| 摘要 |
801,150. Travelling-wave tubes. ENGLISH ELECTRIC VALVE CO., Ltd. Aug. 7, 1956 [Dec. 12, 1955], No. 35582/55. Class 39(1). A radio frequency delay line structure for use in an electron discharge tube comprises a conductive winding of spaced turns, e.g., a helix, and, adjacent the winding, a conductive member extending along substantially its whole length and having a small portion of its surface in contact with successive turns of the winding and a large portion of its surface spaced from but adjacent to successive turns along the length of the winding. As shown in Figs. 3 and 4 the member 22 is of rivet-like X-section the end face of its stem 22S being in contact with the winding turn 33 along the length of the helix and the curved surface 22H of the domed head lying parallel to and adjacent the turns 33. The dimension p is preferably a little less than one half the required wavelength. In the embodiment shown in Fig. 5 the conductive member 22 is of substantially segmental section, its arc being eccentric with respect to the winding and in contact at small middle portions 22C with the windings leaving tapered spaces between the remainder of the member 22 and each turn 33 on either side of the contact area. The member 22, Fig. 7, is located externally of the windings 33 its surface 22F being parallel to but spaced from the windings except for a small central portion 22K raised from the general arcuate surface and contacting with the turns of the winding. The dimension p in these last two embodiments is preferably a little more than half the wavelength. |
