JP2003101318A - Windshield antenna for automobile - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a windshield antenna for automobile that can be improved in sensitivity. SOLUTION: An antenna conductor 4 for low-frequency band is provided with three upper antenna elements 4a and two lower antenna elements 4b, and a feeding point 2 is connected to the right end section of the lowest upper antenna element 4a. The left end sections of the upper antenna elements 4a and lower antenna elements 4b are connected to each other through a connecting element 4c. In addition, a horizontal element 7a is extended in almost parallel with the highest lower antenna element 4b above the element 4b and, in addition, capacitively coupled with the element 4b.

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] The present invention relates to a Japanese radio FM.
Broadcast band (76-90 MHz), US radio FM broadcast band
(88-108 MHz) and AM broadcast band (530-16)
05kHz) Automotive window glass antenna suitable for reception
About. The following are the radio FM broadcast bands in Japan and
The Geo FM broadcast band is simply called the FM broadcast band. [0002] 2. Description of the Related Art Side window for receiving a broadcast shown in FIG.
Side window glass antenna for automobiles provided on the glass
Conventionally known (Japanese Utility Model Publication No. 61-197710)
FIG. 13). In FIG. 2, the side window glass plate of the automobile
21 includes antenna conductors 22 and 23, feeding points 24 and 25.
The antenna conductor 22 is an element 27.
The antenna conductor 23 includes an element 29.
The Element 27 and antenna conductor 23 are capacitively coupled.
ing. In this conventional example, an FM broadcast band or a television broadcast is used.
When receiving the transmission band, the receiving characteristics of the feeding point 24 and the feeding point 25 are
Diversity reception using gender differences
However, since the feeding point 24 and the feeding point 25 are separated from each other,
A coaxial cable connecting points 24 and 25 and a receiver (not shown).
There was a problem that could not be simplified. Anne
Both of the tena conductors 22 and 23 have a low frequency band (30 MHz
Less frequency band) For example, the problem of poor AM broadcast band sensitivity
there were. [0004] The present invention is based on the prior art.
Automotive window glass antenna that eliminates the aforementioned drawbacks
The purpose is to provide. [0005] The present invention solves the aforementioned problems.
It was made to solve the problem, and the antenna
Body, antenna conductor for low frequency band, antenna conductor for high frequency band
The feeding point of the antenna conductor for the low frequency band is the automobile
Car window glass antenna on the window glass plate
In the case of high frequency band
Feeder of antenna conductor and antenna conductor for low frequency band
The point is located near the right edge of the window glass plate,
The waveband antenna conductor is located near the upper edge of the window glass plate.
And a plurality of upper parts arranged substantially parallel to the upper edge.
Side antenna element and low frequency antenna
The conductor is near the lower edge of the window glass plate and
A plurality of lower antenna elements disposed substantially parallel to the edge.
Element, and feeding antenna conductor for low frequency band
The point is one of the multiple upper antenna elements.
Connected to the right end of the upper antenna element
The left end of the antenna is connected to the left end of the lower antenna element
High frequency band antennas connected by elements
Part or all of the conductor is the highest lower antenna element
The antenna guide for the high frequency band is
It is extended from the body feed point and is
A part or whole of the body with the highest lower antenna element
Capacitively coupled at least in the substantially parallel part
An automobile window glass antenna is provided.
The [0006] DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.
Explained. FIG. 1 shows an automotive window glass antenna of the present invention.
It is a block diagram of one Example. Automotive window glass of the present invention
The window glass plate on which the antenna is provided is the front window glass plate,
Rear window glass plate, front side window glass plate, roof window glass
It can be any type of steel plate, but in FIG.
Rear side window glass plate 1 is used instead of these window glass plates
Suppose that In FIG. 1, reference numeral 1 denotes a rear side window of an automobile.
Glass plate 2 is a feeding point of antenna conductor 4 for low frequency band, 3
Is the feeding point of the antenna conductor 7 for the high frequency band, 4a is the low frequency band
Antenna element 4 upper antenna element, 4b is low
Lower antenna element for frequency band antenna conductor, 4c
Is the connection element, 7a is the antenna conductor 7 for the high frequency band
It is a horizontal element. The direction is the direction on the drawing,
The feeding point 2 is arranged above the feeding point 3, and the rear support
The right side of the window glass plate 1 (feed point 2 and feed point 3 are provided
Is the front side of the car. In the present invention, an antenna conductor for a high frequency band
7 means an antenna conductor for a broadcasting band of 30 MHz or higher,
The low frequency band antenna conductor 4 is a broadcasting band of less than 30 MHz.
An antenna conductor. In the example of FIG. 1, the antenna conductor for the high frequency band
7. Low frequency band antenna conductor 4, feed point 3 and feed point 2
Is provided on the rear side window glass plate 1. Feeding point 2
And the feeding point 3 is near the right edge of the rear side window glass plate 1
It is arranged. In FIG. 1, the antenna conductor 4 for low frequency band is
In the vicinity of the upper edge of the rear side window glass plate 1 and above
Three upper antenna elements arranged substantially parallel to the side edge
Rement 4a is provided. Upper antenna element 4
a is three, and in order to secure a good field of view,
3 is preferable, but low frequency is required to improve sensitivity in the low frequency band.
The upper antenna element having four or more waveband antenna conductors 4
May be provided. In FIG. 1, the antenna conductor 4 for low frequency band is
Near the lower edge of the rear side window glass plate 1 and below
Two lower antenna elements arranged substantially parallel to the side edge
Rement 4b is provided. To ensure good visibility
In this case, two lower antenna elements 4b are preferable.
However, to improve the sensitivity of the low frequency band,
The body 4 has three or more lower antenna elements 4b.
May be. In FIG. 1, the feed point 2 is at the lowest upper
Connected to the right end of the tenor element 4a, but others
Connected to the right end of the upper antenna element 4a
May be. A left end portion of the upper antenna element 4a;
The left end of the lower antenna element 4b is connected to the element
Connected by 4c. In FIG. 1, one of the high-frequency band antenna conductors 7 is shown.
Part (horizontal element 7a)
The feed point 3 is approximately parallel to the top of the ment 4b.
And is capacitively coupled. But limited to this
The entire high frequency band antenna conductor 7 (full length)
It becomes almost parallel to the lower antenna element 4b,
Antenna conductor 7 for the frequency band and the highest lower antenna element
And 4b may be capacitively coupled. For the capacitive coupling, a horizontal element
7a and the uppermost lower antenna element 4b are predetermined
They are close to each other, and this proximity
Ment 7a and the highest lower antenna element 4b
Do not send or receive DC current between the two.
Second, the received signal current is capacitively coupled so that it can be transmitted and received.
ing. That is, the horizontal element 7a and the lower most
The antenna element 4b is a capacitive coupling range.
It is separated by a predetermined interval of 0.1-50mm
Is preferred. When viewed as a pattern, FIG.
The window glass antenna for automobiles is seen from the inside of the car
Yes. However, the present invention is not limited to this, and the automobile in FIG.
The window glass antenna pattern is seen from the outside of the car.
There may be. High frequency band antenna conductor 7 (horizontal element
The conductor length of the conductor 7a is not included)
Waves at the center frequency of the broadcast band (frequency band of 30 MHz or higher)
Length to λ_M(Λ_M/ 8) × K˜ (λ_M) × K
It is preferable that (λ _M/ 8) × K˜ (λ_M/
2) It is more preferable to set it as xK. Is within this range
If the desired broadcast compared to when it is out of this range
Band sensitivity is improved. K is the glass shortening rate,
Usually 0.64. The present invention is compatible with the AM broadcast band and the FM broadcast band.
Can be used. Furthermore, the present invention provides a long wave broadcasting band (LW band).
(150-280kHz), shortwave broadcasting band (SW band)
(2.3 to 26.1 MHz), TV VHF band (90 to
108MHz, 170-222MHz), TV UHF
Band (470-770 MHz), North American and European TV V
HF band (45-86 MHz, 175-225 MHz),
800MHz band for automobile phone (810-960MH
z), 1.5 GHz band (1.429 ~
1.501 GHz), UHF band (300 MHz to 3 GHz)
z), GPS (Global Positioning)
  System) Satellite GPS signal 1575.42
Applicable to MHz. [0019] [Example] Using rear side window glass plate of automobile, figure
An automobile window glass antenna as shown in FIG.
The dimensions of each part are as follows. FM broadcast band frequency
-The sensitivity characteristics are shown in Fig. 3, and the frequency-sensitivity characteristics of the AM broadcast band
The properties are shown in FIG. 3 and 4 are 60 dBμV / m.
Measured in an electric field, the vertical axis simply displays dBμV in dB
It was. Conductor length of upper antenna element 4a (same length for all three) 650mm, The distance between each upper antenna element 4a is 32mm, Conductor length of the lower antenna element 4b (both are the same length) 650mm, The distance between the lower antenna elements 4b is 32mm, Conductor length of high frequency band antenna conductor 7 (including horizontal element 7a, including feed point 3) No)                                                             560mm, The conductor length of the connection element 4c is 450 mm, The conductor length of the horizontal element 7a is 300mm, Distance between horizontal element 7a and highest lower antenna element 4b                                                               32 mm. [0020] In the present invention, the feeding point 2 and the feeding point 3 are close to each other.
Therefore, it is necessary to connect the feed points 2 and 3 to the receiver.
Axial cable mounting can be simplified. Also, the feeling of low frequency band
It is also excellent in sensitivity at high temperature and high frequency band.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of an embodiment of an automotive window glass antenna of the present invention. FIG. 2 is a configuration diagram of a conventional automobile window glass antenna. FIG. 3 is a frequency-sensitivity characteristic diagram of an FM broadcast band according to an embodiment. FIG. 4 is a frequency-sensitivity characteristic diagram of an AM broadcast band according to an embodiment. [Description of Symbols] 1: Rear side window glass plate 2, 3: Feeding point 4a: Upper antenna element 4b of low frequency band antenna conductor: Lower antenna element 4c of low frequency band antenna conductor: Connection element 7a: Horizontal element

Claims (1)

What is claimed is: 1. A high-frequency band antenna conductor, a low-frequency band antenna conductor, a feeding point for a high-frequency band antenna conductor, and a feeding point for a low-frequency band antenna conductor are provided on a window glass plate of an automobile. In the automotive window glass antenna, the feeding point of the high frequency band antenna conductor and the feeding point of the low frequency band antenna conductor are arranged in the vicinity of the right edge of the window glass plate when viewed from the inside or outside of the vehicle. The low frequency band antenna conductor includes a plurality of upper antenna elements arranged in the vicinity of the upper edge portion of the window glass plate and substantially parallel to the upper edge portion. The antenna conductor for a low frequency band includes a plurality of lower antenna elements arranged in the vicinity of the lower edge of the window glass plate and substantially parallel to the lower edge. There are multiple feed points It is connected to the right end of one of the upper antenna elements, the left end of the upper antenna element and the left end of the lower antenna element are connected by the connection element, and part of the antenna conductor for the high frequency band Or, all are extended from the feeding point of the antenna conductor for the high frequency band so as to be substantially parallel to the uppermost lower antenna element, and part or all of the antenna conductor for the high frequency band is below the highest position. A window glass antenna for an automobile, which is capacitively coupled at least at a portion substantially parallel to the side antenna element.