Input/output coupling structure for dielectric waveguide

• US 20050099242A1
• Filed: 11/04/2004
• Published: 05/12/2005
• Est. Priority Date: 11/07/2003
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: TOKO Incorporated (Murata Manufacturing Co Limited)
• Inventors: Sano, Kazuhisa
• Granted Patent: US 7,132,905 B2
• Time in Patent Office: Days
• US Class Current: 333/26
• CPC Class Codes: H01P 3/121 integrated in a substrate
• CPC Class Codes: H01P 5/107 Hollow-waveguide/strip-line transitions

Abstract

Disclosed is an input/output coupling structure for coupling a printed circuit board with a dielectric waveguide having a dielectric body and a conductive film covering the dielectric body. The coupling structure comprises a first conductive pattern formed on the bottom surface of the dielectric waveguide to serve as an input/output electrode, in such a manner as to be surrounded directly by an exposed portion of the dielectric body and further by the conductive film formed around the outer periphery of the exposed portion, a spacer having a surface made substantially entirely of a conductive material and a portion for defining a given space, and a second conductive pattern formed on a principal surface of the printed circuit board and electrically connected to the microstrip line. The bottom surface of the dielectric waveguide is joined to the principal surface of the printed circuit board through the spacer, to allow the first and second conductive patterns to be located in opposed relation to one another and define the space therebetween in cooperation with the spacer. The present invention can provide a simplified structure for mounting a dielectric waveguide on a printed circuit-wiring board to couple the dielectric waveguide with a microstrip line of the dielectric waveguide, and achieve a mode conversion mechanism operable in a wide frequency band and less subject to the influence of the possible displacement between the microstrip line and the dielectric waveguide.

Claims

1. An input/output coupling structure for coupling between an input/output electrode of a dielectric waveguide and a microstrip line of a printed circuit board, said dielectric waveguide including a dielectric body and a conductive film covering a surface of said conductive body, said structure comprising:

a first conductive pattern formed on the bottom surface of said dielectric waveguide to serve as said input/output electrode, in such a manner as to be surrounded directly by an exposed portion of said dielectric body and further by the conductive film formed around the outer periphery of said exposed portion;

a spacer having a surface made substantially entirely of a conductive material, and a portion for defining a given space; and

a second conductive pattern formed on a principal surface of said printed circuit board, and electrically connected to said microstrip line,

wherein said bottom surface of said dielectric waveguide is joined to said principal surface of said printed circuit board through said spacer, to allow said first and second conductive patterns to be located in opposed relation to one another and define said space therebetween in cooperation with said spacer.

2. The input/output coupling structure as defined in claim 1, wherein said dielectric waveguide has a rectangular parallelepiped shape, and two of said first conductive patterns are formed, respectively, at the opposite ends of the bottom surface of said dielectric waveguide, wherein one of said first conductive patterns serves as an input electrode for a dielectric waveguide filter, and the other first conductive pattern serves as an output electrode for the dielectric waveguide filter.

3. The input/output coupling structure as defined in claim 1, which includes mean for electrically connecting said spacer to a ground conductor of said microstrip line.

4. The input/output coupling structure as defined in claim 3, wherein said connecting means is a via hole formed in said printed circuit board.