Walter’s work meticulously details the wave mechanics: a slow-wave structure is required, where the phase velocity of the wave along the antenna is less than the speed of light in free space ((v_p < c)). This condition ensures that the wave’s phase fronts align to produce constructive interference in a specific direction, known as the beam angle. The radiation is not generated by a single point source but by a continuous aperture of infinitesimal radiators, each fed with a progressive phase shift. The result is a directive beam that emerges at an angle relative to the antenna axis, determined by the relationship between the free-space wavelength and the guided wavelength along the structure.
(originally published in 1965 by McGraw-Hill and later by Dover), you can find the full text and detailed previews through several authoritative archival and academic sources: Full Digital Copies Internet Archive traveling wave antennas walter pdf high quality
: Offers a PDF download of the book (approx. 15MB). This version is often cited in academic forums for its clear text and readable mathematical formulas. Internet Archive Academic Previews & Related Resources Google Books Walter’s work meticulously details the wave mechanics: a