RF coupling device for connecting a hand held radio to an external device without removing the antenna

• US 4,220,955 A
• Filed: 05/29/1979
• Issued: 09/02/1980
• Est. Priority Date: 05/29/1979
• Status: Expired due to Term

• Current Assignee: Rockwell International Corporation
• Original Assignee: Rockwell International Corporation
• Inventors: Frye, Eugene O.
• Primary Examiner(s): Moore, David K.
• Application Number:
  US06/043,296
• Time in Patent Office: 462 Days
• Field of Search: 343/703, 343/720, 343/872, 343/749
• US Class Current: 343/703
• CPC Class Codes: H01P 1/045 Coaxial joints
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/27 Adaptation for use in or on movable bodies H01Q1/08, H01Q1/12, H01Q1/18 take precedence

Abstract

An R-F coupling device of greatly improved coupling and shielding characteristics is disclosed for inductive connection to the antenna circuitry of a hand-held transceiver without necessitating the removal of the transceiver antenna.

Claims

1. A coupling device providing R-F energy coupling to a compact helical antenna in the absence of fixed mechanical coupling thereto, comprising:

a central cylindrical insulating sleeve open at one end and having an internal diameter in excess of the external diameter of such helical antenna,

a helical coupling coil mounted on said insulating sleeve in coaxial relationship therewith,

an outer casing including a cylindrical electrically conductive sleeve with conductive end caps and having an internal diameter in excess of the external diameter of said coupling coil, said conductive casing being mounted on said central insulating sleeve in coaxial relationship, and

an R-F transmission line connector having first and second contact members and being mounted externally on said casing, and first contact member being insulated from said casing and conductively connected to the end of said helical coupling coil farther from said open end of said insulating sleeve,

the conductive end cap of said casing nearer said open end of said insulating sleeve having a central circular aperture therein having a diameter in excess of the outside diameter of said insulating sleeve,

whereby mere placement of said antenna coupling device over such helical antenna in coaxial telescoping relationship effects inductive coupling of R-F energy between said coupling device and such antenna.

2. A coupling device in accordance with claim 1, wherein the excess of said internal diameter of said insulating sleeve over the external diameter of such helical antenna is just sufficient to permit a sliding fit of said antenna coupling device over such helical antenna.

3. A coupling device in accordance with claim 1, wherein the excess of said internal diameter of said casing over the external diameter of said coupling coil is sufficient to constitute a hollow chamber around said coupling coil of appropriate dimensions for effecting proper impedance matching and tuning.

4. A coupling device in accordance with claim 1, wherein said R-F transmission line connector is mounted on the conductive end cap of said casing remote from said open end of said insulating sleeve.

5. A coupling device in accordance with claim 1, wherein said coil and said insulating sleeve are substantially coextensive.

6. A coupling device in accordance with claim 5, wherein said R-F transmission line connector is mounted on the conductive end cap of said casing remote from said open end of said insulating sleeve.

7. A coupling device in accordance with claims 1, 4 or 6 wherein said R-F transmission line connector is a coaxial connector having said first contact member as a center conductor and said second contact member as a shielding conductor.

8. A coupling device in accordance with claim 1, wherein said open end of said central insulating sleeve is external of said conductive casing, said insulating sleeve extending through said central circular aperture.

9. A coupling device in accordance with claim 8, further comprising an electrically conductive member on the protruding open end of said insulating sleeve, said conductive member being electrically connected to the adjacent conductive end cap and extending to the open end of said insulating sleeve.

10. A coupling device in accordance with claim 9, wherein said conductive member on said protruding sleeve is a conductive foil wrap.

11. An antenna coupler providing R-F energy coupling between a compact helical antenna of a transceiver and an external device, comprising:

a sleeve of insulating material having one open end, said antenna insertable in said sleeve through the open end;

a coil mounted on said sleeve in coaxial relationship therewith, said coil substantially enveloping said antenna when said antenna is fully inserted in said sleeve;

a conductive casing mounted on said sleeve and surrounding said coil, said casing separated dielectrically from said coil, said casing including means for establishing a conductive connection between said casing and a shielding conductor of said transceiver when said antenna is fully inserted in said sleeve, said coil and said casing arranged in coaxial relationship to form, respectively, a center conductor and a shielding conductor of said coupler; and

a R-F energy transmission line coupleable to said external device and including first and second conductors, the first conductor being connected conductively to an end of said coil, the second conductor being connected conductively to said casing, whereby mere insertion of said antenna into said sleeve effects the coupling of R-F energy between said antenna and said transmission line.

12. An antenna coupler as claimed in claim 11, wherein said transmission line includes at least a coaxial connector having a central conductor surrounded by a shielding conductor.

13. An antenna coupler as claimed in claim 12, wherein the coaxial connector extends axially outward from said casing and said sleeve at an end of said sleeve remote from the open end, the conductive connection between the second conductor and said casing being effected by mounting the shielding conductor of the coaxial connector to said casing, the central conductor passing through an aperture in said casing, and the conductive connection between the first conductor and said coil being effected between the central conductor and the end of said coil.

14. An antenna coupler as claimed in claims 11, 12 or 13, wherein said sleeve of insulating material is a cylindrical coil form.

15. An antenna coupler as claimed in claims 11, 12 or 13, wherein said conductive casing comprises a cylindrical chamber having closures at either end thereof, said sleeve passing through a central aperture of the closure nearer the open end of said sleeve, the open end of said sleeve extending outwardly, externally of said casing.

16. An antenna coupler as claimed in claim 15, wherein the means for establishing the conductive connection between said casing and the shielding conductor of said transceiver, comprises conductive foil on and inside the externally extending open end of said sleeve.