JPH077209U - Wind through antenna - Google Patents

Abstract

(57) [Abstract] [Purpose] In a vehicle antenna for a wind-through type mobile phone, which guides radio waves into the vehicle through the window glass 10, enhances the receiving sensitivity in the vehicle. [Construction] An amplifier circuit 33 is built in an indoor antenna unit 30. Radio waves received from the outdoor antenna unit 20 are amplified by the indoor antenna unit 30 and transmitted to the inside of the vehicle. The antenna gain becomes 1 or more, and the reception sensitivity in the vehicle is improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a wind-through antenna used as an automobile antenna for a mobile phone, for example.

[0002]

[Prior art]

 With the spread of mobile phones, the use of mobile phones in the interior of automobiles is increasing rapidly. However, the output of a mobile phone is smaller than that of a car phone, and because the car body shields radio waves, the reception sensitivity inside the car is very poor. Therefore, it is often impossible to make a satisfactory call depending on the radio wave condition.

One of the proposals for eliminating such inconvenience to the user is a wind-through antenna that transmits and receives radio waves through a window glass of an automobile. A wind-through type portable automobile antenna is generally called a repeater antenna, and is composed of a pair of antenna units arranged to face each other with a window glass of a vehicle interposed therebetween.

One set of antenna units is fixed to the inner and outer surfaces of the window glass by, for example, double-sided tape. The attenuation of the radio wave between the antenna units is very small, and the radio wave received by the antenna unit outside the vehicle is transmitted to the antenna unit inside the vehicle with almost the same strength. Therefore, a call can be made inside the vehicle under substantially the same conditions as outside the vehicle.

[0005]

[Problems to be solved by the device]

 These wind-through type mobile phone antennas for mobile phones, which do not require a power supply and can be easily attached to the vehicle body, have rapidly expanded their sales. However, among those who actually used it, there are many opinions that the receiving sensitivity is hardly improved. In other words, in terms of measurement, the reception sensitivity inside the vehicle should be improved to the same level as that outside the vehicle, but in reality, the reception sensitivity is virtually unchanged. As a result, the sales of this type of antenna have slowed considerably since coming here.

The main reason why the perceptual receiving sensitivity in the vehicle is not improved even when the wind-through type mobile phone automobile antenna is used is that the antenna gain is not 1 or more. In order to increase the antenna gain to 1 or more, an internal antenna with a large size and a vehicle-mounted amplifier unit are commercially available. However, the large internal antenna is an obstacle in the car, and is not suitable for in-vehicle use. Since the onboard amplifier unit is also expensive and large, if it is used together, the inherent performance of the wind-through type antenna such as economy and space utilization will be impaired.

The present invention was devised in view of such circumstances, and a wind-through antenna capable of increasing the reception sensitivity indoors without increasing the size of the internal antenna or using an in-vehicle amplifier unit or the like together. The purpose is to provide.

[0008]

[Means for Solving the Problems]

 The wind-through antenna according to the present invention is a wind-through antenna that transmits and receives radio waves between a pair of antenna units that are arranged opposite to each other with a window glass interposed therebetween. It features a built-in amplifier circuit that amplifies the received radio wave and gives it to its own antenna.

[0009]

[Action]

 By incorporating an amplifier circuit in at least the indoor antenna unit, the radio waves received by the outdoor antenna unit are amplified by the indoor antenna unit and transmitted to the room, so there is no loss between the antenna units. However, the gain can be increased to 1 or more. Therefore, the reception sensitivity in the room is better than in the outdoors. When amplification is performed by one antenna unit, the amplified radio wave is received by the other antenna unit, and this is further amplified by one antenna unit. It has been confirmed that the oscillation does not pose a problem in the result of the experiment using the car antenna for automobile.

[0010]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an external view of a mobile phone vehicle antenna showing one embodiment of the present invention, and FIG. 2 is a circuit diagram configuration of a mobile phone vehicle antenna.

In this embodiment, the present invention is applied to a mobile phone automobile antenna.

The present antenna includes an outdoor-side antenna unit 20 attached to the outer surface of a window glass 10 of an automobile, and an indoor unit located behind the antenna unit 20 and attached to the inner surface of the window glass 10. The antenna unit 30.

The outdoor-side antenna unit 20 has a large external antenna 21. The external antenna 21 is connected to the matching circuit 22 built in the antenna unit 20. The outdoor-side antenna unit 30 has a small internal antenna 31, a built-in matching circuit 32, and an amplifier circuit 33.

The matching circuits 22 and 32 are for improving the transmission efficiency of radio waves, and well-known circuits using a coil, a condenser, etc. can be used. The amplifier circuit 33 is driven by the battery of the automobile as a power source, amplifies the output of the matching circuit 32 and gives it to the internal antenna 31. As the amplifier circuit 33, a known circuit having a simple oscillation prevention circuit can be used.

By incorporating the amplifier circuit 33 in the antenna unit 30 on the outdoor side, a decrease in transmission efficiency between the matching circuits 22 and 32 is compensated for, and it is possible to create a reception environment equivalent to that outside the vehicle. Instead, depending on the gain setting of the amplifier circuit 33, a radio wave stronger than the radio wave received by the external antenna 21 can be sent out from the internal antenna 31 into the vehicle. Therefore, the receiving sensitivity of the mobile phone in the vehicle is significantly improved, and even if the radio wave condition is poor, it is possible to make a call without any trouble in the vehicle.

Moreover, the amplifier circuit 33 is inexpensive and does not greatly affect the manufacturing cost of the antenna, and since it is built in the amplifier circuit 30, the interior space of the vehicle is not sacrificed.

Note that this antenna requires a connection line 34 with the power source because the amplifier circuit 33 is powered by the battery of the vehicle. This connection line is a coaxial line that connects the in-vehicle amplifier unit and the antenna unit. It is thinner and more flexible than a cable, and it is very easy to run around.

One of the reasons why the amplifier circuit is not used in the conventional wind-through antenna is considered to be the above-mentioned oscillation phenomenon and the connection line with the power supply, but since it is not a serious problem in practical use. is there.

As a power source for the amplifier circuit 33, a dry battery built in the indoor antenna unit 30 can be used, and in that case, even a connection line with the power source is not necessary.

The amplifier circuit 33 can be provided not only in the indoor-side antenna unit 30 but also in the outdoor-side antenna unit 20. In that case, the radio waves going out of the car can be amplified.

Specific configurations of the matching circuits 22 and 23 and the amplifier circuit 33 are not particularly limited, and well-known configurations can be appropriately adopted.

The external configuration of the antenna units 20 and 30 is not particularly limited, and may be, for example, one that is hooked on the side glass of an automobile.

Further, the present invention can be applied not only to a mobile phone car antenna, but also to a mobile phone call Annate in an apartment house where it is difficult to penetrate a coaxial cable.

[0024]

[Effect of device]

 As described above, the wind-through antenna according to the present invention amplifies the radio wave guided from the outdoor to the indoor by the amplifier circuit, so that the indoor receiving sensitivity can be increased without increasing the size of the indoor antenna. it can. Since the amplifier circuit is built into the indoor antenna unit, there is no need for an in-vehicle amplifier unit. Therefore, for example, it can be used for an automobile antenna for a mobile phone, and it is possible to surely enhance the receiving sensitivity in terms of sensation while maintaining the conventional economical efficiency and space utilization.

[Brief description of drawings]

FIG. 1 is an external view of a mobile phone car antenna showing an embodiment of the present invention.

FIG. 2 is a circuit diagram configuration of an automobile antenna for a mobile phone.

[Explanation of symbols]

 10 Window Glass 20 Outdoor Antenna Unit 21 External Antenna 22 Matching Circuit 30 Outdoor Antenna Unit 31 Internal Antenna 32 Matching Circuit 33 Amplifier Circuit

Claims (1)

[Scope of utility model registration request] 1. A wind-through antenna for transmitting and receiving radio waves between a pair of antenna units arranged opposite to each other with a window glass sandwiched therebetween, wherein at least the indoor-side antenna unit receives the radio waves received from the other-side antenna unit. A wind-through antenna that has a built-in amplifier circuit that amplifies and supplies it to its own antenna.