JP2001326514A - Antenna for portable radio equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna with which portable radio equipment can obtain a satisfactory polarization characteristic in either use state of a voice communication mode (actual speech communication mode in which a user holds the portable radio equipment near the head and performs communication) or a data communication mode. SOLUTION: One or a plurality of switching means 6 for switching electrical connection states are provided on an antenna element 1 in which an electrical length is about one wavelength in an operation frequency, and the main polarization characteristic of the antenna can be switched to horizontal polarization/ vertical polarization by switching the switching means 6 with the control of a switch control circuit part 8 for performing switching control of the means 6. The switch control circuit part 8 is provided with a means for discriminating the communication media of voice communication/data communication and a means for discriminating the existence/absence of the connection of an external device to the portable radio equipment. It is possible to automatically switch to an antenna having a satisfactory plane of polarization by switching the switching means 6 on the basis of discrimination results of these discriminating means without the user being aware of it.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna for a portable radio, such as a portable telephone, having a function of making a call in a state of being close to a human body and capable of obtaining good speech characteristics.

[0002]

2. Description of the Related Art As a conventional antenna for a portable wireless device such as a portable telephone, a monopole antenna having an antenna length of about a quarter wavelength to about a half wavelength is often used. FIG. 7 shows a conventional antenna configuration of the monopole antenna. 7, reference numeral 71 denotes a monopole antenna, 72 denotes a power supply unit, and 73 denotes a housing. Although the directivity of the antenna greatly changes depending on the antenna length, the housing dimensions of the portable wireless device, and the like, the polarization characteristic basically depends on the direction of the antenna radiation conductor, and as shown in FIG. When the mechanical antenna is placed in the vertical direction (that is, in the z-axis direction), the vertical polarization becomes the main polarization.

[0003] On the other hand, such a portable wireless device is generally used at the time of a real human body call in such a manner that the portable wireless device is tilted about 60 degrees close to the head.
A distortion occurs in the horizontal plane directivity, and the main polarization characteristic also becomes a polarization plane inclined by about 60 degrees from the vertical direction (z-axis direction). Also, as an antenna on the base station side of a mobile phone,
In general, since vertically polarized waves are used, the polarization loss due to the inclination of the polarization plane becomes large. The main causes of deterioration of antenna characteristics during real-body communication are absorption loss due to the human body (head and hand), as described above, distortion of directivity due to tilt of the mobile phone, and polarization due to change in polarization plane. Loss and the like.

FIG. 8 shows an antenna disclosed in Japanese Patent Application Laid-Open No. H11-136020, for example, as a conventional antenna configuration technique for reducing such deterioration of antenna characteristics during a real-body call. In FIG. 8, reference numeral 82 denotes a radio base plate, and 81 denotes a loop antenna. In the present embodiment, the loop surface of the loop antenna 81 having a perimeter of 1 wavelength or less is arranged at an angle of approximately 60 degrees from the long axis direction of the ground plane of the wireless device, so that the longitudinal direction of the loop surface is vertical in a real human body communication state. It is configured to be in the direction.

As a configuration example of a loop antenna having a switching circuit, for example, there is a loop antenna disclosed in Japanese Patent Laid-Open No. Hei 5-327335. The loop antenna is provided with a plurality of feed points on a loop antenna that is very small compared to one wavelength, and switches the antenna directivity by switching the feed points.
Since multiple feed points are required on the loop antenna,
The power supply structure becomes complicated. The present embodiment relates to a minute loop antenna, and basically has an operation principle different from that of a loop antenna having one or more wavelengths. In other words, the current on the antenna loops with a substantially uniform amplitude while the loop antenna with one or more wavelengths is a resonance type antenna in which the current on the loop has an amplitude characteristic. Small loop antennas are well known as magnetic current antennas that are less affected by the human body.However, since their gain and efficiency are very small, they are not suitable for antennas that require some gain characteristics, such as antennas for portable radios. It is.
On the other hand, a loop antenna having one or more wavelengths can be operated as an antenna having gain characteristics equal to or higher than a dipole antenna, and can be used as an antenna for a mobile phone.

[0006]

As described above, the antenna characteristic of a conventional portable radio at the time of real-body communication is such that the polarization plane is tilted with the tilt angle of the radio and the polarization loss is increased. was there. In addition, as shown in FIG. 8, there is a conventional example in which a loop antenna is arranged to be inclined as shown in FIG. 8 as an antenna for suppressing deterioration of antenna characteristics at the time of a real human body call. However, as in the conventional example, the loop antenna is arranged to be inclined. In such a case, when the user talks while holding the portable wireless device in the opposite hand, the plane of polarization becomes nearly horizontal. In other words, for example, if the antenna is arranged so that the polarization plane is vertical when talking with the left hand, the polarization plane becomes nearly horizontal when talking with the right hand, and the polarization loss further increases, There is a problem that it leads to deterioration of reception characteristics. Equivalent polarization characteristics when holding a portable wireless device with either the right hand or the left hand and inclining about 60 degrees from the vertical direction, that is, when tilting the portable wireless device to either the left or right As a configuration method of an antenna in which the vertical polarization components are substantially the same, rather, the horizontal polarization becomes the main polarization when the portable wireless device is upright (when the long side of the housing is perpendicular to the ground). Antennas are preferred.

On the other hand, recent portable wireless devices are capable of performing not only voice communication but also various data communication such as transmission and reception of electronic mail, image data or various contents. In general, the usage of the portable wireless device differs between the above-described voice communication and data communication. Regarding voice communication, the case of the wireless device is often used by tilting the housing of the wireless device from the vertical direction in the state close to the human head as described above,
On the other hand, when performing data communication, the portable wireless device housing is used in an upright position in front of the human body for the purpose of image data communication and e-mail communication, and various types of devices such as notebook computers and PDA terminals are used. In many cases, a mobile multimedia terminal or the like is connected to a portable wireless device and used without being tilted. That is, in consideration of the above-described usage form in data communication, the portable wireless device housing is moved in the horizontal direction (ie, ± Z from the z axis in FIG.
Since the use state of the antenna is inclined in the direction of rotation (y-axis), it is not desirable to use the antenna having the main polarization of the horizontal polarization as described above. Is preferably used as the main polarization.

In other words, the desired antenna polarization plane is different between voice communication and data communication, so that it is difficult to obtain good antenna characteristics in any communication. The present invention has been made in view of such a problem, and the antenna polarization characteristics can be improved not only during a real human body call (at the time of voice communication) in which a portable wireless device is brought close to a human head but also at the time of data communication. It is an object of the present invention to provide a small-sized antenna for a portable wireless device which is excellent in each case.

[0009]

The first portable radio antenna according to the present invention has an electric length of about 1 at a working frequency.
A wavelength antenna element, a feed circuit section, a housing ground,
A switching unit for switching an electrical connection state of the antenna element; and a switching control circuit unit for performing switching control of the switching unit. A first end of the antenna element is connected to the power supply circuit unit, and a second terminal A part is connected to the housing ground to form a loop antenna, and one or a plurality of the switching means are provided on the antenna element.

[0010] By switching the switching means in response to a switching control signal output from the switching control circuit section, the electrical connection state of the antenna element is switched on / off. When the connection is on, the entire perimeter operates as a loop antenna having about one wavelength at the operating frequency. On the other hand, when the connection is off, the switching means is electrically open at the insertion position. Therefore, the operation mode of the antenna changes, and the antenna operates as an antenna having a different polarization direction.

A second portable wireless device antenna according to the present invention is the first portable wireless device antenna according to the present invention, wherein a line connecting a position at which the antenna element is electrically bisected and a feeding position is provided. The antenna element is arranged so that the antenna element is substantially parallel to the long side direction of the housing of the portable wireless device.

By arranging the line segment connecting the position where the antenna element is electrically bisected and the feeding position substantially parallel to the direction of the long side of the housing of the portable wireless device, the case where the housing is upright ( In a state where the long side of the housing is perpendicular to the ground), the one-wavelength loop antenna operates so that the main polarization direction component becomes horizontal polarization.

[0013] In a third portable radio antenna according to the present invention, in the first or second portable radio antenna according to the present invention, the switching means may include a second end of the antenna element and the casing. It is characterized in that it is provided near the connection with the body ground.

When the connection of the switching means is on, it operates as a loop antenna of about one wavelength and becomes a horizontally polarized antenna, as described above. On the other hand, when the connection is off, the switching means Is located at the second end of the antenna element, the antenna operates as a one-wavelength folded monopole antenna with an open end, and becomes a vertically polarized antenna.

In a fourth portable radio antenna according to the present invention, in the first or second portable radio antenna according to the present invention, the switching means electrically divides the antenna element into two equal parts. It is provided at a position.

When the connection of the switching means is on, it operates as a loop antenna of about one wavelength and becomes a horizontally polarized antenna, as described above. On the other hand, when the connection is off, the switching means Is positioned to electrically divide the antenna element into two equal parts, so that it operates as an open-ended half-wavelength monopole antenna and becomes a vertically polarized antenna.

A fifth portable radio antenna according to the present invention is the first or second portable radio antenna according to the present invention, wherein the switching means includes a second end of the antenna element and the casing. The antenna element is provided at two locations: near the connection to the body ground and at a position where the antenna element is electrically bisected.

The two switching means are simultaneously switched and controlled,
When the connection of the two switching means is both on, the antenna operates as a loop antenna of about one wavelength, as described above. On the other hand, when the connection is off, the antenna element having the power supply circuit is connected to the tip. While acting as an open half-wave monopole antenna, the other antenna element can act as a driven element and as a director or reflector.

According to a sixth aspect of the present invention, in the antenna for a portable wireless device according to any one of the first to fifth aspects of the present invention, the power supply circuit unit includes a matching circuit provided with impedance switching means. A switching circuit for switching the impedance of the matching circuit unit by switching the impedance switching unit in synchronization with a switching control signal output from the switching control circuit unit.

When the impedance switching unit is switched in synchronization with the switching control signal, the matching circuit unit conforms to the antenna operation mode with respect to two antenna operation modes by switching on / off of the switching unit. Therefore, the antenna operates with good input characteristics.

A seventh portable radio antenna according to the present invention is characterized in that any one of the first to sixth portable radio antennas according to the present invention can perform voice communication or data communication. The switching control circuit outputs a switching control signal for switching the switching means based on a result of determining whether the communication is voice communication or data communication.

As described above, the switching control is performed based on the result of the discrimination between the voice communication and the data communication, so that the operation can be performed so that the antenna operation modes are different between the voice communication and the data communication.

According to an eighth aspect of the present invention, there is provided an antenna for a portable wireless device according to any one of the first to sixth portable wireless devices according to the present invention, comprising: an external device connecting means for connecting to an external device; External device connection determining means for determining the presence or absence of connection of the external device, wherein the switching control circuit unit is based on a determination result of whether or not the external device is connected via the external device connecting means. A switching control signal for switching the switching means is output.

Since switching control is performed based on the result of the determination as to whether or not the external device is connected, the antenna is operated so that the antenna operation mode differs between when the external device is connected and when the external device is not connected. be able to.

The ninth portable radio antenna according to the present invention is the portable radio antenna according to any one of the first to sixth inventions, having a switching diversity reception or transmission function. Is switched to perform polarization switching diversity.

By switching the switching means, the plane of polarization is switched and substantially orthogonal polarization characteristics can be obtained. By performing diversity reception / transmission at the switching timing, good polarization diversity characteristics can be obtained. Can be

A tenth portable radio antenna according to the present invention is the portable radio antenna according to any one of the first to ninth inventions, wherein the first end and the second end of the antenna element are provided. And at a position where the electric length is about 1/4 wavelength, the first radiating section having the feeding circuit section and the second radiating section having no feeding circuit section can be electrically separated. It is assumed that.

1/4 from the feeder of the one-wavelength loop antenna
By using a configuration that uses an inter-antenna connecting means that can be electrically separated at the wavelength position, it operates as a one-wavelength loop antenna at the time of connection, operates as a half-wavelength dipole antenna at the time of separation, and maintains the polarization plane as it is. The size can be reduced.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a first embodiment of the antenna for a portable wireless device of the present invention. An antenna for a portable wireless device shown in FIG. 1 has an antenna element 1 whose electric length is substantially one wavelength at a used frequency, a first end 2 of the antenna element 1, and a second end of the antenna element 1. 3, a power supply circuit section 14 for supplying power to the first end 2, a changeover switch 6 connected to the second end 3, a housing ground 7, and a changeover control of the changeover switch 6. And a switching control circuit section 8. The power supply circuit unit 14 includes an RF circuit unit 5 including a transmission / reception circuit, a matching circuit unit 4 connected to the first end 2, and matching impedance between the antenna element 1 and the RF circuit unit 5. You.

Hereinafter, the operation of the antenna of this embodiment will be described. When the changeover switch 6 is switched to the connection ON state by the changeover control circuit section 8, the second end 3 of the antenna element 1 is electrically connected to the housing ground 7 and the power is supplied from the first end 2. The antenna element 1 thus operated operates as a one-wavelength loop antenna. On the other hand, when the changeover switch 6 is switched to the connection off state by the changeover control circuit unit 8, the second end 3 of the antenna element 1 is not connected to the housing ground 7, so that the antenna element 1 Becomes open and operates as a one-wavelength folded monopole antenna.

A line connecting the position at which the antenna element 1 is electrically bisected and the feeding position, that is, the first end 2, is
By arranging the antenna element so as to be substantially parallel to the long side direction of the housing of the portable wireless device (the z-axis direction shown in FIG. 1), good horizontal polarization characteristics can be obtained when the changeover switch 6 is turned on. When the switch 6 is off, good vertical polarization characteristics are obtained. The detailed operation will be described below.

FIG. 2 is a diagram showing a current distribution during operation of the antenna shown in FIG. FIG. 2A shows an antenna current distribution when the changeover switch 6 is on, and FIG. 2B shows an antenna current distribution when the changeover switch 6 is off. When the changeover switch 6 is on, FIG.
As shown in (A), since the antenna operates as a one-wavelength loop antenna, the current excited on the loop antenna flows in the directions indicated by the current distributions 21 and 22, and the current obtained by combining these current distribution components is The current is considered to be substantially horizontal (y-axis direction shown in FIG. 1) as indicated by the current direction 12, and operates as a horizontally polarized antenna. On the other hand, when the changeover switch 6 is off, as shown in FIG.
To operate as a wavelength folded monopole antenna,
The currents excited on the antenna are current distributions 23 and 2
4, the current obtained by combining the two current distribution components is considered to be a current in a substantially vertical direction (z-axis direction shown in FIG. 1) as shown in a combined current direction 13, and operates as a vertically polarized antenna. I do.

According to the above operation, during a real-body call in which the portable radio is held in the hand and the case is tilted, the switch 6 is turned on so that the left hand or the right hand is switched. When the case is used near the vertical, such as during data communication or during a call through a speakerphone, good characteristics can be obtained in which the polarization characteristics are almost the same even when the case is held. By switching the changeover switch 6 to the off state, the antenna operates as a vertically polarized antenna, so that good communication quality can be maintained.

The matching circuit section 4 is provided with an impedance switching means, and comprises a matching circuit changeover switch 9 using a PIN diode or the like, and first and second reactance elements 10 and 11 exhibiting inductive or capacitive impedance. When the matching circuit changeover switch 9 is on, the matching circuit has a second reactance element 11 connected in parallel with the first reactance element 10. On the other hand, when the matching circuit changeover switch 9 is on, the first reactance element does not. By operating as only the 10 matching circuits, the matching impedance is switched. 1st, 2nd
Each of the reactance elements 10 and 11 may be composed of a plurality of chip components or distributed constant circuits, and the matching circuit changeover switch 9 may be a field effect transistor FET switch or the like. The impedance may be switched using a variable capacitance diode or the like.

When the changeover switch 6 is switched to the connection-on state, that is, when operating as a loop antenna, the input impedance generally exhibits a low impedance, while the changeover switch 6 is set to the connection-off state. When switched, since the input impedance exhibits a high impedance, the matching circuit switch 9 is synchronized with the switching timing of the switch 6.
Is switched so that the impedance of the matching circuit unit 4 can be properly matched with the input impedance in each antenna mode, and good characteristics can be obtained in both antenna modes.

Although the antenna element 1 is formed in a rectangular shape in FIG. 1, the antenna element 1 may be formed in a circular shape, a shape having a zigzag folded pattern in the middle for miniaturization, or a spiral shape. The material may be a conductor wire made of various metal materials, a conductor plate processed by sheet metal, or a pattern formed on a printed board by etching or the like, and is formed on the same board as the board on which the power supply circuit unit 14 is mounted. May be used.

In FIG. 1, the first end 2 of the antenna element 1 is connected to the matching circuit 4 constituting the power supply circuit, and the second end 3 is connected to the housing ground 7. By connecting a balun (balance-unbalance conversion) circuit (not shown) between the first end 2 and the second end 3, unnecessary current is prevented from flowing through the housing ground 7, It is good also as composition which can obtain more favorable antenna characteristics.

As a specific configuration method of the changeover switch 6, for example, there is a method using a PIN diode switch or a method using an FET switch, and a high frequency choke coil is provided near the first end 2 of the antenna element 1. , A bias circuit (not shown) can be connected, and the changeover switch 6 and the matching circuit changeover switch 9 can be simultaneously switched by a bias signal superimposed on the antenna element 1.

Although not shown, in a portable radio having switching diversity receiving or transmitting function, the switching switch 6 is switched by using the antenna shown in this embodiment to receive or transmit switching diversity. Operate as a polarization diversity antenna whose polarization planes are substantially orthogonal to each other, and a good diversity effect can be obtained.

FIG. 3 is a diagram showing the configuration of a second embodiment of the antenna for a portable wireless device according to the present invention. Components common to FIG. 1 are denoted by the same reference numerals. In the antenna for the portable radio shown in FIG. 3, each electric length is about に お い て at the operating frequency.
Antenna elements 32 and 33 each having a wavelength; a matching circuit section 4 to which one end of the antenna element 32 is connected; a housing ground 7 to which one end of the antenna element 33 is connected; The switch 33 includes a changeover switch 31 to which the other end is connected, and a changeover control circuit unit 8 that controls the changeover of the changeover switch 31.

Hereinafter, the operation of the antenna of this embodiment will be described. When the changeover switch 31 is switched to the connection ON state by the changeover control circuit 8, the antenna element 3
2 and the antenna element 33 are connected, and the antenna element 3
2 and 33 operate as a one-wavelength loop antenna, and the combined current direction 34 is substantially horizontal as in the antenna shown in the first embodiment, and operates as a horizontally polarized antenna. On the other hand, when the changeover switch 31 is switched to the connection off state by the changeover control circuit section 8, the antenna element 32 and the antenna element 33 are disconnected, and the antenna element 32 connected to the power supply circuit section 14 is reduced to about 1 / The antenna operates as a two-wavelength monopole antenna, and similarly to the antenna shown in the first embodiment, the combined current direction 35 is substantially vertical, and the antenna operates as a vertically polarized antenna. As described above, the polarization characteristic effect of the changeover switch 31 has the same effect as that of the antenna shown in the embodiment of the first embodiment.

Further, the detailed operation of the switching control circuit section 8 will be described. The switching control circuit unit 8 includes a communication medium determining unit 3 that determines whether the communication is voice communication or data communication.
6 and a switching control signal generator 37. The communication media discriminating unit 36 discriminates whether the use state of the portable wireless device is voice communication or data communication, and outputs a switching control signal from a switching control signal generating unit 37 based on the discrimination result. 31 switching control is performed.

Thus, the polarization plane of the antenna is automatically switched according to the communication medium without the user's awareness, and the antenna can be operated as a horizontal polarization antenna during voice communication and as a vertical polarization antenna during data communication. it can. At the time of voice call, the portable wireless device is held in hand, close to the head, and used with about 60 degrees tilt,
As described above, the horizontally polarized antenna can obtain better antenna characteristics. On the other hand, at the time of data communication, various use forms are conceivable, such as connection to a notebook personal computer or the like, transmission and reception of e-mail in a hand, browsing of a WEB server, and the like. The antenna is rarely used in a state of being tilted in the horizontal direction (the direction of rotation from the z axis to the y axis in FIG. 3), so that the vertical polarization antenna has better antenna characteristics than the horizontal polarization antenna. can get. As described above, there is an effect that good antenna characteristics can be obtained in both voice communication and data communication without the user being conscious.

FIG. 4 is a diagram showing the configuration of a third embodiment of the portable radio antenna according to the present invention. Components common to FIG. 1 are denoted by the same reference numerals. 4 is an example in which a plurality of changeover switches are provided within a one-wavelength loop antenna element, and the antenna elements 41, each having an electrical length of about 波長 wavelength at a used frequency.
42, a matching circuit unit 4 to which one end of the antenna element 41 is connected, a changeover switch 43 connected between the antenna elements 41 and 42, and a connection between the antenna element 42 and the housing ground 7. And a switching control circuit section 8 for controlling the switching of the switching switches 43 and 44.

Hereinafter, the operation of the antenna of this embodiment will be described. The changeover switches 43 and 4 are controlled by the changeover control circuit 8.
4 are switched to the connection on state,
Since the antenna element 41 and the antenna element 42 are connected, the antenna element 41 operates as a one-wavelength loop antenna, and its combined current direction 45 is almost horizontal as in the case of the antenna shown in the first embodiment. Act as an antenna.

On the other hand, when the changeover switches 43 and 44 are switched off by the changeover control circuit section 8, the antenna element 41 and the antenna element 42 are disconnected, and the antenna element connected to the feed circuit section 14 is disconnected. 41 operates as a monopole antenna of about a half wavelength,
Similarly to the antenna shown in the embodiment, the combined current direction 46 is substantially vertical, and the antenna operates as a vertically polarized antenna. Further, since the antenna element 42 is disconnected from the housing ground 7 by the changeover switch 44, about 1 /
As a two-wavelength driven element, it can act as a director or a reflector of a vertically polarized antenna by the antenna element 41, and the negative direction of the directivity in the horizontal plane is set to a high gain.
That is, directivity having high gain in the + y-axis direction or the −y-axis direction can be realized.

Thus, for example, as shown in FIG.
When an external device such as a notebook computer 53 is connected to the portable wireless device, that is, a loop antenna 52 as shown in FIG.
In the case where data communication is performed by connecting the portable wireless device housing 51 having the above, by setting the directivity of the loop antenna 52 to a directivity having a high gain in a direction opposite to the display unit 54, The adverse effect of the display unit 54 on the antenna characteristics can be suppressed.

Further, the detailed operation of the switching control circuit unit 8 will be described. The switching control circuit unit 8 includes an external device connection determining unit 47 that determines whether an external device such as the notebook computer 53 is connected, and a switching control signal generating unit 48. The external device connection determining unit 47 determines whether an external device such as a notebook personal computer is connected to the portable wireless device, and based on the result, a switching control signal is output from the switching control signal generating unit 48, and the switching switch 43 , 44 are controlled.

Thus, even if the user is not aware, the polarization plane of the antenna is automatically switched in accordance with the connection state of the external device. When the external device is not connected, the antenna becomes a horizontally polarized antenna, and when the external device is connected, the vertical polarization antenna is used. Act as an antenna. Here, as the external device to be connected, various mobile multimedia terminals such as a PDA terminal, a digital camera, and the like, in addition to a notebook personal computer, and an earphone microphone or a charger can be considered. Even when connected to a wireless device, it is rarely used in a state close to the head, that is, in a state inclined by 60 degrees as in a normal voice call, and it is considered that vertical polarization is more suitable. . That is, by judging the presence or absence of the connection of the external device, the antenna can be switched to the antenna having the polarization plane which can always obtain good characteristics.
In addition, by this, for example, if you have a multi-call function that can simultaneously communicate both voice and data communication,
Even when a voice call is made using a speakerphone or an earphone microphone while being connected to an external device, an antenna that maintains good communication quality can be provided.

FIG. 6 is a diagram showing the configuration of a fourth embodiment of the portable radio antenna according to the present invention. Components common to FIG. 1 are denoted by the same reference numerals. The portable radio antenna of FIG. 6 is an example of an antenna having a configuration capable of separating the loop antenna shown in FIG. 1. The one-wavelength loop antenna element has an electrical length of about ４ wavelength at the operating frequency. One antenna element 61, a second antenna element 62 also having approximately １ ／ wavelength, and a third antenna element 63 having an electrical length of approximately 波長 wavelength, and one end of the first antenna element 61 is fed. The other end is connected to the third antenna element 63 via the inter-antenna connection part 64. One end of the second antenna element 62 is connected to the housing ground 7 via the changeover switch 6, and the other end is connected to the third antenna element 63 via the inter-antenna connection section 65.

The third antenna element 63 has a configuration in which the relative position between the first antenna element 61 and the second antenna element 62 can be changed at the inter-antenna connection portions 64 and 65 by sliding or rotating. 1 antenna element 6
Connection / disconnection (separation) with first and second antenna elements 62
Is switched. When the third antenna element 63 is connected to the first antenna element 61 and the antenna element 62 (FIG. 6 (A)), the on / off of the changeover switch 6 is turned on similarly to the embodiment shown in the first embodiment. By switching the state, the antenna operates as a one-wavelength loop antenna when in the on state, and its combined current direction 66 becomes horizontal. In the off state, it operates as a one-wavelength folded monopole antenna. The direction 67 is a vertical direction.

On the other hand, the third antenna element 63 is separated at the inter-antenna connection portions 64 and 65, and is not connected to the first antenna element 61 and the antenna element 62 (FIG. 6).
In the case of (B)), the on / off state of the changeover switch 6 is switched to operate as a half-wave dipole antenna in the on state, the combined current direction 68 is horizontal, and the off state is off. Sometimes it operates as a quarter-wave monopole antenna, and its combined current direction 6
9 is almost vertical. That is, the polarization characteristic when the changeover switch 6 is switched when the third antenna element 63 of FIG. 6B is separated is the same as that of the third antenna element 6 of FIG.
The polarization characteristics are almost the same as those when the changeover switch 6 is switched when the switch 3 is connected.

As described above, even when the position of the third antenna element 63 is disengaged at the antenna-to-antenna connection portions 64 and 65 by sliding or rotating, for example, by storing the third antenna element 63 in the housing, etc. Its polarization characteristics are
The same characteristics as in the case where the third antenna element 63 is pulled out from the inside of the housing and brought into the connected state at the inter-antenna connecting portions 64 and 65 are obtained.

Further, as described above, the third antenna element 63 can be mechanically connected / disconnected so that the third antenna element 6 can be used during standby or carrying.
3 can be housed inside the housing, electrically separated, and operated as an antenna with only the first antenna element 61 and the second antenna element 62, so that the portable wireless device can be downsized. However, when the third antenna element 63 is used while housed inside the housing, the antenna configuration includes only the first antenna element 61 and the second antenna element 62. ) Becomes smaller. Therefore, the antenna is easily affected by the human body (head and hand), and the antenna characteristics during actual human body communication are degraded. By connecting the inter-connectors 64 and 65 to operate as a one-wavelength loop antenna, antenna efficiency is improved and good antenna characteristics with small loss due to the human body are obtained.

The connecting means of the inter-antenna connecting portions 64 and 65 may be configured such that the third antenna element 63 is slid or rotated by using a metal spring to mechanically contact / non-contact, or a small connector Or a non-contact type configuration using capacitive coupling between the first antenna element 61 and the third antenna element 63 and between the second antenna element 62 and the third antenna element 63 is used. Connection means may be used.

[0056]

The portable radio antenna according to the present invention is provided with switching means for switching the electrical connection state at one or more locations on the one-wavelength loop antenna element, and by switching the switching means, the antenna of the antenna is provided. The polarization plane can be changed, and good antenna characteristics can be realized by appropriately switching the polarization characteristics according to communication conditions.

Further, by arranging the antenna element such that a line connecting the position where the loop antenna element is electrically divided into two equal parts and the feeding position is substantially parallel to the long side direction of the housing of the portable wireless device, Since the main polarization component of the loop antenna element becomes horizontal polarization when standing upright, almost the same polarization characteristics can be obtained even when holding the portable wireless device with either the left or right hand during real human body communication, Good call characteristics can be realized.

Further, the switching means is provided near the connection between the second end of the antenna element and the housing ground, and / or at a position where the switching means electrically divides the antenna element into two equal parts. Since the main polarization component of the antenna is switched to horizontal polarization / vertical polarization by switching on / off of the switching means, good antenna polarization can be obtained both during real-body communication and during data communication. An antenna capable of realizing characteristics can be provided.

Further, by switching the impedance switching means provided in the matching circuit part constituting the feeding circuit part in synchronization with the switching means, a good input can be obtained in each of the antennas in the horizontal / vertical polarization mode. Characteristics can be realized.

Further, a communication medium discriminating section for discriminating communication media for voice communication / data communication is provided, and by switching the antenna mode based on the discrimination result, a good bias is automatically provided without the user being conscious. Switch to an antenna with a wavefront.

Further, an external device connection determination unit for determining whether or not an external device is connected to the portable wireless device is provided, and the antenna mode is switched based on the determination result. Data communication by connecting a portable wireless device to a multimedia terminal, multi-call for simultaneous data / voice communication, and voice communication using a speakerphone or earphone / microphone with an external device connected Automatically switch to an antenna having a good polarization plane without the user's awareness.

Further, since the polarization characteristics in which the main polarization planes are orthogonal can be obtained by switching the switching means, it is possible to provide an antenna which can obtain a good diversity effect by performing switching diversity reception or transmission.

Further, the first radiating portion having the feeding circuit portion and the first radiating portion having no feeding circuit portion are located at positions each having an electric length of about 波長 wavelength from the first end portion and the second end portion of the antenna element. By providing the inter-antenna connection part which can be electrically separated from the two radiating parts, when the inter-antenna connection part is in a connected state, it shows good characteristics as a one-wavelength loop antenna, while Even when the unit is in the separated state, an antenna element having substantially the same polarization characteristics as the first radiating unit can be obtained. By housing the second radiating unit having no circuit unit in the housing, a portable wireless device having a compact shape can be realized.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment of a portable wireless device antenna according to the present invention.

FIG. 2 is a diagram showing a current distribution during operation of the antenna for a portable wireless device of the mode shown in the first embodiment.

FIG. 3 is a configuration diagram showing a second embodiment of the antenna for a portable wireless device of the present invention.

FIG. 4 is a configuration diagram showing a third embodiment of the antenna for a portable wireless device of the present invention.

FIG. 5 is a diagram showing a state in which the antenna for a portable wireless device of the present invention is connected to an external device such as a notebook computer.

FIG. 6 is a configuration diagram showing a fourth embodiment of the antenna for a portable wireless device of the present invention.

FIG. 7 is a configuration diagram showing an embodiment of a conventional antenna for a portable wireless device.

FIG. 8 is a configuration diagram showing another embodiment of a conventional antenna for a portable wireless device.

[Explanation of symbols]

1 ... antenna element, 2 ... first end, 3 ... second end,
4 matching circuit section, 5 RF circuit section, 6 changeover switch,
7: Housing ground, 8: Switching control circuit section, 9: Matching circuit switching switch, 10, 11: Reactance element, 12, 1
3: combined current direction, 14: feeding circuit section, 21, 22, 2
3, 24: current distribution, 31: changeover switch, 32, 33
... antenna elements, 34, 35 ... combined current direction, 36 ... communication media discriminator, 37 ... switch control signal generator, 41,
42 antenna elements, 43, 44 changeover switches, 4
5, 46: combined current direction, 47: external device connection determination unit,
48: switching control signal generator, 51: portable wireless device housing, 5
2: loop antenna, 53: notebook computer, 54: display unit, 61: first antenna element, 62: second antenna element, 63: third antenna element, 64, 65: inter-antenna connection unit, 66, 67, 68 , 69: combined current direction, 71: monopole antenna, 72: feeding unit, 73 ...
Casing, 81: Loop antenna, 82: Radio base plate.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01Q 9/30 H01Q 9/30 9/42 9/42 21/24 21/24 F-term (Reference) 5J021 AA03 AB03 AB04 CA04 DB04 EA02 FA01 FA02 FA13 HA06 HA10 JA05 JA07 5J046 AA04 AA12 AB06 AB11 BA01 SA00 TA03 5J047 AA02 AA03 AA07 AB06 AB07 AB11 FD01

Claims (10)

[Claims] 1. An antenna element having an electrical length of about one wavelength at a used frequency, a feed circuit unit, a housing ground, and switching means for switching an electrical connection state of the antenna element.
A switching control circuit for performing switching control of the switching means, wherein a first end of the antenna element is connected to the power supply circuit, and a second end is connected to the housing ground to form a loop antenna. And one or a plurality of said switching means are provided on said antenna element. 2. The portable wireless device antenna according to claim 1, wherein a line connecting a position at which the antenna element is electrically bisected and a feeding position is roughly the same as the long side direction of the housing of the portable wireless device. An antenna for a portable wireless device, wherein the antenna elements are arranged so as to be parallel. 3. The antenna for a portable wireless device according to claim 1, wherein said switching means is provided near a connection between a second end of said antenna element and said housing ground. Characteristic antenna for portable radio. 4. The portable wireless device antenna according to claim 1, wherein the switching means is provided at a position where the antenna element is electrically divided into two equal parts. Antenna. 5. The antenna for a portable wireless device according to claim 1, wherein said switching means electrically connects a portion near a connection between a second end of said antenna element and said housing ground and said antenna element. An antenna for a portable wireless device, wherein the antenna is provided at two positions, i. 6. The antenna for a portable wireless device according to claim 1, wherein in the power supply circuit unit,
A matching circuit provided with an impedance switching unit, wherein the impedance of the matching circuit unit is switched by switching the impedance switching unit in synchronization with a switching control signal output from the switching control circuit unit. Antenna for portable radio. 7. The portable wireless device antenna according to claim 1, wherein when the voice communication or the data communication can be performed, the switching control circuit unit is configured to:
An antenna for a portable wireless device, which outputs a switching control signal for switching said switching means based on a result of determination of voice communication or data communication. 8. The portable wireless device antenna according to claim 1, wherein an external device connection means for connecting to the external device, and an external device connection determination for determining whether or not the external device is connected. Means, and the switching control circuit section outputs a switching control signal for switching the switching means based on a determination result as to whether or not the external device is connected via the external device connecting means. Mobile radio antenna. 9. The antenna for a portable wireless device according to claim 1, further comprising a switching diversity receiving or transmitting function, wherein polarization switching diversity is performed by switching said switching means. Mobile radio antenna. 10. The antenna for a portable wireless device according to claim 1, wherein an electrical length from the first end and the second end of the antenna element is about １ ／ wavelength, respectively. An antenna for a portable wireless device, wherein the antenna is configured to be electrically separable into a first radiating portion having a power supply circuit portion and a second radiating portion having no power supply circuit portion.