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. 09, 1991
Filed:
Jan. 09, 1990
Charles P Moeller, Del Mar, CA (US);
General Atomics, San Diego, CA (US);
Abstract
Conversion from a whispering gallery or volume mode to a more useable mode, such as the HE.sub.1,1 mode is achieved in a waveguide mode converter that includes input and output sections. The input section includes overlapping circular and coaxial waveguides. Microwave energy in a whispering gallery or volume mode within the circular waveguide is coupled through an array of N equally spaced axial slots placed in the common wall separating the circular waveguide and the coaxial waveguide to coaxial TE and TM modes. Helical grooves placed in one of walls of the coaxial waveguide convert the coaxial mode to a quasi parallel plate mode wherein the common wall separating the inner circular waveguide from the outer coaxial waveguide functions as one plate, and the outer wall of the coaxial waveguide functions as the other plate. The quasi parallel plate mode propagates microwave energy spirally through the coaxial waveguide in a direction k, where k makes an angle .theta. to the waveguide axis. The helical grooves are placed transverse to k. Such grooves cause the normal modes to no longer be the coaxial TE and TM modes, but modified linear combinations thereof. One such linear combination is a desired TE.sub.0,1 mode, which normal mode is only slightly affected by the grooves. The other normal mode is analogous to the parallel plate TM.sub.0,1 mode, which mode is strongly affected by the grooves. The output section extracts the TE.sub.0,1 energy by helically unwinding the walls of the coaxial waveguide. Additional conversion to the HE.sub.1,1 mode is accomplished by using a compact configuration that makes the wavefront cylindrical using a lens or mirror coupled to a sectoral horn.