Manufacture of a flexible antenna, with or without an inner permeable magnetic layer

• US 5,638,080 A
• Filed: 03/11/1996
• Issued: 06/10/1997
• Est. Priority Date: 01/22/1993
• Status: Expired due to Fees

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Brenninger, Heinrich, Orthmann, Kurt
• Primary Examiner(s): Hajec, Donald T.
• Assistant Examiner(s): PHAN, THO GIA
• Application Number:
  US08/613,875
• Time in Patent Office: 456 Days
• Field of Search: 343/787, 343/788, 343/795
• US Class Current: 343/788
• CPC Class Codes: H01Q 7/08 Ferrite rod or like elongated core

Abstract

An HF antenna comprising a sheet-like, flexible multipart magnet core (16) manufactured of ferromagnetic material is provided with an antenna winding which is made up of a plurality of turns and surrounds the magnet core (16). The turns of the antenna winding are formed by printed wiring (12a and 12b) arranged on a flexible film (10a and 10b) surrounding the magnet core (16).

Claims

1. An antenna comprising a flexible magnetic core or ferromagnetic material, which has one side and another side and lies along a longitudinal axis, and an antenna winding which is made up of a plurality of turns and surrounds the magnetic core, said turns of the antenna winding comprising printed wiring on a flexible film surrounding the magnetic core and wherein the film consists of a first part, having one edge, and a second part, having a second edge and are arranged on either side of said magnetic core, and said printed wiring has more than one start points and end points, characterized in that, the printed wiring on said first and second film parts extends parallel to, at the same distance apart and at such an angle with respect to the longitudinal axis of the magnetic core such that the end points on one edge of said first film part of the printed wiring are offset in relation to the start points on the other edge of said second film part by half the distance between individual ones of the printed wiring as measured in the direction of the longitudinal axis of the magnetic core.

2. The antenna according to claim 1, wherein said first and second film parts are so arranged on each side of the magnetic core such that the start points of the printed wiring on the first film part and the end points of the printed wiring on the second film part are in register with each other such that the in register start and end points of the first and second film parts are electrically connected together in order to constitute a complete winding layer.

3. The antenna according to claim 1, and further comprising a plurality of film parts each constituting a winding layer, wherein the winding layer has many windings each having a start and an end, arranged around the magnetic core such that the end of the winding of one layer is respectively connected with the start of the winding of another winding layer.

4. An antenna comprising a flexible magnetic core or ferromagnetic material, which has one side and another side and lies along a longitudinal axis, and an antenna winding which is made up of a plurality of turns and surrounds the magnetic core, said turns of the antenna winding comprising printed wiring on a flexible film surrounding the magnetic core and wherein the film consists of a first part, having one edge, and a second part, having a second edge and are arranged on either side of said magnetic core, and said printed wiring has more than one start points and end points, characterized in that said first and second film parts define individual printed wires which extend at a selected angle with respect to the longitudinal axis of the magnetic core, and wherein each of said first and second film parts are integrated with each other such that said individual wires of the pr/nted wiring on said first film part extend to and are electrically connected with said individual wires of the printed wiring on said second film part to form continuous printed wiring and that said individual wires of said first and second film parts extend at such an angle to the longitudinal axis of the magnetic core that the end points of the individual wires at one edge of the film of the printed wiring are offset in relation to the start points of the individual wires at the other edge of the integrated film parts by the full distance between the individual wires as measured along the longitudinal axis of the magnetic core and such that the connected first and second film parts constitute a full winding layer, having a midpoint lying parallel to the longitudinal axis of the magnetic core, being folded about the midpoint of the full winding layer through approximately 180 such that the start and end points, are in register and electrically connected with each other.

5. A method of creating an antenna surrounding a flexible magnetic core or ferromagnetic material comprising the steps of:

printing wiring with more than one start and end points which extends parallel to, at the same distance apart, and at such an angle with respect to the longitudinal axis of the magnetic core on a flexible film of a first part with one edge and a second part with an other edge, such that the end points on one edge of said first film part of the printed wiring are offset in relation to the start points on the other edge of said second film part by half the distance between individual ones of the printed wiring as measured in the direction of the longitudinal axis of the magnetic core;

folding said flexible film about a midpoint lying parallel to the longitudinal axis of the magnetic core, being folded about the midpoint of the full winding layer through approximately 180 degrees; and

arranging said folded film on each side of the magnetic core such that the start points of the printed wiring on the first film part and the end points of the printed wiring on the second film part are in register with each other such that the in register start and end points of the first and second film parts are electrically connected together in order to constitute a complete winding layer.