JP2003142928A - Tuning antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a tuning antenna small-sized. SOLUTION: The tuning antenna comprises a 1st tuning antenna 12a and a 2nd tuning antenna 12b and receives a lower frequency band among two or more frequency bands with the 1st tuning antenna 12a and a higher frequency band with the 2nd antenna 12b. The permeability of a 1st antenna core 11a is made larger than that of a 2nd antenna core 11b. Consequently, the tuning antenna which is made small-sized is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tuning antenna used for portable equipment and the like.

[0002]

2. Description of the Related Art A conventional antenna, as shown in FIG. 10, is formed of expandable rod antennas 1a and 1b. Then, at the time of use, the rod antennas 1a and 1b are extended and used. In this case, when the rod antennas 1a and 1b are extended, the length 2 becomes approximately 1 m, which is a large space. In addition, 3 is an output terminal of the rod antennas 1a and 1b. Then, in order to obtain a good reception state, the rod antennas 1a and 1b having a length of about 1 m are moved to search for the position of maximum sensitivity.

Reference numeral 4 is an output of the rod antennas 1a and 1b output from the output terminal 3, and FIG. 11 is an output characteristic diagram thereof. In FIG. 11, the horizontal axis 5 is frequency (MHz)
And the vertical axis 6 is the gain (dBi). Further, 7 is a VHF low band (90 MHz to 108 MHz), and 8 is a VHF high band (170 MHz to 222 M).
Hz).

[0004]

However, in such a conventional configuration, as shown in FIG. 10, when the rod antennas 1a and 1b are extended, the rod antennas 1a and 1b become large and difficult to handle. Also, even if it is shrunk, it becomes quite large and not suitable for carrying.

The present invention solves such problems, and an object thereof is to provide a miniaturized tuning antenna.

[0006]

In order to achieve this object, the tuning antenna of the present invention receives a terrestrial signal consisting of at least two or more frequency bands and individually tunes each of the bands. A tuning antenna including an antenna, comprising: a first conductor wound around a first antenna core; first variable capacitance capacitors connected in parallel to both ends of the first conductor; First
A first tuning antenna having a ground terminal to which one terminal of the parallel connection body is connected, and a first output terminal to which the other terminal of the first parallel connection body is connected, and a second antenna A second conductor wound around the core, and second variable capacitance capacitors connected in parallel to both ends of the second conductor,
Second tuning having a ground terminal connected to one terminal of the second parallel connected body connected in parallel and a second output terminal connected to the other terminal of the second parallel connected body An antenna, the lower frequency band of the two or more frequency bands is received by the first tuning antenna, and the higher frequency band is received by the second tuning antenna. The magnetic permeability of the first antenna core is larger than that of the second antenna core.

As a result, a miniaturized tuning antenna can be realized.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is configured to receive a terrestrial signal composed of at least two or more frequency bands, and to be composed of individual tuning antennas corresponding to the respective bands. A tuning antenna,
The first conductor wound around the first antenna core and the first conductor.
A first variable capacitance capacitor connected in parallel to both ends of the conductor, a ground terminal to which one terminal of the parallel-connected first parallel connection body is connected, and the other of the first parallel-connection body A first tuning antenna having a first output terminal to which a terminal is connected, a second conductor wound around a second antenna core, and a second conductor connected in parallel to both ends of the second conductor. A variable capacitor, a ground terminal to which one terminal of the parallel-connected second parallel connection body is connected,
A second tuning antenna having a second output terminal to which the other terminal of the second parallel connection body is connected, wherein the lower frequency band of the two or more frequency bands is the first frequency band. 1
The higher frequency band is received by the tuning antenna of
Is a tuning antenna in which the magnetic permeability of the first antenna core is larger than the magnetic permeability of the second antenna core, and the antenna is used as the tuning antenna. A sensitive antenna can be realized. Further, since the material having a large magnetic permeability is used for the antenna core of the lower frequency band, the inductance of the conductor wound around this core becomes large, and the size can be further reduced.

The invention according to claim 2 is the tuning antenna according to claim 1, wherein the first antenna core and the second antenna core are linearly connected to each other and arranged. Since the first antenna core and the second antenna core are linearly connected to each other, the directivities of the antennas do not interfere with each other, and good antenna directivity can be obtained.

According to a third aspect of the present invention, a circuit board is mounted on the first antenna core and the second antenna core to be integrally formed, and the first variable capacitor and the first variable capacitor are formed on the circuit board. The tuning antenna according to claim 2, wherein the second variable capacitor is mounted, and the tuning antenna is modularized by integrating electronic components, so that sufficient antenna performance is achieved without considering the arrangement of each component. Can be pulled out.

Further, miniaturization can be realized and handling is easy.

The invention according to claim 4 is the tuning antenna according to claim 1, wherein the first output terminal and the second output terminal are connected to form one output terminal. , The lower frequency band and the higher frequency band are separated from each other, and the attenuation between them is sufficient and they do not interfere with each other. Therefore, the number of output terminals can be one, the size can be reduced, and the handling becomes easy.

According to a fifth aspect of the present invention, the first antenna core is made of a ferrite material, and the second antenna core is made of a dielectric substrate material. Since it is a tuning antenna and uses ferrite material with high magnetic permeability for the material of the antenna core in the lower frequency band, it is possible to increase the inductance and consequently reduce the number of turns, and to achieve miniaturization. be able to. Further, since the dielectric substrate is used as the material of the antenna core in the higher frequency band, the cost can be reduced.

According to a sixth aspect of the present invention, the first tuning antenna is for VHF band low band reception, the second tuning antenna is for VHF band high band, and the second tuning antenna is UHF. The tuning antenna according to claim 2, wherein a third tuning antenna for band reception is connected.
A tuning antenna that can receive three frequency bands and that is small and has high sensitivity can be realized. Therefore, if the tuning antenna according to the present invention is used in a mobile phone or the like, it is possible to enjoy TV reception on the mobile phone.

A first antenna core according to a seventh aspect of the present invention is the tuning antenna according to the second aspect, in which a ferrite paste material is applied to ceramics and fired, and since only the paste material is applied, 2 It is not necessary to connect two materials, which facilitates manufacturing.

The first antenna core of the invention according to claim 8 is the tuning antenna according to claim 2, wherein a hole is provided in the center of the base material, and a ferrite material is inserted in this hole, and the ferrite is inserted in the hole. By inserting the material, a tuning antenna having the performance of a substantially ferrite material can be realized, and it is not necessary to connect the two materials, and the manufacturing is easy.

The invention according to claim 9 is the tuning antenna according to claim 5, in which the conductor wound around the dielectric substrate material of the second antenna core is formed of a pattern and a through hole, and is an etching technique. Since it can be formed by, the cost is low and mass production is easy. Further, it is possible to reduce the thickness.

According to a tenth aspect of the present invention, the conductor wound around the dielectric substrate material of the second antenna core is a tuning antenna according to the fifth aspect, wherein the conductor is used. , Q increases and the output level increases. Further, since the layers can be easily wound, the size can be reduced.

According to a tenth aspect of the present invention, the other terminal of the first parallel connection body forming the first tuning antenna and the first terminal are connected to each other.
A first impedance matching circuit is inserted between the first impedance matching circuit and the output terminal, and a second tuning antenna is formed.
The tuning antenna according to claim 3, wherein the second impedance matching circuit is also inserted between the other terminal and the second output terminal of the parallel connection body of, and impedance matching with an external circuit is performed, Received power can be efficiently supplied.

According to a twelfth aspect of the present invention, one terminal of the first parallel connection body forming the first tuning antenna is the first terminal.
Is connected to the ground via the first capacitor and is connected to the first tuning voltage supply terminal via the first impedance element, and the first impedance matching circuit is the first impedance matching circuit.
Second parallel circuit connected to the ground from the other terminal of the parallel circuit of 1 through the first inductance element and connected to the first output terminal through the third capacitor to form the second tuning antenna. One terminal of the connection body is connected to the ground via the second capacitor and is connected to the second tuning voltage supply terminal via the second impedance element, and the second impedance matching circuit is the second impedance matching circuit. The tuning antenna according to claim 11, wherein the other terminal of the parallel circuit is connected to the ground via the second inductance element and is connected to the second output terminal via the fourth capacitor, wherein the inductance element is , Is used as a part of the impedance matching circuit and is also used as a grounding element for grounding the voltage applied to the tuning voltage supply terminal. Therefore, the number of parts is reduced, which contributes to downsizing and cost reduction.

According to a thirteenth aspect of the present invention, one end of the first impedance element forming the first tuning antenna is
The first variable capacitance capacitor is mounted in the vicinity of the cathode terminal, and one end of the second impedance element forming the second tuning antenna is mounted in the vicinity of the cathode terminal of the second variable capacitor. The tuned antenna according to Item 12, in which the variation of the inductance between the variable capacitor and the impedance element is reduced, and the resonance characteristic is stabilized.

According to a fourteenth aspect of the present invention, the first impedance element forming the first tuning antenna and the second impedance element forming the second tuning antenna are reflow-soldered. In the tuning antenna described in (3), since the mounting position of the impedance element is fixed by the self-alignment effect of the solder melted during reflow, the variation in the inductance between the variable capacitor and the impedance element is reduced, and the tuning characteristics are improved. Stabilize.

According to a fifteenth aspect of the present invention, the first inductance element forming the first tuning antenna and the second inductance element forming the second tuning antenna are formed in a pattern on the circuit board. The tuning antenna according to claim 12, wherein the inductance element does not need to be specially provided and can be formed at the same time as the other wiring when the circuit board is etched. Therefore, reduction in thickness and cost can be achieved without increasing man-hours. Can contribute to.

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of tuning antenna 12 in accordance with the first exemplary embodiment of the present invention.
The tuning antenna 12 in the first embodiment is the tuning antenna 1 using a ferrite core as the antenna core 11a.
2a and a tuning antenna 12b using a dielectric substrate as the antenna core 11b are linearly connected at one end 13. Here, the tuning antenna 12a is for the low band of VHF, and the tuning antenna 12b is for the high band of VHF. Note that the tuning antenna 12a has a subscript a
, And the tuning antenna 12b has a subscript b.
Then, for the tuning antenna 12b, the tuning antenna 1
Only the configuration different from 2a is described and the description is simplified.

First, the tuning antenna 12a will be described. In FIG. 1, reference numeral 14a denotes a conductor wound around the antenna core 11a, which is connected in parallel with a varicap diode (used as an example of a variable capacitor) 15a to form a parallel connection body 16a.

One end 17a of the parallel connection body 16a is connected to the ground terminal 19 via a fixed capacitor 18a, and a tuning voltage is supplied via a fixed resistor (used as an example of an impedance element) 20a. It is connected to the terminal 21.

The other end 22a of the parallel connection body 16a is also provided.
Is connected to the ground terminal 19 via the impedance element 23a formed by the pattern, and is also connected to the output terminal 25 via the fixed capacitor 24a.

The tuning antenna 12a is for low band reception in the VHF band, and the fixed capacitor 18a is 10 PF.
Chip capacitor, fixed capacitor 24a is 10PF
As the chip capacitor and the fixed resistor 20a, a chip resistor of 100 kΩ was used. In addition, the impedance element 2
An impedance matching circuit 26a is formed by 3a and the fixed capacitor 24a. The impedance matching circuit 26a is inserted to perform impedance matching between the parallel connection body 16a and an external circuit connected to the output terminal 25 and reduce the loss due to the connection.

The fixed capacitor 24a and the output terminal 2
An amplifier formed of a transistor may be inserted between the amplifier and the transistor 5. By inserting the amplifier in this way, S /
N can be improved and a large signal can be output.

Next, although the tuning antenna 12b is different from the tuning antenna 12a in structure, a dielectric substrate is used for the antenna core 11b and a conductor is formed by a pattern and a through hole by an etching technique to reduce the cost. be able to.

The output of the capacitor 24b is connected to the output of the capacitor 24a and is also connected to the output terminal 25. The output of the resistor 20b is connected to the output of the resistor 20a and is connected to the tuning voltage supply terminal 21.

This tuning antenna 12b is for high band reception in the VHF band, and the fixed capacitor 18b is 10 PF.
Chip capacitor, fixed capacitor 24b is 10PF
As the chip capacitor and the fixed resistor 20b, a chip resistor of 100 kΩ was used. In addition, the impedance element 2
An impedance matching circuit 26b is formed by 3b and the fixed capacitor 24b. The impedance matching circuit 26b is inserted to perform impedance matching with the parallel connection body 16b and reduce loss due to connection.

The fixed capacitor 24b and the output terminal 2
An amplifier formed of a transistor may be inserted between the amplifier and the transistor 5. Thus, by inserting the amplifier, S
/ N can be improved and a large signal can be output.

Further, since the ferrite material is used for the VHF low band antenna core 11a, the number of windings can be reduced and the size can be reduced.

FIG. 2 is a gain characteristic diagram showing the relationship between the voltage applied to the tuning voltage supply terminal 21 and the signal output output from the output terminal 25. The horizontal axis 31 is the frequency (M
Hz), and the vertical axis 32 is the gain (dBi) of the signal output from the output terminal 25. 7 is the VHF low band (90 MHz to 108 MHz), and 8 is the VHF
Of the high band (170 MHz to 222 MHz).

In the tuning antenna 12a, the gain characteristic curve 33 changes the frequency of the low band width 34 of VHF by applying 0.5 to 2.5 volts to the tuning voltage supply terminal 21.

In the tuning antenna 12b, the gain characteristic curve 35 changes the frequency of the high band width 36 of VHF by applying 0.5 to 2.5 volts to the tuning voltage supply terminal 21.

Here, the highest frequency of VHF low band 1
Lowest frequency 170MHz of 08MHz and VHF high band
It is 62 MHz away from z. Therefore, both outputs are sufficiently attenuated (37), and even if the outputs of the output terminals 25 are connected, they do not interfere with each other. Note that this is the tuning voltage supply terminal 21 of the tuning antenna 12a and the tuning antenna 12b.
However, in the present embodiment, the tuning antenna 1
Since the same tuning voltage is supplied by connecting the tuning voltage supply terminals 21 of 2a and 12b, the attenuation is further increased and the interference is reduced.

As described above, the voltage applied to the tuning voltage supply terminal 21 enables tuning near the desired signal. Therefore, the tuning antenna 12 with high output and less interference
a and the tuning antenna 12b can be obtained.

FIG. 3 is an exploded perspective view of the tuning antenna 12 (tuning antennas 12a and 12b). In FIG.
The antenna core 11a and the antenna core 11b have one end 13
Are connected by. The antenna core 11a is formed with a recess 42 having a step 41, and the conductor 1
4a is wound. A polyurethane copper wire, a tin-plated wire, a solder-plated wire, an aluminum wire, or the like can also be used as the conductor 14a.

The antenna core 11b is a dielectric substrate having a relative dielectric constant of 10, and the conductor 43b is formed on the surface thereof by the pattern 43 and the through hole 44. This conductor 14
b is spirally wound from one end 45 to the other end 46 of the antenna core 11b.

The length 47 of the tuning antenna 12 is 4 to 10c.
m, the vertical 48 of the cross section is 3 mm, and the horizontal 49 is 4 mm.

A circuit board 50 made of glass epoxy resin has the same size as the upper surfaces of the antenna cores 11a and 11b. This facilitates component management and enables automatic mounting. On the circuit board 50, the varicap diodes 15a, 15
b, the fixed capacitors 18a and 18b, and the fixed resistor 20.
a, 20b, impedance elements 23a, 23b formed in a pattern, and capacitors 24a, 24b are mounted.

Here, it is important that the fixed resistors 20a and 20b are arranged near the cathodes of the varicap diodes 15a and 15b, respectively. This is a fixed resistor 2
This is to stabilize the tuning characteristic by reducing the impedance variation due to the pattern on the circuit board 50 by soldering 0a and 20b.

All these parts are soldered by reflow soldering. By reflow soldering, all components are stably mounted at predetermined positions due to the self-alignment effect, so that the change in impedance due to the pattern length and the like is reduced and stable performance is obtained. Especially, when the fixed resistors 20a and 20b are mounted, the effect is remarkably exhibited.

It should be noted that all of the above components are circuit boards 5
The components other than the varicap diodes 15a and 15b and the fixed resistors 20a and 20b can be provided on the circuit board 50 other than the circuit board 50.

Here, the conductor 14b formed in a pattern
Polyurethane copper wire, tin plated wire, solder plated wire,
Aluminum wire or the like can also be used. By using these wire rods, Q (cucumber) can be increased.
In addition, if the wire material coated with insulation is used, it is possible to perform lap winding and increase the inductance. Therefore, a glass epoxy resin material having a small relative dielectric constant can be used for the antenna core 11b, and the cost can be reduced. In addition, miniaturization can be achieved by lap winding.

In the tuning antenna 12, the ground terminal 19 and the output terminal 25 are separately provided near one end and near the other end.
2 can be directly soldered to the printed circuit board inside the portable device. In this case, all the terminals such as the ground terminal 19 and the output terminal 25 can be directly surface-mounted on the printed circuit board with cream solder if they are led out through the through holes on the lower surface of the antenna core 11b.

FIG. 4 shows a directivity pattern when viewed from the front of the tuning antenna 12, and has substantially uniform characteristics 51 and 52 before and after the tuning antenna 12 at a right angle. Also,
FIG. 5 is a directivity pattern viewed from the side surface of the tuning antenna 12, and has a substantially circular characteristic 53 (omnidirectional) centering on the tuning antenna 12.

(Second Embodiment) FIG. 6 shows a tuning antenna 60 according to the second embodiment. This tuning antenna 60
Forms the antenna core 61 from a ceramic substrate,
The F low band tuning antenna 60a is coated with a ferrite paste material 62. The VHF high-band tuning antenna 60b is the ceramic substrate as it is. Other parts are the same as those in the first embodiment.

By thus integrating the antenna cores 61, it is not necessary to connect the antenna cores to each other, which facilitates manufacturing.

(Third Embodiment) FIG. 7 shows a tuning antenna 70 according to the third embodiment. This tuning antenna 70
Forms an antenna core 71 with a dielectric substrate, forms a hole 72 in one side of the dielectric substrate 71, and inserts a ferrite material 73 into the hole 72 to form an antenna core 71a for the VHF band low band. There is. Then, a conductor is wound on the antenna core 71a to form the VHF low-band tuning antenna 70a. In addition, this conductor is
For both the low band and the high band, the pattern and the through hole may be formed as in the first embodiment, or the wire may be wound.

VHF high-band tuning antenna 70b
The part remains the dielectric substrate. Other parts are the same as those in the first embodiment.

As described above, by integrating the antenna cores 71, it is not necessary to connect the antenna cores to each other, which facilitates the manufacturing. In this case as well, in the low band of VHF, the impedance value can be increased due to the effect of ferrite, and as a result, the number of windings can be reduced, so that miniaturization can be realized.

(Fourth Embodiment) FIG. 8 shows the first to first embodiments.
Tuning antenna 80a for VHF low band shown in FIG.
And a tuning antenna 80b for VHF high band,
The tuning antenna 80b is a UHF band tuning antenna 80.
It is a tuning antenna 80 in which c is connected. In this case, the tuning antennas 80a, 80b, 80c are linearly integrated. In addition, the UHF band is 470 MHz to 770 MHz
Therefore, the output terminal 81 can be united by connecting the above three bands. The tuning voltage supply terminal 82 is also
The tuning voltage supply terminals of the above bands can be connected to be one.

FIG. 9 is a gain characteristic diagram showing the relationship between the voltage applied to the tuning voltage supply terminal 82 and the signal output output from the output terminal 81. The horizontal axis 83 is the frequency (MHz), and the vertical axis 84 is the gain (dBi) of the signal output from the output terminal 82. 7 is VHF low band (90 MHz to 108 MHz), and 8 is V
HF is a high band (170 MHz to 222 MHz), and 85 is a UHF band (470 MHz to 770 MHz).

In the tuning antenna 80a, the gain characteristic curve 33 changes the frequency of the VHF low band width 34 by applying 0.5 to 2.5 volts to the tuning voltage supply terminal 82.

In the tuning antenna 80b, the gain characteristic curve 35 changes in frequency within the width 36 of the VHF high band by applying 0.5 to 2.5 volts to the tuning voltage supply terminal 82.

In the tuning antenna 80c, the gain characteristic curve 86 changes the frequency of the UHF band width 87 by applying 0.5 to 2.5 volts to the tuning voltage supply terminal 82.

Here, the highest frequency of VHF low band 1
Lowest frequency 170MHz of 08MHz and VHF high band
Since it is separated from z by 62 MHz, its output is sufficiently attenuated (37), and connecting the output of the tuning voltage supply terminal does not interfere with each other. Also, regarding the UHF band, the maximum frequency of the VHF high band is 222 MHz and UH.
Since it is 248 MHz away from the minimum frequency 470 MHz of F, its output is sufficiently attenuated (88), and connecting the output of the tuning voltage supply terminal does not interfere with each other. Therefore, the number of output terminals 81 can be one.

As described above, the voltage applied to the tuning voltage supply terminal 82 allows tuning to be performed near the desired signal to be received. Therefore, it is possible to obtain the tuning antenna 80 with high output and less interference.

As described above, by incorporating the tuning antenna 80 inside the portable device, it is not necessary to move the antenna to search for maximum sensitivity (it is substantially omnidirectional), and the operation is simple. Also, the antenna is not exposed to the outside, which is excellent in design.

The ground terminal 8 of the tuning antenna 80
9 and the output terminal 81 through the circuit board, the tuning antenna 80
It can also be provided in the vicinity of one end. In this case, a fulcrum is provided near one end of the tuning antenna 80, and the tuning antenna 80 is rotatably attached to the mobile device. By mounting the antenna in this way, the antenna can be lowered to make it convenient to carry when not in use, and can be rotated upward to improve the reception sensitivity of the antenna when in use.

[0064]

As described above, according to the present invention, since the antenna is the tuning antenna, the antenna can be downsized and a highly sensitive antenna can be realized. Further, since the material having a large magnetic permeability is used for the antenna core of the lower frequency band, the inductance of the conductor wound around this core becomes large, and the size can be further reduced.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a tuning antenna according to a first embodiment of the present invention.

[Fig. 2] Same as above

FIG. 3 is a perspective view of the assembly

FIG. 4 is a characteristic diagram of directivity seen from the front.

FIG. 5 is a characteristic diagram of directivity when viewed from the side.

FIG. 6 is a front view of the antenna core of the tuning antenna according to the second embodiment of the present invention.

FIG. 7 is a sectional view of an antenna core of a tuning antenna according to a third embodiment of the present invention.

FIG. 8 is a circuit diagram of a tuning antenna according to a fourth embodiment of the present invention.

FIG. 9 is a characteristic diagram of the same.

FIG. 10 is a front view of a conventional antenna.

FIG. 11 is a characteristic diagram of the same.

[Explanation of symbols]

11a antenna core 11b Antenna core 12a Tuning antenna 12b tuning antenna 14a conductor 14b conductor 15a Varicap diode 15b Varicap diode 17a One end 17b One end 19 ground terminal 22a the other end 22b the other end 25 output terminals 26a Impedance matching circuit 26b Impedance matching circuit

Continued front page    (72) Inventor Yasuhiro Hibino             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Tatsuya Nagatsu             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5J021 AA02 AB04 CA05 FA03 HA05                       JA03

Claims (15)

[Claims] 1. A tuning antenna for receiving a terrestrial signal composed of at least two frequency bands and comprising individual tuning antennas corresponding to the respective bands, which is wound around a first antenna core. A first conductor provided with the first conductor, a first variable capacitance capacitor connected in parallel to both ends of the first conductor, and a ground terminal to which one terminal of the first parallel connection body connected in parallel is connected. , The first
A first tuning antenna having a first output terminal connected to the other terminal of the parallel connection body, a second conductor wound around a second antenna core, and both ends of the second conductor. A second variable capacitance capacitor connected in parallel, a ground terminal to which one terminal of the second parallel connection body connected in parallel is connected, and the other terminal of the second parallel connection body connected to each other. A second tuning antenna having a second output terminal, wherein a lower frequency band of the two or more frequency bands is received by the first tuning antenna, and a higher frequency band is received by the first tuning antenna. A tuning antenna in which reception is performed by a second tuning antenna, and the magnetic permeability of the first antenna core is larger than that of the second antenna core. 2. The tuning antenna according to claim 1, wherein the first antenna core and the second antenna core are linearly connected and arranged. 3. A circuit board is mounted on the first antenna core and the second antenna core to be integrally formed, and
The tuning antenna according to claim 2, wherein the first variable capacitor and the second variable capacitor are mounted on the circuit board. 4. The tuning antenna according to claim 1, wherein the first output terminal and the second output terminal are connected to form one output terminal. 5. The tuning antenna according to claim 1, wherein a ferrite material is used as a material of the first antenna core, and a dielectric substrate material is used as a material of the second antenna core. 6. The first tuning antenna is for low band reception in the VHF band, the second tuning antenna is for high band in the VHF band, and the second tuning antenna is U
The third tuning antenna for receiving the HF band is connected to the third tuning antenna.
The tuning antenna described in. 7. The tuning antenna according to claim 2, wherein the first antenna core is formed by coating a ceramic paste with a ferrite paste material and firing it. 8. The tuning antenna according to claim 2, wherein the first antenna core has a hole at the center of the base material, and a ferrite material is inserted into the hole. 9. The tuning antenna according to claim 5, wherein the conductor wound around the dielectric substrate material of the second antenna core is formed of a pattern and a through hole. 10. The tuning antenna according to claim 5, wherein the conductor wound around the dielectric substrate material of the second antenna core is formed of a wire material. 11. A first output terminal between the other terminal of the first parallel connection body forming the first tuning antenna and the first output terminal.
The impedance matching circuit of is inserted and the second
The tuned antenna according to claim 3, wherein a second impedance matching circuit is also inserted between the other terminal and the second output terminal of the second parallel-connected body forming the tuned antenna. 12. One terminal of a first parallel-connected body forming a first tuning antenna is connected to a ground via a first capacitor and a first tuning voltage via a first impedance element. The first impedance matching circuit is connected to the supply terminal, the first impedance matching circuit is connected to the ground from the other terminal of the first parallel circuit via the first inductance element, and the first output terminal is also connected via the third capacitor. And one terminal of the second parallel connection body that forms the second tuning antenna is connected to the ground via the second capacitor, and the second tuning voltage is supplied via the second impedance element. The second impedance matching circuit is connected to the terminal, is connected to the ground from the other terminal of the second parallel circuit through the second inductance element, and is connected to the fourth impedance matching circuit. The tuning antenna according to claim 11, wherein the tuning antenna is connected to the second output terminal via a capacitor. 13. One end of a first impedance element forming the first tuning antenna is mounted in the vicinity of the cathode terminal of the first variable capacitance capacitor, and a second tuning element forming a second tuning antenna. The tuning antenna according to claim 12, wherein one end of the impedance element is mounted near the cathode terminal of the second variable capacitor. 14. The tuning antenna according to claim 13, wherein the first impedance element forming the first tuning antenna and the second impedance element forming the second tuning antenna are reflow-soldered. 15. The method according to claim 12, wherein the first inductance element forming the first tuning antenna and the second inductance element forming the second tuning antenna are patterned on the circuit board. Tuning antenna.