JP2012182706A - Portable terminal device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable terminal device which selects an antenna element so as to maintain communication quality.SOLUTION: Processing performed by a control circuit of a portable terminal device includes: a step (S510) of detecting reception start based on a signal from a receiving circuit; a step (S520) of detecting an inclination angle of the portable terminal device based on a signal from an angle sensor; a step (S530) of selecting an antenna element having a main polarization surface closest to a polarization plane of an electric wave based on the detected inclination angle; a step (S540) of connecting the antenna and receiving circuit so as to receive the signal via the selected antenna element; and a step (S550) of processing the signal received via the antenna element selected by a switch and outputting the processed signal to a display part or a speaker.

Description

  The present invention relates to a mobile terminal device, and more particularly to a mobile terminal device that selects and uses a plurality of antenna elements according to the inclination angle of the mobile terminal device.

  In general, in wireless communication, energy efficient communication can be performed by matching the directivity of an antenna to the communication direction, or by combining the polarization plane of a radio wave used for communication with the main polarization plane of an antenna. It becomes possible.

  However, in the case of wireless communication using a mobile terminal device, the user's way of holding the mobile terminal device, the tilt angle of the mobile terminal device, the influence of nearby objects, etc. always change. Therefore, the directionality of the antenna system including the proximity object of the mobile terminal device or the angle of the main polarization plane varies with respect to the base station and the broadcast station. As a result, it may be difficult to maintain stable communication quality.

  In order to solve such a problem, a technique has been proposed in which communication quality is maintained by selecting and using an antenna element having a plurality of antenna elements and having good reception sensitivity in the apparatus. However, according to such an antenna switching function, it is necessary to always measure and compare the reception level of each antenna element. As a result, since the power consumption of the mobile terminal device increases, a problem may occur in terms of operation duration when the mobile terminal device is mounted on a mobile terminal device with limited battery capacity. In addition, the configuration of the mobile terminal device may be complicated and cost may increase.

  Therefore, the portable terminal device is provided with an angle sensor, and based on the inclination angle of the device detected by the angle sensor, an antenna element having directivity in the direction of the base station or the broadcasting station is selected and used from the plurality of antenna elements. A portable terminal device having an antenna switching function with a simple configuration has been proposed.

  For example, Japanese Patent Laid-Open No. 2008-187485 (Patent Document 1) states that “the reception sensitivity is maintained well and stable regardless of how the user grips the device housing or changes in the user's standing position with respect to the base station. A mobile terminal device capable of maintaining communication quality is disclosed (see [Problem] in [Summary]). Specifically, “in the mobile terminal device 10, at least three or more antenna elements 31, 32, 33 for transmitting and receiving data by wireless communication are distributed on the device housing 11 and wireless communication is performed. The control circuit 41 that controls data transmission / reception according to the above-mentioned selection and use of the antenna element with the best reception sensitivity among the antenna elements 31, 32, 33 provided on the basis of the output of the angle sensor during transmission / reception processing. It has an antenna switching function ”(see [Solution] in [Summary]).

  Further, JP 2009-81769 A (Patent Document 2) states that “a wireless communication that can stably communicate with a specific communication target even when the installation direction of the apparatus is changed, and has low power consumption and low power consumption. "Communication device" is disclosed (see [Problem] in [Summary]).

JP 2008-187485 A JP 2009-081769 A

  In general, in wireless communication using a mobile terminal device, radio waves used for communication arrive from all directions while causing reflection, diffraction, scattering, and the like. Therefore, directing the antenna directivity of the device to the base station or the broadcast station is not always optimal for maintaining communication quality. In particular, in a communication environment where the base station or broadcasting station is out of sight, there are obstacles in the direction of the base station or broadcasting station, so the antenna directivity is also directed toward the base station or broadcasting station. It is unlikely that quality will be improved.

  Further, according to the technique disclosed in Japanese Patent Application Laid-Open No. 2008-187485, the directivity of the antenna element varies depending on how the user holds the device and the proximity of the device. With only information, the antenna switching function for controlling the directivity of the antenna system including the user and nearby objects may not operate efficiently.

  Therefore, the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a mobile terminal device in which stable communication quality is maintained.

  A mobile terminal device according to an embodiment detects a plurality of antenna elements having different main polarization planes in an operating frequency band, a receiving circuit for receiving data via each antenna element, and an inclination angle of the mobile terminal device And an antenna switching means for selecting, from a plurality of antenna elements, an antenna element having a main polarization plane closest to a polarization plane of a radio wave used for wireless communication based on an inclination angle detected by the angle sensor. Is provided.

  Preferably, the mobile terminal device stores a position sensor for detecting the position of the mobile terminal device and a type of polarization plane pre-defined for each region as a polarization plane of a radio wave used for wireless communication. Means. The antenna switching means is used for wireless communication based on the tilt angle detected by the angle sensor, the position of the mobile terminal device detected by the position sensor, and the type of polarization plane in the area where the mobile terminal device exists. An antenna element having a main polarization plane closest to the radio wave polarization plane is selected.

Preferably, the plurality of antenna elements operate with linearly polarized waves.
Preferably, at least two main polarization planes of the plurality of antenna elements are configured to intersect at an angle of 10 degrees or more.

  Preferably, at least two main polarization planes of the plurality of antenna elements are configured to be orthogonal to each other.

  Preferably, the angle sensor includes any of a gyro sensor, a capacitive acceleration sensor, and a geomagnetic sensor.

Preferably, the position sensor is a global positioning system.
Preferably, the position sensor detects the position of the mobile terminal device based on information obtained from a base station of the mobile phone system.

  Preferably, the position sensor detects the position of the mobile terminal device based on information obtained by receiving digital terrestrial broadcasting.

  Preferably, the position sensor detects the position of the mobile terminal device based on information obtained by receiving the multimedia broadcast.

According to the mobile terminal device according to a certain aspect, stable communication quality is maintained.
The above and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description of the present invention taken in conjunction with the accompanying drawings.

It is a figure which shows the tablet-type portable terminal device 10 which enables reception of terrestrial digital broadcasting. 2 is a block diagram illustrating a hardware configuration of a mobile terminal device 10. FIG. 2 is a diagram illustrating a usage mode of the mobile terminal device 10. FIG. It is a table | surface showing the receiving characteristic of the antenna elements 31 and 32 about two use situations as FIG. 3 shows. 4 is a flowchart showing a part of a series of processes executed by mobile terminal device 10. 3 is a block diagram illustrating a hardware configuration of portable terminal device 600. FIG. It is a block diagram showing the hardware constitutions of the portable terminal device 700 which concerns on 2nd Embodiment. FIG. 3 is a diagram conceptually illustrating one aspect of data storage in a storage device 43. 7 is a flowchart showing a part of a series of processes executed by control circuit 42 constituting mobile terminal device 700.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a diagram showing a tablet-type mobile terminal device 10 that can receive terrestrial digital broadcasting. The mobile terminal device 10 is, for example, a mobile phone, a smartphone, a mobile television receiver, a portable computer, or the like, but is not limited thereto. The portable terminal device 10 only needs to have at least a signal reception function or a transmission function.

  With reference to FIG. 1, the mobile terminal device 10 includes a housing 11, a display unit 21, an operation unit 22, antenna elements 31 and 32, and an angle sensor 41. The display unit 21 and the operation unit 22 are configured on the surface of the housing 11.

  The operation unit 22 includes, for example, an operation key 23 for receiving input of data and processing instructions, or a pointing device 24 for inputting data and processing instructions. In a certain aspect, display unit 21 is a touch panel. In this case, the touch panel also functions as the operation unit 22. The user of the mobile terminal device 10 can input data and processing instructions to the mobile terminal device 10 by performing operations such as pressing the display on the display unit 21, pinching in, or pinching out.

  The mobile terminal device 10 further includes a speaker 25 for reproducing and outputting sound at the upper ends of both side surfaces of the housing 11. In addition, the mobile terminal device 10 includes two antenna elements 31 and 32 for receiving terrestrial digital broadcasting inside the housing 11. Specifically, the antenna elements 31 and 32 are arranged around a unit constituting the display unit 21.

  In one aspect, the antenna element 31 is disposed along the upper side surface of the housing 11. The antenna element 32 is disposed along the right side surface of the housing 11. By making the direction in which the antenna elements 31 and 32 are arranged orthogonal, the main polarization planes of the antennas are also orthogonal. The main polarization planes of the antenna elements 31 and 32 are configured to intersect at an angle of 10 degrees or more in a certain aspect.

  As the antenna elements 31 and 32, for example, a dipole antenna, a monopole antenna, an inverted F antenna, or the like can be selected according to an empty space in the housing 11. As the antenna elements 31 and 32, a rod antenna, a sheet metal antenna, a flexible substrate antenna, a resin molded antenna, or the like can be used according to the required output performance.

  The angle sensor 41 is arranged inside the housing 11 and configured to detect the inclination angle of the mobile terminal device 10. In one aspect, the angle sensor 41 is realized by a gyro sensor, a capacitive acceleration sensor, a geomagnetic sensor, or the like.

  FIG. 2 is a block diagram illustrating a hardware configuration of the mobile terminal device 10. The mobile terminal device 10 includes a control circuit 42, a storage device 43, a switch 45, and a reception circuit 46 in addition to the configuration shown in FIG.

  The control circuit 42 processes input data and received signals. The control circuit 42 is configured to output a control signal 44 for switching the antenna element to the switch 45. For example, in communication in a mobile communication network called cellular communication, vertical polarization is always used as the polarization of a base station antenna in Japan. Therefore, the control circuit 42 selects the antenna element whose main polarization plane is closest to the vertical.

  The storage device 43 stores various data. The stored data includes a program for driving the mobile terminal device 10, data for controlling the operation of the mobile terminal device 10, and the like.

  The switch 45 is connected to the antenna elements 31 and 32 and the receiving circuit. The switch 45 is configured to switch the antenna element used for signal reception based on the control signal 44 output from the control circuit 42.

  The receiving circuit 46 demodulates the signal received by the antenna element. In a certain aspect, the reception circuit 46 is configured as a circuit for receiving a telephone call, a circuit for receiving a digital television broadcast, or the like.

  With reference to FIG. 3, the usage aspect of the portable terminal device 10 which concerns on this Embodiment is demonstrated. FIG. 3A is a diagram illustrating the mobile terminal device 10 arranged in the vertical direction. FIG. 3B is a diagram illustrating the mobile terminal devices 10 arranged in the horizontal direction. Since the directions of the main polarization planes of the antenna elements 31 and 32 change according to the mode in which the mobile terminal device 10 is used, the reception characteristics of the antenna elements 31 and 32 also change.

  With reference to FIG. 4, the reception characteristics of antenna elements 31 and 32 according to the present embodiment will be described. FIG. 4 is a table showing the reception characteristics of the antenna elements 31 and 32 for two usage situations as shown in FIG.

  When receiving a signal with the display unit 21 as a vertical screen as shown in FIG. 3A, for example, when viewing a terrestrial digital broadcast, the main polarization plane of the antenna element 31 is horizontal, and the main element of the antenna element 32 is The plane of polarization is vertical. When viewing digital terrestrial broadcasting with the display unit 21 as a horizontal screen as shown in FIG. 3B, the main polarization plane of the antenna element 31 is vertical and the main polarization plane of the antenna element 32 is horizontal. Therefore, depending on the usage situation, the antenna element 31 and the antenna element are used for reception so that the polarization plane of the radio wave used for terrestrial digital broadcasting matches the main polarization plane of the reception antenna of the mobile terminal device 10. By switching between them, the reception characteristics of the antenna element can be improved according to the usage status of the mobile terminal device 10.

  With reference to FIG. 5, the control structure of the portable terminal device 10 is demonstrated. FIG. 5 is a flowchart showing a part of a series of processes executed by the mobile terminal device 10.

  In step S <b> 510, the control circuit 42 of the mobile terminal device 10 detects the start of reception based on the signal from the operation unit 22. As will be described later, in another aspect, the mobile terminal device 10 may also have a transmission function. In this case, the control circuit 42 detects the start of transmission or communication based on the output from the operation unit 22.

  In step S520, the control circuit 42 detects the tilt angle of the mobile terminal device 10 based on the signal from the angle sensor 41.

  In step S530, control circuit 42 selects an antenna element having a main polarization plane closest to the polarization plane of the radio wave based on the detected tilt angle.

  In step S540, the control circuit 42 transmits a control signal for switching the antenna element to the switch 45 so as to receive the signal via the selected antenna element. The switch 45 connects the antenna element specified by the control signal among the antenna elements 31 and 32 and the receiving circuit 46.

  In step S550, control circuit 42 processes the signal received via the antenna element selected by switch 45, and outputs the processed signal to display unit 21 or speaker 25. When the mobile terminal device 10 is a digital television broadcast receiving terminal, the display unit 21 displays a program broadcast on television.

  Note that, in one aspect, when the mobile terminal device 10 is in a standby state, the control circuit 42 does not perform processing for selecting an antenna element. At this time, the control circuit 42 connects a predetermined antenna element (hereinafter also referred to as “primary antenna”) to the receiving circuit 46. As the primary antenna, for example, an antenna element that has the best antenna radiation efficiency among the plurality of antenna elements and consumes the least power in the switch 45 is desirable.

  As described above, according to the mobile terminal device 10 according to the first embodiment, in the wireless system in which the polarization plane is constant without depending on the region or time, the mobile terminal device 10 It operates to select the nearest antenna element and receive a signal from that antenna element. Thereby, communication quality can be maintained regardless of the attitude of the mobile terminal device 10.

<Modification>
A modification of the first embodiment will be described with reference to FIG. FIG. 6 is a block diagram showing a hardware configuration of portable terminal device 600. The mobile terminal device 600 is realized as a mobile phone, for example. A portable terminal device 600 according to this modification includes a transmission / reception circuit 610 instead of the reception circuit 46 and a microphone 620 with respect to the configuration shown in FIG.

  When the control circuit 42 according to this modification detects that transmission is performed based on a signal from the operation unit 22, the control circuit 42 is used for transmission from the antenna elements 31 and 32 based on a signal from the angle sensor 41. Select an antenna element. When selecting the antenna element, the control circuit 42 sends a signal for connecting the transmission / reception circuit 610 to the selected antenna element to the switch 45. For example, when the mobile terminal device 600 is realized as a mobile phone, when the mobile terminal device 600 detects an outgoing call, an antenna element having a main polarization plane closest to the polarization plane of the radio wave is selected from the antenna elements 31 and 32. . Thereby, the voice quality at the time of a telephone call can be maintained favorable.

  In Japan's terrestrial digital broadcasting, the polarization plane of radio waves used varies from region to region. Therefore, when switching the antenna as described above, the mobile terminal device 10 holds the polarization plane information of the radio wave used in terrestrial digital broadcasting in the area where the mobile terminal device 10 exists as polarization plane information. It is necessary to keep.

  Therefore, the mobile terminal device 10 according to the present embodiment stores in the storage device 43 the polarization plane information according to the radio wave region used in terrestrial digital broadcasting. The storage of the polarization plane information may be downloaded from the provider of the polarization plane information via the Internet at the time of manufacturing the mobile terminal device 10 or according to an operation by the user of the mobile terminal device 10. Thus, the function of selecting and switching the antenna by using the polarization plane information of the area where the mobile terminal device 10 exists, the inclination angle of the mobile terminal device 10 by the angle sensor 41, and the position information of the mobile terminal device 10 is provided. Can be realized.

  In one aspect, position information can be acquired using a position sensor. For example, the position information can be acquired from a signal included in a digital broadcast on the ground or from a result of positioning by a global positioning system (GPS).

  The mobile terminal device 10 uses the polarization plane information of each region stored in the storage device 43 and the location information of the mobile terminal device 10 acquired by the position sensor, so that the terrestrial digital signal in the region where the mobile terminal device 10 is present. When it is determined that the broadcast radio wave is transmitted in the horizontal polarization, if it is determined that the display unit 21 is used as a vertical screen based on the information of the angle sensor, the control circuit 42 uses an antenna as a receiving antenna. The element 31 is selected, and a control signal 44 for connecting the antenna element 31 and the receiving circuit 46 is sent to the switch 45 so that the signal from the antenna element 31 is sent to the receiving circuit 46.

  On the other hand, when the control circuit 42 determines that the display unit 21 is used as a horizontal screen based on the information of the angle sensor, the control circuit 42 selects the antenna element 32 as a reception antenna, and a signal from the antenna element 32 is sent to the reception circuit 46. The control signal 44 for connecting the antenna element 32 and the receiving circuit 46 is sent to the switch 45 so as to be sent. By doing so, the reception performance of the antenna of the mobile terminal device 10 is improved, and stable communication quality can be ensured.

  In the mobile terminal device 10 described above, the antenna elements 31 and 32 arranged in the casing 11 are orthogonal to each other, and the main polarization planes are also orthogonal to each other. Therefore, even when the display unit 21 changes from a state where the display unit 21 is used as a vertical screen to a state where the display unit 21 is used as a horizontal screen, the main polarization plane of one of the antenna elements is This is a favorable condition for the polarization plane. Therefore, by switching to an antenna element having excellent reception characteristics according to the inclination angle that changes depending on the usage status of the mobile terminal device 10, the reception characteristics of the antenna element can always be kept good.

  In addition, the main polarization planes of the antenna elements 31 and 32 themselves are less likely to fluctuate with respect to changes in the way the user of the mobile terminal device 10 is gripped and the influence of nearby objects. Communication quality is also maintained by antenna switching based on the above.

  Therefore, the control circuit 42 has an antenna switching function capable of maintaining good reception characteristics by switching the antenna elements 31 and 32 having different main polarization planes based on the inclination angle of the mobile terminal device 10 detected by the angle sensor 41. Can be realized. As a result, stable communication quality is maintained while realizing low cost while suppressing power consumption with a simple configuration.

  Further, according to the mobile terminal device 10 of the present embodiment, the function of the position sensor is such that when the radio wave of terrestrial digital broadcasting includes information capable of determining the reception area such as broadcast station information or relay station information. This is realized by receiving such information. Therefore, a simple configuration can be realized without using a positioning device such as GPS as a position sensor. A positioning device such as GPS may be used as the position sensor. Since the position information of the mobile terminal device 10 is acquired in detail, detailed control for selecting an antenna is possible.

<Second Embodiment>
Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. FIG. 7 is a block diagram showing a hardware configuration of portable terminal device 700 according to the second embodiment. The mobile terminal device 700 further includes a position sensor 710 in addition to the configuration shown in FIG. The output of the position sensor 710 is input to the control circuit 42. The position sensor 710 detects the position of the mobile terminal device 700.

  Regarding the detection of the position of the mobile terminal device 700, in one aspect, the position sensor 710 is realized by the GPS system described above. In another aspect, when mobile terminal device 700 functions as a mobile phone, position sensor 710 uses data included in radio waves sent from base stations that constitute the mobile phone system as position information of mobile terminal device 700. get. In another aspect, when the mobile terminal device 700 is a terminal capable of receiving digital television broadcasts and the broadcast signal includes information capable of determining a reception area such as broadcast station information or relay station information, the position sensor 710 detects, as the position of the mobile terminal device 700, a range in which digital television broadcasting is performed by a broadcasting station or a relay station that broadcasts the received signal based on information on the broadcast signal. In yet another aspect, when the mobile terminal device 700 can receive multimedia broadcasts and the broadcast signal includes information capable of determining a reception area such as broadcast station information or relay station information, the position sensor 710 includes: Based on the information of the broadcast signal, the range where the multimedia broadcast is performed by the broadcast station or relay station that broadcasts the received signal is detected as the position of the mobile terminal device 700.

  With reference to FIG. 8, the data structure of portable terminal device 700 will be described. FIG. 8 is a diagram conceptually showing one mode of data storage in storage device 43. The storage device 43 stores a region and polarization plane information. In the example shown in FIG. 8, it is defined for each of the four regions whether the signal in the region is horizontal polarization or vertical polarization. Therefore, when the position of the mobile terminal device 700 is detected as one of the regions 1 to 4, it is specified whether the radio waves in the detected region are horizontally polarized waves or vertically polarized waves.

  With reference to FIG. 9, the control structure of the portable terminal device 700 is demonstrated. FIG. 9 is a flowchart showing a part of a series of processes executed by the control circuit 42 configuring the mobile terminal device 700. In addition, the same number is attached | subjected to the process same as the process in 1st Embodiment. Therefore, the description of the same process will not be repeated.

  In step S910, control circuit 42 detects the position of portable terminal device 700 based on the detection of the start of communication or reception. When the mobile terminal device 700 has a positioning function such as GPS, the control circuit 42 performs positioning of the mobile terminal device 700. When the mobile terminal device 700 receives a digital television broadcast or a multimedia broadcast, the control circuit 42 specifies a place where the broadcast is performed based on the data included in the received broadcast signal. When the mobile terminal device 700 is a mobile phone, the control circuit 42 acquires base station information included in the received signal as information for specifying the position of the mobile terminal device 700.

  In step S920, the control circuit 42 specifies the polarization plane information (storage device 43) at the position based on the detected position.

  In step S930, the control circuit 42 selects an antenna element having a main polarization plane closest to the polarization plane of the radio wave based on the specified polarization plane (S920) and the detected tilt angle (S520) as the antenna element 31. , 32. Thereafter, the control circuit 42 switches the switch so as to receive a signal via the selected antenna element (S540).

  As described above, according to the mobile terminal device 700 according to the second embodiment of the present invention, even if the polarization plane is different for each region, the mobile terminal device 700 is able to Since an antenna element corresponding to the wavefront can be selected, radio waves can be received reliably. As a result, communication quality is maintained.

  In addition, the specific structure of the portable terminal device 10 is not limited to a single housing as shown in the above embodiment. For example, in another aspect, a configuration including two separable casings (for example, an upper casing and a lower casing) or a configuration in which the casing is foldable may be used.

  Further, the number and arrangement of antenna elements mounted in the apparatus housing are not limited to the above-described embodiment.

  Three or more antenna elements may be arranged. Increasing the number of antenna elements to be mounted increases the number of antenna element candidates with excellent reception characteristics with respect to changes in the tilt angle of the mobile terminal apparatus 10, so that the reception characteristics are maintained in detail according to the attitude of the mobile terminal apparatus 10. can do.

  In addition, the mobile terminal device 10 according to the present embodiment is not limited to a tablet information terminal. For example, it can be applied to a mobile phone or a notebook computer equipped with a wireless communication function.

  Note that the timing for selecting the antenna is not limited to when the start of communication or reception is detected. For example, during communication or reception, the user of the mobile terminal device 10 may change the tilt angle of the mobile terminal device 10 by changing the mobile terminal device 10. In this case, when detecting that the tilt angle exceeds a predetermined value, the mobile terminal device 10 may switch the antenna element. This prevents quality degradation during communication or reception.

  Also, in order to prevent unnecessary frequent switching, the threshold of the tilt angle may have a hysteresis property, or the average value of the tilt angles detected during a predetermined time period. The antenna element may be selected based on the above.

  There may also be a wireless communication system in which the plane of polarization changes depending on the region. For example, in terrestrial digital broadcasting, there are some which have different planes of polarization depending on areas. In this case, since the polarization plane may change when the broadcast area changes, the mobile terminal device selects an antenna element when detecting a change in the broadcast area. Thereby, since the antenna element once selected can be selected again, the communication quality can be prevented from deteriorating.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 10 Portable terminal device, 11 Case, 21 Display part, 22 Operation part, 23 Operation key, 24 Pointing device, 25 Speaker, 31, 32 Antenna element, 41 Angle sensor, 42 Control circuit, 43 Memory | storage device, 45 Antenna selector switch 46, receiving circuit, 600 portable terminal device, 610 transmission / reception circuit, 620 microphone, 700 portable terminal device, 710 position sensor.

Claims (10)

A portable terminal device,
A plurality of antenna elements having different main polarization planes in the operating frequency band;
A receiving circuit for receiving data via each of the antenna elements;
An angle sensor for detecting an inclination angle of the mobile terminal device;
Antenna switching means for selecting, from the plurality of antenna elements, an antenna element having a main polarization plane closest to a polarization plane of a radio wave used for radio communication based on the tilt angle detected by the angle sensor; A portable terminal device. A position sensor for detecting the position of the mobile terminal device;
Storage means for storing the type of polarization plane defined in advance for each region as the polarization plane of the radio wave used for wireless communication;
The antenna switching means is based on the tilt angle detected by the angle sensor, the position of the mobile terminal device detected by the position sensor, and the type of polarization plane in the region where the mobile terminal device exists. The portable terminal device according to claim 1, configured to select an antenna element having a main polarization plane closest to a polarization plane of a radio wave used for wireless communication.   The mobile terminal apparatus according to claim 1, wherein the plurality of antenna elements operate with linearly polarized waves.   The portable terminal device according to claim 1 or 2, wherein at least two main polarization planes of the plurality of antenna elements are configured to intersect at an angle of 10 degrees or more.   The mobile terminal device according to claim 1, wherein at least two main polarization planes of the plurality of antenna elements are configured to be orthogonal to each other.   The mobile terminal device according to claim 1, wherein the angle sensor includes any one of a gyro sensor, a capacitive acceleration sensor, and a geomagnetic sensor.   The mobile terminal device according to claim 2, wherein the position sensor is a global positioning system.   The mobile terminal apparatus according to claim 2, wherein the position sensor detects a position of the mobile terminal apparatus based on information obtained from a base station of a mobile phone system.   The portable terminal device according to claim 2, wherein the position sensor detects a position of the portable terminal device based on information obtained by receiving digital terrestrial broadcasting.   The mobile terminal device according to claim 2, wherein the position sensor detects a position of the mobile terminal device based on information obtained by receiving multimedia broadcast.

Images