JPS6335001A - On-vehicle antenna - Google Patents

Abstract

PURPOSE:To obtain the sufficiently excellent reception state by arranging a pole antenna and a glass antenna respectively to the right/left of a vehicle body and near imaginary diagonal lines tying two optional corners of the vehicle body opposed to each other. CONSTITUTION:The pole antenna 1 is arranged to a front pillar 3a of the vehicle body and the glass antenna 2 is arranged to a rear window 6 near a corner 5 of the vehicle body opposed to the pole antenna 1 and opposed to a corner 4 of the vehicle body of the front pillar 3a. That is, the glass antenna 2 is arranged near an imaginary diagonal line 11 tying the corners 4, 5 of the vehicle body. A notch A1 of the sensitivity is caused in the directivity A of the pole antenna 1 with respect to a radio wave from the rear side of the vehicle body 3 and the sensitivity in the other directions is excellent. On the other hand, the directivity B of the glass antenna 2 is low in the sensitivity than that of the pole antenna 1, but it has a uniform characteristic close to a circle. Thus, the sensitivity notch A1 in the pole antenna 1 is corrected by the glass antenna 2 as shown in hatched part C to obtain a uniform directivity as a whole.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention improves radio broadcasting, etc. by appropriately switching two antennas placed at an appropriate distance to the one with better reception. The present invention relates to a vehicle antenna that is provided to a receiving diversity antenna system.

[Prior art]

Conventional vehicle antennas of this type include
There is a "vehicle antenna" disclosed in Japanese Patent No. 510. This antenna has two antennas, one of which is installed on the front window of the vehicle and the other on the side window, and by switching between these antennas as appropriate,
This is to ensure good reception conditions.

However, with the above-mentioned conventional structure, it is still not possible to obtain a sufficiently good reception condition, and since one antenna is installed in the front window, it has the disadvantage that forward visibility is slightly obstructed. Ta.

[Purpose of the invention]

The present invention has been made in consideration of the above conventional problems, and an object of the present invention is to provide a vehicle antenna that can obtain sufficiently good reception conditions without obstructing the forward view. It is.

[Structure of the invention]

In order to achieve the above object, the vehicle antenna of the present invention includes a pole antenna and a glass antenna provided on the side glass of the vehicle.
In the vehicle antenna that constitutes the system, the above-mentioned pole antenna and glass antenna are respectively arranged on the left and right sides of the vehicle, and each is arranged near a virtual diagonal line connecting arbitrary two corners of the cabin facing each other. The present invention is characterized in that it is configured such that a sufficiently good reception condition can be obtained.

〔Example〕

An embodiment of the present invention will be described below based on FIGS. 1 to 6.

As shown in FIG. 1, the vehicle antenna consists of a pole antenna 1 and a glass antenna 2 provided on the side window of the vehicle, which constitute a privacy antenna system. The pole antenna 1 is disposed on the front pillar 32 of the vehicle, and the glass antenna 2 is located on the left and right opposite sides of the pole antenna 1 and on the front pillar 3a.
It is disposed on the rear window glass 6 near the corner 5 of the vehicle interior on the side opposite to the corner 4 of the vehicle interior. That is, the glass antenna 2 is connected to the virtual diagonal line 11 connecting the corner 4 and the corner 5 of the vehicle interior.
Located nearby. Note that the left-right and front-back relationships between the pole antenna 1 and the glass antenna 2 may be reversed. The pole antenna 1 and the glass antenna 2 are connected to a radio receiver, etc. via a switching means (not shown), and the switching means connects the antenna with a better reception condition to the radio receiver, etc. is configured so that it can be switched as appropriate.

In the above configuration, the directivity characteristics and phase characteristics of the vehicle antenna are as shown in FIGS. 2 and 3. In FIG. 2, the directional characteristic A of the pole antenna 1 is
A sensitivity depression A is generated for radio waves from the rear of the vehicle 3, and the condition is good in other directions. On the other hand, the directional characteristic B of the glass antenna 2 has a lower sensitivity than that of the pole antenna 1, but has a substantially uniform shape close to a circle. Therefore, by correcting the sensitivity recess A in the pole antenna 1 with the glass antenna 2 as shown by the shaded area C, uniform directivity characteristics can be obtained as a whole.

Furthermore, in Fig. 3, as shown in Fig. 3 (a), the strength of the radio waves is repeated every 1/2 cycle, so theoretically the distance between the pole antenna l and the glass antenna 2 is
As shown in FIG. 6(b), it is thought that it is best to provide them at a distance of 1/2 wavelength. However, in reality, both antennas are usually arranged at a distance of 1/2 wavelength or more due to the structure of the arrangement position in the vehicle 3 and various influences on radio wave propagation. In this vehicle antenna, the pole antenna 1 and the glass antenna 2 are switched as appropriate depending on the reception condition, so that it is less susceptible to changes in electric field strength.

Here, Table 1 shows the results of a test to confirm the guivacity effect of this vehicle antenna. As shown in Fig. 4, the test method involved placing a pole antenna 1 on the front pillar 7a of the test vehicle 7, and placing a dipole antenna 8 at a position 1.600 mg+ behind this pole antenna 1. do. Furthermore, a dipole antenna 9 is arranged on the opposite side of the test vehicle 7, separated by 1.500 m from this dipole antenna 8, and at a position equal to the distance from the front end of the test vehicle 7 to the dipole antenna 8. . Therefore, the dipole antenna 9 is disposed near the rear window glass near the corner of the vehicle interior on the side opposite to the corner of the vehicle interior on the front pillar 7a side. Here, since the glass antenna 2 can obtain the same performance as the dipole antennas 8 and 9 by tuning, the dipole antennas 8 and 9 were used as the glass antenna 2 in this test. There are three types: (1) pole antenna l only, (2) diversity antenna system with pole antenna l and dipole antenna 8, and (3) diversity antenna system with pole antenna 1 and dipole antenna 9 (this invention). configured the receiving status. Then, while receiving vertically polarized waves of 95.75 MH2 transmitted from the transmitting antenna 10, the test vehicle 7 was run on a circumferential test course with a radius of 10 m, and the noise from the receiver at this time, that is, each antenna The number of times a buzzing sound occurred due to a drop in the induced voltage at the antenna and the induced voltage of each antenna were measured.

[Margin below]

Table 1 As shown in Table 1 above, (3) Diversity antenna with pole antenna 1 and dipole antenna 9.
It is recognized that in the system, compared to cases (1) and (2), the number of occurrences of noise due to a drop in the induced voltage is extremely small, and excellent reception conditions can be obtained. In addition, the measurement results of the induced voltage are as follows: (2) In the case of a diversity antenna system using the pole antenna 1 and the dipole antenna 8, as shown in FIG. Many depressions D occur. On the other hand, in (3) a diversity antenna system using the pole antenna 1 and the dipole antenna 9, as shown in FIG. On the contrary, the pole antenna 1 corrects the portions where the induced voltage of the dipole antenna 9 drops, so that a fairly uniform level of induced voltage is obtained. As is clear from the above results, (3) the diversity antenna system using the pole antenna 1 and the dipole antenna 9, that is, the present vehicle antenna, can provide good reception conditions.

〔Effect of the invention〕

As described above, the vehicle antenna of the present invention is a vehicle antenna that constitutes a diversity antenna system by a pole antenna and a glass antenna provided on the side glass of a vehicle, and the vehicle antenna comprises a pole antenna and a glass antenna provided on the side glass of a vehicle. Each antenna is arranged on the left and right sides of the vehicle, and is arranged near a virtual diagonal line connecting arbitrary two opposing corners of the vehicle interior, so that forward visibility is not obstructed by any of the above antennas. do not have. Further, the pole antenna and the glass antenna reliably correct each other for sensitivity, noise, etc., thereby achieving the effect that good reception conditions can be obtained.

[Brief explanation of drawings]

1 to 6 show an embodiment of the present invention, and FIG. 1 is a perspective view showing the arrangement of a vehicle antenna;
Fig. 2 is an explanatory diagram of directional characteristics, Fig. 3 (a) and (b) are explanatory diagrams of phase characteristics, Fig. 4 is an explanatory diagram showing test conditions of a vehicle antenna, and Fig. 5 is an explanatory diagram of pole antenna 1 and dipole. FIG. 6 is a graph showing the guihacity effect due to the pole antenna 1 and the dipole antenna 9. 1 is a pole antenna, 2 is a glass antenna, 3 is a vehicle,
3a is a front pillar, 4 and 5 are corners of the vehicle interior, 6 is a rear window glass (rear side glass), and 11 is a virtual diagonal line.

Claims (1)

[Claims] 1. Diversity antenna by the pole antenna and the glass antenna provided on the side glass of the vehicle.
In the vehicle antenna that constitutes the system, the above-mentioned pole antenna and glass antenna are respectively arranged on the left and right sides of the vehicle, and each is arranged in the vicinity of a virtual diagonal line connecting arbitrary two opposing corners of the vehicle interior. A vehicle antenna characterized by: 2. The above-mentioned pole antenna is disposed on the front pillar of the vehicle, and the glass antenna is disposed on the rear side glass near the corner of the vehicle interior on the side opposite to the corner of the vehicle interior on the side of the front pillar. A vehicle antenna according to claim 1.