The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 03, 1989
Filed:
Jul. 14, 1988
Raymond W Conrad, Russellville, AL (US);
The United States of America as represented by the Secretary of the Army, Washington, DC (US);
Abstract
A superconducting, superdirective antenna array wherein a superconductive terial is employed for the elements of the array which are arranged in a uniform half-wave dipole has low ohmic resistance and a very high radiation efficiency. The superdirective antenna array which is a linear array has element spacing less than .lambda.o/2 where .lambda.o is the center frequency of the dipoles. The material of the array elements has a very high critical current (i.e., and a critical magnetic field), a requirement for maximum efficiency. The superconducting, superdirective antenna array is housed in a vacuum insulated container and is provided outlet connecting to means for obtaining and sustaining a vacuum as required for element material of fabrication. The material of fabrication for the antenna array elements is selected from a type II superconductor material selected from the group consisting of iridiumm, lead, mercury, tantalum, vanadium, a composite of niobium-tin-bronze, and alloys of the same. The antenna array element material of fabrication, as fabrication techniques become available, can be a superconductive material selected from the ceramic oxides composition group consisting of La.sub.2-x Ba.sub.x CuO.sub.x and YBa.sub.2 Cu.sub.3 O.sub.x wherein x is an integer and wherein the transition temperature ranges from about 30.degree. K. to about 93.degree. K., and the thallium-calcium-barium-copper oxide family of compounds with a transition temperature as high as 125.degree. K. A dielectric window is employed for directing radiation of a very high directivity from the superconducting, superdirective antenna array.