JP3230278B2 - Mobile antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mobile antenna suitable for use as a car antenna for a television.

[0002]

2. Description of the Related Art A so-called monopole antenna is widely and generally marketed as a car antenna for receiving radio and FM broadcasts, and a car body is also configured on the premise that the car antenna as described above is mounted. When the monopole antenna is mounted at a predetermined position on the vehicle body, the monopole antenna is grounded by the vehicle body.

[0003]

As described above, the vehicle body is generally configured on the assumption that a monopole antenna for receiving a radio or FM broadcast is mounted. It can be easily mounted on the vehicle body and grounded on the vehicle body. However, when a car antenna for a TV is mounted as an after-sales service, there are the following problems.

(1) Since the vehicle body surface is insulated by paint or the like, the paint or the like must be partially destroyed in order to ground the antenna near the antenna mounting position.

(2) In order to ground without destroying the paint etc., it is necessary to connect to a position where grounding is possible without breaking the paint etc. via a ground wire or the like, so that workability is poor, and Damage the appearance of the body.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems and to provide a mobile antenna capable of reliably grounding without destroying the paintwork of the vehicle body.

[0007]

SUMMARY OF THE INVENTION A mobile antenna according to the present invention.
Is attached to the end of the first antenna element.
A second antenna element extending on the opposite side of the
Balloon between the first antenna element and the second antenna element
Is arranged, and a power supply line is connected to the balloon.
Done.

[0008]

The mobile antenna is located at the end of the first antenna element.
A second antenna extending on the opposite side of the first antenna element.
A first antenna element and a second antenna element.
A balloon is placed between the tena elements, and a feeder is connected to the balloon.
Having connect, destroying the body such as coating the same effect to that ground can be obtained by, it can widen the band and high sensitivity of the mobile antenna as a car antenna and the like for television it can.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

FIGS. 1 to 6 show a first embodiment.

[0011] Figure 1 is a diagram showing a use state of the mobile antenna 1 of the present invention, the mobile antenna 1 of the present invention includes a first antenna element 2 retractable, the first antenna element 2 An antenna storage case 3 attached so as to be able to be pulled out from one end side, and a second antenna element (hereinafter, ground) attached to the other end side of the antenna storage case 3
The side of the antenna element hereinafter) 4, substantially parallel to the antenna element 4 of the ground side, bundling the feed line 5 drawn from the antenna housing case 3, a feed line 5 and the antenna element 4 of the ground-side holder 6 And

The telescopic first antenna element 2 is formed by sequentially connecting a plurality of rods 2a to 2d having different diameters so as to be freely slidable. the length L ₁ is adapted to be 1/4, for example, about 82cm in length average frequency wavelength of the television row channels (1-3 channels).

The largest diameter rod 2a is mounted in the antenna housing case 3, and the smaller diameter rods 2b to 2d are sequentially inserted into the largest diameter rod 2a. As a result, the rods 2a to 2d are inserted. All of 2d, ie the first
The entire antenna element 2 is stored in the antenna storage case 3.

A double-sided adhesive tape 11 is provided on the bottom surface of the antenna housing case 3.
1, the antenna storage case 3 is attached to the center pillar 13 of the vehicle body 12 of the automobile.

When the first antenna element 2 is pulled out from the antenna housing case 3 to the maximum extent,
Overlap the first antenna element 2 is part the center pillar 13 of length L _2, the portion of the remaining length L ₃ extends above the body 12, this portion of the television high channels (4-12 (Channel) as an antenna element.

Further, the antenna element 4 on the ground side is made of a coaxial cable, and its length L ₄ is about 1 / the length of the wavelength of the average frequency of the high channel (4 to 12 channels) of the television. The first antenna element 2 has a length of, for example, about 36 cm, and extends linearly with respect to the first antenna element 2.

The feeder line 5 drawn from the antenna housing case 3 is connected to the ground-side antenna element 4.
It extends to the door 14 side of the vehicle body 12 while being parallel to, and is introduced into the vehicle interior from the door portion and connected to the television.

The holder 6 is for fixing the antenna element 4 on the ground side and the feeder line 5 to the center pillar 13 of the vehicle body 12 in parallel.

The holder 6 is made of plastic in the shape of a channel having a concave cross section. By inserting the antenna element 4 on the ground side and the feeder line 5 into a groove 16 provided on the upper surface side, the holder 6 is connected to the ground side. The element 4 and the power supply line 5 can be locked in a state of being bundled in parallel, and the double-sided adhesive tape 17 provided on the bottom side is provided.
Thereby, it can be attached to the front pillar 13 of the vehicle body 12.

Further, in the antenna housing case 3, as shown in FIG. 4, a balloon (common mode current blocking filter) 21 is provided at a feeding point.

The mobile antenna 1 according to the first embodiment has the above-described configuration, and has a high channel (4 to 12) of a television.
When receiving the radio wave of the channel), as shown in FIG. 5, the portion of the first antenna element 2 of the length L ₃ (the portion not overlapping the vehicle body) is effectively act as an antenna, a first the length L ₂ of the portion of the antenna element 2 (the portion overlapping the vehicle body) will play a role of a feed line leading to electromotive force generated in the portion of the L ₃ to the point B.

The ground-side antenna element 4
The length L ₄ is about １ ／ of the length of the wavelength of the average frequency of the high channel.
The points are grounded with low impedance, and the component (electromotive force) guided to the point B is effectively guided to the power supply line 5 side.

When receiving radio waves of low channels (1 to 3 channels), as shown in FIG.
Since the points A and G have a capacitive low impedance, a sensitivity that does not affect practically is obtained.

Accordingly, a wideband antenna having sensitivity in both the low channel and the high channel can be obtained.

When the performance of the mobile antenna of the present invention provided with the ground-side antenna element and the performance of the mobile antenna provided with no ground-side element were tested, the measurement results shown in FIG. 11 were obtained. It has been proved that the effect of the mobile antenna of the invention is excellent.

FIG. 7 shows a second embodiment of the present invention.

In this embodiment, the equivalent impedance at the points A and G described with reference to FIG. 6 is further lowered to improve the matching in the low channel. Low channel (1
1 to 3 of the wavelength length of the average frequency
4 with the addition of a ground side of the antenna element 22 of the two first (second) of the length L _5.

By lowering the point A equivalently to the ground by the second ground-side antenna element 22, the sensitivity in the low channel can be further improved.

FIG. 8 shows a third embodiment.

This embodiment is a modification of the second embodiment.
The second ground-side antenna element 22 from the feed point
By placing the balloon 21 to the position of the length L ₅ of the, in which so as to have the same function as the antenna element 22 of the two first ground-side outer skin conductor of the feed line 5.

FIG. 9 shows a fourth embodiment.

[0032] This embodiment of the provided two second antenna elements 23 for separate high-channels from the first antenna element 2 to the mobile antenna of the second embodiment, the two first Ann <br/> antenna the antenna elements 4 of the element 23 and the ground side and a high channel, the first antenna element 2 and two second
By using the low-channel antenna elements 22 on the ground side, the antenna elements 22 are formed to have the lengths at which resonance is most likely to occur, so that a higher sensitivity and wider bandwidth can be achieved.

FIG. 10 shows a fifth embodiment.

This embodiment is different from the mobile antenna of the fourth embodiment in that the balloon 21 and the feed line 5 are provided independently for the high channel and the low channel, and diversity is formed as two independent antennas. It is intended to be able to suppress a change in the reception intensity with respect to the traveling direction (direction) of the automobile.

[0035]

The mobile antenna of the present invention has the following effects.

(1) For example, at the end of the first antenna element,
For example, about 1/4 of the wavelength of the peripheral wavelength of the high channel of TV
The length of the second antenna element (the antenna element on the ground side
), And a barrier is provided between the first and second antenna elements.
I placed the runes and connected the feeder to the balloon
The antenna without destroying the paintwork etc. on the vehicle body surface.
The same effect as that obtained by land can be obtained.

(2) Make the antenna element flexible and
As it can be stored in the antenna storage case,
Even when driving, it is necessary to remove the antenna
Absent. In addition, the antenna storage case is
Can be easily attached to moving objects such as automobiles.
You.

(3) The mobile antenna can have a wide band and high sensitivity.

[Brief description of the drawings]

FIG. 1 is a perspective view of a use state of a first embodiment.

FIG. 2 is a side view of a main part.

FIG. 3 is a plan view of a main part.

FIG. 4 is an explanatory diagram of a state where an antenna storage case is removed.

FIG. 5 is an explanatory diagram showing an equivalent circuit in the case of a high channel.

FIG. 6 is an explanatory diagram showing an equivalent circuit in the case of a low channel.

FIG. 7 is an explanatory view of a second embodiment.

FIG. 8 is an explanatory view of a third embodiment.

FIG. 9 is an explanatory view of a fourth embodiment.

FIG. 10 is an explanatory view of a fifth embodiment.

FIG. 11 is a graph showing an effect.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Mobile antenna 2 ... 1st antenna element 3 ... Antenna storage case 4 ... 2nd antenna element ( antenna element on the ground side) 5 ... Feeding line 21 ... balloon 22 ... 2nd antenna element on the ground side

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01Q 1/32 H01Q 1/22 H01Q 9/18

Claims (5)

(57) [Claims] A first antenna element provided at an end of the first antenna element;
A second antenna element extending on the opposite side of the antenna element
Between the first antenna element and the second antenna element
A mobile antenna, characterized in that a balloon is disposed on the balloon and a feeder is connected to the balloon . 2. The television set according to claim 2, wherein the second antenna element is a television set.
Formed about 1/4 of the wavelength of the peripheral wavelength of the channel
The mobile antenna according to claim 1 . 3. The first antenna element is configured to be extendable and contractible.
And can be stored in the antenna storage case.
The mobile antenna according to claim 1 . 4. The antenna storage case is a double-sided adhesive tape.
The mobile antenna according to claim 3, wherein the mobile antenna is attached to the mobile body by means of: 5. A second antenna element comprising multiple antennas having different lengths.
The mobile antenna according to claim 1, comprising a plurality of antenna elements .