EP0295257B1 - Motor vehicle aerial system - Google Patents

Motor vehicle aerial system Download PDF

Info

Publication number
EP0295257B1
EP0295257B1 EP87901567A EP87901567A EP0295257B1 EP 0295257 B1 EP0295257 B1 EP 0295257B1 EP 87901567 A EP87901567 A EP 87901567A EP 87901567 A EP87901567 A EP 87901567A EP 0295257 B1 EP0295257 B1 EP 0295257B1
Authority
EP
European Patent Office
Prior art keywords
wires
bus
window
heater
bar
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.)
Expired - Lifetime
Application number
EP87901567A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0295257A1 (en
Inventor
Jerzy Jacek Kropielnicki
James David Last
Brian Easter
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.)
BSH Industries Ltd
Original Assignee
BSH Industries 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 BSH Industries Ltd filed Critical BSH Industries Ltd
Publication of EP0295257A1 publication Critical patent/EP0295257A1/en
Application granted granted Critical
Publication of EP0295257B1 publication Critical patent/EP0295257B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/28—Adaptation for use in or on aircraft, missiles, satellites, or balloons
    • H01Q1/30—Means for trailing antennas
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/1271—Supports; Mounting means for mounting on windscreens
    • H01Q1/1278—Supports; Mounting means for mounting on windscreens in association with heating wires or layers

Definitions

  • This invention relates to antenna or aerial systems for motor vehicles.
  • U.K. Patent 1520030 describes a system using a bifilar coil which separates RF signals from the usual dc heater circuit for a heated rear window.
  • U.K.Patent 1600987 describes a system using matching and isolating circuitry to enable a heated rear window to be used as a transmitting aerial while dc ger is supplied to the window for heaating purposes.
  • U.K.Patent Application 2152760A describes a system using tuning and isolating circuitry to enable a heated rear window which is essentially aperiodic and non-resonant at VHF frequencies to be used as an efficient VHF receiving aerial while dc power is supplied to the window for heating purposes, the window being brought to series or parallel resonance near the centre of the VHF band by the tuning and isolating circuitry.
  • the described window heater structure corresponds to that conventionally used solely for heating purposes and comprises multiple horizontal wires which connect with bus-bars at opposite upright side edges of the windows, such busbars providing a means of linking the wires to each other and to leads of the heater circuit.
  • This structure can give most heating in the region where this is required (i.e. the horizontal central band of the window) with a relatively small spread of parallel wires ⁇ because the wires run between the busbars along such region.
  • bus-bars Such a small spread of wires is advantageous from the point of view of aerial characteristics because relatively short bus-bars can be used whereby adverse parasitic capacitive and inductive effects can be minimised.
  • bus-bars to avoid intrusion into the field of view it is normally desired to locate the bus-bars as close as possible to the edges of the window and this inevitably gives rise to parasitic capacitance to the body of the vehicle.
  • Parasitic series inductance arises as a function of the length of the bus-bars.
  • a window heater structure having vertical wires i.e wires running in the direction from the bottom edge to the top edge of the window rather than from one side edge to the other side edge
  • vertical wires i.e wires running in the direction from the bottom edge to the top edge of the window rather than from one side edge to the other side edge
  • the parallel wires would have to spread along all or a major part of the window and insofar as this would require the use of relatively long bus-bars it is to be expected that serious problems due to parasitic capacitance and inductance would arise.
  • U.K. patent 1439689 describes the use as an aerial of a heated front window having parallel vertical wires with long top and bottom bus-bars.
  • the main aerial components are not the vertical wires but constitute horizontal parts of the bottom bus-bar, which parts are spaced well away from the edge of the window and are extended to define substantial structures in themselves.
  • EP-A-146339 illustrates schematically, in Fig. 5 thereof, a heated window for use as an aerial having horizontal wires which are straight in their central regions and inwardly inclined at their end regions. There is no reference to the possible use of this arrangement in a vertical disposition.
  • DE-A-3409876 describes a heated window for use as an aerial having vertical wires extending in two sets between a continuous top bus-bar and a divided bottom bus-bar. The wires are straight throughout their lengths.
  • the present invention is based on the realisation that it is in fact feasible to use vertical wire of a heated window as an aerial.
  • a motor vehicle aerial system having a motor vehicle window with a heater structure comprising a series of heater wires running alongside each other between opposite bus-bars, a linking and isolating circuit arranged for linking said heater structure to a d.c. power supply and to radio apparatus of said motor vehicle so that said heater structure can act as an aerial for said radio apparatus whilst it is powered by said d.c. supply to heat said window, said linking circuit is arranged to effect efficient transfer of vertically polarised VHF signals between said radio apparatus and said wires, and wherein said heater wires extend in the vertical direction and are straight or substantially straight in central regions thereof, characterised in that the top and bottom end regions of the said wires are inwardly inclined (i.e.
  • the degree of inclination decreases towards the middle of the window, the separation of adjacent wires is less at their ends than in their central regions, and the length of the associated bus-bars is less than the maximum horizontal separation of the central regions of the two outermost wires.
  • the effective transmission and/or reception of vertically polarised VHF signals can be achieved by used of the vertically extending heater wires.
  • the term vertical is used to mean wires which run in the direction from the bottom edge to the top edge of the window as distinguished from wires which run from one to the other of the window side edges.
  • the window may be sloping and accordingly the wires may be at an angle, possibly a large angle to the true vertical.
  • the inward inclination of the end regions of the wire is such that at at least one end (preferably both) the separation of the ends of the two outermost wires and the length of the associated bus-bar is no greater than one half (and preferably less than one half)of the said maximum horizontal separation.
  • bus-bars terminate at or close to the connections with the outermost heater wires.
  • bus-bar Although the term bus-bar is used, it is possible to use structures which are not straight strips e.g. curved strips or other shapes.
  • a folded configuration whereby one bus-bar is continuous and the other is divided into two lengths so that in use the heater current flows from one divided length through some of the wires to the continuous bus-bar and then back to the other divided length via the other wires.
  • the configuration is symmetrical about a vertical plane between the divided lengths.
  • the heater structure is preferably matched to the radio apparatus (i.e. to the transmitter/receiver and/or the characteristic impedance of the feeder cable which connects the heater structure to the transmitter/receiver) by means of matching and tuning elements of said linking and isolating circuit.
  • Such elements are preferably such as to bring the heater structure including the wires to series or parallel resonance at or near the centre of the VHF bands. Since wires with inclined end regions are used as mentioned above, by selection of a wide range and smooth gradation of the length of the wires a relatively slow variation of aerial impedance with signal frequency can be achieved thereby simplifying the design of even relatively broadband matching circuits. By suitable choice of dimensions for the heater wire pattern the matching circuitry can be made extremely simple or even eliminated.
  • the heater wires are of a conventional nature with regard to thickness and spacing so that manufacture can be effected in a convenient manner using normal production techniques.
  • the bus-bars these are preferably located close to the window edges to minimise intrusion into the field of view. Since an inclined arrangement is used as mentioned above, the possible consequent shortening of the bus-bars permits location close to the vehicle body at the edges of the window without undue parasitic capacitance and series inductance.
  • the linking and isolating circuit of the invention may incorporate any suitable isolating arrangement.
  • a bifilar coil arrangement may be used, as described in the above mentioned prior patent specifications 1520030, 1600987 and 2152760A.
  • this shows a heater structure of a motor car heated rear window 2.
  • the structure comprises multiple thin heater wires embedded in or bonded to the window glass.
  • the wires run between top and bottom bus-bars 17, 18.
  • the bus-bars 17, 18 are in the form of generally straight strips.
  • the top strip 17 is continuous whereas the bottom strip 18 is divided in the middle (at the vertical centre plane) into two parts 18 a , 18 b .
  • All wires are electrically connected at their top ends to the top bus-bar 17.
  • the wires are separated into two equal sets, each being connected at the bottom end to a respective one of the bottom bus-bar parts 18 a , 18 b , thereby giving a 'folded' configuration.
  • Power supply leads 10 are connected to the heater structure at terminals 11 at the spaced inner ends of the two bottom bus-bar parts 18 a , 18 b .
  • the wires 13 of the heater structure 12 have generally straight, parallel vertical central regions 14 and are inclined inwardly (towards the central vertical plane) at their top and bottom end regions 15, 16 and the top and bottom bus-bars 17, 18 are shorter than (by about half) the maximum horizontal spacing of the two outermost wires 13.
  • the arrangement of Figure 2 differs from that of Figure 1 in that the wires 19 of the heater structure 20 have end regions 21, 22 with inclinations which are greater, and the bus-bars 23, 24a, 24b are much shorter.
  • These bus-bars 23, 24 may be slightly curved rather than straight strip shaped to accommodate the close connections of the wire 19.
  • Figs. 1 and 2 are all symmetrical about the vertical central plane (i.e. both the vertical wires and the bus-bars are symmetrical) and it will be noted that the bus-bars are as short as possible (i.e. they terminate level with the connections to the outermost wires) and they are very close to the top and bottom window edges.
  • Fig. 3 shows the circuitry 25 used to connect a window heater structure of the kind shown in any one of Figs. 1 and 2 (although the configuration of Fig. 1 is illustrated) to radio apparatus having a VHF receiver and/or transmitter and if desired also an AM receiver.
  • the power supply leads from the heater terminals 11 are connected to inputs 26 of the circuitry which is within a housing which is located as close as possible to the terminals 11.
  • the circuitry 25 has an earth connection 27 which is connected to the vehicle earth, a power supply connection 28 which is connected to the vehicle dc power supply, and VHF and AM aerial outputs 29, 30 which are connected to an aerial feeder cables of radio apparatus via an inductance/capacitance arrangement 31 which recombines the VHF/am signals.
  • the circuitry 25 comprises two VHF chokes 23, 24 (which may be coupled as windings of a bifilar coil) in series with coupled windings 35, 36 of a ferrite pot cored bifilar coil interposed between the inputs 26 and the outputs 27, 28 whereby dc power can flow freely to the heater structure 12 (when switched on) to heat the window 2.
  • the isolated AM signals are fed to the AM output 30 via an optional AM preamplification stage 40 of the circuitry 25.
  • the capacitor 38 of the VHF isolating part of the circuitry 25 is connected to the VHF output 29 via a matching and tuning circuit 41.
  • the heater is not designed to be an antenna which is periodic and resonant at VHF frequencies and matching and tuning is necessary to give efficient operation of a VHF transmitter and/or receiver connected to the output.
  • the matching and tuning circuit is preferably such as to bring the heater structure 12 and particularly the vertical wires 13 to resonance at or near the centre of the VHF operating band of frequencies.
  • the two terminals 11 of the heater are coupled together via the capacitor 37 which has negigible impedance at the frequencies at which the aerial is to be used.
  • a reactive tuning element 42 inductance or capacitance
  • the series-tuned matching circuit a reactive tuning element (the capacitance 38 alone or in series with an inductance 43) is connected in series with one (or both) of the heating structure terminals 11 so that the input impedance of the combination is resonant at the centre freqnency of the operating band of frquencies.
  • the impedance of the resonant arrangement achieved in either the parallel-tuned or series-tuned circuit is then transformed to the desired terminal value by means of a tuned (or untuned) transformer 44.
  • the arrangement need not be symmetrical about the division in the bottom bus-bar but instead may have a degree of asymmetry.
  • a continuous, rather than divided bottom bus-bar may be used in which case connections are taken from the top and bottom bus-bars respectively with, an appropriate compensatory filter arrangement as required.
  • the bifilar coil other isolating arrangements involving mutually coupled coils or the like may be used as described in the prior patent specification referred to.
  • Capacitor 37 gives common mode operation. Where common mode operation is not desired, capacitor 37 would be omitted. Thus, capacitor 37 would be omitted whore diversity reception or transmission is required as described in U.K.Patent Application No. 2173644A. That is, capacitor 37 would be omitted where the heater wires are to be used as a radio aerial in two different configurations permitting diversity reception or transmission. As described in the above mentioned application, in this context, provision is made for switching between the two configurations so that fading in one configuration can be compensated by better receiving or transmitting characteristics in the other. The two configurations may be separated by a centre-tapped transformer which gives balanced and unbalanced aerial characteristics. A switching circuit may be provided to switch repeatedly between the two configurations. Alternatively, switching may be effected under the control of a circuit which monitors signal strengths.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Astronomy & Astrophysics (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • General Physics & Mathematics (AREA)
  • Remote Sensing (AREA)
  • Details Of Aerials (AREA)
EP87901567A 1986-03-05 1987-03-04 Motor vehicle aerial system Expired - Lifetime EP0295257B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8605381A GB2173644B (en) 1985-03-30 1986-03-05 Signal separating device
GB8605381 1986-03-05

Publications (2)

Publication Number Publication Date
EP0295257A1 EP0295257A1 (en) 1988-12-21
EP0295257B1 true EP0295257B1 (en) 1991-09-25

Family

ID=10594052

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87901567A Expired - Lifetime EP0295257B1 (en) 1986-03-05 1987-03-04 Motor vehicle aerial system

Country Status (7)

Country Link
EP (1) EP0295257B1 (ja)
JP (2) JPH01501747A (ja)
KR (1) KR880701026A (ja)
BR (1) BR8707627A (ja)
DE (1) DE3773378D1 (ja)
GB (2) GB2173644B (ja)
WO (1) WO1987005446A1 (ja)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0277910U (ja) * 1988-08-24 1990-06-14
JPH0722892Y2 (ja) * 1988-11-22 1995-05-24 日本板硝子株式会社 自動車用受信装置

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1510158A (fr) * 1966-12-09 1968-01-19 Saint Gobain Antenne
FR2250329A5 (ja) * 1973-10-31 1975-05-30 Saint Gobain
JPS50102492A (ja) * 1974-01-14 1975-08-13
DE2440439A1 (de) * 1974-08-23 1976-03-04 Delog Detag Flachglas Ag Kraftfahrzeug mit antennenscheibe
IT1115050B (it) * 1979-02-26 1986-02-03 Siv Soc Italiana Vetro Lunotto termico a riscaldamento accelerato
JPS5723449A (en) * 1980-07-18 1982-02-06 Toshiba Corp Electron gun for cathode ray tube
JPS57188102A (en) * 1981-05-15 1982-11-19 Asahi Glass Co Ltd Glass antenna for automobile
JPS5817705A (ja) * 1981-07-23 1983-02-02 Mazda Motor Corp 自動車の窓ガラス加熱用導電線を兼ねたアンテナ
JPS6021005A (ja) * 1983-07-15 1985-02-02 Nippon Telegr & Teleph Corp <Ntt> 金属被覆フアイバの金属被覆除去方法
DE146339T1 (de) * 1983-12-20 1985-11-21 Bsh Electronics Ltd., Manchester Trennungsvorrichtung fuer elektrisches signal mit isolierungs- und anpassungsschaltung.
GB8402244D0 (en) * 1984-01-27 1984-02-29 Pilkington Brothers Plc Glass window
DE3409876A1 (de) * 1984-03-17 1985-09-19 Robert Bosch Gmbh, 7000 Stuttgart Heizscheibenantenne
GB8508402D0 (en) * 1985-03-30 1985-05-09 Bsh Electronics Ltd Signal separating device

Also Published As

Publication number Publication date
GB8605381D0 (en) 1986-04-09
BR8707627A (pt) 1989-03-14
EP0295257A1 (en) 1988-12-21
GB8820753D0 (en) 1988-10-26
KR880701026A (ko) 1988-04-13
GB2209876A (en) 1989-05-24
DE3773378D1 (de) 1991-10-31
GB2173644A (en) 1986-10-15
JPH0681113U (ja) 1994-11-15
JPH01501747A (ja) 1989-06-15
JP2565669Y2 (ja) 1998-03-18
GB2173644B (en) 1989-06-28
GB2209876B (en) 1989-12-28
WO1987005446A1 (en) 1987-09-11

Similar Documents

Publication Publication Date Title
KR100386994B1 (ko) 차량용유리안테나장치
US5905468A (en) Glass antenna device for vehicles
US3972048A (en) FM-AM windshield antenna
US5266960A (en) Pane antenna having at least one wire-like antenna conductor combined with a set of heating wires
US4928108A (en) Electrical signal separating device having isolating and matching circuitry for split passband matching
US5801663A (en) Pane antenna having at least one wire-like antenna conductor combined with a set of heating wires
KR100349260B1 (ko) 안테나
JPH09172315A (ja) 広帯域ｆｍ受信を有するａｍ／ｆｍ車両ラジオ用バックライト・アンテナ
EP0197650B1 (en) Signal separating device
US5790079A (en) Backlite antenna for AM/FM automobile radio
EP0295257B1 (en) Motor vehicle aerial system
EP0346089B1 (en) Reception system
JPH1079615A (ja) 車両用ガラスアンテナ装置
EP0456337A2 (en) Radio receiver antenna systems
EP1301963B1 (en) Antenna
JPS61121603A (ja) 自動車用窓ガラスアンテナ
JPH11205023A (ja) 車両用ガラスアンテナ装置
EP0885485A1 (en) Antenna arrangement
JPH03254206A (ja) 窓ガラスアンテナを使用した受信装置
JPH08321711A (ja) 高周波用ガラスアンテナ及び高周波用ダイバーシティガラスアンテナ
EP0438247B1 (en) Antenna apparatus for a motor vehicle
JPS63292702A (ja) 除曇ヒ−タ線付き自動車用窓ガラス
JP2000252732A (ja) 自動車用ガラスアンテナ
JPH0611673Y2 (ja) 自動車用受信装置
JPH03254205A (ja) 自動車用ダイバーシティ受信装置

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19880902

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB IT SE

17Q First examination report despatched

Effective date: 19891005

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB IT SE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 19910925

Ref country code: SE

Effective date: 19910925

REF Corresponds to:

Ref document number: 3773378

Country of ref document: DE

Date of ref document: 19911031

RBV Designated contracting states (corrected)

Designated state(s): DE FR IT SE

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: BSH INDUSTRIES LIMITED

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20010315

Year of fee payment: 15

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20010327

Year of fee payment: 15

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20021001

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20021129

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST