effect of Dielectric Loss on RF Characteristics of Helical SWS

A general theory has been developed to account for the effect of the dielectric loss of discrete rods on the performance characteristics of an actual helical slow wave structure (SWS). The effect of the lossy dielectric rods has been studied on various propagation parameters, namely, phase propagation constant, interaction impedance and attenuation constant at different operating frequency. It is clearly shown that the influence of dielectric loss on RF characteristics is much larger at the millimeter frequency band than that at the microwave frequency band, especially on interaction impedance and attenuation constant. The general theory developed here has been further confirmed by comparing the results with those obtained elsewhere for some special cases.