JPS6258705A - Antenna system for mobile station - Google Patents

Abstract

PURPOSE:To sufficiently miniaturize a device to the degree that the visual field of an operator is not prevented by constituting the height of a dielectric substrate is formed in the same size as the longitudinal width of a waveguide element and providing a compaction element mounted so as to be connected to the tip part of a radiation element position at the edge of the dielectric substrate and to intersect orthogonally with the dielectric substrate. CONSTITUTION:The height (longitudinal width) of a dielectric substrate 1 is constituted in the same size of the longitudinal width l3 of a waveguide element 3 and at one end sides of both planes of the dielectric substrate 1, the waveguide element 3 is formed and also, at the other end side, a radiation element 2 is formed. And the intermediate part of the radiation element 2 is connected to that of the waveguide 3 with a strip line 4, and a connecting plug 5 is connected to the end of the waveguide 5. Also, at the tip part of the radiation element 2 arranged at the upper and the lower parts of the dielectric substrate 1, two plate-shaped compaction elements 7 are arranged so as to intersect orthogonally against the dielectric substrate 1. Thus, these compaction elements 7 are arranged in parallel with each other and also, their intermediate parts are connected respectively to the tip part of the radiation element 2.

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Industrial Application The present invention relates to a mobile station antenna comprising a dielectric substrate, and a waveguide element and a radiating element formed on the dielectric substrate.

b. Prior Art Conventionally, rod-shaped antennas such as sleeve antennas, whip antennas, collinear antennas, etc., have been used as mobile station antennas for automobiles. It was attached to the side, etc. Therefore, when parking the vehicle in a garage, it is necessary to fold the antenna or remove it from the vehicle body. Another problem is that the antenna is easily damaged due to theft or mischief. Furthermore, it was necessary to waterproof the entrance of the power supply cable from the antenna outside the vehicle to the inside of the vehicle.

In order to eliminate the various inconveniences mentioned above, there has been a demand for a type of mobile station antenna that is installed inside the vehicle instead of a type of mobile station antenna that is installed outside the vehicle. A station antenna device (two-element Yagi antenna with waveguide element) is used.

This antenna consists of a dielectric substrate 1 as shown in FIG.
, a radiating element 2 and a waveguide element 3 formed on the dielectric substrate 1, a strip line 4 connecting these elements 2.3 to each other, and a plug 5 connected to the waveguide element 3.
and a case 6 that houses them.

In an antenna with such a configuration, if the wavelength used is λ, the width of the antenna is 111 "Aλ, and the vertical width is l1z".
Aλ, length and line width of waveguide element 3) 7! ,<! /Gλ, and considering the use of 800MH2 band car phone, Nz=150 Tsuru,! , = about 100 m1 is required.

Therefore, when the antenna described above is installed inside the vehicle, its installation position is limited to the rear tray 10 or the front dash board 11, as shown in FIG. 8+a) or FIG. 8(b).

Problems to be solved by the C0 invention However, conventional mobile station antennas have limited dimensions (especially height).
Since the antenna becomes quite large, there is a problem in that the presence of the antenna obstructs the driver's field of view, causing trouble in driving.

The present invention was devised in view of the above-mentioned circumstances, and an object thereof is to provide a mobile station antithesis that can be constructed sufficiently compact to the extent that it does not obstruct the driver's field of view.

d. Means for Solving the Problems In order to solve the above problems, the present invention includes a dielectric substrate, and a waveguide element and a radiation element formed on the dielectric substrate, respectively. In the mobile station antenna device, the height of the dielectric substrate 1 is defined as the line width β of the waveguide element 3,
A shortening element 7 is provided which is connected to the tip of the radiating element 2 located at the edge of the dielectric substrate 1 and is attached perpendicularly to the dielectric substrate 1.

An embodiment of a mobile station antenna to which the present invention is applied will be described below with reference to FIGS. 1 to 5.

In addition, in FIGS. 1 to 5, the parts common to those in FIG. 1 are given the same reference numerals, and the explanation thereof will be omitted.

FIG. 1 shows a first embodiment of the present invention, in which a mobile station antenna device (a two-element Yagi antenna with a waveguide) A is a dielectric substrate 1. Radiating element 2. Waveguide element 3.
Strip line 4. Each of the connectors includes a plug 5 and a case 6, and further includes a shortening element 7.

The height and line width of the dielectric substrate 1 described above are configured to be the same as the line width l of the waveguide element 3, and the waveguide element 3 is formed on both sides of the dielectric substrate Fi1 at one end thereof. , a radiating element 2 is formed on the other end side. The middle part of the radiating element 2 is connected to the middle part of the waveguide element 3 by a strip line 4, and a plug 5 is connected to the end of the waveguide element 3.

Furthermore, two plate-shaped shortening elements 7 are disposed at the tips of the radiating elements 2 disposed at the upper and lower ends of the dielectric substrate 1 so as to be perpendicular to the dielectric substrate 1. . These shortening elements 7 are arranged parallel to each other, and their intermediate portions are connected to the tip of the radiating element 2, respectively.

Next, the effectiveness of the mobile station antenna device of this example provided with the shortening element 7 as described above will be explained.

FIG. 2(a) is a current distribution diagram of the radiating element 2 in the conventional device, and FIG. 2(b) is a current distribution diagram of the radiating element 2 in the device of this example. As is clear from Figure 2(a),
In conventional devices, the current distribution on the radiating element 2 has a minimum current at the tip of the radiating element 2 and a maximum current at the center of the radiating element 2. Note that this current distribution is the characteristic of the antenna, such as the gain.

The range that contributes to directivity, etc. is a shaded area a in FIG. 2(a). On the other hand, regarding the device of this example, the second
As can be seen from Figure 2(b), even though the total length of the radiating element 2 is shortened to 13, the shortened element 7 functions as the radiating element 2, so the current distribution is similar to the shaded area B in Figure 2(a). It will be almost the same.

FIG. 3 shows the gain characteristics of the conventional device and the device of the present invention, and FIG. 4 is a diagram showing the directivity characteristics of the conventional device and the device of the present invention. As is clear from these figures, the shortening element 7 is used. Therefore, it is possible to obtain characteristics in both gain and directivity that are almost the same as those of conventional large-sized devices.

Therefore, according to the mobile station antenna device A of this example, although it has the same characteristics as the conventional one, it can be sufficiently miniaturized, as shown in FIG. 5(a).

As shown in FIGS. 5(b) and 5(c), a rear rear tray 10. Even if the front dash board 11° is placed at the rear 12 of the room mirror, it will not obstruct the driver's field of view.

Although one embodiment of the present invention has been described above, the present invention is not limited to the embodiment described above, and various modifications and changes can be made based on the technical idea of the present invention.

For example, in the embodiment described above, the shortening elements 7 are attached at right angles to both the upper and lower ends of the dielectric substrate 1 and arranged parallel to each other.
If the length of the shortening element 7 becomes long and the width of the entire device becomes long, both ends 7a of the pair of shortening elements 7 may be folded back at right angles, as shown in FIG. In this case, the width can be shortened by the length of both folded edges 7a, and further miniaturization can be achieved.

Effect of C1 invention As described above, in the present invention, the height l of the dielectric substrate 1.

is made to match the line width of the waveguide element 3, and a shortening element is provided that is connected to the tip of the radiating element 2 and perpendicular to the dielectric substrate 1, so that it can have the same antenna characteristics as the conventional one. Regardless, the length of the radiating element 2 can be made the same as the line width β of the waveguide element 3, and the size of the entire device can be reduced by about 30% compared to the conventional one. In other words, the antenna height has been reduced from the conventional 150 u to 1
00 tm. Therefore, even when the device of the present invention is installed on the seat tray or front dash board of an automobile, there is little risk of narrowing the driver's field of view. Further, since the conventional device was large, it was impossible to attach it to the rear of the rearview mirror, but the device according to the present invention is sufficiently small, so it can be attached to such a location.

[Brief explanation of the drawing]

FIGS. 1 to 5 are for explaining one embodiment of the present invention, in which FIG. 1 is a perspective view of a mobile station antenna device (two-element Yagi antenna with waveguide), and FIG. (Al is a current distribution diagram of the radiating element of the conventional mobile station antenna device, FIG. 2(b) is a current distribution diagram of the radiating element of the mobile station antenna device of the present invention, and FIG. Figure 4 is a characteristic diagram of the gain of the device of the invention, and Figure 5 (a) is a characteristic diagram of these directivity characteristics.
1, (bl and (C1) are schematic perspective views showing the case where the device of the present invention is attached to the passenger tray, front dash board, and rear rear view mirror of an automobile, respectively; FIG. 6 is a schematic perspective view showing a modification of the present invention; Similar perspective views, FIGS. 7 and 8, are for explaining a conventional mobile station antenna device, and FIG. 7 is a perspective view similar to FIGS. 1 and 6, and FIG. fat and (bl are shown in FIG. 5(a) and (bl
It is a perspective view similar to. A... Mobile station antenna (two-element Yagi antenna with waveguide) 1... Dielectric substrate, 2... Radiation element,
3... Waveguide element, 4... Strip line, 5... Junction, 6... Case, 7... Shortening element, 7a... Bending portion. Figure 3 Frequency (MHz) Figure 4

Claims (1)

[Claims] In a mobile station antenna device comprising a dielectric substrate and a waveguide element and a radiating element formed on the dielectric substrate, the height of the dielectric substrate 1 is defined as the vertical width l of the waveguide element 3.
The structure is the same as that of _3, and the dielectric substrate 1 is connected to the tip of the radiating element 2 located at the edge of the dielectric substrate 1.
1. An antenna device for a mobile station, characterized in that a shortening element 7 is installed so as to be orthogonal to the antenna.