JP3129618B2 - Glass antenna device for car phone - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass antenna device for an automobile telephone which is formed on a window glass of an automobile and mainly transmits and receives signals in an 800 MHz band (UHF). The present invention relates to a glass antenna device for a mobile phone that can be used.

[0002]

2. Description of the Related Art As disclosed by the present applicant in Japanese Patent Application Laid-Open No. Hei 6-237109, a conventional glass antenna device for a car telephone has a monopole-shaped radiation pattern and a substantially mouth-shaped grounding pattern. It is composed of a conductor pattern.

FIG. 5 is a configuration diagram of a conventional glass antenna device for a mobile phone. In FIG. 5, a glass antenna device 50 for a mobile phone includes a radiation pattern 53 and a signal extraction pattern extending from the radiation pattern 53 near a side edge of a window glass 51 of a vehicle having an anti-fog heater wire 52. A grounding pattern 55 provided at one end of a shield pattern 56 provided around the signal extraction pattern 54 is formed by a conductor pattern.

[0004] At the feeding point A of the signal extraction pattern 54,
The core wire 57a of the coaxial cable 57 (characteristic impedance 50Ω) is connected to the grounding point B of the shielding pattern 56.
Is connected to the outer conductor 57b of the coaxial cable 57.

[0005] The conductor pattern of the antenna is arranged close to the side edge of the window glass 51, power is supplied from the side edge (side power supply), and the side power supply portion is hidden by the interior material.

As described above, in the conventional monopole-shaped glass antenna apparatus 50 for a mobile phone, the conductor pattern of the antenna is arranged close to the side edge of the window glass 51, and a power supply (side power supply) portion from the side edge is provided. Since the antenna device is configured to be hidden by the interior material, the aesthetic appearance of the antenna device is maintained.

[0007]

In the conventional glass antenna device 50 for a mobile phone, the conductor pattern of the antenna is formed on the side edge of the window glass 51 in the shape and arrangement shown in FIG. There is a problem that the receiving sensitivity is reduced in the low band and the high band of the 800 MHz frequency band due to the influence of the shield pattern 56 that is turned around. Therefore, there is a demand for a glass antenna device for a mobile phone having good reception sensitivity over the entire frequency band.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a glass antenna apparatus for a mobile phone having good reception sensitivity even in side power supply over the entire 800 MHz frequency band. .

[0009]

[MEANS FOR SOLVING THE PROBLEMS]
The glass antenna device for a car telephone according to the present invention is arranged such that an anti-fog heater wire is provided near a side edge of a window glass surface of an automobile, and a coaxial cable is provided below the anti-fog heater wire.
It has a feed point, and a coaxial cable
And a monopole-shaped radiation pattern extends downward from the feed point via the signal extraction pattern, and extends downward from the ground point to the power supply point and the signal extraction pattern. of extending out shield pattern travels through the periphery, in car phone glass antenna device having one end to form a grounding pattern-shaped <br/> Hollow shielding pattern out this extends, in the vicinity of the ground point shield Parallel to the antifogging heater line from the
The conductor pattern having a predetermined width extends a predetermined length while keeping a predetermined distance from the lowermost end of the center wire, and serves as an impedance adjustment unit that matches the impedance with the coaxial cable at the ground point. And

Further, another glass antenna device for a mobile phone according to the present invention is provided with an anti-fogging film near one side edge of a window glass surface of an automobile provided with an anti-fogging heater wire . Under heater line
Has a feeding point from the coaxial cable and
With a ground point for coaxial cable above
From the feed point to the ground point below the feed point and the ground point.
In a glass antenna device for a mobile phone having a radiation pattern of a loop antenna shape, a predetermined distance from the lowermost end of the heater wire for anti-fog is set in parallel along the heater wire for anti-fog from the shield pattern near the ground point. Torigana
Then, a conductor pattern with a predetermined width extends by a predetermined length and
Characterized in that the impedance adjusting unit to match the impedance of the coaxial cable at the point.

[0011] These car phone for the glass antenna device
In the above, the impedance adjustment unit can match the impedance with the coaxial cable connected to the feeding point and the ground point.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a configuration diagram of a glass antenna device for a mobile phone according to the present invention. In FIG. 1, a glass antenna device 1 for a mobile phone includes a radiation pattern 4 and a signal extraction pattern 5 extending from the radiation pattern 4 near a side edge of a window glass 2 of a vehicle having an anti-fog heater wire 3. A substantially square-shaped grounding pattern 6 provided at one end of a shielding pattern 7 around the signal extraction pattern 5, and a parallel pattern from the shielding pattern 7 along the anti-fog heater wire 3. The impedance adjustment unit 9
It is formed by a conductor pattern.

A feeder point A of the signal extraction pattern 5 has a core wire 8a of a coaxial cable 8 (characteristic impedance 50Ω).
And the outer conductor 8b of the coaxial cable 8 is connected to the ground point B of the shield pattern 7.

In the embodiment, the conductor pattern of the antenna is formed below the anti-fog heater wire 3 .

The heater wire 3 for anti-fog is, for example, a thin nichrome wire or a heater wire formed by screen-printing a silver conductive paste on the window glass 2 and firing it.
Power is supplied from the heater power supply terminals 3b and 3c at both ends.

The conductive pattern of the antenna is, for example, screen-printed on the window glass 2 with a conductive paste obtained by forming fine particles of silver, low-melting glass powder or the like into a paste with an organic solvent.
Furthermore, conductive filaments formed by firing, conductive metal fine wires,
Alternatively, it is formed using a conductive member such as a conductive metal foil.

The radiation pattern 4 is formed to have a length of about λ / 4 (where λ indicates the wavelength of a radio wave). Each of the four sides of the outer frame of the grounding pattern 6 is formed to have a length of about λ / 4. The reason why the length of the radiation pattern 4 and the length of each of the four sides of the outer frame of the grounding pattern 6 are set to about λ / 4 is that 900 MHz when the shortening rate of the antenna formed on the glass base material is 0.6. Corresponding to λ / 4.

Further, a glass antenna device 1 for an automobile telephone
In order to match the impedance of the impedance adjusting section 9 and increase the sensitivity over the entire frequency band, the length L of the impedance adjusting section 9 is adjusted.
Is 120 mm, the width W is 0.4 mm, and the distance between the impedance adjusting section 9 and the lowermost end 3a of the heater wire for anti-fog is 10 mm.
mm.

FIG. 2 is a graph showing the reception sensitivity frequency characteristics of the glass antenna device for a mobile phone according to the present invention. The measurement of the receiving sensitivity was performed with reference to a dipole antenna.
In FIG. 2, the receiving sensitivity of the glass antenna device for a mobile phone according to the present invention is improved in the lower and higher frequency bands, and especially in the lower band, as compared with the conventional glass antenna device for a mobile phone. The sensitivity can be improved.

FIG. 3 is a voltage standing wave ratio frequency characteristic diagram of the glass antenna device for a mobile phone according to the present invention. The smaller the voltage standing wave ratio representing the transmission performance of the antenna, the more the impedance of the antenna and the coaxial cable can be matched. In FIG. 3, the glass antenna device for a mobile phone according to the present invention has a smaller voltage standing wave ratio over the entire frequency band and a lower impedance than the conventional glass antenna device for a mobile phone. Is consistent.

FIG. 4 is a block diagram showing another embodiment of the glass antenna device for a mobile phone according to the present invention. In FIG.
The glass antenna device 10 for a mobile phone differs from the glass antenna device 1 for a mobile phone in FIG. 1 in that a loop antenna 11 is formed instead of a monopole antenna.

The glass antenna device 10 for a car telephone is
By providing a parallel impedance adjustment section 9 from the ground point B of the loop antenna 11 along the lowermost end 3a of the anti-fog heater wire, impedance matching between the antenna and the coaxial cable is achieved, and reception sensitivity is improved. be able to. As described above, the antenna having a different shape from the monopole-shaped glass antenna device 1 for a mobile phone can also be provided with the impedance adjuster 9.

[0023]

As described above, the glass antenna device for a mobile phone according to the present invention is provided in parallel with the vicinity of the ground point of the shield pattern or the vicinity of the ground point of the loop antenna along the heater wire for anti-fog. Equipped with an impedance adjustment part formed of a conductor pattern that matches the impedance of the antenna and the coaxial cable, and the impedance can be matched with the coaxial cable connected to the feed point and the ground point, so that sensitivity can be improved over the entire frequency band. it can.

Further, in the glass antenna device for a mobile phone according to the present invention, the impedance adjusting section is set to a predetermined length and a predetermined width, and is arranged at a predetermined distance from the lowermost end of the heater wire for anti-fog. Since the impedance is matched with the coaxial cable connected to the feeding point and the ground point, the sensitivity can be improved over the entire frequency band.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a glass antenna device for a mobile phone according to the present invention.

FIG. 2 is a diagram showing the reception sensitivity frequency characteristics of the glass antenna device for a mobile phone according to the present invention

FIG. 3 is a voltage standing wave ratio frequency characteristic diagram of the glass antenna device for a mobile phone according to the present invention.

FIG. 4 is a configuration diagram of another embodiment of the glass antenna device for a mobile phone according to the present invention.

FIG. 5 is a configuration diagram of a conventional glass antenna device for a mobile phone.

[Explanation of symbols]

1,10 ... Glass antenna device for car phone, 2,51
... window glass, 3,52 ... heater wire for anti-fog, 3a ... lowermost end of heater wire for anti-fog, 3b, 3c, 52b, 52c
... Power supply terminals, 4, 53 ... radiation pattern patterns, 5,
54: Signal extraction pattern, 6, 55: Grounding pattern, 7, 56 Shielding pattern, 8, 57: Coaxial cable, 8a, 57a: Core wire, 8b, 57b: Outer conductor,
9: impedance adjustment unit, 11: loop antenna, 5
0: Conventional glass antenna device for a car phone.

Claims (2)

(57) [Claims] 1. An automotive vehicle having an anti-fogging heater wire, which is coaxially located below one side of an anti-fogging heater wire near one side edge of a window glass surface.
It has a feeding point from the cable, and
It has a ground point for the coaxial cable and
A monopole-shaped radiation pattern extends downward from the electric point via a signal extraction pattern, and extends downward from the ground point.
Direction extending out shielding pattern travels through the periphery of the feed point and the signal lead pattern, <br/> forming a grounding pattern of the shaped end portion of the sealing <br/> de pattern that began this extends the B In the glass antenna device for a car telephone, the predetermined pattern is provided from the lowermost end of the heater wire for anti-fog parallel to the heater wire for anti-fog from the shield pattern near the ground point.
While keeping the distance, the conductor pattern of the specified width is the specified length
Only extend out to the glass antenna device for an automobile telephone, characterized in that the impedance adjusting unit for matching impedances of the coaxial cable in the ground. 2. An automotive vehicle having an anti-fogging heater wire, which is coaxially located near one side edge of a window glass surface and below the anti-fogging heater wire.
It has a feeding point from the cable, and
It has a ground point for the coaxial cable and a feed point
In a glass antenna device for a mobile phone having a radiation pattern of a loop antenna shape from to a ground point ,
From the lowermost end of the heater wire for fogging in parallel along the heater wire for fogging from the shield pattern near the ground point
While keeping a fixed distance, the conductor pattern of the specified width is the specified length
Car phone glass antenna device characterized by comprising an impedance adjusting unit to match the impedance of the coaxial cable at the ground point extending out only.