JPH07111415A - Antenna system - Google Patents

Abstract

PURPOSE:To provide a broad band frequency characteristic used in common use for plural frequencies without the need for a matching circuit as a separate circuit for a feeding path by providing a degree of sensitivity capable of receiving a radio wave in the standby state even when a retractable antenna element is accommodated so as to allow the antenna to hardly receive effects of a human body in contact with a case or the like. CONSTITUTION:A metallic cylinder 2 accommodating a 1st antenna rod element 1 in its inside retractably is provided, a linear metal 3 is arranged nearly along a center axis of the metallic cylinder 2 and a feeder 4 is connected to a lower part of the metallic cylinder 2 and the linear metal 3. Furthermore, a contact fixture 5 in slide contact with the 1st antenna element 1 connecting to the linear meal 3 and a 2nd antenna coil element 6 in contact with a tip of the element 1 while the 1st antenna element 1 is accommodated in the inside of the metallic cylinder 2 are provided to an upper part of the metallic cylinder 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used in small radios.
In particular, it is used for mobile phones, cordless phones, and other mobile wireless devices. The present invention relates to a retractable antenna device that is used by pulling out an antenna element during communication or when the electric field strength is small, and otherwise accommodates and uses the antenna element for convenience of carrying. The present invention relates to an antenna device having a corresponding sensitivity even in a contracted state.

[0002]

2. Description of the Related Art In a portable radio device, there is widely used a telescopic antenna device in which an antenna element can be pulled out from a device housing when performing communication and can be housed in the housing when carried in a bag or a pocket. Are known. Figure 1
FIG. 0 is a diagram showing a conventional device, in which (a) shows a state where the antenna element 31 is drawn out of the housing 35, and (b) shows the antenna element 31 inside the housing 35. The state where it accommodated is shown.

Generally, an antenna device having such a structure is
It is convenient to carry without a radio,
A matching circuit 32 for matching impedance is provided between the power supply line 33 and the wireless circuit 34, except when the length of the antenna element 31 resonates at a quarter of the used wavelength.

[0004]

A wireless device such as a mobile phone is in a standby reception state in which it continues to receive radio waves from the base station even when no call is being made. In the above-described conventional example device, if the antenna element is housed inside the housing, the sensitivity is almost lost, so that it cannot be used in principle for a device that performs standby reception when a call is not performed.

Further, in the above-mentioned conventional device, since power is supplied from the radio circuit between the antenna element and the casing, an antenna current is also generated on the casing surface. Therefore, in a mobile phone or the like in which the housing itself is held by hand, the radiation characteristics of the antenna are easily affected by the hand or the human body. That is, since the antenna current flowing on the surface of the housing also flows to the human body, the radiation characteristics change depending on how the device is held by the hand, the movement of the human body, or the like, and the communication state is changed. It will change.

[0006] Further, in recent years, due to the frequency allocation for small radios, there are some that perform frequency switching for a plurality of frequencies. In that case, one having a wide band frequency characteristic that can be shared by a plurality of frequencies with one antenna device is used. Is needed.

The present invention has been made against such a background, and is sensitive enough to perform standby reception even in a state where a retractable antenna element is housed, and influences the human body in contact with the housing and other influences. It is an object of the present invention to provide an antenna device that is hard to receive and does not need to provide a matching circuit as a separate circuit in a power feeding path. A further object of the present invention is to provide an antenna device having wideband frequency characteristics that can be shared by a plurality of frequencies.

[0008]

The first object of the present invention is to provide a rod-shaped first antenna element (1), a metal cylinder (2) for retractably housing the first antenna element therein, and a metal cylinder (2). Linear metal (3) arranged approximately along the central axis of the cylinder
And a feeder line (4) connected between the linear metal (3) and the metal cylinder (2) below the metal cylinder (2).
A contact fitting (5) connected to the linear metal (3) at the upper part of the metal cylinder (2) and slidingly contacting the first antenna element (1), and arranged near the upper part of the metal cylinder (2). And a coiled second antenna element (6), one end of which is in contact with the tip of the first antenna element (1) in a state where the first antenna element (1) is housed inside the metal cylinder (2). It is characterized by that.

The first antenna element (1) has a two-stage structure, the length of the first antenna element (1) is approximately one half of the resonance wavelength (λ) in the extracted state, and the length of the metal cylinder (2). Is about a quarter of the resonance wavelength (λ), and its metal cylinder (2)
A non-conductive guide (7) for accommodating the first antenna element (1) in a substantially central position is provided inside the first antenna element (1), and the tip of the first antenna element (1) has the first antenna element (1). ) Is provided inside the metal cylinder (2) and has a tip metal part (10) for contacting the tip of the second antenna element (6), and a conductive ring is provided under the guide (7). It is desirable that (13) be provided.

A second aspect of the present invention is that a rod-shaped first antenna element (1), a metal cylinder (2) that accommodates the first antenna element in a retractable manner, and a substantially central axis of the metal cylinder. A linear metal (3) arranged along the feed line (4) connected between the linear metal (3) and the metal cylinder (2) below the metal cylinder (2); Contact metal fittings (5) connected to the linear metal (3) at the upper part of the metal cylinder (2) and slidingly contacting the first antenna element (1), and arranged near the upper part of the metal cylinder (2). A coil-shaped second antenna element (6) whose one end is connected to the contact fitting (5) through a capacitor (14) is provided with a tap (15). 15) The first antenna element (1) is housed inside the metal cylinder (2) Characterized by contacting the tip of the first antenna element in a state.

The first antenna element (1) has a two-stage structure, the length of the first antenna element (1) is approximately one half of the resonance wavelength (λ) in the extracted state, and the length of the metal cylinder (2). Is about a quarter of the resonance wavelength (λ), and its metal cylinder (2)
A non-conductive guide (7) for accommodating the first antenna element (1) in a substantially central position is provided inside the first antenna element (1), and the tip of the first antenna element (1) has the first antenna element (1). It is desirable to provide a tip metal part (10) for contacting the tap (15) of the second antenna element (6) in a state where (1) is housed inside the metal cylinder (2).

A third aspect of the present invention is that a rod-shaped first antenna element (1), a metal cylinder (2) that accommodates the first antenna element in a retractable manner, and a substantially central axis of the metal cylinder. A linear metal (3) arranged along the feed line (4) connected between the linear metal (3) and the metal cylinder (2) below the metal cylinder (2); A metal fitting (5) connected to the linear metal (3) at the upper part of the metal cylinder (2) and slidingly contacting the first antenna element (1) and a tip of the first antenna element (1) are provided. A second antenna element (19) electrically connected to the tip is provided, and the second antenna element (19) has the first antenna element (1) housed inside the metal cylinder (2). It is characterized in that the structure is such that it projects above the metal cylinder (2) even in the state.

In a fourth aspect of the present invention, a rod-shaped first antenna element (1), a metal cylinder (2) for retractably housing the first antenna element therein, and a substantially central axis of the metal cylinder. A linear metal (3) arranged along the feed line (4) connected between the linear metal (3) and the metal cylinder (2) below the metal cylinder (2); A metal fitting (5) connected to the linear metal (3) at the upper part of the metal cylinder (2) and slidingly contacting the first antenna element (1) and a tip of the first antenna element (1) are provided. A second antenna element (19) that is electrically non-contact is provided at this tip,
The second antenna element (19) projects above the metal cylinder (2) when the first antenna element (1) is housed inside the metal cylinder (2), and the second metal element (19) is electrically connected to the contact fitting (5). The feature is that they are in contact with each other.

In a fifth aspect of the present invention, a rod-shaped first antenna element (1), a metal cylinder (2) which accommodates the first antenna element in a retractable manner, and a substantially central axis of the metal cylinder. A linear metal (3) arranged along the feed line (4) connected between the linear metal (3) and the metal cylinder (2) below the metal cylinder (2); A contact metal fitting (5) connected to the linear metal (3) at the upper part of the metal cylinder (2) and slidingly contacting the first antenna element (1), and provided near the upper part of the metal cylinder (2). When the first antenna element (1) is pulled out from the metal cylinder (2), it is not in contact, and when the first antenna element (1) is housed inside the metal cylinder (2), the contact fitting is Is provided with a second antenna element that is in electrical contact with.

[0015]

The first antenna element (1) is retractably housed inside the metal cylinder (2) arranged in the housing (11). At the time of communication or when the electric field strength is low, the first antenna element (1) is pulled out and used, and at other times, it is used in a housed state so as to be convenient for carrying.

The metal cylinder (2) and the linear metal (3) arranged inside the metal cylinder (2) form a coaxial structure. This coaxial structure is connected to the coaxial feed line (4) at the lower part of the metal cylinder (2) and is connected to the rod-shaped first antenna element (1) at the upper part thereof.
Therefore, this coaxial structure acts as an impedance conversion circuit provided between the feeder line (4) and the first antenna element (1). Since the characteristic impedance of the coaxial structure is determined by the ratio of the inner diameter of the metal cylinder (2) and the outer diameter of the linear metal (3), this characteristic impedance is matched with the characteristic impedance of the power supply line (4) to obtain the coaxial structure. By adjusting the length, the impedance of the feeding point of the first antenna element (1) can be matched.

Further, in the structure of the present invention, the metal cylinder (2)
A metal fitting (5) which is connected to the linear metal (3) at the upper part of the and slidably contacts the first antenna element (1), and one end of which is arranged near the upper part of the metal cylinder (2) and which has the first antenna element (1).
Is provided with a coiled second antenna element (6) which contacts the tip of the first antenna element (1) while being housed inside the metal cylinder (2).

The impedance conversion circuit having the coaxial structure composed of the metal cylinder (2) and the linear metal (3) has the first antenna element (1) by selecting design conditions.
Since the second antenna element (2) and the second antenna element (2) can be resonated to have substantially the same wavelength, there is sensitivity even when the first antenna element (1) is housed inside, so that standby reception can be performed.

With such a coaxial structure, it is not necessary to provide a matching circuit as a separate circuit in the power feeding path, and wide band frequency characteristics that can be shared by a plurality of frequencies can be obtained. In addition, since the outer body can be electrically separated from the housing by adopting the coaxial structure, the current distribution on the ground side is generated in the outer conductor of the coaxial structure and hardly occurs in the housing. The influence of the human body approaching to can be reduced.

[0020]

Embodiments of the present invention will now be described with reference to the drawings.

(First Embodiment) (Resonance to Almost Same Wavelength) FIG. 1 (a) is a perspective view showing the structure of the first embodiment of the present invention with a first antenna element pulled out, and FIG. 2 is a perspective view showing the configuration of one antenna element in a housed state, FIG.
(A) is sectional drawing which shows the structure in the state which pulled out the 1st antenna element in 1st Example of this invention, (b) is a cross section which shows the structure in the accommodation state of a 1st antenna element.

In the first embodiment of the present invention, a rod-shaped first antenna element 1, a metal cylinder 2 that accommodates the first antenna element 1 in a retractable manner, and a substantially central axis of the metal cylinder 2. Connected to each other, a feeder 4 connected between the linear metal 3 and the metallic cylinder 2 below the metallic cylinder 2, and a linear metal 3 connected above the metallic cylinder 2. The contact fitting 5 that slidably contacts the first antenna element 1 and one end of the metal fitting 2 that is arranged near the upper portion of the metal cylinder 2.
The coil-shaped second antenna element 6 that contacts the tip of the first antenna element in a state in which is housed inside the metal cylinder 2.
And the first antenna element 1 has a two-stage structure, the length of which is approximately one half of the resonance wavelength λ in the extracted state, and the length of the metal cylinder 2 is approximately four of the resonance wavelength λ. And a non-conductive guide 7 for accommodating the first antenna element 1 in a substantially central position is provided inside the metal cylinder 2, and the first antenna element 1 is provided at the tip thereof. A metal tip 1 for contacting the tip of the second antenna element 6 in a state in which 1 is housed inside the metal cylinder 2.
Equipped with 0.

Next, the operation principle of the first embodiment of the present invention thus constructed will be described with reference to FIG.

The first antenna element 1 is housed in two stages, and the length of the extended state is approximately 1/2 wavelength. At the time of pulling out as shown in FIG.
It is necessary to match the impedance of 50 Ω with the impedance of several hundred Ω when the first antenna element 1 of ½ wavelength is fed from the lower end, and in this embodiment, a matching circuit having a coaxial structure is installed between them. This coaxial structure is composed of a metal cylinder 2 and a thin linear metal 3 that form an outer conductor, and its length is about 1/4 in order to set the characteristic impedance to a value close to the geometric mean value of 50Ω and several hundreds Ω. The wavelength is used.
In order to set the characteristic impedance of the coaxial structure to about 200Ω, the diameter ratio of the inner conductor to the outer conductor should be 6. That is, if the inner conductor has a diameter of 1 mm, the outer conductor has a diameter of 6 mm. As a result, impedance conversion is performed. In the first embodiment, since the non-conductive guide 7 for accommodating the first antenna element 1 is provided, the linear metal 3 cannot pass through the complete center of the metal cylinder 2, but it is also suitable in that state. The characteristic impedance can be obtained. Further, in this case, since the coiled second antenna element 6 is not connected anywhere and has no resonance wavelength, the operation of the first antenna element 1 is not affected at all.

On the other hand, when the first antenna element 1 is housed as shown in FIG. 2B, the inner conductor of the power supply line 4 is housed in the non-conductive guide 7 via the first contact terminal 8. The first antenna element 2 is connected to the first antenna element 2, and the tip of the first antenna element 1 is connected to the second contact terminal 9 of the second antenna element 6 by the tip metal portion 10. The second antenna element 6 is designed in advance to resonate with a low impedance. In this case, the housed first antenna element 1 operates as an internal conductor of the coaxial impedance converter. The first antenna element 1 is thicker than the linear metal 3, and the characteristic impedance of the coaxial structure changes to a low value. As an example, the diameter of the first antenna element 1 is 3 mm
If the diameter of the metal cylinder 2 is 6 mm, the characteristic impedance of this coaxial structure is about 50Ω. That is, in this case, the coaxial formed by the metal cylinder 2 and the first antenna element 1 housed therein operates as a simple 50Ω transmission line, not as an impedance converter, and also at the second contact terminal 9 of the second antenna element 6. It has a low impedance.

As a result, the second antenna element 6 is matched with the coiled second antenna element 6 which operates with a low impedance, and the second antenna element 6 operates to radiate. In this case, the first antenna element 1 acts as a transmission line and has no influence on the operation of the second antenna element 6. Therefore, with such a configuration, it is possible to configure an antenna device having a high gain both when the first antenna element 1 is pulled out and when it is stored.

In the above description, the first antenna element 1 is 1 /
Although about 2 wavelengths and the metal cylinder 2 are set to 1/4 wavelength, the length of the first antenna element 1 may be arbitrary. In that case, if the length of the coaxial impedance converter and the characteristic impedance are appropriately set. Good.

Further, in the first embodiment, when the first antenna element is pulled out, the metal cylinder 2 operates as a stub and blocks the current flowing in the housing 11, so that it is less affected by the antenna installation object. Further, since the matching circuit is a coaxial type configured with distributed constants, a wide bandwidth and high gain can be obtained.

FIGS. 3 (a) and 3 (b) are diagrams showing experimental results in the first embodiment of the present invention. This is because the metal cylinder 2 has a length of 5 cm, a diameter of 1 cm, and the first antenna element 1
10a, the second antenna element 6 has a diameter of 1 cm, the number of turns is about 2.5, and the impedance characteristics are shown when the second antenna element 6 is installed in a metal housing of about 200 cc. The characteristics when one antenna element is pulled out are shown, and the figure (b) shows the characteristics when the first antenna element is housed.

According to this, when the first antenna element 1 is pulled out, it resonates at about 1.44 GHz, and when it is stored, it resonates at 1.46 GHz, and resonates at about the same frequency. This is because when the first antenna element 1 is pulled out, it operates as a 1/2 wavelength antenna because the length of the antenna element is 10 cm, and when it is stored, the line length of the second antenna element 6 is about 2.5 cm.
Therefore, it can be seen that the antenna operates as a quarter-wave antenna. This demonstrates that the characteristic impedance of the coaxial converter changed and resonated in each state.
Further, in this case, the band when the first antenna element 1 is pulled out is 150 MHz when VSWR <2, the specific bandwidth is 10% or more, which is very wide, and the gain is almost the same as that of the 1/2 wavelength dipole.

(Second Embodiment) (Resonant at almost the same wavelength) FIG. 4 (a) is a perspective view showing the configuration of the second antenna of the present invention with the first antenna element pulled out, and FIG. It is a perspective view which shows the structure in the antenna element accommodation state.

In the second embodiment of the present invention, a conductive ring 13 is provided below the non-conductive guide 7 in the first embodiment, and the other structures are the same.

The conductive ring 13 has substantially the same diameter as the non-conductive guide 7 for housing the first antenna element 1 and is connected to the internal conductor of the power supply line 4 and the opposite side thereof is connected to the linear metal 3. To be done. Further, when the first antenna element 1 is stored, the tip of the first antenna element 1 is wrapped. With this structure, the coaxial structure is formed by the metal cylinder 2, and the characteristic impedance is different between the portion where the linear metal 3 is the inner conductor and the portion where the conductive ring 13 is the inner conductor. Therefore, the degree of freedom of the impedance converter is increased. That is, if such a two-stage impedance conversion circuit is configured, the band can be further widened and two resonance characteristics can be obtained.

If the characteristic impedance of the portion where the conductive ring 13 is the internal conductor is 50Ω, only the portion where the linear metal 3 is the internal conductor operates as an impedance converter, so the metal cylinder 2 It is possible to change the length of only the impedance conversion unit while fixing the wavelength of 1/4 wavelength. Also in this case, since the conductive ring 13 and the housed first antenna element 1 are integrated when the first antenna element 1 is housed, the state becomes the same as that shown in FIG.
The operating principle is the same.

Therefore, in the second embodiment as well, a high gain can be obtained, a wide band characteristic can be easily obtained, the influence of the installation is small, and a high gain can be obtained even when the antenna element is housed. To be

(Third Embodiment) (Resonance at Two Wavelengths) FIG. 5A is a sectional view showing the structure of the third embodiment of the present invention in the pulled-out state of the first antenna element, and FIG. 5B is the first antenna element. It is sectional drawing which shows the structure in a accommodated state.

In the third embodiment of the present invention, a rod-shaped first antenna element 1, a metal cylinder 2 which accommodates the first antenna element 1 in an expandable and contractible manner, and a substantially central axis of the metal cylinder 2. Connected to each other, a feeder 4 connected between the linear metal 3 and the metallic cylinder 2 below the metallic cylinder 2, and a linear metal 3 connected above the metallic cylinder 2. The contact fitting 5 slidingly contacting the first antenna element 1 and the coil-shaped second antenna element 6 arranged near the upper portion of the metal cylinder 2 and having one end connected to the contact fitting 5 via the capacitor 14.
And a tap 15 is provided on the second antenna element, and the tap 15 contacts the tip of the first antenna element with the first antenna element 1 housed inside the metal cylinder 2.

The first antenna element 1 has a two-stage structure, and has a length of about ½ of the resonance wavelength λ when it is pulled out.
And the length of the metal cylinder 2 is about a quarter of the resonance wavelength λ.
And the first antenna element 1 is inside the metal cylinder 2.
A non-conductive guide 7 for correctly accommodating the first antenna element 1 in the center position, and the tap of the second antenna element 6 with the first antenna element 1 accommodated inside the metal cylinder 2 at the tip of the first antenna element 1. Tip plate 10 for contacting 15
Equipped with.

The third embodiment having the above-mentioned structure obtains two resonance characteristics at the time of extraction and resonates at one wavelength at the time of accommodation. That is, when the first antenna element 1 is pulled out, a resonance circuit composed of the coil-shaped second antenna element 6 and the capacitor 14 is added in parallel with the first antenna element 1 to obtain the second resonance characteristic. When the one antenna element 1 is housed, the contact fitting 5 and the second contact terminal 9 are connected and the second antenna element 6 is connected through the tap 15, so that the second antenna element 6 is 1/4.
It radiates as a wavelength radiating element. In this case, when the first antenna element 1 is stored, the capacitor 14 to the tap 15
The part of the coil-shaped second antenna element 6 up to is short-circuited, and almost no current flows through that part.

FIG. 6A is a diagram showing a return loss characteristic when the first antenna element is pulled out in the third embodiment of the present invention, and FIG. 6B is a diagram showing a return characteristic when the first antenna element is housed. In the figure, f1 and f2 indicate the resonance frequency when the first antenna element is pulled out, and f3 indicates the resonance frequency when the first antenna element is housed.

In this experiment, the length of the metal cylinder 2 was 8 cm,
The diameter is 1 cm, and the length of the first antenna element 1 is 15 c
m, the diameter of the second antenna element 6 is 1 cm, and the number of turns is about 3
The capacitor 14 was set to about 1 pF and installed in a small housing of about 200 cc. As a result, as shown in FIG. 6A, f1 = 835 MHz, and f = 1005 MHz
Two-resonance characteristics that resonate at z were obtained. Also, FIG.
As shown in, when the first antenna element 1 is housed,
By connecting the tap 15 to the place where the number of turns of the second antenna element 6 is about 2.5, a characteristic of resonating at f3 = 990 MHz was obtained. In this way, by adjusting the number of turns of the second antenna element 6, the value of the capacitor 14, and the connection point of the taps 15, it is possible to obtain a two-resonance characteristic when the first antenna element 1 is pulled out, and a single resonance characteristic when the first antenna element 1 is stored. The characteristics can be obtained.

(Fourth Embodiment) (One-Wavelength Resonance) FIG. 7A is a sectional view showing the structure of the fourth embodiment of the present invention with the first antenna element pulled out, and FIG. 7B is the first antenna. It is sectional drawing which shows the structure in an element accommodation state.

In the fourth embodiment of the present invention, a rod-shaped first antenna element 1, a metal cylinder 2 which accommodates the first antenna element 1 in an expandable and contractible manner, and a substantially central axis of the metal cylinder 2. Connected to each other, a feeder 4 connected between the linear metal 3 and the metallic cylinder 2 below the metallic cylinder 2, and a linear metal 3 connected above the metallic cylinder 2. This second antenna element 1 is provided with a contact fitting 5 that is in sliding contact with the first antenna element 1 and a second antenna element 19 that is provided at the tip of the first antenna element 1 and is electrically non-contact with the tip.
Reference numeral 9 is configured to project above the metal cylinder 2 when the first antenna element 1 is housed inside the metal cylinder 2.

In the fourth embodiment, a 1/4 wavelength linear element as the first antenna element 1 and a 1 element added to the 1/4 wavelength linear element are further provided.
This shows an example using the second antenna element 19 in the form of a / 4 wavelength coil. In the case of this example, the first antenna element 1 and the second antenna element 19 are integrated, but It can be designed so that the position where power is supplied changes, and both can be matched.

The principle is the same as that of the first embodiment, except that the first antenna element 1 and the second antenna element 19 are integrated. The lower part of the first antenna element 1 is a linear element with a large diameter and a quarter wavelength, and the upper part is a coiled second antenna element 19 with a quarter wavelength. Since the first antenna element 1 is fed from the bottom when it is pulled out, it needs to be fed with a high impedance with a total of 1/2 wavelength, and the metal cylinder 2 and the linear metal 3 operate as a coaxial impedance converter.

On the other hand, when the first antenna element 1 is stored,
The accommodated first antenna element 1 serves as a coaxial inner conductor, operates as a transmission line of approximately 50Ω, and supplies the second antenna element 19 of ¼ wavelength with low impedance. Therefore, also in this embodiment, it is possible to perform matching when the first antenna element 1 is pulled out and stored.

(Fifth Embodiment) (One-wavelength Resonance) FIG. 8A is a sectional view showing the structure of the fifth embodiment of the present invention with the first antenna element pulled out, and FIG. 8B is the first antenna. It is sectional drawing which shows the structure in an element accommodation state.

In the fifth embodiment of the present invention, a rod-shaped first antenna element 1, a metal cylinder 2 that accommodates the first antenna element 1 in an expandable and contractible manner, and a substantially central axis of the metal cylinder 2. Arranged in a line, a feeder 4 connected between the linear metal 3 and the metallic cylinder 2 at the lower part of the metallic cylinder 2, and a linear metal at the upper part of the metallic cylinder 2. The contact fitting 5 connected to the first antenna element 1 and slidably contacting the first antenna element 1, and the second antenna element 19 provided at the tip of the first antenna element 1 and electrically non-contacting the tip are provided. The antenna element 19 is structured so as to project above the metal cylinder 2 and make electrical contact with the contact fitting 5 when the first antenna element 1 is housed inside the metal cylinder 2.

In the fifth embodiment of the present invention thus constructed, the 1/4 wavelength coil-shaped second antenna element 19 which is not electrically connected to the tip of the 1/2 wavelength first antenna element 1 is used. To provide. The second contact terminal 21 contacts the contact metal 5 when the coil-shaped first antenna element 19 is housed. In the case of this structure, when the first antenna element 1 is pulled out, the first antenna element 1 operates as a 1/2 wavelength antenna element, and when housed, only the second antenna element 19 operates as a radiating element. At the time of storage, as in the first embodiment, the first antenna element 1 itself acts as a thick feed line and reaches the contact fitting 5 with a low impedance, so that the second contact terminal 21 resonates at a quarter wavelength. The antenna element 19 can be fed.

(Sixth Embodiment) (One-Wavelength Resonance) FIG. 9A is a sectional view showing the configuration of the sixth embodiment of the present invention in a state where the first antenna element is pulled out, and FIG. It is sectional drawing which shows the structure in a state.

In the sixth embodiment of the present invention, a rod-shaped first antenna element 1, a metal cylinder 2 which accommodates the first antenna element 1 in a retractable manner, and a substantially central axis of the metal cylinder 2. Connected to each other, a feeder 4 connected between the linear metal 3 and the metallic cylinder 2 below the metallic cylinder 2, and a linear metal 3 connected above the metallic cylinder 2. The contact fitting 5 slidingly contacting the first antenna element 1 and the first antenna element 1 provided near the upper portion of the metal cylinder 2 are not in contact with each other when the first antenna element 1 is pulled out from the metal cylinder 2. The second antenna element 23, which makes electrical contact with the contact fitting 5 in the state of being accommodated in the metal cylinder 2, is provided.

In the sixth embodiment having such a structure, another second antenna element 23 is installed as an antenna element at the time of storage. When the first antenna element 1 is housed, the tip plate 10 and the second contact terminal 21 connected to the power supply line 22 are connected to each other, whereby the second antenna element 23 is connected.
Can be powered with low impedance. Therefore, the same effect as the first embodiment can be obtained.

[0053]

As described above, according to the present invention, the antenna element is pulled out and used during communication or when the electric field strength is low, and otherwise, the antenna element is housed so as to be convenient for carrying. It can be used, and there is an effect that standby reception can be performed even in a state where the expandable antenna element is housed.

Further, it is possible to provide a wide band frequency characteristic which can be shared by a plurality of frequencies without requiring a matching circuit as a separate circuit in the power feeding path, and to reduce the influence of a human body approaching the housing. Further, since the impedance converter has a coaxial structure and it is not necessary to provide a circuit element at an intermediate position of the antenna element, there is an effect that the mechanical structure of the antenna device can be made solid.

[Brief description of drawings]

FIG. 1A is a perspective view showing a configuration of a first antenna element according to a first embodiment of the present invention with a first antenna element pulled out, and FIG.
FIG. 3 is a perspective view showing a configuration of the first antenna element in a housed state.

FIG. 2A is a cross-sectional view showing the structure of the first embodiment of the present invention with a first antenna element pulled out, and FIG.
FIG. 3 is a cross-sectional view showing a configuration of the first antenna element in a housed state.

FIG. 3A is a diagram showing impedance characteristics when the first antenna element is pulled out in the first embodiment of the present invention;
FIG. 6B is a diagram showing impedance characteristics when the first antenna element is housed.

FIG. 4A is a perspective view showing the configuration of the second embodiment of the present invention when the first antenna element is pulled out, and FIG. 4B is a perspective view showing the configuration when the first antenna element is stored.

5A is a cross-sectional view showing a configuration of a third antenna device according to a third embodiment of the present invention in a pulled-out state, and FIG. 5B is a cross-sectional view showing a configuration of the first antenna element in a stored state.

6A is a diagram showing a return loss characteristic when the first antenna element is pulled out in the third embodiment of the present invention, FIG.
FIG. 4 is a diagram showing a return loss characteristic when the first antenna element is housed.

FIG. 7A is a sectional view showing a configuration of a fourth antenna element according to a fourth embodiment of the present invention in a pulled-out state, and FIG. 7B is a sectional view showing a configuration of the first antenna element in a housed state.

FIG. 8A is a cross-sectional view showing the configuration of the fifth embodiment of the present invention when the first antenna element is in a pulled-out state, and FIG. 8B is a cross-sectional view showing the configuration when the first antenna element is in a housed state.

FIG. 9A is a sectional view showing the configuration of the sixth embodiment of the present invention when the first antenna element is pulled out, and FIG. 9B is a sectional view showing the configuration when the first antenna element is stored.

FIG. 10A is a perspective view showing a configuration in a state where an antenna element is pulled out in a conventional example, and FIG. 10B is a perspective view showing a configuration in a state where an antenna element is housed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st antenna element 2 Metal cylinder 3 Wire-shaped metal 4, 22, 33 Feeding wire 5 Contact metal fittings 6, 19, 23 2nd antenna element 7 Non-conductivity guide 8 1st contact terminal 9, 21 2nd contact terminal 10 Tip Metal part 11,35 Housing 12,34 Radio circuit 13 Conductive ring 14 Capacitor 15 Tap 31 Antenna element 32 Matching circuit

Claims (8)

[Claims] 1. A rod-shaped first antenna element (1), a metal cylinder (2) for accommodating the first antenna element in a retractable manner, and a metal cylinder (2) arranged substantially along the central axis of the metal cylinder. The linear metal (3), a feeder line (4) connected between the linear metal (3) and the metallic cylinder (2) below the metallic cylinder (2), and the metallic cylinder (2). ), A metal fitting (5) connected to the linear metal (3) at the upper part of the above) and slidably contacting the first antenna element (1), and one end of the metal fitting (5) arranged near the upper part of the metal cylinder (2). An antenna comprising: a coil-shaped second antenna element (6) which contacts the tip of the first antenna element in a state where the antenna element (1) is housed inside the metal cylinder (2). apparatus. 2. The first antenna element (1) has a two-stage structure, and has a length of a resonance wavelength (λ) in a pulled-out state.
½ of the resonance wavelength (λ), and the length of the metal cylinder (2) is approximately ¼ of the resonance wavelength (λ). A non-conductive guide (7) for accommodating the first antenna element (1) inside the metal cylinder (2) is provided at the tip of the first antenna element (1). The antenna device according to claim 1, further comprising a tip metal part (10) for contacting a tip of the second antenna element (6) in a housed state. 3. A conductive ring (1) is provided below the guide (7).
The antenna device according to claim 2, wherein 3) is provided. 4. A rod-shaped first antenna element (1), a metal cylinder (2) for accommodating the first antenna element in a retractable manner, and a metal cylinder (2) arranged substantially along the central axis of the metal cylinder. The linear metal (3), a feeder line (4) connected between the linear metal (3) and the metallic cylinder (2) below the metallic cylinder (2), and the metallic cylinder (2). ) Which is connected to the linear metal (3) at the upper part of (1) and is in sliding contact with the first antenna element (1), and one end of which is located near the upper part of the metal cylinder (2). (5) is provided with a coiled second antenna element (6) connected via a capacitor (14), and the second antenna element is provided with a tap (15).
5) An antenna device, wherein the first antenna element (1) contacts the tip of the first antenna element (1) in a state of being housed inside the metal cylinder (2). 5. The first antenna element (1) has a two-step structure, and has a length of a resonance wavelength (λ) in an extracted state.
½ of the resonance wavelength (λ), and the length of the metal cylinder (2) is approximately ¼ of the resonance wavelength (λ). A non-conductive guide (7) for accommodating the first antenna element (1) inside the metal cylinder (2) is provided at the tip of the first antenna element (1). The tap (1) of the second antenna element (6) in the housed state
The antenna device according to claim 4, further comprising a tip metal part (10) for contacting with (5). 6. A rod-shaped first antenna element (1), a metal cylinder (2) for accommodating the first antenna element in a retractable manner, and a metal cylinder (2) arranged substantially along the central axis of the metal cylinder. The linear metal (3), a feeder line (4) connected between the linear metal (3) and the metallic cylinder (2) below the metallic cylinder (2), and the metallic cylinder (2). ), A metal fitting (5) connected to the linear metal (3) on the upper part of (1) and slidably contacting the first antenna element (1), and an electrical member provided at the tip of the first antenna element (1). And a second antenna element (19) connected to the metal cylinder, the second antenna element (19) having the first antenna element (1) housed inside the metal cylinder (2). An antenna device having a structure protruding to the upper part of (2). 7. A rod-shaped first antenna element (1), a metal cylinder (2) for accommodating the first antenna element in a retractable manner, and a metal cylinder (2) arranged substantially along the central axis of the metal cylinder. The linear metal (3), a feeder line (4) connected between the linear metal (3) and the metallic cylinder (2) below the metallic cylinder (2), and the metallic cylinder (2). ), A metal fitting (5) connected to the linear metal (3) on the upper part of (1) and slidably contacting the first antenna element (1), and an electrical member provided at the tip of the first antenna element (1). A non-contact second antenna element (19), and the second antenna element (19) is a metal cylinder when the first antenna element (1) is housed inside the metal cylinder (2). It has a structure that protrudes above the (2) and makes electrical contact with the contact fitting (5). Characteristic antenna device. 8. A rod-shaped first antenna element (1), a metal cylinder (2) for accommodating the first antenna element in a retractable manner, and a metal cylinder (2) arranged substantially along the central axis of the metal cylinder. The linear metal (3), a feeder line (4) connected between the linear metal (3) and the metallic cylinder (2) below the metallic cylinder (2), and the metallic cylinder (2). ), A metal fitting (5) connected to the linear metal (3) at the upper part of the above) and slidingly contacting the first antenna element (1), and the first antenna element (5) provided near the upper part of the metal cylinder (2). When the first antenna element (1) is housed inside the metal cylinder (2), it is not in contact with the metal cylinder (2) and is in electrical contact with the contact fitting. An antenna device comprising a second antenna element for