JP3083274B2 - Broadband antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to each of the HF band, VHF band and UHF band corresponding to the operating frequency of a radio communication device and the like, and the setting of these frequency bands is performed by using a motor to control a tuning coil. The present invention relates to a variable-width antenna.

[0002]

2. Description of the Related Art A conventional broadband antenna of this type has a configuration in which a tuning coil and a coil housing are brought into contact with a contact and further includes an antenna rod as shown in FIG. Tune to the desired frequency.

The tuning of the frequency is determined by the antenna rod, the tuning coil, and the contact provided at the upper end of the coil housing, and the variable range is determined by the length of insertion and removal of the tuning coil. It is usually tuned to the HF band and the VHF band from its structure.

As means for rotating the coil bobbin, the rotational force of the motor is applied to a male screw-shaped rotation transmitting member,
Also, when tension is applied to the female screw-shaped perforation guide portion by the rotational force of the motor, the tension of the contactor is slid, and the coil bobbin moves up and down by sliding the spirally wound tuning coil. It was done.

[0005]

However, in the prior art as described above, since the contact portion between the contact and the tuning coil is a point contact, a particularly high frequency (for example, 28 MHz) is used.
In the case of a z-band or a 50-MHz band), there is a disadvantage that the tuning coil is housed in the coil housing portion and thus is electrically affected, and there is also a problem in mechanical strength.

Further, when the tuning coil is moved up and down, the coil bobbin idles depending on the tension of the contact, so that there is a drawback that stable tuning of the frequency cannot be achieved.

The present invention has been made for the purpose of improving such a drawback of a conventionally known broadband antenna.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in order to achieve the above-mentioned object, and has a rotary shaft of a motor attached to a substantially lower end portion of a coil housing portion, and a rotation transmission member provided in a drilling guide portion. On the other hand, the tuning coil connected to the antenna rod portion is wound in advance along the spiral groove of the coil bobbin, and the coil guide portion and the contact having the groove matching the spiral groove of the coil bobbin are inserted into the coil rod. It is characterized in that it can be tuned to an arbitrary frequency by being integrated with a storage portion and further rotating the motor and slidingly rotating the tuning coil.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described in detail with reference to the drawings. In FIG. 1, a spiral groove is cut in advance in a coil bobbin 7 and further tuned to the spiral groove. Along with winding the coil 5, a spiral groove matching the tuning coil 5 is also provided in the coil guide 6.

Next, a drilling guide portion 3 provided with a square hole at the lower end of the coil bobbin 7 is attached, and inserted through the upper end of the rotation conductive member 2 which matches the square hole. Is attached to the rotating shaft of the motor 1.

The tuning coil 5 wound around the coil bobbin 7 rotates together with the rotation transmitting member 2 due to the rotational force of the motor 1, and the rotation direction at this time depends on whether the motor 1 rotates forward or backward. Switching is performed, and the coil bobbin 7 and the tuning coil 5 are rotated and slid in either upward or downward direction.

On the other hand, the coil guide section 6 is
And electrically connected to the coil housing 4
A contact 8 is attached to the upper end of the tune coil 5, and the contact 8 is pressed against the tuning coil 5 by using an elastic member such as a spring.

The frequency of the HF band and the VHF band (for example, 3.5 MHz band to 28 MHz band and 50 MHz band)
The band includes a portion where the tuning coil 5 protrudes from the contact 8, the antenna rod 9 and the coil housing 4.
Is tuned to an arbitrary frequency by the radiating portion of.

As a method of tuning the frequency between the VHF band and the UHF band, for example, 144M which is the frequency of the VHF band is used.
Hz is about 2 m, so if this is used as a 1/4 wavelength grounded antenna (about 50 cm in length),
At 30 MHz (approximately 70 cm in wavelength), considering the gain of the antenna, it is most appropriate to use で wavelength for に 対 し て wavelength, and to set this to 2/8.
If used in stages, the antenna can be shared with the 144 MHz grounded quarter-wave antenna.

By applying the above-mentioned common antenna for the VHF band and the UHF band to the coil housing 4, the antenna operates as a broadband antenna.

At this time, the influence of the antenna rod portion 9 can be prevented by operating the tuning coil 5 as a high-frequency inductance with respect to the frequency of the 144 MHz band or the 430 MHz band.

[0017]

Since the present invention is configured as described above, it has the following excellent effects.

Since the motor and the rotation transmitting member are directly connected to each other, the rotational force of the motor can be surely converted into the vertical movement of the tuning coil and the coil bobbin in combination with the holding force of the contact and the coil guide. The number of turns of the tuning coil and its angle are known from the number of rotations or the rotation angle,
The exact tuning frequency can be known.

Further, by providing the coil guide portion, the area in contact with the tuning coil in the coil housing portion can be increased, so that more stable operation can be performed.

Since the area where the tuning coil is held by the coil guide portion is large, the mechanical strength can be increased, and the influence between the coils at the contact can be eliminated. .

Furthermore, since the tuning coil rotates and slides up and down spirally, fine tuning of the tuning frequency can be easily performed by reducing the number of rotations of the motor.

Further, since the effective area of the coil housing portion is wide, when this is used as a component of the antenna, the range of operable frequencies is widened.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2 Rotation transmission member 3 Perforation guide part 4 Coil accommodation part 5 Tuning coil 6 Coil guide part 7 Coil bobbin 8 Contact 9 Antenna rod part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01Q 5/00-11/20 H01Q 1/00-1/52

Claims (1)

(57) [Claims] 1. A tuning coil (5) connected to an antenna rod (9) is wound in advance along a spiral groove of a coil bobbin (7), and further matches the spiral groove of the coil bobbin (7). The coil guide portion (6) and the contact (8) having the groove are integrated with the coil housing portion (4), and the rotating shaft of the motor (1) attached to a substantially lower end portion of the coil housing portion (4). , The rotation conducting member (2) is inserted into and attached to the drilling guide portion (3), and the drilling guide portion (3) is attached to the lower end portion of the coil bobbin (7). A rotational force is transmitted to the tuning coil (5) via the rotation transmission member (2), and the tuning coil (5) is rotationally slid while elastically pressing and holding the contact (8). To tune to any frequency And a broadband antenna.