(under subclass 700) Subject matter wherein an active antenna
element, which may be a complete antenna or a portion of one (such as an arm of a dipole), is formed as a cylinder, prisms, or frustum of a cone or prism, or defines such a surface (such as series of circularly arranged parallel wires), is combined with a feed line which supplies radiating energy to or from this antenna element or to or from another antenna element; and which enters the cylinder at one end and extends within the cylinder at least a portion of the distance to the other end; and where the feed line is electrically coupled to this cylinder the coupling is remote from the entrance end, there being a substantial insulating space between the inner surface of the sleeve and the portion of the feed line extending within the cylinder.
(1) Note. The feed line may be the feed to the sleeve element, or to another active element, or to both. The feed line may also be a support for the sleeve element or for other antenna elements. The feed line may be the ground return, such as the connection to the outer conductor of a coaxial line where the inner conductor is connected to any portion of the active element.
(2) Note. In this subclass the feed line is spaced along its length from the inner surface of the sleeve, as opposed to the case of telescoping parts as in subclasses 823 and 901+, wherein the parts are in substantial engagement over their telescoping length. Further, in these last mentioned subclasses, the feeding portion usually surrounds the free end portion.
(3) Note. The sleeves forming active antennas of this subclass are distinguished from superficially similar sleeves as found in subclass 830 in that the latter sleeves form ground planes performing no active function as collectors or emitters of radiation (though they usually have reflecting properties); whereas the sleeves of this subclass are active radiators or collectors of radiation.
SEE OR SEARCH THIS CLASS, SUBCLASS:
773, for bi-conical horn wave guide type antennas. 807, for doublets whose active elements are thick or enlarged to form a sleeve.
823, for doublet type antennas having telescoping arms. See (2) Note, above.
830, for fractional, multiple or full wave linear antenna with grounding structure, and having coaxial feed line. See (3) Note, above.
884, for antennas where a plural wire transmission line or wave guide is the support.
901+, for rod type telescoping antennas. See (2) Note, above.
