JP2010130668A - Analog radio receiving system for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a receiving system for reducing/canceling the influence of noise generated on a receiving path of an analog radio inside a vehicle. <P>SOLUTION: An analog radio receiving system comprises: an antenna mounted in a vehicle; a first converter for converting a radio frequency signal of analog radio received by the antenna into a second radio frequency signal at a higher frequency than that of the radio frequency signal or into an optical signal; a coaxial cable for transmitting the second radio frequency signal converted by the first converter or an optical fiber cable for transmitting the optical signal; a second converter connected to the other end of the coaxial cable for converting the second radio frequency signal or the optical signal into the original radio frequency signal; and a receiver connected to the second converter. The coaxial cable or the optical fiber cable is bundled together with an electrical wire group wired inside the vehicle to constitute a wire harness. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an analog radio reception system for a vehicle, and more specifically, in the process of receiving an antenna mounted on a vehicle and transmitting it to a receiver mounted in a vehicle interior, an electronic device, an electrical component, and a wire mounted in the vehicle The effect of noise received from the harness is reduced and eliminated.

  Conventionally, in order to remove this type of noise, a method of removing a noise by providing a noise canceling circuit in the receiving circuit has been adopted. For example, in Japanese Patent Application Laid-Open No. 2007-325225, as shown in FIG. 7, a detector 102 and a noise detector 103 are provided in a parallel circuit in a circuit connecting an antenna 100 and a speaker 101, and the detector 102 The noise canceller 104 is provided in the output circuit of the noise detector 103.

JP 2007-325225 A

Including the noise removal device of Patent Document 1, conventionally, external noise already included in a signal received by an antenna, for example, noise emitted from a streetcar or power transmission line described in Paragraph No. 0004 of Patent Document 1 The target noise is removed.
However, in an on-vehicle broadcasting device, while transmitting a frequency signal received by an antenna to a receiver through a transmission line, switching or operation of an electronic device or electrical component such as an electronic control unit mounted in the vehicle Noise that sometimes occurs is radiated as radio waves to the transmission line. This radiation noise is large in a low frequency band of 2000 kHz or less.
In particular, in Japanese analog radio, the AM radio frequency band is 0.1 to 2.1 MHz and the FM radio frequency band is a low frequency band of 70 to 120 MHz, and therefore, it is affected by the radiation noise. Therefore, even if a noise canceller as described in Patent Document 1 is provided, noise removal is insufficient.

Specifically, the present inventor conducted a measurement test of noise generated in the vehicle.
This measurement test consists of a current probe (frequency range 1M to 1GHz) in each part of the wire harness of the drive circuit, such as power window, fuel filler opening / closing, door lock, electric mirror, stop lamp, hazard lamp, sunroof motor / light, etc. Each noise waveform was measured in a range of 10 MHz or less, 100 MHz or less, and 1 GHz or less.
FIG. 8 shows the noise generated in the opening and closing of the fuel filler opening. Especially, a large noise is generated in the AM radio low frequency band (526.5 kHz to 1606.6 kHz), and in the high frequency band exceeding 1 GHz. It was confirmed that the noise was reduced. The measurement results for the electric mirror, stop lamp, hazard lamp, power window and sunroof showed the same tendency.

Thus, the level of radiation noise from electronic equipment and electrical equipment is large in the low frequency band of radio frequencies. Therefore, a countermeasure is used in which the wire harness in which the noise is generated and the transmission line of the radio reception system are separately routed as a separate wire harness and separated from each other.
However, when assembled as a separate wire harness and routed separately, there are problems such as an increase in work processes.

  The present invention has been made in view of the above problems, and it is an object of the present invention to avoid being affected by noise in a low frequency band from electronic devices and electrical components that affect analog radio broadcasting.

In order to solve the above problems, the present invention includes an antenna mounted on a vehicle,
A first converter for converting an analog radio radio frequency signal received by the antenna into a second radio frequency signal or an optical signal having a frequency higher than that of the radio frequency signal;
A coaxial cable for transmitting the second radio frequency signal converted by the first converter, or an optical fiber cable for transmitting an optical signal;
A second converter connected to the other end of the coaxial cable or optical fiber cable to convert a second radio frequency signal or optical signal into the original radio frequency signal;
A receiver connected to the second converter;
The coaxial cable or the optical fiber cable is converged together with a group of electric wires routed in the vehicle to form a wire harness, and provides an analog radio reception system for vehicles.

  As described above, in the vehicle analog radio reception system according to the present invention, strong noise is generated in the low frequency band in the vehicle. Therefore, the radio frequency signal received by the antenna is converted to a high frequency radio frequency by the first converter. It is converted into a signal or optical signal so that it is not affected by strong noise in the low frequency band in the vehicle. And the high frequency radio frequency signal or optical signal received via the transmission line without being influenced by noise is returned to the original low frequency band radio frequency signal by the second converter. As a result, it is possible to reduce or eliminate noise received from the electronic device, the electrical component, and the wire harness in the radio signal transmission wiring to be wired in the vehicle interior. Therefore, coaxial cables or fiber optic cables that transmit radio signals can be converged and routed as wire harnesses together with other wire groups wired in the passenger compartment, and need to be routed separately from other wire groups. Absent. When the transmission line is a coaxial cable, the coaxial cable does not need to be a high shield type, and a commonly used coaxial cable can be used.

The analog radio received by the antenna is at least one of AM radio and FM radio,
The first converter is a frequency converter composed of an up-converter, and converts the second radio frequency exceeding the frequency of noise generated from an electronic control unit mounted along the wiring path of the wire harness,
The second converter is a frequency converter composed of a down converter, and is built in the receiver or directly connected to the receiver.

Specifically, the analog radio is a medium wave (MF) band AM radio, the FM radio is a very high frequency (VHF) band radio,
The second radio frequency signal converted by the first frequency converter is in the ultra high frequency (UHF) band. Specifically, the UHF band is about 400 MHz.
As described above, when the radio frequency transmitted through the transmission line is set to the UHF band, it is possible to reduce and eliminate the influence of the noise in the low frequency band generated in the vehicle interior.

  On the other hand, when converting to an optical signal to reduce or eliminate the influence of noise, the first converter is composed of an optical converter having an electro-optical converter, and the second converter has an optical-electric converter. It consists of an electrical converter and is built in the receiver or directly connected to the receiver.

  In the vehicle analog radio reception system of the present invention, the antenna is made of copper foil on the rear or rear quarter glass or copper foil provided on a flexible substrate attached to the glass surface, or a pole installed on the rear side of the roof, The receiver is placed in the instrument panel, and the receiver and antenna placed in the front-rear direction of the vehicle are routed by bundling coaxial cables or optical fiber cables together with other wires in the floor harness or roof harness. .

  Even if the coaxial cable or fiber optic cable that connects the antenna and receiver arranged in the front-rear direction of the vehicle is bundled together with other electric wires constituting the floor harness or roof harness routed in the front-rear direction of the vehicle, The influence of noise from these electric wire groups can be removed. Therefore, by assembling the floor harness or the roof harness as a wire harness together with another electric wire group, the number of wire harnesses can be reduced, and the production cost and the routing work can be reduced.

  The antenna is not limited to one antenna arranged at the rear window or the rear of the roof, but two antennas arranged at the front window or the front of the roof, and four at the front, rear, left and right of the vehicle, and mixed at the receiver In the case of a diversity receiving system, the radio frequency signals transmitted via the transmission lines between the respective antennas and the receivers are converted using the first converters respectively, and the second converters on the receiver side To restore the original radio frequency signal.

The present invention provides an automobile wire harness in which the coaxial cable or the optical fiber cable is converged with a group of electric wires for other circuits.
Furthermore, an automobile equipped with the analog radio reception system for vehicles is provided.

  As described above, in the vehicle analog radio reception system of the present invention, a high-frequency signal or optical signal is transmitted by the first converter in the process of transmitting the radio frequency signal received by the antenna to the receiver via the transmission line. Therefore, it is possible to reduce or eliminate the influence of noise in a low frequency band generated from electronic devices, electrical components, and wire harnesses in the vehicle. In addition, since the high frequency signal or optical signal received by the receiver via the transmission line is returned to the original low frequency radio frequency signal, it is possible to output a radio broadcast with high accuracy.

Embodiments of an analog radio reception system for a vehicle according to the present invention will be described below with reference to the drawings.
1 to 4 show a first embodiment.

  In 1st Embodiment, the 1st converter which consists of an up converter which converts a low frequency into a high frequency via the coaxial cable 3 directly under the antenna 2 stuck on the glass surface of the rear window 1 of the motor vehicle shown in FIG. 4 is connected. The antenna 2 is an antenna element formed of a conductive circuit made of copper foil provided on a flexible printed circuit board, the flexible printed circuit board is attached to a glass surface, and the output end of the conductive circuit serving as the antenna element is connected to the coaxial cable 3. is doing. In addition, when the copper foil used as an antenna element is previously incorporated and printed on the glass surface, the output end of the antenna element is connected to a coaxial cable.

  The coaxial cable 3 is connected to the first converter 4 that is disposed directly below the rear window 1 as a short length. The first converter 4 converts a low frequency radio frequency signal into a high frequency second radio frequency signal.

  The first converter 4 is connected to a transmission line comprising a coaxial cable 5, and the coaxial cable 5 is bundled together with other electric wire groups 7 (7A, 7B, 7C... 'N) as shown in FIG. The harness 8 is used. The floor harness 8 is routed in the front-rear direction along the floor panel of the automobile, and the coaxial cable 5 routed as the floor harness 8 is connected to the receiver 10 disposed in the instrument panel 9.

  A second converter 11 composed of a down converter for converting a high frequency into a low frequency is accommodated in a receiver 10 mounted in the instrument panel 9, and the coaxial cable 5 is connected to the second converter 11. ing. The second converter 11 returns the high frequency second radio frequency signal received from the coaxial cable 5 to the original low frequency radio frequency signal. The second converter 11 may be directly connected to the receiver 10 and attached externally.

The analog radio received by the antenna 2 is an AM radio in the medium wave (MF) band or an FM radio in the very short wave (VHF) band.
The frequency band of the medium wave AM radio is 0.1 to 2.1 MHz, and the frequency band of the FM radio is 70 to 10 MHz.
The first converter 4 converts the frequency of the AM radio and FM radio into an ultra high frequency (UHF) band of about 400 MHz. The ultra-high frequency (UHF) frequency signal converted by the second converter 11 is returned to 0.1 to 2.1 MHz for the original AM radio and 70 to 10 MHz for the FM radio.

As shown in FIG. 2, the first converter 4 of the up-converter includes an amplifier 4a that amplifies a low-frequency signal received by the antenna 2, a local oscillator 4b, a frequency from the amplifier 4a and the local oscillator 4b. And a mixer 4c that mixes the high frequency from the local oscillator 4b, and a low frequency radio frequency signal is converted into an ultra high frequency (UHF) of about 400 MHz.
The second converter 11 of the downconverter includes a mixer 11a and a local oscillator 11b. The low frequency from the local oscillator 11b is added by the mixer 11a, and the ultra-high frequency (UHF) frequency is reduced to the original low frequency. The radio frequency signal is restored.

  As described above, in the present invention, the low frequency radio frequency signal received by the antenna is converted into the high frequency second radio frequency signal by the first converter 4 and then sent to the receiver 10 via the coaxial cable 5. Sending. Therefore, the coaxial cable 5 routed from the rear side to the front side on the instrument panel arrangement side in the vehicle interior can eliminate the influence of low-frequency noise generated from electronic devices and electrical components in the vehicle interior. it can.

FIG. 4 shows a result of a measurement experiment of noise generated in the coaxial cable when the inventor converts the radio frequency signal into a high frequency by the first converter 4.
As shown in the figure, noise generated at the electromagnetic wave level is large in the frequency band of AM radio, and noise is also generated in the frequency band of FM radio. When the radio frequency signal transmitted through the coaxial cable is converted to up to 400 MHz (up-conversion), the noise is drastically reduced when the frequency is 200 MHz or more, and the influence of the noise disappears near 400 MHz.

  As described above, when the first converter 4 converts the radio frequency signal having a low frequency into a high frequency and transmits the signal through the coaxial cable, it is possible to eliminate the influence of the low frequency noise generated from the electronic device or the electrical component in the vehicle interior. And even if the low frequency noise has generate | occur | produced in the other electric wire group converged as the floor harness 8, it does not receive to the influence of this noise. Therefore, it can assemble as floor harness 8 with other electric wire groups, and can be wired with other electric wire groups.

5 and 6 show a second embodiment.
In the second embodiment, the first converter 20 converts a low frequency signal into an optical signal, and the second converter 21 returns the optical signal to a low frequency signal. Further, an optical fiber cable 22 is used instead of a coaxial cable as a signal transmission line for connecting the first converter 20 and the second converter 21.
The first converter 20 is composed of an optical converter provided with an electric-optical converter 20a, and the second converter 21 is composed of an electric converter provided with an optical-electric converter 21a. The second converter 21 is not housed in the receiver 10 but is externally attached to the receiver 10 and directly connected thereto.
Since other configurations are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

  As described above, when a radio frequency signal is converted into an optical signal and the optical fiber cable 22 is used as a transmission line, noise can be generated even if it is routed close to an electronic control unit that becomes a noise source and electrical equipment that performs drive control. The effect can be reduced or eliminated. Therefore, when wiring in the front-rear direction of the vehicle through the floor harness or the roof as in the first embodiment, the roof harness can be bundled and assembled together with other electric wire groups.

  The present invention is not limited to the above-described embodiment, and the antenna may be affixed to the windshield and may be a diversity reception system that receives analog radio with two front and rear antennas. In that case, the first frequency converter is arranged directly under each antenna, converted into a high frequency band signal or optical signal, and transmitted to the receiver arranged on the instrument panel with a coaxial cable or an optical fiber cable, The signal is converted to the original radio frequency signal by a second frequency converter attached to the receiver or externally attached to the receiver. Furthermore, the antenna may be a commonly used pole type antenna.

1 is a schematic overall view showing a first embodiment of the present invention. It is a block diagram which shows the receiving path | route of the said 1st Embodiment. It is an expanded sectional view of the coaxial cable of the first embodiment. It is a graph which shows a measurement experiment result. It is a schematic whole figure which shows 2nd Embodiment. It is a block diagram which shows the receiving path | route of 2nd Embodiment. It is drawing which shows a prior art example. It is a graph which shows the measurement result of the noise which has occurred inside vehicles.

Explanation of symbols

1 Rear window
2 Antenna 3, 5 Coaxial cable 4, 20 First converter 8 Floor harness 9 Instrument panel 10 Receiver 11, 21 Second converter 22 Optical fiber cable

Claims (7)

An antenna mounted on the vehicle,
A first converter for converting an analog radio radio frequency signal received by the antenna into a second radio frequency signal or an optical signal having a frequency higher than that of the radio frequency signal;
A coaxial cable for transmitting the second radio frequency signal converted by the first converter, or an optical fiber cable for transmitting an optical signal;
A second converter connected to the other end of the coaxial cable or optical fiber cable to convert a second radio frequency signal or optical signal into the original radio frequency signal;
A receiver connected to the second converter;
The analog radio receiving system for a vehicle, wherein the coaxial cable or the optical fiber cable is converged together with a group of electric wires arranged in the vehicle to constitute a wire harness. The analog radio received by the antenna is at least one of AM radio and FM radio,
The first converter is a frequency converter composed of an up-converter, and converts the second radio frequency exceeding the frequency of noise generated from an electronic control unit mounted along the wiring path of the wire harness,
2. The vehicle analog radio reception system according to claim 1, wherein the second converter is a frequency converter including a down converter and is built in the receiver or directly connected to the receiver. The analog radio received by the antenna is at least one of AM radio and FM radio,
The first converter is composed of an optical converter having an electrical-to-optical conversion unit, and the second converter is composed of an electrical converter having an optical-to-electrical conversion unit, and is built in the receiver or directly connected to the receiver. The vehicular analog radio receiving system according to claim 1.   The analog radio is a medium wave (MF) band AM radio, the FM radio is a very high frequency (VHF) band radio, and the second radio frequency signal converted by the first converter is a very high frequency ( The vehicle analog radio reception system according to claim 1 or 2, which is a UHF band.   The antenna consists of copper foil on the rear or rear quarter glass or copper foil provided on a flexible board attached to the glass surface, or a pole installed on the rear side of the roof, and the receiver is placed in the instrument panel. 5. The vehicle analog radio reception system according to claim 1, wherein the wire harness for binding the coaxial cable or the optical fiber cable includes a floor harness or a roof harness. 6.   An automotive wire harness in which the coaxial cable or the optical fiber cable according to any one of claims 1 to 5 is converged with a group of electric wires for other circuits.   An automobile equipped with the vehicular analog radio reception system according to any one of claims 1 to 5.

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