Coupling of Modes in Helixes
- 1 September 1954
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in Proceedings of the IRE
- Vol. 42 (9) , 1389-1396
- https://doi.org/10.1109/jrproc.1954.274571
Abstract
Propagation on a. helix as a function of frequency is characterized by ranges in which there is a slow wave which can be explained as very nearly a transverse electromagnetic wave traveling along the wire, and ranges in which the helix does not propagate; these are associated with "forbidden regions" of propagation constant pointed out by Sensiper. Each mode of propagation consists of an infinite number of spatial Fourier components called spatial harmonics. The complicated behavior with frequency of the modes of a helix is explained as an effect of the coupling through spatial harmonics of the slow wave which travels with about the velocity of light along the wire to fast free-space or waveguide waves which travel with about the velocity of light along the axis. The qualitative effects of such coupling agree with a tape-helix analysis of helixes in free space and helixes surrounded by a conducting tube. The case of the bifflar helix is also treated.Keywords
This publication has 2 references indexed in Scilit:
- Coupling of Modes of PropagationJournal of Applied Physics, 1954
- Theory of the Beam-Type Traveling-Wave TubeProceedings of the IRE, 1947