JPS59207705A - Antenna for vehicle - Google Patents

Abstract

PURPOSE:To obtain sending and receiving function similar to a rod type vertical whip antenna by determining diameter of metallic disks, axial length of a metallic rod and the height of the second metallic disk to the first metallic disk in relation to wavelength of sending signals. CONSTITUTION:Eight metallic rods 28-28 are erected vertically at nearly equal intervals on a metallic disk 24 along circumference of the metallic disk 24 corresponding to the outer periphery of a metallic disk 27. At the same time, upper ends of them support outer periphery of the metallic disk 27 to short- circuit the outer periphery to the metallic disk 24. In this constitution, the diameters D<phi>1-S<phi>4 of metallic disks 22, 24, 26, 27, total length H of the metallic rod 23, height H1 of the metallic disk 24 to metallic disk 22, height H2 of the metallic disk 27 to metallic disk 26 and height H3 of the metallic disk 24 to metallic disk 26 are determined in relation to the wavelength of sending signals. Thus, sending and receiving function similar to a rod type whip antenna can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to antennas for various transmitting/receiving devices such as radios, radios, televisions, etc., and particularly to various transmitting/receiving devices such as personal radios, wireless telephones, radios, televisions, etc. installed in vehicles. This invention relates to a vehicle antenna suitable for use in a vehicle.

Conventionally, this type of vehicle antenna includes, for example, a frame-shaped vertical whip antenna extending upward from a portion of a vehicle body or a modified antenna thereof. however,
The axial length of such antennas is usually 50(7) or more, which is quite long, so the antenna extends high from the surface of the vehicle body. Various problems have occurred, such as the antenna being broken due to contact with the vehicle, or the antenna having to be temporarily removed from the vehicle body when parking the vehicle in a garage or during an automatic car wash.

The present invention has been made to address these problems.
The purpose is to provide a low-height vehicle antenna that has the same transmitting and receiving functions as the above-mentioned frame-shaped vertical whip antenna or its modified antenna.

In order to achieve such an object, the present invention has a structure including: a metal rod erected on a part of the outer wall of the vehicle so as to transmit and receive signals to and from a transmitting/receiving device installed in the cabin of the vehicle; first and second metal discs are pivotally supported substantially horizontally at the base end and intermediate portions of the metal rod via electrical insulating members, respectively; and a second metal disk is pivotally supported substantially horizontally at the upper end of the metal rod. 6 a metal disk, a capacitive electric element interposed in an intermediate portion of the metal rod and capacitively coupled to the second metal disk, and a space provided at an outer peripheral edge of the second metal disk; It has a plurality of connected one-side terminals and a plurality of other-side terminals connected to each surface portion of the first metal disk corresponding to each connection position of each negative side terminal on the second metal disk. A first electrical load element, a plurality of one side terminals connected at intervals to the outer peripheral edge of the sixth metal disk, and respective connection positions of these negative side terminals on the sixth metal disk. a second electrical load element having a plurality of other side terminals respectively connected to respective surface portions of the corresponding second metal discs, the diameter of each of the metal discs, the axial length of the metal rod, and said second
The height of the metal disk relative to the first metal disk is determined in relation to the wavelength of the transmitted/received signal.

By configuring the present invention in this way, each horizontal opening surface is uniformly formed between the first, second, and sixth metal disks over their respective entire peripheries, and the first and second
Based on the input resistance matching effect of the electrical load element, it is possible to ensure omnidirectionality in the horizontal direction similar to that of conventional body-shaped antennas, and because the distance between the first and third metal discs is short, Compared to body-shaped antennas, the extent to which it protrudes from the vehicle's outer wall is significantly reduced, and as a result, it will not be damaged by contact with objects around the vehicle while it is running, and it will not be damaged when the vehicle is parked in a garage. , it won't get in the way during automatic car washes, etc. Further, since the capacitive electric element is capacitively coupled to the second metal disk, each horizontal opening formed by each metal disk can be used in conjunction with the function as an antenna. can be used effectively,
Therefore, the gain is higher than in the case of a horizontal aperture formed by the first and second metal disks or in the case of a rod-shaped antenna.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.
The figure shows that an antenna 20 according to the present invention is installed on a roof 11 of a vehicle 10.
It is shown mounted approximately in the center of the The antenna 20 is for a personal radio placed in the cabin of the vehicle 10, and has a connector 21, as shown in FIG.
2 is positioned parallel to the roof 11, and is fixed to the approximate center of the roof 11 at the base 21b via a metal attachment (not shown). The flange 21a of the connector 21 includes
A metal disk 22 having a diameter of φ is fixed by fitting a through hole 22a provided at its center to the outer circumference of an insulating ring 21C protruding from the connector 21 through the flange 21a,
It is grounded via the flange 21a, the main body of the connector 21, the attachment, and the vehicle 10.

The metal rod 26 has its base connected to the insulating ring 2 of the connector 21.
10 and is assembled to the connector 21 so as to protrude perpendicularly from the metal disk 22 by a height H (hereinafter referred to as the total length H). A coil portion 23a functioning as an inductive load is integrally formed in the upper portion. In this case, the base of the metal rod 26 is connected to the power supply terminal of the personal radio via a coaxial cape (not shown).

As shown in FIGS. 2 and 6, a metal disk 24 having a diameter D2φ is provided on the upper surface of the metal disk 22 with a through hole 2412 provided at the center of the metal disk 24 on the lower side of the coil portion 23a of the metal rod 26. Four heights are fitted into the intermediate portion, and their outer peripheral edges are hung vertically at equal intervals above the same circumferential portion of the metal disk 22 (corresponding to the outer peripheral edge of the metal disk 24). The metal rod 25 is fixedly attached to each upper end of the metal rod 25 having a diameter Hl, and together with the metal disk 22, forms a horizontal opening surface that is uniform over the entire horizontal circumference thereof.

In such a case, the four metal rods 25 support the outer peripheral edge of the metal disk 24 on the metal disk 22 at equal intervals and short-circuit the metal disk 22, so that the distance between the two metal disks 22 and 24 is reduced. The mounting structure of the antenna 20 is made more solid, and the input resistances are precisely matched to realize horizontal omnidirectionality of the antenna 20.

In addition, when attaching each metal rod 25 to both metal discs 22 and 24, each metal rod 25 is vertically placed on the metal disc 22 at approximately equal intervals in line with the outer peripheral edge of the metal disc 24. This makes it easy to perform such mounting work and to match the input resistance. Note that the inner diameter of the through hole 24a of the metal disk 24 is made larger than the outer diameter of the metal rod 26, so that the metal disk 24 is out of contact with the metal rod 26 at its center. electrically isolated.

Below the metal disk 24, a metal disk 26 having a diameter D3φ is fixed at its center to the intermediate portion of the metal rod 23, so that the metal disk 24 is capacitively coupled to the metal disk 24.
On the other hand, on the upper surface of the metal disk 24, a metal disk 27 having a diameter D4φ is fixed to the upper end of the coil portion 23a of the metal rod 23 to form a metal circle. It is assembled in parallel to the plate 24, and together with the metal disk 24, it forms a horizontal opening surface that is uniform over its entire horizontal circumference. In such a case, the phase difference between the opening plane formed by both metal disks 24.27 and the opening plane formed by both metal disks 22.24 will be
12, the transmission/reception signal wavelength of the personal radio device is 4, so that it can be effectively utilized to improve the function as an antenna based on the capacitive coupling between the two metal disks 24 and 26.

Further, both metal discs 26 and 27 transmit and receive signals to and from the personal radio device via the metal rod 26 at their centers.

The eight metal rods 28 to 28 are connected to the four metal rods 25 to 25 in order to realize horizontal omnidirectionality of the antenna 20.
It precisely matches the input resistance by cooperating with the
As shown in FIGS. 2 and 3, the metal disks 24 are vertically disposed at approximately equal intervals along the circumferential portion of the metal disk 24 corresponding to the outer peripheral edge of the metal disk 27. Along with
Each upper end portion supports the outer peripheral edge of the metal disk 27 and short-circuits the outer peripheral edge to the metal disk 24. In such a case, when attaching each metal rod 28 to both metal discs 24, 27, each metal rod 28 may be vertically provided on the metal disc 24 at approximately equal intervals on the outer peripheral edge of the metal disc 27. So,
Such mounting work can be easily performed, and input resistance matching is also facilitated.

In this embodiment configured as described above, the antenna 20
Regarding the size and shape of the personal radio and its main characteristics as an antenna, the radio frequency band (903-905 M
When we conducted an experiment regarding the relationship with Hz), we obtained the following results.

1. Each diameter of each metal disk 22, 24, 26.27 is D1φ-180 (shoulder'l) l D2φ=135 (
shoulder N).

D3φ=125 (ffff), D4φ=120
C wing), and the total length of the metal rod 26, the metal disc 24
The height of the metal disc 22 with respect to the metal disc 22, the height of the metal disc 27 with respect to the metal disc 26, and the height of the metal disc 24 with respect to the metal disc 26 are respectively H-185 (MM), H1=22
(shoulder WI), H2 = 24 (fight), U3 = 3 (shoulder) closed 2, and as a result of experimenting with various changes to D1φ to D4φ and H to H3 mentioned above, we found that a wave with a frequency of 900 MHz When is λ, D1φ-: 0.54λ, D2φ key 0.405λ+ 0.375λ in D3φ, D4φ±0
．． 66λ, H-! -0,555λ, Hl Ki0.0
66 λ, Hi! = 0.072λ
.

If H3ki is 0.01λ, the same electrical characteristics as the above experimental results can be obtained, and as a result, the antenna according to the present invention has
It was found that the antenna can exhibit characteristics equivalent to or better than conventional frame antennas.

In addition, in the embodiment, four metal discs 22.2
4.26.27 has been described, but instead of this, the metal disc 22 may be replaced by the roof 11 of the vehicle. In such a case, except that the absolute gain is 7 dB, Experimental results substantially similar to those of the previous example were obtained.

Further, in the embodiment, the antenna 20 is connected to the vehicle 10.
I explained the example of installing it in the center of the roof 11 of
The present invention is not limited to this, and the attachment location of the antenna 20 to the vehicle 10 may be changed as appropriate. In such a case, the connector 21 may be omitted and the coaxial cable may be directly connected to the base of the metal rod 23.

Further, in the embodiment described above, an example was explained in which the metal disk 26 was placed below the metal disk 24 for capacitive coupling. Alternatively, a capacitor may be used instead of the metal disk 26 and this capacitor may be interposed in the intermediate portion of the metal rod 26.

In addition, in the above embodiment, the input impedance (5
0Ω), the metal rods 25 and 2
Although examples have been described in which four and eight metal rods 25 and 28 are adopted, respectively, the number of metal rods 25 and 28 is not limited to this, and the number of metal rods 25 and 28 may be increased or decreased depending on the value of input impedance, or instead of these metal rods. Therefore, electrical load elements such as capacitors and coils may be used.

Further, in the above embodiment, an example was explained in which the power phase adjustment between the two metal discs 24 and 28 was performed by the coil part 2312 of the metal rod 26, but a capacitor was used in place of the coil part 23a to adjust the power phase. Adjustments may also be made.

Further, in the embodiment described above, an example was explained in which the central part of the metal disk 24 was insulated from the metal rod 26 by air. The metal disc 24 is fitted into the hole 24a.
The center portion of the metal rod 26 may be insulated from the metal rod 26.

Further, in the above embodiment, an example was explained in which the antenna 20 was configured for a personal radio, but the present invention is not limited to this, and the present invention may also be applied to a car radio or other vehicle receiver. In such a case, each height H-H3 and each diameter D1φ to D4φ may be changed as appropriate depending on the reception frequency of each receiver.

[Brief explanation of drawings]

1 is a diagram showing the antenna according to the present invention installed on the roof of a vehicle, FIG. 2' is a partially cutaway side view of the antenna in FIG. 1, and FIG. 6 is a diagram showing the antenna in FIG. 1. The plan view and FIG. 4 are characteristic curve diagrams showing the relationship between the standing wave ratio (V, S, W, R,) and the reflection coefficient 1β1 of the antenna in FIG. 1 and the radio frequency, and FIG. FIG. 1 is a characteristic curve diagram showing the horizontal plane directional electric field pattern of the antenna, and FIG. 6 is a characteristic curve diagram showing the vertical plane directional electric field pattern of the antenna. Explanation of symbols 10...Vehicle, 11...Roof, 21...Connector, 22.24, 26.27...Metal disk, 23.25
. 28...Metal rod, 22c...Insulating ring. Applicant Nippondenso Co., Ltd. Agent Patent Attorney Teru Hase - 15- Figure 4 aoo 9oo
Too. Frequency (MH) Figure 6-26 = Vertical plane directional electric field pattern

Claims (1)

[Claims] A metal rod is erected on a part of the outer wall of the vehicle to transmit and receive signals to and from a transmitter/receiver installed in the vehicle interior, and electric wires are installed at the base end and intermediate portion of this metal rod. first and second metal disks supported substantially horizontally via an insulating member; a third metal disk supported substantially horizontally at one end of the metal rod; and an intermediate portion of the metal rod. a capacitive electric element interposed in the portion and capacitively coupled to the second metal disk; a plurality of one-side terminals connected at intervals to the outer peripheral edge of the second metal disk; a first electrical load element having a plurality of other side terminals respectively connected to each surface portion of the first metal disk corresponding to each connection position of the second metal disk of the side terminal; 6. A plurality of one-side terminals connected at intervals to the outer peripheral edge of the metal disk and the third metal disk of each of these negative side terminals] 2) of the second metal disk corresponding to each connection position; a second electrical load element having a plurality of other side terminals respectively connected to each surface portion, the diameter of each metal disk, the axial length of the metal rod,
and a vehicle antenna, wherein the height of the second metal disk relative to the first metal disk is determined in relation to the wavelength of the transmitted and received signal.