WO2002050949A9

WO2002050949A9 - Integrated dual function circuitry and antenna system

Info

Publication number: WO2002050949A9
Application number: PCT/US2001/048978
Authority: WO
Inventors: Thomas Marx
Original assignee: Textron Automotive Co Inc; Thomas Marx
Priority date: 2000-12-18
Filing date: 2001-12-18
Publication date: 2003-07-17
Also published as: US7113136B2; US20040080459A1; WO2002050949A1; AU2002234045A1

Abstract

A trim panel for a vehicle containing a vehicular antenna system comprising a substrate, an outer skin and a foam disposed between the substrate and the outer skin. An antenna/circuitry system (2) is located on the upper surface of the substrate (1) and is in contact with the urethane foam (7), the antenna/circuitry system (2) comprising an insulating base layer (12) including upper and lower surfaces and an electro-conductive antenna layer on the upper surface of the base layer (12) and an electro-conductive circuit layer on the lower surface of the base layer (12).

Description

INTEGRATED DUAL FUNCTION CIRCUITRY

AND ANTENNA SYSTEM Field of the Invention

This invention relates to an integrated antenna system suitable for vehicular

use. hi such regard, a complete vehicle antenna system is disclosed that can be

integrated with one or more other vehicle components and, in particular, with interior components such as the instrument panel. The invention also relates to an antenna

system which is integrated with a flexible printed circuit or other flat wire which

replaces current wire harness construction (i.e. with round wire) in providing an

electrical circuit routing electric current between one or more connected electrical devices. Such an antemia with the flexible printed circuit may also be integrated with

one or more other vehicle components and, in particular, with interior components such as the instrument panel.

Background of the Invention general, two forms of automotive antennas find widespread use, i.e., the

mast antenna and the windshield antenna. The mast antenna comprises a rod conductor projecting from the vehicle body. It is fairly well established that the mast

antenna is subject to deterioration', by exposure, is prone to damage from external

objects, and is easy prey for vandals. Further, mast antennas may detract from the aesthetic appearance of the vehicle. Of course, the mast antenna may be powered to retract, which adds cost to the vehicle.

Windshield antennas make use of one or more thin conductors embedded

within the windshield of the automobile. Windshield antennas are also susceptible to their own problems, such as unnecessary replacement simply because the glass has

been damaged. In addition, windshield antennas are reportedly susceptible to various

forms of FM distortion, such as "station swapping" and may be sensitive to the

direction of vehicle travel. Moreover, operation of the windshield washers may create

undesirable effects upon the performance of a windshield antemia including the

generation of noise. Furthermore, by mounting the antenna on the exterior or interior

of the vehicle as separate components or integrating the antenna into window glass, a

need is developed to route antenna cables between the electronic component and the

antenna location. Such antenna cable is typically installed and connected by the auto manufacturer during assembly of the vehicle.

In related context, current vehicle electrical systems also require the

manufacturer to route a wire harness throughout the vehicle body, and more specifically, through the instrument panel cockpit system. Such wire harnesses are generally bulky, expensive, heavy, difficult to install and often a source of a variety of

warranty problems .

Attention is directed to the following U.S. Patents and the art cited therein to

provide an even broader consideration of the variety of problems and solutions that

have been proposed to date to improve upon antenna placement and/or wiring within

an automotive environment: U.S. Patent No. 3,896,448 "Instrument Panel Radio Antenna"; 4,758,166 "Concealed Radio Antenna"; 4,853,793 "Microstrip Antenna with Stripline And Amplifier"; 5,811,732 "Modular Wiring System for Vehicle Instrument Panel Wire"; 5,861,857 "Vehicular Windshield Wiper Antenna System"; 6,081,239 "Planar Antenna Including A Superstate Lens Having An Effective

Dielectric Constant"; and 6, 144,343 "Display Antenna Center".

It is therefore an object of this invention to provide a remedy to the problems noted above in addition to the development of an vehicular antenna system that

provides some unique advantages not reported in the prior art to date.

Summary of the Invention

A trim panel for a vehicle containing a vehicular antenna system comprising a

substrate, an outer skin and a foam disposed between the substrate and the outer skin. An antemia/circuitry system is located on the upper surface of the substrate and is in

contact with the urethane foam, the antenna/circuitry system comprising an insulating

base layer including upper and lower surfaces and an electro-conductive antenna layer on the upper surface of the base layer and an electro-conductive circuit layer on the lower surface of the base layer.

Brief Description of the Drawings

These and other objects, features and advantages of the invention will become apparent upon consideration of the description of the invention and the appended

drawings in which:

Figure 1 is a representative exploded perspective view of an exemplary vehicle instrument panel which contains the invention.

Figure 2 is a representative cross-sectional view taken through the

antenna/circuit system. Figure 3 is a representative cross-sectional view of one type of instrument

panel construction of the invention.

The above and other objects, features and advantages of the present invention

will be apparent in the following detailed description thereof when read in conjunction

with the appended drawings wherein the same reference characters denote the same or

similar paths throughout the several views.

Description of the Preferred Embodiments For elements common to the various embodiments of the invention, the

numerical reference character between the embodiments is held constant, but

distinguished by the addition of an alphanumeric character to the existing numerical

reference character, i other words, for example, an element referenced at 10 in the

first embodiment is correspondingly referenced at 10A, 10B, and so forth in

subsequent embodiments. Thus, where an embodiment description uses a reference

character to refer to an element, the reference character applies equally to other

embodiments as distinguished by alphanumeric character.

Attention is now directed to FIG. 1, which best illustrates a preferred

embodiment of the subject invention. As shown therein, the rigid substrate 1 is

designed to accommodate the dual-function antenna/circuitry system. The dual-

function antemia/circuitry system 2 is then mounted on the rigid substrate, followed by

incorporation of the skin/foam layer 3 to form the instrument panel. In this manner,

the dual-function antenna/circuitry system is retained as to not rattle and comply with

NVH (noise, vibration, harshness) requirements and BSR (buzz, squeak, rattle)

requirements. As can be seen, the upper (topside) surface 13 of the antenna/circuitry system

2 comprises the antenna array, suitable for reception of radio transmissions, cellular

phone frequencies, global positioning systems (GPS) and other miscellaneous transmissions, such as locking/unlocking signals, keyless ignition, alarm, wireless

internet access, etc. Placement of the antenna array on the upper (topside) surface

maximizes the efficiency of signal reception. On the bottom side 14 of the

antenna/circuitry system 2 is located the electro-conductive circuitry which would

replace all or part of the electrical wire harness that supplies power in the vehicle

dashboard area. Inclusion of flexible printed circuitry into vehicle interior trim panels is disclosed in U.S. Patent Application Serial Nos. 09/625,113 and 09/625,117 to the

same assignee as this invention and are incorporated herein by reference. Trim panels are generally multi-layered components formed by a variety of

processes including but not limited to, injection molding, blow-molding, lamination,

foaming-in-place, thermo forming, etc. The preferred construction consists of a

skin/foam/substrate construction as shown in FIGS. 1 and 2. To include the

antenna/circuitry system of the present invention into a trim panel of this type, the

antenna/circuitry system 2 is attached to or through the instrument panel substrate 1 by

adhesive or other mechanical attachment means known to those skilled in the art. The

antenna circuitry system 2 may also be fitted into a slightly recessed area of the top

surface of the substrate 1 for attachment and location. Alternatively, as shown in

FIG. 1, extensions 4, 4' and 4" of the antenna circuitry/system 2 may be provided to

include connectors (not shown) which are passed through slotted openings 5, 5' and 5" in the substrate which also serve to locate and attach the antenna circuitry system

to the substrate. The connectors (not shown) are used to connect the antenna and electrical

circuitry to the radio and other electrical devices in the cockpit area of the vehicle. As

shown in FIG. 1, typical locations include, but are not limited to, the

speedometer/gauge area 5 and the passenger side air bag area 5". For connection to

the radio through slot 5', the antenna electro-conductive layer 13 can be configured

such that the impedance for the receiver and antenna match, minimizing power loss. The antenna/circuitry system is included in the construction of the instrument

panel 20 in a manner known to those skilled in the art, by mounting the substrate 1

containing the antenna/circuitry system 2 to the lid of a foaming mold, placing a skin

6 (see FIG. 3) into the corresponding cavity of a foaming mold and dispensing

urethane foam precursor between the substrate 1A and skin 6. The foam precursor

expands to fill the cavity between the skin and substrate at least partially or fully

encapsulating the antenna/circuitry system 2B in a cellular foam layer 7. In FIG. 3,

the antenna/circuitry system 2B is on the surface of the substrate 1A, and in contact

and/or embedded in the urethane foam 7. It can therefore be appreciated that the foam

layer 7 in contact with the antenna/circuitry system 2B can serve to immobilize and

locate the antenna/circuitry system in a convenient manner. As alluded to above with respect to the use of a recess in the top surface of the substrate, other constructions may include thermoforming a grained skin/foam laminate directly over the substrate in which the antenna/circuitry system has been

counter-sunk into a corresponding groove or shallow depression on the surface of the substrate. In this manner the antenna/circuitry system substantially fills in the groove

or depression to yield a substantially smooth surface over which the skin foam

laminate can be formed. Polymeric materials are preferred for the skin 6, foam 7 and

or substrate 1A, as they are substantially transparent to electromagnetic radio wave

energy. Such polymer materials for the skin 6 include polyurethanes and poly(vinyl chloride) type materials. Suitable polymer materials for the foam layer also include

the polyurethanes. The substrate may be prepared from acrylonitrile-butadiene-

styrene (ABS) type materials, and blends thereof with materials such as polycarbonate.

Turning to FIG. 2, the construction of another preferred antenna/circuitry

system 2A is shown. The system comprises a multilayer structure which includes a

base layer 12 made up of an insulator such as a polyimide, a first antenna pattern layer

13 comprising an electro-conductive film, such as a copper film, formed on the upper

side of base layer 12 and a first circuit pattern layer 14 comprising an electro-

conductive film, such as a copper film, formed on the lower side of base 12, a first

cover layer 12' made up of an insulator such as a polyimide located on the upper

surface of the antenna pattern layer 13 and a second cover layer 12" made up of an

insulator such as a polyimide located on the lower side of circuit pattern layer 14.

In accordance with the above, it can be appreciated by those of skill in the art

that the use of a base layer 12 of polyimide, and a first antenna pattern layer 13

comprising copper film, and a first circuit pattern 14 also of copper film, creates a flexible antenna/circuitry system in the sense that such system can be flexed without

disrupting the conductivity and performance of the copper film and will readily configure and locate on the upper surface of a vehicle substrate. In such regard, the

antenna/circuitry system herein can alter its shape to adjust to the varying contours of

a trim panel substrate, and then be uniquely immobilized on the substrate, when

positioned under the instrument panel skin layer and within the foam layer, as previously described.

h yet other methods of integration, the dual purpose electrical and antenna

system could be fastened (e.g. mechanically) or bonded (e.g. adhesive, welded) or otherwise affixed or connected to another supporting vehicle component (i.e. a

component which would physically provide support to the dual purpose electrical and

antenna system in its use state). For example, the dual purpose electrical and antenna

system could be mounted to the interior surface of the instrument panel substrate, a rear package shelf, a pillar trim panel, a headliner, an exterior cowl panel, etc.

In sum, several advantages are now possible via the use of the present

invention, which are summarized below:

• an antenna system that is upwardly facing through the front window of the

vehicle thereby providing maximum exposure to radio signal reception;

• the reduction in cost necessary to manufacture window glass antennae;

• the elimination of exterior antenna components;

• the elimination of costly antenna leads between the radio and current antenna systems;

• the elimination of antenna cable installation in vehicular assembly plants;

• the elimination of the need to seal external antenna components against the

environment; • the elimination of conventional wire harnessing in instrument panel

assembly;

• the elimination of wire harness assembly requirements;

• the reduction in warranty claims as related to wire harness and antenna

system performance;

• the reduction in cost of the electrical system;

• the reduction in weight of the vehicular electrical system;

• increased usable space in the instrument panel assembly; and

• the elimination of associated wire harness and antenna connectors.

Finally, in the context of the present invention, it can be appreciated that the

specific antenna/circuitry combination for the instrument panel can be customized for each vehicle dependent upon vehicle design requirements. In addition, once the vehicle design is considered, the antenna/circuitry combination herein can itself be

adjusted to maximize its broadband characteristics so that it will efficiently receive

and/or transmit as necessary. In such regard, antenna length can be conveniently

varied across the instrument panel surface in length/width and/or depth from the

surface to optimize transmission and reception functionality.

Claims

We claim:

1. A trim panel for a vehicle containing a vehicular antenna

system comprising: a substrate;

an outer skin; a foam disposed between said substrate and said outer skin;

an antenna/circuitry system located on the upper surface of said

substrate in contact with said foam, said antenna/circuitry system comprising printed circuitry comprising an insulating base layer with an upper and lower surface, an electro-conductive antenna layer on the upper surface of said base layer, an electro-

conductive circuit layer on the lower surface of said base layer, said electro- conductive circuit layer providing a source of electrical current for said vehicle; and

a first insulating cover layer on the upper surface of said antenna electro- conductive layer and a second insulating cover layer on the lower surface of said

electro-conductive circuit layer.

2. The trim panel of claim 1 wherein said antenna layer comprises copper.

3. The trim panel of claim 1 wherein said flexible circuit layer comprises copper.

4. The trim panel of claim 1 wherein said insulating base layer comprises a polyimide.

5. The trim panel of claim 1 wherein said first and second insulating cover layers comprise a polyimide.

6. The trim panel of claim 1 wherein said electro-conductive antenna layer and said electro-conductive circuit layer are connected to a radio in said vehicle.

7. The trim panel of claim 6, wherein said electro-conductive antenna

layer has an impedence, and said radio has an impedence, and said electro-conductive

antenna layer is configured to match said radio impedence.

8. The trim panel of claim 1 wherein said electro-conductive antenna

layer is configured to receive one or more of a radio transmission, a cellular phone

frequency, a global positioning transmission, a locking/unlocking signal for said

vehicle, a keyless ignition frequency and/or a wireless internet access transmission.

9. A trim panel for a vehicle containing a vehicular antenna system

comprising: a substrate;

an outer skin;

foam disposed between said substrate and said outer skin; an antenna/circuitry system located on the upper surface of said

substrate in contact with said urethane foam, said antenna/circuitry system comprising

an insulating base layer including upper and lower surfaces and an electro-conductive

antenna layer on the upper surface of said base layer and an electro-conductive circuit layer on said lower surface of said base layer.

10. The trim panel of claim 9 wherein said antemia layer comprises copper.

11. The trim panel of claim 9 wherein said circuit layer comprises copper.

12. The trim panel of claim 9 wherein said insulating base layer comprises a polyimide.

13. The trim panel of claim 9 including a first insulating cover layer on

said antenna electro-conductive layer and a second insulating cover layer on said

electro-conductive circuit layer.

14. A trim panel for a vehicle containing a vehicular antenna system

comprising

a substrate containing a recessed portion; an outer skin;

a foam disposed between said substrate and said outer skin;

an antenna/circuitry system located within said recessed portion of substrate

and covered by said urethane foam;

said antenna/circuitry system comprising an insulating base layer including upper and lower surfaces and an electro-conductive antenna layer on the upper surface

of said base layer and an electro-conductive circuit layer on said lower surface of said base layer.