JPH0878941A - Repeater antenna system - Google Patents

Abstract

PURPOSE: To provide the repeater antenna system with which fitting is facilitated, the loss of coupling is hardly generated and band can be widened by connecting the power feeding parts of loop antennas respectively composed of receiving parts and power feeding parts. CONSTITUTION: A loop antenna 2 equipped with a receiving part 3 and a power feeding part 7 with the lead wire of required width is formed, and a repeater antenna system 1 is formed by connecting this antenna 2 and a similar loop antenna 2A through power feeding lead wires 8 and 8A of power feeding parts 7 and 7A. Thus, the antenna system can be formed on the same plane without providing any coupling circuit and the repeater antenna system, with which the fitting is facilitated, the loss of coupling is hardly generated and the band can be widened in comparison with the case of providing loop antennas on both the respective sides of glass or the like and joining them with the coupling circuit, can be provided.

Description

Detailed Description of the Invention

[0001]

The present invention relates to transmission in the 400 MHz band, 800 MHz band and quasi-microwave band (1500 MHz band) used in low power radio stations of mobile communication systems represented by mobile phones, car phones and the like. The present invention relates to an antenna that receives and relays radio waves having a relatively weak output, and particularly relates to an ungrounded dipole antenna.

[0002]

2. Description of the Related Art First, although strong radio waves are emitted in broadcasting of televisions, radios, etc., the output of radio waves used in mobile communication systems such as mobile phones is a weak radio wave of 1 W or less. Therefore, the output of radio waves is significantly reduced outside and inside a moving body such as an automobile, resulting in insufficient sensitivity. Especially when moving by car, the distance from the base station is constantly changing from moment to moment, which has a great influence. Therefore, even if the base station is far away or in a place where the radio wave is weak, in order to use the mobile phone with good sensitivity, a so-called repeater antenna is attached to amplify the radio wave and remove noise, improving the sensitivity. It is necessary to plan. As shown in FIGS. 2 and 3, the repeater antenna device in the prior art is composed of an indoor side antenna 10 and an outdoor side antenna 11, and is well known to be formed of a non-grounded dipole antenna.

Indoor antenna 10 and outdoor antenna 11
Has a structure in which a tuning circuit 13 formed of a metallic material in the same rectangular shape is attached to an adhesive film 12 formed of a transparent resin.

The tuning circuit 13 includes a receiving unit 14 and a power feeding unit 15.
It consists of and. The receiver 14 is made of a metallic material having a predetermined width and has a predetermined length parallel to the longitudinal direction (in the embodiment, a length of 1/2 · λ where λ is the wavelength of the radio wave).
Parallel conductors 16 are arranged, and a first connecting line 17 which is continuous and orthogonal to one end of the connecting line 16 is arranged, and the first connecting line 17 is continuous with the parallel connecting lines 16 and more than the first connecting line 17. The first inner side has a predetermined width, which is 1/6 · λ in the embodiment.
The second connecting line 18 is provided in parallel with the connecting line 17 of.

The power feeding portion 15 has first and second connecting wires 17 and 1 provided at one end of a conductor 16 which is a parallel metal tape wire.
It has a structure in which feeding points 19 formed at the opposite end of 8 and facing each other at a predetermined interval are provided.

The antenna in this embodiment is a so-called half-wave dipole type antenna, and in a non-grounded type antenna, a receiver is installed in a power feeding portion 15 provided by separating the midpoints of conducting wires having a predetermined length. It has the structure of an antenna that is designed to do so. Further, even if a receiver is not connected to the power feeding unit 15, the receiver in the vicinity also has a function as a relay antenna capable of supplying a radio wave in which radio waves are amplified and noise is removed.

In the non-grounded antenna having such a structure, when a standing wave of voltage and current is placed on the conductor 16, the voltage is maximized in the released power supply section 15 and the current is zero. It is a well-known fact that such a relationship is satisfied when the length of the conductive wire 16 is an integral multiple of 1/2 · λ when the wavelength is λ.

As shown in FIG. 3, the indoor side antenna 10 and the outdoor side antenna 11 are arranged so that only their electrode portions 19 face each other with a glass serving as a dielectric member between them. Are arranged so that they are opposite to each other by 180 degrees.

The antenna 10 thus arranged,
In 11, a coil is formed by the first and second connecting portions 17 and 18, and a tuning circuit is formed by the capacitor formed by the power feeding portion 15 with glass interposed. That is, it is possible to receive a radio wave having a predetermined wavelength λ.

Indoor antenna 10 and outdoor antenna 11
The performance of the repeater antenna device can be confirmed by experiments. It has a frequency of 400-140
It can be confirmed by changing it stepwise within the range of 0 MHz and measuring the standing wave ratio (SWR) at each frequency. The measuring device is a scalar network analyzer, and the structure of the antennas 10 and 11 at this time is that the length of the conductor 16 is 1 / 2.λ = 160 mm. The distance between the first and second connecting portions is 1 / 6.λ = 55 mm. The width of 16 was set to = 4.5 mm and the interval between the parallel conductors 16 was set to 55 mm, and the measurement results were as shown in Table 1.

[0011]

[Table 1]

The result shows that the frequency is 800
The standing wave ratio (SWR) in the MHZ band range is "2"
It is the following. Here, the standing wave ratio (SWR) is "2.5"
The following is equivalent to an ordinary TV antenna and has no problem in practical use.

[0013]

However, the repeater antenna device according to the prior art described above requires an antenna inside and outside the glass, which is a dielectric, due to structural and electrical problems, and therefore the internal and external antennas are not required. Created separately, two antennas are fixed via glass, a capacitor using glass as a dielectric is configured, and the structure uses a coupling circuit that electrically connects the inside and outside. A loss (a loss of 2 to 3 dB in the above conventional technique) occurs, and it is difficult to widen the band of the antenna because the coupling circuit has a frequency band. For example, in the case of two bands of 800 MHz and 1500 MHz, there is a problem that it is difficult to manufacture with one coupling circuit.

Further, there is a problem that the place where the antenna is mounted is limited in order to form the coupling circuit.

Therefore, there is a problem to be solved in the structure of the repeater antenna, in particular, the structure of the relay antenna which does not depend on a specific member and the structure capable of widening the band.

[0016]

In order to solve the above problems, a repeater antenna apparatus according to the present invention is provided with a receiving portion in which a conductor having a predetermined width is looped in a planar shape, and provided on both end sides of the receiving portion. And a power feeding section, and is formed by connecting at least two power feeding sections of the loop antenna.

Further, the loop antenna is formed in a rectangular shape, the receiving section has two conducting wires arranged in parallel, and a first connecting section in which one end side thereof is vertically connected and the first connecting section. A second connecting portion arranged in parallel from the connecting portion at a predetermined distance in parallel, and a power feeding portion protruding at a predetermined distance from both ends on the other end side of the receiving portion; The connection of the two loop antennas at the power feeding portion is a repeater antenna device in which they are connected symmetrically.

[0018]

The repeater antenna device configured as described above is a loop antenna including a receiving portion and a feeding portion, which are formed by looping a conductor having a predetermined width in a planar shape, and connecting the feeding portions of at least two loop antennas. By forming a symmetrical shape, it is not necessary to form a coupling circuit, and the restriction on the mounting position of a moving body such as an automobile is loosened.

Further, since the dielectric plate such as glass of the moving body is not used, the antenna gain can be improved.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A repeater antenna device according to the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the repeater antenna device 1 has a plurality of loop antennas (two loop antennas in FIG. 1) 2 and 2A formed in a planar shape on a transparent film 1a. The individual loop antennas 2 and 2A are composed of receiving portions 3 and 3A and power feeding portions 7 and 7A. The film 1a made of a transparent member does not have to be for closely attaching the antenna.

The receiving portions 3 and 3A are formed of a conductive wire made of a metal material having a predetermined width L1 into a rectangular shape, and have two parallel conductive wires 4 and 4A having a length L2 in the longitudinal direction and the conductive wires 4 and 4A.
A first connecting portion 5, 5A having a length L3 continuously from one end of the first connecting portion, and two parallel conductors 4, 4A inside the first connecting portion 5, 5A by a predetermined distance L4. The structure is such that the second connecting portions 6 and 6A are continuously provided in the orthogonal direction.

The feeding parts 7 and 7A are composed of two parallel conductors 4,
4A is formed continuously from the other end, and is formed of conductive wires 8 and 8A which vertically project inward at a predetermined interval L5.

The loop antenna 2 having such a structure,
2A is a conducting wire 4, 4A and the first and second connecting portions 5,
The widths of the lines forming the power lines 6, 5A, 6A and the power feeding units 7, 7A are the same width L1, and the length L2 of the parallel conductors 4, 4A is 1/2 · λ of the wavelength λ of the received radio wave. The length of the first and second connecting portions 5, 6, 5A, 6A is 1/6 · λ,
Interval L between the first connecting portions 5 and 5A and the second connecting portions 6 and 6A
4 is 1/6 · λ. In the example, L1 = 6 mm L2 = 150 mm L3 = 50 mm L4 = 50 mm L5 = 6 mm.

Further, in this embodiment, as shown in FIG. 1, the feeding portions 7 and 7A of the two loop antennas 2 and 2A are connected to each other to have a symmetrical shape.

In this way, the two loop antennas 2, 2
The repeater antenna device 1 formed by connecting A by the power feeding portions 7 and 7A is attached to the glass of the automobile, which is a moving body, in close contact with the glass, regardless of whether the glass is inside or outside. If it is attached to the outside of the glass, the radio waves from the inside to the outside propagate in the order of air → glass → antenna → air, and the radio waves from the outside to the inside are air → antenna → glass → air.
If it is stuck inside the glass, the opposite is true.

The problem here is the transmission loss of the glass, but since the glass used in cars and buildings is a dielectric plate that is sufficiently thinner than the wavelength λ, the transmittance of radio waves is high, As described in the technology, the transmission loss of the radio wave transmitted through the glass is about -0.1 to 0.7 dB, as compared with the structure in which the coupling circuit is configured by using the glass as the capacitor.
Therefore, the gain of the antenna 1 in this embodiment is 1.5 as compared with the antenna using the coupling circuit described in the prior art.
~ 3 dB increase.

Here, antenna gain (also called gain)
dB is a number indicating how many times the transmission output is applied to the reference 1/2 wavelength dipole antenna, and the same effect is obtained, and 2 dB means that 1.585 times radio waves often enter. The standing wave ratio (SWR) is a measurement of antenna efficiency in a predetermined frequency band.

Therefore, even if the antenna is mounted inside the glass of the automobile, the same effect as mounting the antenna outside can be obtained. Moreover, its installation is extremely simple, since no coupling circuit is required. Further, since it has a flat shape, it produces no wind noise, and it is safe because it has no protrusions, and the antenna 1 is not damaged by car washing or the like. Further, in manufacturing the antenna, die-cutting, hot stamping, plating, and various manufacturing methods can be used. Then, by separately attaching a power supply line, it can be used not only as a repeater antenna but also as a high gain stack antenna or array antenna.

[Experimental Example] In order to confirm the effect of improving the sensitivity by using the repeater antenna device 1 of the present embodiment, the frequency is changed stepwise within the range of 750 MHz to 1050 MHz, and the standing wave at each frequency is changed. Ratio (SW
An experiment was conducted to measure R). The standing wave ratio (SWR)
2 is connected by the power supply units 7 and 7A described above.
The loop antennas 2 and 2A were connected to a scalar network analyzer.

[0031]

[Table 2]

As shown in Table 1, the standing wave ratio (SWR) used in the 800 MHz band is "2" as in the prior art.
Needless to say, the results are as shown in Table 3 below.

[0033]

[Table 3]

The meaning of Table 3 is that the standing wave ratio (SWR) is "2" or less, that is, if the standing wave ratio (SWR) is "2.5" or less, it is a normal television. Similar to the antenna, there is no practical problem, but the experimental example of this embodiment shows that the standing wave (SW
It is clearly seen that an improved value can be obtained over R). This has a larger gain than the antenna in the prior art, and enables widening of the frequency band of the antenna.

[0035]

As described above, the repeater antenna device according to the present invention is a loop antenna composed of a receiving part and a feeding part in which a conductor having a predetermined width is looped in a planar shape, and at least two loops are provided. By connecting the feeding parts of the antenna and forming the antenna in a symmetrical shape, the mounting can be performed very easily without being restricted by the mounting position.

Further, since a coupling circuit using a dielectric plate such as glass is not required, the antenna gain can be improved and the band can be widened. For example, 800 MHz band, 1500 MH
The effect is that it can be used as an antenna for the z band.

[Brief description of drawings]

FIG. 1 is a plan view of a repeater antenna device according to the present invention.

FIG. 2 is a plan view of a repeater antenna device in the related art.

FIG. 3 is a schematic perspective view showing how a conventional antenna is attached to a moving body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Repeater antenna device 2, 2A loop antenna 3, 3A receiving part 4, 4A conducting wire 5, 5A 1st connecting part 6, 6A 2nd connecting part 7, 7A feeding part 8, 8A feeding conducting wire

Claims (3)

[Claims] 1. A loop antenna comprising: a receiving unit in which a conductive wire having a predetermined width is looped in a planar shape; and a feeding unit provided at both ends of the receiving unit, wherein at least two feeding units of the loop antenna are provided. A repeater antenna device formed by connecting to each other. 2. The loop antenna is formed in a rectangular shape, the receiving section has two conducting wires arranged in parallel, and a first connecting section in which one end side thereof is vertically connected and the first connecting section. 2. A second connecting part, which is arranged in parallel from the connecting part at a predetermined distance in parallel, and a power feeding part projecting at both ends on the other end side of the receiving part at a predetermined interval. The repeater antenna device described. 3. The connection of the at least two loop antennas at the feeding portion is symmetrical to each other.
Alternatively, the repeater antenna device according to item 2.