WO2000070708A1 - Dispositif antenne de vitre pour vehicule et recepteur radio l'utilisant - Google Patents

Dispositif antenne de vitre pour vehicule et recepteur radio l'utilisant Download PDF

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Publication number
WO2000070708A1
WO2000070708A1 PCT/JP2000/002827 JP0002827W WO0070708A1 WO 2000070708 A1 WO2000070708 A1 WO 2000070708A1 JP 0002827 W JP0002827 W JP 0002827W WO 0070708 A1 WO0070708 A1 WO 0070708A1
Authority
WO
WIPO (PCT)
Prior art keywords
antenna
window glass
heater unit
antenna device
vehicle window
Prior art date
Application number
PCT/JP2000/002827
Other languages
English (en)
Inventor
Hitoshi Kakizawa
Original Assignee
Nippon Sheet Glass Co., 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 Nippon Sheet Glass Co., Ltd. filed Critical Nippon Sheet Glass Co., Ltd.
Priority to CA002373258A priority Critical patent/CA2373258C/fr
Priority to DE60018917T priority patent/DE60018917T2/de
Priority to EP00922904A priority patent/EP1177596B1/fr
Priority to AU43152/00A priority patent/AU762198B2/en
Priority to JP2000619055A priority patent/JP4112807B2/ja
Publication of WO2000070708A1 publication Critical patent/WO2000070708A1/fr

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q21/00—Antenna arrays or systems
    • H01Q21/30—Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
    • 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
    • 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
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
    • H01Q5/40—Imbricated or interleaved structures; Combined or electromagnetically coupled arrangements, e.g. comprising two or more non-connected fed radiating elements
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
    • H01Q5/50—Feeding or matching arrangements for broad-band or multi-band operation

Definitions

  • the present invention relates to glass antenna devices for use on motor vehicles and radio receiver apparatus using such glass antenna devices.
  • glass antenna devices which comprise antenna conductor elements formed on a window glass of a motor vehicle, are being used more popularly than the traditional rod antennas primarily due to the facts that the glass antenna devices are esthetically superior because they not protrude outside the motor vehicle, they are very unlikely to be damaged, and they do not produce air-cutting sounds .
  • the glass antenna device is installed on a vehicle's rear window glass where a defogging heater unit is provided; thus, the antenna conductor elements must be provided on a limited area of the rear window glass, so as not to overlap the defogging heater unit.
  • the glass antenna device is to be provided for radio communications using the AM, FM, TV, cellular telephone frequency bands, etc.
  • designing and adjusting the glass antenna device tend to be cumbersome and time-consuming work.
  • the antennal pattern would become very complicated in structure (see, for example, Japanese Utility Model Publication No. HEI-1-59309) .
  • the receiving sensitivity in the AM band is generally proportional to the area occupied by the AM antenna pattern on the vehicle window glass, it is important to reserve a large area for the antenna pattern on the window glass if high receiving sensitivity is to be obtained.
  • the defogging heater unit it has been proposed to arrange the defogging heater unit to also function as an AM antenna on the vehicle rear window; however, using the defogging heater unit directly as the AM antenna would produce a problem of unwanted noise and thus can not suit practical use.
  • some of the known vehicle glass antenna devices employ, in between a power source and the defogging heater unit, a choke coil capable of bearing great electric currents so that the heater unit can be used also as an AM antenna, as typically disclosed in Japanese Patent Laid- Open Publication No. SHO-56-42401.
  • a dual-purpose glass antenna device capable of receiving both AM signals and FM signals using the above-mentioned arrangements (e.g., Japanese Patent Laid-Open Publication No. SHO-57 -188102 ) .
  • Japanese Utility Model Publication No. SHO- 59-3604 discloses such a sophisticated vehicle glass antenna device.
  • the disclosed vehicle glass antenna device 101 is installed on a vehicle rear window glass 102 and includes an AM antenna 104 provided above a defogging heater unit or defogger 103.
  • the defogger 103 is arranged to also function as an FM antenna 105, and the AM antenna 104 and FM antenna 105 are connected to a radio receiver apparatus (not shown) via respective amplifiers 108 and 109.
  • the defogger 103 and a power feeding point 105b are connected in series with each other via a lead 120.
  • the No. SHO-59-3604 publication has a description which reads "the above-mentioned defogger is connected to a lead of a suitable length such that an impedance matching is effected to allow the defogger to work as an FM antenna section".
  • No subsidiary FM antenna is provided in the vehicle glass antenna device according to the No. SHO-59-3604 publication.
  • U.S. Patent No. 4,791,426 discloses an antenna device provided on a rear window glass of a motor vehicle.
  • the disclosed antenna device 201 includes an antenna 204 for reception of long-wave, medium-wave and shortwave signals, and a plurality of defogging heater elements 203 capable of also functioning as an antenna 205 for reception of ultra-short-wave signals.
  • the signals received via the antennas 204 and 205 are coupled via respective amplifiers 208 and 209 to a radio receiver apparatus (not shown).
  • reference numeral 210 represents a frequency separator.
  • Japanese Patent Laid-open Publication No. SHO- 53-97353 teaches an antenna device where a field effect transistor is connected to a glass antenna and used as a preamplifier to minimize spurious reception.
  • the defogger is used also as the FM antenna, which, however, is not practical because power is supplied to the defogger directly from the power feeding point 205b and thus a sufficient FM receiving sensitivity can not be attained.
  • the defogger is used as the FM antenna 105 without such a choke coil provided between the defogger and the power source. Unlike in the AM frequency band, the defogger may be allowed to operate properly in the FM frequency band without the provision of the choke coil. However, because the defogger and power feeding point 105b are connected directly by the lead 120, there would arise the problem that a sufficient FM receiving sensitivity can not be attained. Thus, currently, the antenna device as disclosed in Japanese Utility Model Publication No. SHO-59-3604 has not yet been put to actual use. In addition, as shown in Fig. 11, the lead 120 has a length greater than one half of the width of the window glass.
  • the amplifiers may produce an unwanted distortion in their output FM signals due to an excessive gain when the input or received FM signals are of high level (great electric field intensity).
  • the glass antenna devices with amplifiers would present the problem that, these FM signals may be mutually modulated with each other and a resultant mutually-modulated signal, corresponding to a difference between the close frequencies, may assume a frequency belong to the AM frequency band and thereby exert undesired influences on the reception of FM signals.
  • a first object of the present invention to provide a vehicle window glass antenna device which is cable of receiving AM and FM waves with high sensitivity without using a choke coil.
  • a vehicle window glass antenna device which comprises: a defogging heater unit provided on a window glass of a vehicle; an AM antenna provided above the defogging heater unit for receiving a signal of an AM frequency band; an FM antenna provided between the defogging heater unit and the AM antenna for receiving a signal of an FM frequency band, the FM antenna comprising a single horizontal antenna conductor element; an AM amplifier for amplifying the signal received via the AM antenna; and an FM amplifier for amplifying the signal received via the FM antenna.
  • the defogging heater unit is capacitively coupled with the FM antenna to function as a subsidiary FM antenna.
  • the vehicle window glass antenna device of the present invention may further comprise a separate subsidiary FM antenna provided below the defogging heater unit.
  • the subsidiary FM antenna constitutes a diversity antenna with the above-mentioned FM antenna provided between the defogging heater unit and the AM antenna functioning as a main antenna.
  • the AM antenna employed in the inventive vehicle window glass antenna device may comprise a plurality of horizontal antenna conductor elements.
  • the horizontal antenna conductor elements of the AM antenna each have a length in the range of 800 mm to 1,300 mm.
  • the AM antenna may also include a short-circuiting line interconnecting the plurality of horizontal antenna conductor elements.
  • the defogging heater unit may comprise a plurality of heater lines and a short-circuiting line interconnecting these heater lines.
  • the AM amplifier comprise an electric circuit including a common-source FET (Field Effect
  • AM amplifier may include a choke coil provided at its output stage and have an output impedance of 100 ⁇ or less.
  • the FM amplifier comprises an electric circuit including a grounded-base transistor or grounded-gate FET.
  • the FM amplifier has an input impedance of 50 ⁇ or less.
  • the FM amplifier preferably has a gain of 3 dB or less.
  • the FM amplifier may include, at its output stage, a filter in the form of a tank circuit which acts to prevent generation of a mutually-modulated signal of the AM frequency band through a mutual modulation between a plurality of output FM signals from the FM amplifier.
  • a radio receiver apparatus for a vehicle which comprises : a defogging heater unit provided on a window glass of a vehicle; an AM antenna provided above the defogging heater unit for receiving a signal of an AM frequency band; an
  • AM antenna for receiving a signal of an FM frequency band
  • FM antenna comprising a single horizontal antenna conductor element; an AM amplifier for amplifying the signal received via the AM antenna; an FM amplifier for amplifying the signal received via the FM antenna; and a radio receiver connected with respective output terminals of the AM amplifier and FM amplifier via a signal-transmitting cable having a diameter of 3 mm or less.
  • the signal-transmitting cable have an impedance of 75 ⁇ or less.
  • the present invention is based on the following basic designing policies.
  • each of the AM and FM antennas is designed as a dedicated simple antenna pattern so that basic designing and adjustment of the AM and FM antennas can be substantially facilitated.
  • the defogging heater unit is equipped with no choke coil and therefore can not be used as an AM antenna in the present invention.
  • a separate AM antenna pattern having as large an area as possible is provided in a space above the defogging heater unit in such a manner that the AM antenna pattern is not capacitively coupled with the defogging heater unit.
  • Lowering the impedance of the AM antenna is very effective in enhancing the receiving sensitivity of the AM antenna.
  • the area and length of the AM antenna conductor pattern be maximized so as to provide a greatest possible antenna capacity.
  • the AM antenna pattern having as large an area as possible is provided in a space above the defogging heater unit in such a manner that the AM antenna pattern is not capacitively coupled with the defogging heater unit.
  • the AM antenna comprise a plurality of horizontal antenna conductor elements connected together to constitute a fork-shaped AM antenna pattern.
  • the AM antenna may comprise a plurality of antenna conductor elements connected to form a loop-shaped AM antenna pattern.
  • the fork-shaped or loop-shaped AM antenna pattern include a short-circuiting line extending centrally across the antenna pattern.
  • the AM antenna pattern it is preferable that the AM antenna pattern have as large an area as possible, as noted earlier. Flexibility in choosing a vertical dimension of the AM antenna pattern is limited inevitably by factors such as the size of the vehicle window glass, region where the defogging heater unit is installed and necessary spacings between the AM antenna, FM antenna and defogging heater unit. Thus, to maximize the area of the AM antenna pattern as desired, the horizontal dimension or length of the antenna pattern has to be increased.
  • the FM antenna is constructed as follows.
  • the inventive glass antenna device includes a single horizontal FM antenna conductor element disposed between the defogging heater unit and the AM antenna.
  • the reasons why the FM antenna comprises only one horizontal antenna conductor element are to make the shape of the FM antenna as simple as possible in order to facilitate necessary adjustment of the FM antenna, and to make the area of the FM antenna as small as possible in order to allow the area of the AM antenna to be maximized.
  • the FM frequency band is 76 - 90 MHZ in Japan and 88 - 108 MHZ in North America, and the designed wavelength is selected from among such FM frequency bands.
  • the FM antenna pattern be capacitively coupled with the defogging heater unit.
  • the inventive glass antenna device includes no choke coil between the defogging heater unit and a power source.
  • the inventive glass antenna device where the FM antenna pattern and defogging heater unit are capacitively coupled with each other, there would not arise the inconveniences as presented by the device of Japanese Utility Model Publication No. SHO-59-3604 having been discussed earlier, and the defogging heater unit can be used appropriately as a subsidiary FM antenna.
  • the inventive glass antenna device achieves an enhanced FM-wave receiving sensitivity. Because the FM antenna pattern and defogging heater unit are capacitively coupled with each other, the above-mentioned contraction ratio must be determined taking the antenna's coupling capacitance into account.
  • the FM antenna employed in the inventive glass antenna device comprises only a single horizontal antenna conductor element that is therefore very simple in construction.
  • the vehicle window glass antenna device of the invention can be used appropriately in various places or destinations of different frequency bands, by just modifying its frequency setting and changing the length of the FM antenna. Namely, with the inventive vehicle window glass antenna device, there is no need to change or adjust the shape of the FM antenna.
  • the subsidiary FM antenna may be constructed to function as a diversity antenna with the FM antenna provided between the defogging heater unit and the AM antenna functioning as a main antenna.
  • a subsidiary FM antenna comprises a single horizontal antenna conductor element, for the same reason as stated above in relation to the main FM antenna.
  • the subsidiary FM antenna may also be capacitively linked with the defogging heater unit. The length of this subsidiary FM antenna may also be determined in the same manner as set forth above in relation to the main FM antenna.
  • the defogging heater unit include a short- circuiting line extending substantially centrally across its heater elements or lines to interconnect the heater lines at their substantial central points.
  • the short-circuiting line acts to control coupling, in a high-frequency operating state, of distributed capacitance of the main FM antenna, defogging heater unit and subsidiary FM antenna, to thereby enhance the overall receiving sensitivity of the FM antennas.
  • Two or more short-circuiting lines, rather than just one, may be provided in the defogging heater unit.
  • the AM amplifier employed in the inventive glass antenna device is constructed as follows .
  • the defogging heater unit occupying a large area on the window glass is not constructed to also function as an AM antenna, and therefore a separate AM antenna is provided in the limited space above the defogging heater unit.
  • the separate AM antenna can not have a sufficiently large area, so that the receiving voltage can not be increased sufficiently.
  • the AM amplifier is provided to make up for the shortage of the receiving voltage.
  • the AM amplifier comprises a semiconductor element such as a transistor or FET, resistor, coil and capacitor, so as to amplify a received signal of the AM frequency band and match input and output impedances of the amplifier.
  • the AM amplifier has a high output impedance and a low output impedance.
  • a high-frequency transformer may be provided at the output stage of the AM amplifier, so as to cause the output impedance to be 1,000 ⁇ or less.
  • the FM amplifier employed in the inventive glass antenna device is constructed as follows.
  • the FM amplifier comprises a semiconductor element such as a transistor or FET, resistor, coil and capacitor, so as to amplify a received signal of the FM frequency band and match input and output impedances of the amplifier. It is preferred that the FM amplifier have low noise in order to increase its S/N ratio. Further, in order to properly receive an input signal of great electric field intensity, it is also preferred that the FM amplifier comprise a grounded-gate circuit using a low-noise FET and be set to a gain of 3 dB (i.e., an amplification rate of one) or less. Preferably, the FM amplifier has an input impedance of 50 ⁇ or less.
  • the FM amplifier include, at its output stage, a filter in the form of a tank circuit which can prevent generation of a mutually-modulated signal of the AM frequency band through a mutual modulation between a plurality of output FM signals from the FM amplifier.
  • the FM amplifier may comprise a grounded-base circuit using a low- noise transistor.
  • the inventive glass antenna device is characterized in that it includes dedicated FM and AM antennas and dedicated amplifiers are provided respectively for the FM and AM antennas; thus, the inventive glass antenna device can receive both FM-wave signals and AM-wave signals with superior sensitivity.
  • the AM and FM amplifiers can be set to sufficiently low output impedances, which allows the antenna device to be connected to the radio receiver apparatus using a signal-transmitting cable having a diameter of just 3 mm or less.
  • a signal-transmitting cable typically, a coaxial cable
  • Such a signal-transmitting cable having a diameter of 3 mm or less is very pliable and can be handled with utmost ease, so that the coaxial cable can be readily laid in place on the vehicle.
  • the signal-transmitting cable include ones commonly known as “1.5C2N” (about 2.3 mm in diameter) or “1.5C2V” or “1.5C2E” (about 2.9 mm in diameter) (applicable standard: JIS C 3501).
  • FIG. 1 is a diagram showing a basic structure of a vehicle window glass antenna device in accordance with an embodiment of the present invention.
  • Fig. 2 is a diagram showing a basic structure of a vehicle window glass antenna device in accordance with another embodiment of the present invention.
  • Fig. 3 is a diagram showing a basic structure of a vehicle window glass antenna device in accordance with still another embodiment of the present invention.
  • Fig. 4 is a circuit diagram illustrating an embodiment of an AM amplifier employed in the present invention.
  • Fig. 5 is a graph showing variations in noise that occur as the value of a gate resistance is varied.
  • Fig. 6 is a circuit diagram illustrating an embodiment of an FM amplifier employed in the present invention.
  • Fig. 7 is a block diagram showing a basic construction of a synthesizer section employed in the present invention.
  • Fig. 8 is a diagram illustrating an exemplary circuit organization of the synthesizer section.
  • Fig. 9 is a view showing a specific example of antenna patterns employed in the vehicle window glass antenna device of the present invention.
  • Figs. 10A and 10B are diagrams explanatory of two different FM antenna constructions selectively usable depending on presence/absence of a connecting lead.
  • Fig. 11 is a diagram explanatory of a prior art glass antenna device (Japanese Utility Model Laid-open Publication No. 59-3604).
  • Fig. 12 is a diagram explanatory of another prior art glass antenna device (U.S. Patent No. 4,791,426).
  • a vehicle window glass antenna device 1 includes the following components provided on a window glass (e.g., rear window glass) 2 of a motor vehicle. Namely, the glass antenna device 1 includes a dedicated AM antenna 4 , a dedicated FM antenna 5 and a defogging heater unit 3 in the form of a printed conductor pattern.
  • the vehicle window glass antenna device 1 also includes an amplification section 7 for amplifying input AM and FM signals V A and V F received via the AM and FM antennas 4 and 5 (hereinafter called “received AM and FM signals”), respectively, and a radio receiver apparatus 10 that reproduces amplified AM and FM signals V A0 and V F0 output from the amplification section 7 (hereinafter called “output AM and FM signals” ) .
  • amplification section 7 for amplifying input AM and FM signals V A and V F received via the AM and FM antennas 4 and 5 (hereinafter called “received AM and FM signals”), respectively, and a radio receiver apparatus 10 that reproduces amplified AM and FM signals V A0 and V F0 output from the amplification section 7 (hereinafter called “output AM and FM signals” ) .
  • the motor vehicle is also provided with a heater power source 6 for heating the defogging heater unit 3.
  • the defogging heater unit 3 includes a pair of opposed bus bars 3a and 3b disposed and extending along left and right side edges of the vehicle window glass, power feeding patterns 3c and 3d for coupling the heater power source 6 to the respective bus bars 3a and 3b, and a plurality of horizontal heater elements 3e extending between the opposed bus bars 3a and 3b.
  • power V H is fed from the heater power source 6, such as a battery, via the feeding patterns 3c and 3d to the defogging heater unit 3, a heater current, whose value is determined by a voltage V H between the bus bars 3a and 3b and respective resistance values of the heater elements 3e, flows through the defogging heater unit 3 to thereby resistively heat the heater elements 3e.
  • the defogging heater unit 3 is heated and causes condensation on the window glass 2 to evaporate, so as to defog the window glass surface.
  • the defogging heater unit 3 in this embodiment is connected directly to the heater power source 6 via the feeding patterns 3c and 3d. In this way, the defogging heater unit 3 can present a low impedance to an AM wave and is prevented from functioning as an AM antenna.
  • the AM antenna 4 in this embodiment comprises a plurality of AM antenna conductor elements extending horizontally in a region between the uppermost heater element 3e of the defogging heater unit 3 and the top edge of the window glass 2; these AM antenna conductor elements 4a together constitute a fork-shaped AM antenna pattern.
  • the AM antenna receives an AM wave by means of the antenna conductor elements 4a and supplies a received AM signal V A to an AM amplifier 8 of the amplification section 7 via the AM feeding pattern 4b.
  • the AM antenna 4 is constructed of the plurality of horizontal AM antenna conductor elements.
  • the receiving sensitivity to the incoming AM wave depends on a total area of the AM antenna pattern 4a and it is preferable that the total area of the AM antenna pattern 4a be as large as possible and the AM antenna conductor elements 4a be formed into a simple antenna pattern.
  • the AM antenna 4 is constructed of five horizontal AM antenna conductor elements each having a length L ⁇ of 1,000 mm and spaced from each other by about 20 mm.
  • the 1,000 mm length L ⁇ is a value determined such that the AM antenna 4 does not exert adverse influences on the receiving sensitivity of the FM antenna 5.
  • each of the AM and FM antennas 4 and 5 is designed as a dedicated simple antenna pattern, so as to minimize interferences between the AM antenna and the FM antenna.
  • a certain degree of such interferences may be unavoidable due to the fact that the AM and FM antennas and defogging heater unit are all provided on the rear window glass having a limited area.
  • TABLE 1 shows measurements of the receiving sensitivity of the FM antenna in relation to EXAMPLE 1 where each of the AM antenna conductor elements is set to the 1,000 mm length L M and EXAMPLE 2 where each of the AM antenna conductor elements is set to a maximum length.
  • the AM antenna 4 be spaced from the uppermost heater element 3e by more than a predetermined distance (e.g., 30 mm) so that it can be reliably prevented from being capacitively linked with the defogging heater unit 3.
  • the AM antenna's receiving sensitivity to the AM wave can be set to a desired value by coupling the heater power source 6 directly to the power feeding patterns 3c and 3d to thereby set the impedance of the heater pattern 3e to a value low enough to significantly reduce electrical coupling from the defogging heater unit 3.
  • the FM antenna 5 comprises a single horizontal antenna conductor element positioned between the uppermost heater element of the defogging heater unit 3 and the AM antenna 4.
  • the FM antenna 5 supplies a received FM signal to an FM amplifier 9 of the amplification section 7 via the FM feeding pattern 5a.
  • the FM antenna 5 is not directly connected with the defogging heater unit 3, but it is preferred that the FM antenna 5 be capacitively linked with the defogging heater unit 3.
  • a distance from the FM antenna 5 to the uppermost heater element of the defogging heater unit 3 be set to a predetermined value (e.g., in the range of 5 mm - 10 mm) so that the FM antenna 5 is capacitively linked with the heater unit 3 (see Fig. 2).
  • the FM antenna 5 is set to a length L FM ranging from 300 mm to 500 mm.
  • the length L FM is varied depending on a particular way of power feeding to the FM antenna, i.e., whether (a) the FM feeding pattern 5a on the window glass is used as the power feeding point or (b) the FM feeding pattern 5a is connected via a connecting lead to the FM amplifier 9 and the connection point therebetween is used as the power feeding point.
  • the connecting lead functions also as an FM antenna conductor element and the FM feeding pattern functions only as a mere connecting pattern.
  • the length L FM of the FM antenna be set, on the basis of a designed wavelength, in accordance with mathematical expression (1) above.
  • the FM antenna be set to a length calculated by subtracting the length of the connecting lead from the designed length L FM .
  • the length of the FM antenna 5 formed on the window glass has to be made smaller as the length of the connecting lead increases.
  • the FM antenna 5 be spaced from the AM antenna 4 by more than a predetermined distance (e.g., 25 mm) so as to minimize interferences between the FM and AM antennas 5 and 4.
  • the inventive glass antenna device can minimize mutual interferences between the AM antenna 4 and the FM antenna 5, between the AM antenna 4 and the defogging heater unit 3 and between the FM antenna 5 and the defogging heater unit 3.
  • a separate subsidiary FM antenna may be provided as necessary (see Fig. 3); for example, such a subsidiary FM antenna 5s may be provided in a marginal region below the defogging heater unit 3.
  • the FM antenna 5 may be constructed as a main antenna and the subsidiary FM antenna 5s may be constructed as a diversity antenna.
  • the subsidiary FM antenna 5s also comprises a single horizontal antenna conductor element, for the same reason as set forth above in relation to the main FM antenna. It is further preferred that the subsidiary FM antenna 5s be also capacitively linked with the defogging heater unit 3.
  • the length of this subsidiary FM antenna 5s may also be determined in the same manner as set forth above in relation to the main FM antenna. Specifically, the subsidiary FM antenna 5s may be set to a length L FMS ranging from 300 mm to 500 mm.
  • the inventive glass antenna device includes the dedicated FM antenna and AM antenna, each of which is operable independently of the other and designed basically as a straight-shaped antenna pattern.
  • these antennas can be designed and adjusted with utmost ease.
  • the amplification section 7 includes the AM and FM amplifiers 8 and 9 which amplify received AM and FM signals V A and V F supplied via the AM and FM feeding patterns 4b and 5a of the AM and FM antennas 4 and 5, respectively.
  • the amplification section 7 supplies the radio receiver apparatus 10 with amplified output FM and AM signals V A0 and V F0 .
  • the AM amplifier 8 has a high input impedance and low output impedance and amplifies the received AM signal V A to supply the amplified output AM signal V A0 to the radio receiver apparatus 10.
  • Fig. 4 is a circuit diagram illustrating an embodiment of the AM amplifier employed in the present invention.
  • the AM amplifier 8 comprises a common-source amplifier circuit, which includes an input capacitor Cl, an input resistor Rl, an FET (Field Effect Transistor) Ql, a load resistor R2 , a choke transformer Ll, a source resistor R3, and an output capacitor C2.
  • a common-source amplifier circuit which includes an input capacitor Cl, an input resistor Rl, an FET (Field Effect Transistor) Ql, a load resistor R2 , a choke transformer Ll, a source resistor R3, and an output capacitor C2.
  • the input impedance of the AM amplifier 8 is determined by a resistance value (e.g., 1 M ⁇ ) of the input resistor Rl connected between the gate G and the ground GND.
  • Fig. 5 shows variations in noise occurring as the input resistance Rl, acting as a gate resistance, is varied from 500 k ⁇ to 2 M ⁇ .
  • the noise can be reduced by setting the input resistance Rl to a small value. For instance, setting the input resistance Rl to a value of 1 M ⁇ or more will attain better results in actual use. Therefore, if the input impedance is set to a high level, the AM amplifier can effectively prevent unwanted noise from being introduced into the amplifier via the resistor Rl . It is also preferred that the AM amplifier be set to a low output impedance.
  • the output impedance of the AM amplifier 8 is determined by a composite impedance of the load resistor R2 connected to the drain D and the choke transformer Ll connected in parallel with the load resistor R2.
  • the choke transformer Ll includes a tap positioned at a point thereof corresponding to a 2:1 turns ratio and an output from the amplifier is extracted via this tap, so that the extracted output assumes one quarter of the composite impedance.
  • a high-frequency transformer is preferably provided at the output stage of the AM amplifier 8, so as to cause the output impedance to be 1,000 ⁇ or less.
  • ground (GND) terminal of the AM amplifier 8 be connected to the body earth of the motor vehicle. The following paragraphs describe behavior of the AM amplifier 8.
  • the received AM signal V A input to the gate G is multiplied by a voltage amplification coefficient (gm) of the FET Ql and load impedance (i.e., the composite impedance of the load resistor R2 and the choke transformer Ll connected in parallel with the resistor R2 ) , and the output from the drain D of the FET Ql corresponds in value to a product of "gm * V A x load impedance". Consequently, the output AM signal V A0 corresponds in value to one half of the product of "gm V A * load impedance".
  • gm voltage amplification coefficient
  • the AM amplifier 8 can effectively prevent unwanted noise from being introduced into the amplifier via the resistor Rl .
  • the output impedance can be set to a low value even when the amplification gain is increased.
  • the output AM signal V A0 can be taken out at a high level, and also an impedance matching can be made between a coaxial cable connecting to the radio receiver apparatus 10 and the output impedance.
  • the AM amplifier 8 may be constructed as a grounded-emitter amplifier using an ordinary transistor (and, if necessary, a darlington connection) in place of the FET.
  • Fig. 6 is a circuit diagram illustrating an embodiment of the FM amplifier 9 employed in the present invention.
  • the FM amplifier 9 is constructed as a grounded-gate amplifier circuit, which includes resistors Rll, R13, an inductor L12, an FET Q2, a resistor R12, a capacitor Cll and a choke transformer Lll.
  • the input impedance of the FM amplifier 9 is determined by the resistor Rll.
  • the resistor R13 and inductor L12 connected in series with each other constitute a bias circuit for the FET
  • the output impedance of the FM amplifier 9 is determined by an impedance Z F0 of a parallel circuit that consists of the load resistor R12 connected to the drain D, capacitor Cll and choke transformer Lll.
  • the output FM signal V F0 is taken out via a center tap positioned on the choke transformer Lll, so that the output impedance of the FM amplifier 9 equals one quarter of the impedance Z F0 of the parallel circuit.
  • the ground (GND) terminal of the FM amplifier 9 be connected to the body earth of the motor vehicle.
  • Appropriate impedance matching can be made by setting the output impedance of the FM amplifier 9 (Z F0 /4) to be substantially the same as an impedance of the coaxial cable connecting to the radio receiver apparatus 10.
  • the FM amplifier 9 be set to a gain on the order of 0 - 3 dB so as to prevent a waveform distortion from occurring in the received FM signal V F when the signal V F has an excessive level.
  • the output FM signal V FO is supplied to the radio receiver apparatus 10.
  • a tank circuit comprising the capacitor Cll and the choke transformer Lll connected in parallel with each other, constitutes a band-pass filter which permits a signal of the FM frequency band to pass therethrough.
  • the above-mentioned tank circuit can eliminate the mutually modulated signal representing the difference (f2-fl) to thereby effectively prevent the mutually modulated signal from being output from the amplifier and thus avoid a waveform distortion resulting from such a mutual modulation.
  • the FM amplifier employed in the present invention can properly perform impedance conversion and signal amplification at an appropriate level without producing a waveform distortion in the output FM signal from the FM amplifier.
  • the FM amplifier employed in the present invention can reliably prevent the output of the mutually modulated signal and thus avoid a waveform distortion resulting from such a mutual modulation.
  • the FM amplifier 9 may be constructed as a grounded-base amplifier using an ordinary transistor in place of the FET.
  • the inventive glass antenna device may further include a synthesizer section 71 that synthesizes the output signals from the above-mentioned AM and FM amplifiers 8 and 9 as shown in Fig. 7.
  • Fig. 8 is a circuit diagram illustrating an example of the synthesizer section 71.
  • the synthesizer section 71 includes passive components such as capacitors and inductance elements.
  • the amplified output signal from each of the AM and FM amplifiers 8 and 9 is filtered so as not to flow back into the corresponding amplifier, and the thus-filtered signals are combined together or synthesized so that the synthesized result is supplied to the radio receiver apparatus 10 via the coaxial cable.
  • the synthesizer section 71 includes capacitors C31 and C32 and choke coils L31 and L32.
  • the synthesizer section 71 also has an AM signal input terminal connected to one end of the choke coil L32, which is connected at the other end to an output terminal of the synthesizer section 71.
  • the synthesizer section 71 also has an FM signal input terminal connected to one end of the capacitor C31, which is connected at the other end to the choke coil L31 and capacitor C32.
  • the other end of the choke coil L31 is grounded, and the other end of the capacitor C32 is connected to the output terminal of the synthesizer section 71.
  • the AM antenna 4 comprises a plurality of horizontal AM antenna conductor elements 4a that together constitute a fork- shaped AM antenna pattern.
  • the AM antenna 4 also includes a short-cutting line 42 extending centrally across the fork- shaped AM antenna pattern.
  • a horizontal bypass element 41 is disposed above the horizontal AM antenna pattern 4a. This horizontal bypass element 41 is additionally provided here because there is formed a relatively large marginal gap between the upper end of the horizontal AM antenna pattern 4a and an upper window frame portion of the vehicle when the rear window glass is actually fitted in the window frame, although such a large gap is not clearly visible in Fig. 9 that is a plan of the antenna patterns as viewed from the inside of the vehicle.
  • the AM antenna has been described above as comprising the fork-shaped AM antenna pattern, the present invention is not so limited; for example, the AM antenna may comprise a loop-shaped antenna pattern. In the case of such a loop-shaped antenna pattern, a short-circuiting line may be provided centrally across the antenna pattern.
  • Fig. 10 A shows one example of the FM antenna that is suitable for use in the case where the FM feeding point 5a is used as the power feeding point
  • Fig. 10 B shows another example of the FM antenna that is suitable for use in the case where the FM feeding pattern 5a is connected via the connecting lead.
  • the designed length of the FM antenna based on the basic design specifications is the same for both the Fig. 10A example and the Fig. 10B example
  • the FM antenna pattern 5 of Fig. 10B is constructed to be shorter than that of Fig. 10A by an amount corresponding to the length of the connecting lead. Note that even in the Fig. 10A example, the FM antenna 5 does not extend beyond the centerline of the window glass.
  • each of the AM and FM antennas comprises a dedicated simple antenna pattern; thus, basic designing of these antenna patterns can be made with facility.
  • a region on the read window glass where defogging is required and other regions where the glass antenna patterns may be provided are determined depending on the type of the vehicle body (such as the sedan, wagon or hatch-back type). More particularly, these regions will be determined taking into account particular design specifications, such as the size, mounting angle, etc. of the rear window glass and presence/absence of a trunk room. Thus, for a given vehicle type, the size of the window glass and the regions where the antenna patterns may be provided are determined, and then the inventive vehicle window glass antenna device is designed for application to such a window glass.
  • the inventive vehicle window glass antenna device can be applied appropriately to various types of motor vehicles, without changing its basic design, as long as the size and mounting areas of the window glass are similar between the vehicle types. Therefore, the necessary time for adjusting the design of the antenna device can be minimized by the present invention.
  • the inventive glass antenna device includes the dedicated FM antenna and AM antenna, each of which is constructed basically as a straight antenna pattern.
  • these antennas can be designed and adjusted with increased ease.
  • the inventive glass antenna device can receive both of FM and AM waves with high sensitivity, thereby achieving superior FM- and AM-wave reception.
  • the FM amplifier employed in the present invention can properly perform impedance conversion and signal amplification at an appropriate level without producing an unwanted waveform distortion in the output FM signal from the FM amplifier, with the result that the FM signal can be reproduced with high quality.
  • the present invention can reliably prevent output of the mutually modulated signal in the AM frequency band and thus avoid a waveform distortion resulting from such a mutual modulation.
  • the FM signal can be reproduced with high quality.
  • the AM and FM amplifiers are set to sufficiently low output impedances, which allows the antenna device to be connected to the radio receiver apparatus using a signal-transmitting cable having a diameter of 3 mm or less that is quite easy to handle.
  • the present invention can be used advantageously as a vehicle window glass antenna device for receiving AM and FM waves with high sensitivity.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Details Of Aerials (AREA)
  • Circuits Of Receivers In General (AREA)

Abstract

L'invention concerne un dispositif antenne de vitre qui reçoit des ondes AM et FM avec une sensibilité élevée, sans bobine de choc, et facilite par conséquent la conception et le réglage de base de ses diagrammes d'antenne. Ledit dispositif comporte une antenne AM conçue de façon à ne pas être couplée de manière capacitive à désembueur, également installé sur une vitre de véhicule. Une antenne FM, sous la forme d'un conducteur d'antenne horizontal simple, est placée sur ladite vitre entre le désembueur et l'antenne AM. Le dispositif antenne de vitre comporte en outre un amplificateur AM amplifiant un signal reçu par le biais de l'antenne AM et un amplificateur FM amplifiant un signal reçu par le biais de l'antenne FM.
PCT/JP2000/002827 1999-05-13 2000-04-28 Dispositif antenne de vitre pour vehicule et recepteur radio l'utilisant WO2000070708A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
CA002373258A CA2373258C (fr) 1999-05-13 2000-04-28 Dispositif antenne de vitre pour vehicule et recepteur radio l'utilisant
DE60018917T DE60018917T2 (de) 1999-05-13 2000-04-28 Scheibenantennenanordnung für fahrzeug und funkempfänger mit einer derartigen anordnung
EP00922904A EP1177596B1 (fr) 1999-05-13 2000-04-28 Dispositif antenne de vitre pour vehicule et recepteur radio l'utilisant
AU43152/00A AU762198B2 (en) 1999-05-13 2000-04-28 Glass antenna device for vehicle and radio receiver apparatus using the same
JP2000619055A JP4112807B2 (ja) 1999-05-13 2000-04-28 車両用ガラスアンテナ装置およびそれを用いた受信装置

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP11/133078 1999-05-13
JP13307899 1999-05-13
JP2000021398 2000-01-31
JP2000/21398 2000-01-31

Publications (1)

Publication Number Publication Date
WO2000070708A1 true WO2000070708A1 (fr) 2000-11-23

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PCT/JP2000/002827 WO2000070708A1 (fr) 1999-05-13 2000-04-28 Dispositif antenne de vitre pour vehicule et recepteur radio l'utilisant

Country Status (6)

Country Link
EP (1) EP1177596B1 (fr)
JP (1) JP4112807B2 (fr)
AU (1) AU762198B2 (fr)
CA (1) CA2373258C (fr)
DE (1) DE60018917T2 (fr)
WO (1) WO2000070708A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1434301A1 (fr) * 2002-12-27 2004-06-30 HONDA MOTOR CO., Ltd. Antenne montée sur une vitre d'un véhicule
US6906671B2 (en) 2001-01-04 2005-06-14 Nippon Sheet Glass Company, Limited Glass antenna and glass antenna system using the same
FR2866155A1 (fr) * 2004-02-06 2005-08-12 Composants Electr Soc D Antenne serigraphiee pour lunette arriere de vehicule automobile de type berline.
EP1643587A1 (fr) * 2004-09-30 2006-04-05 Nippon Sheet Glass Company, Limited Dgivreur
EP2051326A1 (fr) 2007-10-15 2009-04-22 Asahi Glass Company, Limited Antenne pour vitre d'une automobile
EP2159872A1 (fr) * 2008-08-29 2010-03-03 Asahi Glass Company, Limited Antenne pour vitre et vitre de fenêtre pour véhicule
EP2355237A1 (fr) * 2010-02-01 2011-08-10 Asahi Glass Company, Limited Antenne de vitre et vitre de fenêtre de véhicule la comportant
CN115632222A (zh) * 2022-12-19 2023-01-20 零八一电子集团四川力源电子有限公司 一种天线融雪除冰系统

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2006033498A (ja) 2004-07-16 2006-02-02 Nippon Sheet Glass Co Ltd 車両用ガラスアンテナ装置
JP4370303B2 (ja) * 2005-03-29 2009-11-25 セントラル硝子株式会社 車両用ガラスアンテナ
WO2008096751A1 (fr) 2007-02-06 2008-08-14 Nippon Sheet Glass Company, Limited Antenne de vitre de véhicule
US20120038527A1 (en) 2009-04-28 2012-02-16 Kosuke Tanaka Glass antenna
JP2015106906A (ja) * 2013-12-03 2015-06-08 日本電信電話株式会社 無線受信装置
JP2017175290A (ja) * 2016-03-22 2017-09-28 旭硝子株式会社 バックドア、及びガラスアンテナ

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5870646A (ja) * 1981-10-22 1983-04-27 Toyota Motor Corp 自動車用受信装置
JPS5870644A (ja) * 1981-10-22 1983-04-27 Toyota Motor Corp 自動車用受信装置
EP0367555A2 (fr) * 1988-11-02 1990-05-09 Nippon Sheet Glass Co., Ltd. Système de réception sur vitre
EP0506333A1 (fr) * 1991-03-26 1992-09-30 Sumitomo Chemical Company, Limited Système d'antenne de vitre pour une voiture automobile
US5408242A (en) * 1991-02-05 1995-04-18 Harada Kogyo Kabushiki Kaisha Glass antenna for automobiles
GB2316538A (en) * 1996-08-21 1998-02-25 Antiference Ltd Vehicle windscreen antenna and heater element arrangement

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5870646A (ja) * 1981-10-22 1983-04-27 Toyota Motor Corp 自動車用受信装置
JPS5870644A (ja) * 1981-10-22 1983-04-27 Toyota Motor Corp 自動車用受信装置
EP0367555A2 (fr) * 1988-11-02 1990-05-09 Nippon Sheet Glass Co., Ltd. Système de réception sur vitre
US5408242A (en) * 1991-02-05 1995-04-18 Harada Kogyo Kabushiki Kaisha Glass antenna for automobiles
EP0506333A1 (fr) * 1991-03-26 1992-09-30 Sumitomo Chemical Company, Limited Système d'antenne de vitre pour une voiture automobile
GB2316538A (en) * 1996-08-21 1998-02-25 Antiference Ltd Vehicle windscreen antenna and heater element arrangement

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 007, no. 162 (E - 187) 15 July 1983 (1983-07-15) *

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6906671B2 (en) 2001-01-04 2005-06-14 Nippon Sheet Glass Company, Limited Glass antenna and glass antenna system using the same
EP1434301A1 (fr) * 2002-12-27 2004-06-30 HONDA MOTOR CO., Ltd. Antenne montée sur une vitre d'un véhicule
US7321338B2 (en) 2002-12-27 2008-01-22 Honda Motor Co., Ltd. On-board antenna
FR2866155A1 (fr) * 2004-02-06 2005-08-12 Composants Electr Soc D Antenne serigraphiee pour lunette arriere de vehicule automobile de type berline.
WO2005078857A1 (fr) * 2004-02-06 2005-08-25 Societe De Composants Electriques Antenne serigraphiee pour lunette arriere de vehicule automobile de type berline
EP1643587A1 (fr) * 2004-09-30 2006-04-05 Nippon Sheet Glass Company, Limited Dgivreur
EP2051326A1 (fr) 2007-10-15 2009-04-22 Asahi Glass Company, Limited Antenne pour vitre d'une automobile
EP2159872A1 (fr) * 2008-08-29 2010-03-03 Asahi Glass Company, Limited Antenne pour vitre et vitre de fenêtre pour véhicule
EP2355237A1 (fr) * 2010-02-01 2011-08-10 Asahi Glass Company, Limited Antenne de vitre et vitre de fenêtre de véhicule la comportant
CN115632222A (zh) * 2022-12-19 2023-01-20 零八一电子集团四川力源电子有限公司 一种天线融雪除冰系统

Also Published As

Publication number Publication date
CA2373258A1 (fr) 2000-11-23
JP2003500870A (ja) 2003-01-07
AU762198B2 (en) 2003-06-19
EP1177596A1 (fr) 2002-02-06
JP4112807B2 (ja) 2008-07-02
AU4315200A (en) 2000-12-05
DE60018917T2 (de) 2006-03-30
EP1177596B1 (fr) 2005-03-23
DE60018917D1 (de) 2005-04-28
CA2373258C (fr) 2004-04-06

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