GB2330694A - Antenna connection to a printed circuit board - Google Patents

Antenna connection to a printed circuit board Download PDF

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Publication number
GB2330694A
GB2330694A GB9722659A GB9722659A GB2330694A GB 2330694 A GB2330694 A GB 2330694A GB 9722659 A GB9722659 A GB 9722659A GB 9722659 A GB9722659 A GB 9722659A GB 2330694 A GB2330694 A GB 2330694A
Authority
GB
United Kingdom
Prior art keywords
circuit board
printed circuit
antenna
flexible member
layers
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB9722659A
Other versions
GB9722659D0 (en
Inventor
Kenneth William Steele
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Ramar Technology Ltd
Original Assignee
Ramar Technology Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ramar Technology Ltd filed Critical Ramar Technology Ltd
Priority to GB9722659A priority Critical patent/GB2330694A/en
Publication of GB9722659D0 publication Critical patent/GB9722659D0/en
Publication of GB2330694A publication Critical patent/GB2330694A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/16—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole
    • H01Q9/26—Resonant antennas with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole with folded element or elements, the folded parts being spaced apart a small fraction of operating wavelength
    • H01Q9/265—Open ring dipoles; Circular dipoles
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
    • H01Q1/38—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith formed by a conductive layer on an insulating support
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q7/00—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/16—Printed circuits incorporating printed electric components, e.g. printed resistor, capacitor, inductor
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/18—Printed circuits structurally associated with non-printed electric components
    • H05K1/189—Printed circuits structurally associated with non-printed electric components characterised by the use of a flexible or folded printed circuit

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Details Of Aerials (AREA)

Abstract

An antenna (14) and connecting portions (16) are formed as conducting tracks on a laminar flexible member (10) preferably by etching away unwanted portions of a conductive layer on a surface of a flexible plastics backing material. The backing material can be cut to form a connecting portion (20) which is trapped between layers of a multi-layer PCB (12) to connect to a circuit thereto. An antenna portion (22) of the flexible member can be angled to any desired orientation relative to the plane of the PCB (12) within a housing for the printed circuit board (12).

Description

ANTENNA CONNECTION TO A PRINTED CIRCUIT BOARD The present invention relates to a method of connecting an antenna to a printed circuit board (PCB)as well as a printed circuit board and antenna assembly.
It is frequently necessary to provide an antenna which is associated with a circuit on a printed circuit board in circumstances where there is a necessity for the complete assembly to be compact and low cost. Typical applications are cellular telephones and hand held radios as well as transponders and readers associated with automatic meter reading systems.
Prior art solutions include printing the antenna onto the printed circuit board either as a patch antenna or as a linear antenna which can be constructed as a dipole or monopole. This solution has its limitations. Patch antennas are not easily realisable at cellular frequencies and are directional. A linear antenna requires large areas of printed circuit board and must be in the plane of the printed circuit board. The antenna is also close to sources of interference on the printed circuit board and is loaded by the loss in the printed circuit board dielectric. Therefore, although these solutions provide for a good connection between the antenna and the circuit, they leave the technical problems of providing for compact design and the possible need for the antenna and the circuit board to be in different planes.
These technical problems have in the past been overcome by providing a separate antenna which is connected by means of a coaxial cable and separate radio frequency (RF) connectors to connect the cable to the antenna and to the circuit board. However, such RF connectors are relatively expensive. Soldering can be used but this is inconvenient on high volume production lines. The manual operation can significantly increase the production cost.
A solder connection is also inherently unreliable.
According to the present invention, as defined in the appended claims, there is provided a printed circuit board and antenna assembly which seeks to overcome the limitations described above.
In order that the invention may be well understood a preferred embodiment thereof will now be described, by way of example only, with reference to the accompanying drawing, which is a perspective view of one embodiment of a PCB with antenna attached.
An electrical circuit (not shown) is formed on at least one layer of a multi-layer PCB 12. The circuit requires an antenna. A laminar flexible member 10 comprising a non-conductive backing sheet with a layer of conductive material such as copper overlaid on to it is used to form both the connection between the antenna and the antenna itself. This type of material has been used for various purposes including the interconnection of circuits on different multi-layer PCBs. It is a commercially available material. The conductive layer can be etched to remove portions of the material to leave tracks 14 defining an antenna and connecting conductors 16. A simple dipole antenna is illustrated. It will be appreciated that any type of antenna design can readily be etched on to the laminar flexible member 10 and the dipole antenna illustrated is simply one example.
In the embodiment illustrated the laminar flexible member 10 is cut to a T shape to form a connecting portion 20 and an antenna portion 22. Normally the antenna portion 22 will be supported against a wall of a housing surrounding the PCB. The length of the connecting portion 22 is chosen to allow the antenna portion to be positioned against the wall of the housing. It will be appreciated that it is easy for the plane of the antenna to be at any angle relative to the plane of the PCB 12.
The antenna portion 22 may be mounted to a housing wall via the non-conductive plastics backing sheet.
In the assembling the circuit a free end of the connecting portion with exposed conductor tracks 16 is sandwiched between two layers of the multi-layer PCB so that the conductors 16 make contact with the circuit. If the circuit design does not necessarily call for a multilayer PCB it will be appreciated that an additional layer can readily be provided at least in the region of the antenna coupling to trap the portion 20 against appropriate connecting pads on the main PCB.
Preferably the electrical connection is made solely by the trapping process. In an alternative embodiment the antenna conductor tracks 16 could be soldered to the pads on a double sided board.
The described assembly overcomes the unreliability and expense of a solder operation or the use of miniature RF connectors. The antenna can easily be manipulated to be multidirectional. The antenna connection is reliable and is made at the time of the of printed circuit board manufacture rendering additional operations on the production line or at the assembly stage redundant. The antenna can survive a standard infra-red surface mount technology reflow profile.
A 'smooth' launch into the antenna feeder cable formed by the connecting portion 20 is achieved at very low cost.
A close tolerance antenna can be designed without using space on the multi-layered printed circuit board. The benefits of a printed antenna are obtained without dielectric losses of the printed circuit board.
It is within the scope of the invention to use a range of materials for the insulating and conducting parts of the laminar flexible member 10. Suitable materials are polyimide and copper respectively. A material suitable for use as a flexible laminar member is commercially available in quantity from Swift Circuits of 100 Trostre Road, Llanelli and tracks can readily be etched using standard printing processes.

Claims (5)

  1. CLAIMS 1. A printed circuit board and antenna assembly comprising a printed circuit board having at least two layers of circuit board material, and a laminar flexible member supporting conducting tracks defining an antenna and connections to a circuit formed on the printed circuit board when a portion of the laminar flexible member is sandwiched between layers of the printed circuit board.
  2. 2. A printed circuit board and antenna assembly according to claim 1, further comprising a housing for the printed circuit board, and wherein the member comprises a connecting portion and an antenna portion, so that the antenna portion can be mounted to the housing at an angle to a plane of the printed circuit board.
  3. 3. A method of providing an antenna for an electric circuit on a printed circuit board having at least two layers of printed circuit board material, comprising the steps of: etching a pattern of conducting tracks on a laminar flexible member in order to define an antenna and connections; and trapping the member between layers of the printed circuit board such that the connections make electrical connections to said electric circuit on said printed circuit board.
  4. 4. A printed circuit board and antenna assembly substantially as herein described with reference to the accompanying drawing.
  5. 5. A method of connecting an antenna to a printed circuit board substantially as herein described with reference to the accompanying drawing.
GB9722659A 1997-10-27 1997-10-27 Antenna connection to a printed circuit board Withdrawn GB2330694A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9722659A GB2330694A (en) 1997-10-27 1997-10-27 Antenna connection to a printed circuit board

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB9722659A GB2330694A (en) 1997-10-27 1997-10-27 Antenna connection to a printed circuit board

Publications (2)

Publication Number Publication Date
GB9722659D0 GB9722659D0 (en) 1997-12-24
GB2330694A true GB2330694A (en) 1999-04-28

Family

ID=10821149

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9722659A Withdrawn GB2330694A (en) 1997-10-27 1997-10-27 Antenna connection to a printed circuit board

Country Status (1)

Country Link
GB (1) GB2330694A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2359664A (en) * 2000-01-11 2001-08-29 G Com Internat Ltd Improvements in or relating to antennae
GB2397697A (en) * 2003-01-22 2004-07-28 Roke Manor Research Folded flexible antenna array
EP1662605A1 (en) * 2004-11-25 2006-05-31 Samsung Electronics Co., Ltd. FM transmission antenna device in a portable terminal

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5093761A (en) * 1989-08-21 1992-03-03 O.K Print Corporation Circuit board device
EP0631341A1 (en) * 1993-06-28 1994-12-28 Seiko Instruments Inc. An electric device having a circuit wiring in a band
EP0632683A2 (en) * 1993-07-02 1995-01-04 Sheldahl, Inc. Rigid-flex board with anisotropic interconnect and method of manufacture
JPH07221822A (en) * 1994-02-05 1995-08-18 Kenwood Corp Cordless telephone set
EP0743615A1 (en) * 1995-05-19 1996-11-20 Disys Corporation Radio frequency identification tag

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5093761A (en) * 1989-08-21 1992-03-03 O.K Print Corporation Circuit board device
EP0631341A1 (en) * 1993-06-28 1994-12-28 Seiko Instruments Inc. An electric device having a circuit wiring in a band
EP0632683A2 (en) * 1993-07-02 1995-01-04 Sheldahl, Inc. Rigid-flex board with anisotropic interconnect and method of manufacture
JPH07221822A (en) * 1994-02-05 1995-08-18 Kenwood Corp Cordless telephone set
EP0743615A1 (en) * 1995-05-19 1996-11-20 Disys Corporation Radio frequency identification tag

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2359664A (en) * 2000-01-11 2001-08-29 G Com Internat Ltd Improvements in or relating to antennae
GB2397697A (en) * 2003-01-22 2004-07-28 Roke Manor Research Folded flexible antenna array
EP1662605A1 (en) * 2004-11-25 2006-05-31 Samsung Electronics Co., Ltd. FM transmission antenna device in a portable terminal

Also Published As

Publication number Publication date
GB9722659D0 (en) 1997-12-24

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Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)