JP5871378B2 - Multi-frequency antenna and portable terminal - Google Patents

Description

  The present invention relates to a multi-frequency shared antenna that operates in different frequency bands, and a portable terminal including the multi-frequency shared antenna.

  2. Description of the Related Art Conventionally, a multi-frequency shared antenna that has an antenna element and a resonance circuit and operates in different frequency bands is known. For example, a resonance circuit composed of a coil and a capacitor is provided in an intermediate portion of an elongated antenna, Some have been designed to resonate in the frequency band (see Patent Document 1 (page 2, FIG. 10)).

JP-A-9-139618

  By the way, when the resonance circuit is provided in the middle part of the antenna as described above, there is a merit that the resonance circuit of the communication device main body can be eliminated or the structure can be simplified, but usually the installation part of the resonance circuit in the antenna. Therefore, it is difficult to use the antenna for an antenna of a portable terminal or the like that is strongly required to reduce the size, the diameter, and the space for storing the housing. In addition, when a resonance circuit is provided in the middle part of the antenna, there is a problem that the mechanical structure is usually complicated, the bending is easily caused at the installation part of the resonance circuit, and the number of parts increases.

  The present invention has been proposed in view of the above problems, and it is possible to configure a resonance circuit at the middle portion of an antenna while meeting the demand for downsizing, diameter reduction, space saving, and the like. An object of the present invention is to provide a multi-frequency shared antenna that can eliminate the resonance circuit of the above-described circuit or simplify the structure thereof, and a portable terminal including the multi-frequency shared antenna. Another object of the present invention is to provide a multi-frequency antenna that can be bent with a simple mechanical structure and can be configured with a minimum increase in the number of parts, and a portable terminal equipped with the multi-frequency antenna. It is to provide.

Multi-frequency antenna of the present invention includes an antenna element portion, the antenna element portion held directly or indirectly, and a holding portion which is electrically connected to a power source, the holding portion is cylindrical An antenna element conducting portion provided to conduct with the antenna element portion, a feeding conducting portion provided to conduct with the feeding portion, and between the antenna element conducting portion and the feeding conducting portion. An insulating tube interposed in the coil, and a coil that is disposed in the insulating tube with its shape and position fixed in alignment with the insulating tube in the axial direction, and provided in a non-contact manner with the antenna element conducting portion and the feeding conducting portion And the cylindrical body of the antenna element conducting portion is provided so as to cover the outer periphery of the coil .
According to this configuration, the resonance circuit can be provided in the middle portion of the antenna with a simple mechanical structure of the antenna element conducting portion, the feeding conducting portion, the insulating cylinder, and the coil. Therefore, the resonance circuit can be configured in the middle part of the antenna while meeting the demand for downsizing / reducing the diameter of the antenna, space saving, etc. It can be simplified. In addition, the antenna can be a multi-frequency antenna that is difficult to bend with a simple mechanical structure, and can be configured with a small number of components, so that an increase in the number of components can be minimized. Further, it is possible to flexibly adapt to the increase or decrease of the resonance frequency by increasing or decreasing the number of turns of the coil.

In the multi-frequency antenna according to the present invention, either one of the antenna element conducting portion and the feeding conducting portion is fitted inside on one end side of the insulating cylinder, and the other sandwiches the other end side of the insulating cylinder. It is characterized by being fitted.
According to this configuration, the antenna element conducting portion, the insulating cylinder, and the power feeding conducting portion are engaged and held with each other to increase strength and improve durability. Further, the insulating cylinder can be easily interposed between the antenna element conducting portion and the power feeding conducting portion by utilizing the connection state of the antenna element conducting portion, the insulating cylinder, and the power feeding conducting portion.

In the multi-frequency antenna of the present invention, a bobbin is provided inside the insulating tube so as to be engaged with the antenna element conducting portion and the power feeding conducting portion, and a spiral groove is formed on an outer periphery of the bobbin. And the coil is wound around.
According to this configuration, the shape and position of the coil provided in alignment with the insulating cylinder and the axial direction can be easily and stably fixed, and the characteristics as the resonance circuit can be stably exhibited.

The multi-frequency antenna according to the present invention is characterized in that the insulating cylinder and the coil are provided apart from each other.
According to this configuration, a capacitor can be formed using both of the insulating cylinder and the air layer, and a multi-frequency shared antenna with a higher degree of freedom of adjustment can be obtained.

In the multi-frequency shared antenna of the present invention, the holding unit directly holds the antenna element unit, and the holding unit is connected to another holding unit electrically connected to the power feeding unit via an angle adjustment mechanism. It is retained.
According to this configuration, it is possible to reduce the relationship with the conduction structure with the power supply unit of the communication device, and to more easily configure the multi-frequency shared antenna.

In the multi-frequency shared antenna of the present invention, the holding portion indirectly holds the antenna element portion, and the holding portion directly connects another holding portion that directly holds the antenna element portion via an angle adjustment mechanism. It is characterized by holding.
According to this configuration, it is possible to further reduce the size of another holding portion and the angle adjustment mechanism that directly hold the antenna element portion, reduce the load applied to the angle adjustment mechanism, and increase the durability. In addition, since the tip side of the antenna can be made thinner, the design can be improved.

The multi-frequency shared antenna of the present invention includes the multi-frequency shared antenna of the present invention.
According to this configuration, a mobile terminal having the effect of the multi-frequency shared antenna of the present invention can be obtained.

  According to the multi-frequency shared antenna of the present invention or a portable terminal equipped with the same, it is possible to configure a resonance circuit in the middle part of the antenna while meeting demands such as downsizing, downsizing, and space saving. The resonance circuit of the communication device main body can be eliminated or the structure thereof can be simplified. In addition, the antenna can be made difficult to bend with a simple mechanical structure, and a multi-frequency antenna can be configured with a minimum increase in the number of components.

The front view of the multifrequency shared antenna of the embodiment. (A) is a partial front view which shows the part by the side of the base of the multi-frequency common antenna of embodiment, (b) is a fragmentary sectional view which shows the part by the side of the root rather than the angle adjustment mechanism. The longitudinal cross-sectional view which shows the 1st holding | maintenance part in the multifrequency shared antenna of embodiment. The circuit explanatory view of the multi-frequency common antenna of the embodiment. The graph which shows the example of the frequency characteristic (SWR) of the multifrequency shared antenna of embodiment.

[Multi-frequency antenna of embodiment]
The multi-frequency shared antenna 1 of this embodiment is used for a mobile terminal that receives both mobile multimedia broadcast (MM broadcast) and mobile phone / mobile terrestrial digital broadcast (one-segment), for example. As shown in FIG. 2, the extendable antenna element portion 2, the first holding portion 3 that directly holds the antenna element portion 2, and the second holding connected to the first holding portion 3 via an angle adjustment mechanism. The second holding unit 4 is slidably provided in a substantially cylindrical holder 5 attached to the mobile terminal housing.

  The antenna element portion 2 is provided for the first cylindrical antenna element 21, the second cylindrical antenna element 22 that can be projected and retracted with respect to the first cylindrical antenna element 21, and the second cylindrical antenna element 22. A third cylindrical antenna element 23 that can be projected and retracted, and a rod-shaped antenna element 24 that can be projected and retracted with respect to the third cylindrical antenna element 23, and in the first cylindrical antenna element 21 at the time of shortening, The second cylindrical antenna element 22, the third cylindrical antenna element 23, and the rod-shaped antenna element 24 can be accommodated in a multistage manner.

  A resin cap 211 is provided at the upper end of the first cylindrical antenna element 21, and the lower end thereof is formed with a slightly reduced diameter. A contact spring 221 bulging outward is provided around the upper end of the second cylindrical antenna element 22, and the upper end of the second cylindrical antenna element 22 and the contact spring 221 are in the first cylindrical shape. The antenna element 21 is inserted.

  The contact spring 221 slides while contacting the inner wall of the first tubular antenna element 21, and the second tubular antenna element 22 and the first tubular antenna element 21 are electrically connected via the contact spring 221. . When the first cylindrical antenna element 21 is extended from the second cylindrical antenna element 22, the length at which the reduced diameter portion of the lower end of the first cylindrical antenna element 21 abuts on the contact spring 221 and extends. The upper end of the second cylindrical antenna element 22 and the contact spring 221 are always present in the first cylindrical antenna element 21. Further, when the first cylindrical antenna element 21 is shortened with respect to the second cylindrical antenna element 22, the second cylindrical antenna element 22 has almost the entire length within the first cylindrical antenna element 21. It is stored over.

  The lower end of the second cylindrical antenna element 22 is also formed with a slightly reduced diameter, and a contact spring 231 that bulges outward is also provided around the upper end of the third cylindrical antenna element 23. The upper end portion of the third cylindrical antenna element 23 and the contact spring 231 are inserted into the second cylindrical antenna element 22. Even in the second and third cylindrical antenna elements 22 and 23, sliding of the contact spring 231, conduction through the contact spring 231, restriction of the extension length by contact between the reduced diameter portion and the contact spring 231, third The cylindrical antenna element 23 has a configuration similar to that of the first and second cylindrical antenna elements 21 and 22 for storing the cylindrical antenna element 23 in the second cylindrical antenna element 22 over almost the entire length.

  The lower end of the third cylindrical antenna element 23 is also formed with a slightly reduced diameter, and a substantially spherical diameter-enlarged portion 241 is formed at the upper end of the rod-shaped antenna element 24 so that the rod-shaped antenna below the diameter-enlarged portion 241 is formed. A contact spring 242 bulging outward is provided around the vicinity of the upper end of the element 24. The rod-shaped antenna element 24 is inserted into the third tubular antenna element 23, the contact spring 242 slides while contacting the inner wall of the third tubular antenna element 23, and the rod-shaped antenna element 24 is interposed via the contact spring 242. And the third cylindrical antenna element 23 are electrically connected.

  When the third cylindrical antenna element 23 is extended from the rod-shaped antenna element 24, the length at which the reduced diameter portion of the lower end of the third cylindrical antenna element 23 contacts the contact spring 242 is extended, The enlarged diameter portion 241 and the contact spring 242 of the rod-shaped antenna element 24 are always present in the third cylindrical antenna element 23. Further, when the third cylindrical antenna element 23 is shortened with respect to the rod-shaped antenna element 24, the rod-shaped antenna element 24 is accommodated in the third cylindrical antenna element 23 except for the lower portion.

  As shown in FIGS. 1 to 3, the first holding unit 3 is configured to hold a rod-shaped antenna element 24 that is fitted and inserted, and the second holding unit 4 and the holder 5 described later are interposed therebetween. It is electrically connected to a power supply unit provided in the mobile terminal casing. The first holding unit 3 is supported by the cylindrical body 31, the upper connector 32 and the insulating cylinder 33 fitted in the cylindrical body 31, the lower connector 34 fitted in the insulating cylinder 33, and the upper connector 32 and the lower connector 34. And a coil 36 wound around the bobbin 35 and disposed in the insulating cylinder 33.

  The cylindrical body 31 is formed in a substantially elongated cylindrical shape by a conductive material, and has a thick upper end 311 at the upper end thereof. A holding hole 312 is formed at the center of the upper end 311. . The rod-shaped antenna element 24 is fitted and fixed in the holding hole 312 to hold the antenna element portion 2.

  The upper connector 32 is formed in a substantially bottomed cylindrical shape from a conductive material such as brass, and is fitted and disposed in the cylindrical body 31 so that the upper bottom portion thereof is in contact with the lower surface of the upper end portion 311. A fitting hole 321 into which a bobbin 5 described later is fitted is formed at the lower center of the upper connector 32, and a notch 322 into which an insulating cylinder 33 described later is fitted is formed around the lower portion. . The cylindrical body 31 and the upper connector 32 correspond to an antenna element conducting portion provided so as to conduct with the antenna element portion 2.

  The insulating cylinder 33 is provided so as to be interposed between the cylindrical body 31 and the upper connector 32 constituting the antenna element conducting portion, and the lower connector 34 constituting the power feeding conducting portion described later, and is made of polyacetal resin (POM). ) Etc. and is formed into an elongated cylindrical shape. The thickness of the insulating cylinder 33 is preferably about 0.1 mm to 0.3 mm, for example. The insulating cylinder 33 is mounted so as to be fitted in the cylinder 31, the upper end of which is in contact with the upper surface of the notch 322 of the upper connector 32, and the vicinity of the upper end is formed by the side surface of the notch 322 to be fitted and the inner wall of the cylinder 31. It is pinched. The lower end of the insulating cylinder 33 is in contact with the upper surface of a large-diameter portion 341 of the lower connector 34 described later, and the vicinity of the lower end is exposed from the covering of the cylindrical body 31.

  The lower connector 34 is formed in a substantially cylindrical shape with a conductive material such as brass, and the lower side thereof is a large diameter portion 341. A substantially arc-shaped plate-shaped portion 342 is provided at the lower end portion of the large-diameter portion 341, and a hole 343 is formed in the approximate center of the plate-shaped portion 342. A concave groove (not shown) is formed on the outer periphery of the lower end surface. A plurality are formed at predetermined intervals. The upper side of the lower connector 34 is a small diameter portion 344 having a smaller diameter than the large diameter portion 341, and a fitting hole 345 into which a bobbin 5 described later is fitted is formed at the center of the small diameter portion 344. . The small diameter part 344 is fitted inside the insulating cylinder 33, and the lower end of the insulating cylinder 33 is in contact with the upper end surface of the large diameter part 341. The lower connector 34 is installed so as not to be directly connected to the upper connector 32. Further, the lower connector 34 corresponds to a power feeding conduction portion provided so as to be conducted with the power feeding portion.

  The bobbin 35 is formed in a substantially cylindrical shape by an insulating material such as polyacetal resin (POM), and small diameter portions 351 and 352 are provided at the upper end portion and the lower end portion thereof. The small-diameter portion 351 at the upper end is inserted into the fitting hole 321 of the upper connector 32, and the small-diameter portion 352 at the lower end is inserted into the fitting hole 345 of the lower connector 34, and the bobbin 35 is The upper connector 32 constituting the antenna element conducting portion and the lower connector 34 constituting the power feeding conducting portion are engaged and provided in the insulating cylinder 33 and fixed. A spiral groove 353 is formed on the outer peripheral surface of the central portion of the bobbin 35.

  The coil 36 is disposed inside the insulating cylinder 33 so as to be aligned with the insulating cylinder 33 in the axial direction and fixed in shape and position, and is provided in a non-contact manner with the antenna element conduction portion and the power feeding conduction portion. It is disposed in the insulating cylinder 33 by being engaged with and wound around the spiral groove 353 on the outer peripheral surface, and is provided at a position away from both the upper connector 32 and the lower connector 34. The coil 36 can be provided so as to be in contact with the insulating cylinder 33 or separated from the insulating cylinder 33. In the latter case, both the insulating cylinder 33 and the air layer are used. Thus, a capacitor is formed, and the multi-frequency antenna 1 having a higher degree of freedom of adjustment can be obtained.

  The second holding portion 4 has a substantially cylindrical main body 41, and the upper end portion of the main body 41 is divided into bifurcated plate-like portions 42 and 42, and the plate-like portions 42 and 42 are the first holding portion 3. The lower connector 34 is disposed on both sides of the plate-like portion 342. A hole is formed in the approximate center of the plate-like portions 42, 42, and a shaft support portion 43 is formed by inserting a pin or the like into this hole and the hole 343 of the plate-like portion 342. The part 3 is pivotally supported by the second holding part 4. The first holding part 3 is electrically connected to the second holding part 4 via the shaft support part 43.

  Inside the second holding part 4, there are a locking body 44 such as a sphere disposed in the vicinity of the upper end in the main body 41, and a coil spring which is disposed in the main body 41 and biases the locking body 44 upward. An elastic material 45 is provided. The locking body 44 is urged upward by the elastic material 45 in the tip direction of the second holding portion 4, and the engaging surface of the locking body 44 such as a spherical surface of the sphere is recessed in the plate-like portion 342 of the first holding portion 3. The groove is detachably engaged. That is, an angle adjustment mechanism is configured by engaging / disengaging the shaft support portion 43 and the locking body 44 with the concave groove, and the first holding portion 3 is held by the second holding portion 4 via the angle adjustment mechanism. The element part 2 and the first holding part 3 are rotatably supported by the second holding part 4, and the antenna element part 2 and the first holding part 3 can be placed in a predetermined direction.

  The holder 5 has a contact spring 52 disposed in the vicinity of the opening in the substantially cylindrical main body 51, and power is supplied to the holder 5 and the contact spring 52 from the power supply unit of the mobile terminal housing. When the antenna element portion 2 is extended, the second holding portion 4 is in contact with and electrically connected to the contact spring 52 to supply power. When the antenna element portion 2 is shortened, the first cylindrical antenna element is supplied. 21 is in contact with the contact spring 52 and is electrically connected to supply power.

  And in the 1st holding | maintenance part 3, the path | route of the conductive cylinder 31-insulating cylinder 33-coil 36-insulating bobbin 35-conductive lower connector 34, or the conductive cylinder 31-insulating cylinder 33- A plurality of pseudo capacitors 7 are formed in the path of air layer-coil 36-insulating bobbin 35-conductive lower connector 34, and as shown in FIG. A circuit equivalent to a state where a plurality of capacitors 7 are connected to the coil 36 at intervals is formed.

  In other words, a circuit equivalent to a circuit in which a parallel resonance circuit in which a partial coil of the coil 36 and the capacitor 7 are connected in parallel is connected in series is configured. A plurality of resonance frequencies of two or more parallel resonance circuits connected in series are set to a predetermined frequency, a required resonance circuit is provided between the antenna element portion 2 and the power feeding portion 6, and two different resonance frequencies are provided. The multi-frequency shared antenna 1 that operates in the above plurality of frequency bands can be configured.

  FIG. 5 shows an example of frequency characteristics of the multi-frequency shared antenna 1. In FIG. 5, the horizontal axis represents frequency, and the vertical axis represents SWR (standing wave ratio). In the illustrated example, the SWR is minimum at around 213 MHz and around 487 MHz, and it can be seen that the multi-frequency shared antenna 1 has excellent resonance with respect to two different frequency bands.

  According to the multi-frequency antenna 1 of the above embodiment, the resonance circuit can be provided in the middle portion of the antenna by the simple mechanical structure of the first holding unit 3. Therefore, a resonance circuit can be formed in the middle part of the antenna while meeting the demands for downsizing / reducing the diameter of the antenna, space saving, etc., eliminating the resonance circuit of the communication device main body such as a portable terminal. Alternatively, the structure can be simplified. Moreover, it is hard to bend with a simple mechanical structure, and can be configured with a small number of parts. Further, it is possible to flexibly adapt to the increase or decrease of the resonance frequency by increasing or decreasing the number of turns of the coil.

  Further, the antenna element conducting portion constituted by the cylindrical body 31 and the upper connector 32 is fitted with the upper end of the insulating cylinder 33 sandwiched therebetween, and the power feeding conducting portion constituted by the lower connector 34 is located on the inner side at the lower end side of the insulating cylinder 33. Due to the configuration of being fitted to each other, they can be engaged and held to increase the strength and improve the durability. Furthermore, the insulating cylinder 33 can be easily interposed between the antenna element conducting portion and the power feeding conducting portion by utilizing the connected state. Moreover, in the 1st holding | maintenance part 3, since the cylinder 31, the upper connector 32, the lower connector 34, the bobbin 35, and the coil 36 are also engaged and hold | maintained in a required location, strength is improved further and durability is improved. Can do.

  In addition, the bobbin 35 is locked and installed inside the insulating cylinder 33, and the coil 36 is wound around the outer periphery of the coil tube 353 so that the shape and position of the coil 36 can be fixed easily and stably. Therefore, the characteristics as a resonance circuit can be stably exhibited. Further, by providing the first holding unit 3 with a resonance circuit, it is possible to reduce the relationship with the conduction structure with the power feeding unit of a communication device such as a portable terminal, and to configure the multi-frequency shared antenna 1 more easily.

[Modifications of Embodiment, etc.]
In addition to the configurations of the inventions and embodiments, the invention disclosed in the present specification includes those specified by changing these partial configurations to other configurations disclosed in the present specification within the applicable range, or These components may be specified by adding other components disclosed in this specification, or may be a higher-level concept that is specified by deleting these partial configurations to the extent that partial effects can be obtained. The following modifications are also included.

  For example, in the above-described embodiment, the first holding unit 3 is provided with a resonance circuit. However, the second holding unit 4 that indirectly holds the antenna element unit 2 includes the cylindrical body 31, the upper connector 32, the insulating cylinder 33, By providing members corresponding to the lower connector 34, the bobbin 35, and the coil 36 in a corresponding arrangement, a resonance circuit is provided in the holding portion closer to the base than the holding portion that directly holds the antenna element portion 2, such as the second holding portion 4. It is also possible to provide a configuration. At this time, when the first holding unit 3 is a normal holding unit that holds the antenna element unit 2 and the second holding unit 4 that holds the first holding unit 3 via the angle adjustment mechanism is provided with a resonance circuit, Since the first holding unit 3 and the angle adjustment mechanism can be further reduced in size, the load applied to the angle adjustment mechanism can be reduced, the durability can be increased, and the tip end side of the antenna can be further narrowed. There is an advantage that the design can be improved.

  In the above embodiment, the antenna element conducting portion is fitted so as to sandwich the upper end side of the insulating cylinder 33, and the power feeding conducting portion is fitted inside on the lower end side of the insulating cylinder 33. Including a suitable configuration in which either one of the first and second power supply conducting parts is fitted inside on one end side of the insulating cylinder and the other is fitted so as to sandwich the other end side of the insulating cylinder. Is a small-diameter portion or the like that is fitted inward on the upper end side of the insulating cylinder 33, and the power supply conduction portion is fitted so as to sandwich the lower end side of the insulating cylinder 33 with a member corresponding to the cylindrical body 31 and the upper connector 32. It is good.

  Further, the configuration of the antenna element conducting portion provided so as to be conducted with the antenna element portion 2 and the power feeding conducting portion provided so as to be conducted with the feeding portion are appropriate within the scope of the gist of the present invention. Although the antenna element conducting portion is constituted by the cylindrical member 31 and the upper connector 32 which are separate members, these may be constituted by an integral conductive member or the like.

  In addition, the coil 36 is installed in the insulating tube 33 with the shape and position fixed in alignment with the insulating tube 33 in the axial direction, and provided in a non-contact manner with the antenna element conducting portion and the power feeding conducting portion. If necessary, for example, a configuration in which the coil 36 is wound around the bobbin 35 having an outer peripheral surface without a spiral groove so as not to be displaced is also possible.

  In addition, the multi-frequency shared antenna of the present invention can be applied to an antenna that does not have an angle adjustment mechanism or an antenna in which the antenna element portion does not expand and contract. The multi-frequency antenna of the present invention is preferably applied to a mobile terminal, but can also be applied to other communication devices.

  The present invention receives, for example, both mobile multimedia broadcasting (MM broadcasting) using a frequency band of 207.5 MHz to 222 MHz and terrestrial digital broadcasting (one seg) for mobile phones / mobiles using a frequency band of 470 MHz to 770 MHz. It can be used as a multi-frequency antenna for portable terminals.

DESCRIPTION OF SYMBOLS 1 ... Multi-frequency common antenna 2 ... Antenna element part 21 ... 1st cylindrical antenna element 211 ... Cap 22 ... 2nd cylindrical antenna element 221 ... Contact spring 23 ... 3rd cylindrical antenna element 231 ... Contact spring 24 ... Rod-shaped antenna element 241 ... Expanded diameter part 242 ... Contact spring 3 ... First holding part 31 ... Cylindrical body 311 ... Upper end part 312 ... Holding hole 32 ... Upper connector 321 ... Fitting hole 322 ... Notch 33 ... Insulating cylinder 34 ... Lower part Connector 341 ... Large diameter part 342 ... Plate-like part 343 ... Hole 344 ... Small diameter part 345 ... Fitting hole 35 ... Bobbins 351 and 352 ... Small diameter part 353 ... Spiral groove 36 ... Coil 4 ... Second holding part 41 ... Main body 42 ... Plate-like part 43 ... Shaft support part 44 ... Locking body 45 ... Elastic material 5 ... Holder 51 ... Main body 52 ... Contact spring 6 ... Feeding part 7 ... Capacitor

Claims (7)

An antenna element,
Holding the antenna element part directly or indirectly, and a holding part electrically connected to the feeding part;
Have
The holding part is
An antenna element conducting portion that has a cylindrical body and is provided so as to be conducted with the antenna element portion;
A power supply conducting part provided to conduct with the power supply part;
An insulating cylinder interposed between the antenna element conducting portion and the feeding conducting portion;
Inside the insulating cylinder, the coil is provided in a non-contact manner with the antenna element conducting part and the power feeding conducting part, arranged in a fixed shape and position in alignment with the insulating cylinder and the axial direction ,
The multi-frequency shared antenna , wherein the cylindrical body of the antenna element conducting portion is provided so as to cover an outer periphery of the coil . Either one of the antenna element conduction part and the power feeding conduction part is fitted inside on one end side of the insulating cylinder,
2. The multi-frequency antenna according to claim 1, wherein the other is fitted so as to sandwich the other end of the insulating tube. Inside the insulating cylinder, a bobbin is provided to be engaged with the antenna element conducting portion and the feeding conducting portion,
A spiral groove is formed on the outer periphery of the bobbin;
The multi-frequency antenna according to claim 1 or 2, wherein the coil is wound around the spiral groove.   The multi-frequency antenna according to any one of claims 1 to 3, wherein the insulating cylinder and the coil are provided apart from each other. The holding part directly holds the antenna element part,
The multi-frequency shared antenna according to any one of claims 1 to 4, wherein the holding unit is held by another holding unit electrically connected to the power feeding unit via an angle adjustment mechanism. The holding portion indirectly holds the antenna element portion;
The multi-frequency antenna according to claim 1, wherein the holding unit holds another holding unit that directly holds the antenna element unit via an angle adjustment mechanism. A portable terminal comprising the multi-frequency antenna according to claim 1.

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