JP2006186677A - Portable terminal unit and antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable terminal unit for suppressing deterioration in the performance of an antenna and for miniaturizing the antenna. <P>SOLUTION: The frame 201 of a ringer speaker 20 is connected to a reception circuit 17 via antennas 181, 182 for matching, thus composing a receive-only subantenna 18, and hence miniaturizing the antenna as compared with when the antenna is composed only of a strip line since the frame 201 operates as the antenna. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a mobile terminal device such as a mobile phone, and more particularly to a mobile terminal device in which the size of an antenna is reduced.

In portable terminal devices represented by mobile phones, size reduction is often a major issue from the viewpoint of portability. In that case, the structure and arrangement of the antenna used for wireless communication may become a problem.
For example, in Patent Document 1, in order to solve the problem that the human body comes closer to the built-in antenna as the size is reduced and the radiation characteristics of the antenna are easily deteriorated, the built-in antenna is attached to the inner wall of the lower end of the front case. A directly fixed mobile phone is described.
JP 2002-171112 A

  On the other hand, for example, a PDC (personal digital cellular) mobile phone and a mobile phone compatible with high-speed data communication technology called EV-DO (evolution data only) have a main antenna for transmission and reception and a sub antenna for reception only. Some are equipped with. In general, a reception-specific sub-antenna is used for processing for suppressing degradation of reception performance in a multipath environment, such as diversity reception.

As a sub antenna for exclusive use for reception, a strip line antenna is generally used in which a strip line is formed on a ground conductor with a dielectric such as ceramic interposed therebetween. The length of the stripline is normally set to one quarter (λ / 4) of the reception wavelength λ. For example, in the case of a mobile phone using a frequency in the 800 MHz band, the length of the stripline is set to about 95 mm. Since a 95 mm strip line formed in a straight line cannot be accommodated in a mobile phone, the line length is usually shortened by increasing the dielectric constant of the ceramic substrate forming the strip line, and the strip line is overlapped several times. The size has been reduced by bending it.
However, when the dielectric constant is increased or the line is bent for miniaturization, there is a problem that the performance (gain, etc.) as an antenna is lowered.

  This invention is made | formed in view of this situation, The objective is to provide the portable terminal device which can reduce the size, suppressing the fall of the performance of an antenna.

  A portable terminal device according to a first aspect of the present invention is a portable terminal device that includes a receiving circuit and a receiving antenna connected to the receiving circuit, and includes a conductive frame, a diaphragm, A speaker unit having a coil that vibrates the diaphragm, a speaker terminal that supplies power to the coil, a drive circuit that outputs a drive signal for the coil, an output terminal for the drive signal of the drive circuit, and the speaker terminal And a high-frequency attenuation circuit that attenuates a predetermined high-frequency component propagating through the wiring. The antenna is configured by connecting the frame and the receiving circuit via at least one matching antenna for matching a resonance frequency to a predetermined value.

  The present invention may include a substrate on which the high-frequency attenuation circuit, the drive circuit, and the speaker unit are mounted. In that case, it is preferable that a conductive shield grounded at a predetermined reference potential is formed on a layer or a surface of the substrate interposed between the high-frequency attenuation circuit and the frame.

  An electrode for supplying power to the speaker terminal may be formed on the same layer or surface of the substrate as the conductive shield. In this case, the high-frequency attenuation circuit is preferably mounted on a layer or surface of the substrate different from the conductive shield and the electrode.

  The frame may be grounded to a predetermined reference potential.

  The present invention may include a plurality of housings that are connected to each other through a connecting portion so as to be opened and closed. In that case, it is preferable that the receiving circuit, the matching antenna, and the speaker unit are included in the same casing.

  The present invention may further include a transmission circuit and a transmission antenna connected to the transmission circuit.

  An antenna according to a second aspect of the present invention is an antenna that is used by being connected to a receiving circuit of a portable terminal device having a speaker having a conductive frame, and for matching a resonance frequency to a predetermined value. The antenna has an antenna, and is configured by connecting the receiving circuit and the frame through the matching antenna.

  In the first aspect and the second aspect, the matching antenna may include a microstrip antenna.

  According to the present invention, by configuring the antenna using the speaker frame, the size of the antenna can be reduced while suppressing a decrease in the performance of the antenna.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration example of a mobile terminal device according to an embodiment of the present invention, and shows an example in which the present invention is applied to a mobile phone.
The mobile terminal device shown in FIG. 1 includes a control unit 10, a memory 11, a display unit 12, a key operation unit 13, a transmission circuit 14, reception circuits 15 and 17, antennas 16 and 18, and an audio processing unit 19. And a ringer speaker 20, a microphone 21, and an ear speaker 22.

The control unit 10 performs various processes related to the overall operation of the mobile terminal device. For example, as processing related to the function of the telephone, processing for controlling a calling / incoming sequence according to the operation of the key operation unit 13, and voice data input / output in the voice processing unit 19 are transmitted to the transmission circuit 14 and the reception circuit. 15 performs the process of transmitting and receiving.
As processing related to the data communication function, the transmission circuit 14 and the reception circuits 15 and 17 are operated according to the operation of the key operation unit 13 to communicate with a predetermined mail server device, and exchange of data such as e-mails. Perform the process.
Further, as processing related to the display function, processing for displaying a predetermined image on the display unit 12 according to the operation state (when waiting, during a call, when creating a mail, etc.) is performed.
Further, the data received by the main receiving circuit 15 and the sub receiving circuit 17 is subjected to signal processing such as diversity reception to improve reception performance.

  For example, the control unit 10 includes a computer that executes processing based on a program stored in the memory 11 and executes the above-described processing according to the program. In particular, data (electrical signals) transmitted and received by the transmission circuit 14 and the reception circuits 15 and 17 are exchanged with the audio processing unit 19, the display unit 12, the memory 11, and the key operation unit 13.

  The memory 11 stores various data (programs) used in the processing of the control unit 10 and data temporarily generated during the processing.

  The display unit 12 includes an image display device such as a liquid crystal display panel or an organic EL panel, for example, and displays an image (still image or moving image) according to the image data supplied from the control unit 10.

  The key operation unit 13 has keys having various functions such as numeric keys, character keys, arrow keys, and decision keys. When these keys are operated by the user, the operation contents are electrically stored. It converts into a signal and notifies the control part 10.

The transmission circuit 14 performs predetermined modulation processing on the digital transmission data under the control of the control unit 10, converts the digital transmission data into a high-frequency transmission signal, and transmits the high-frequency transmission signal from the main antenna 16.
The reception circuit 15 performs predetermined demodulation processing on radio waves from the base station received by the main antenna 16, converts the radio waves into digital reception data, and outputs the digital reception data to the control unit 10.
Here, if the mobile terminal device according to the present embodiment is a mobile phone conforming to a communication standard referred to as “CDMA2000 1x”, for example, the transmission circuit 14 and the reception circuit 15 have both voice communication and data communication. Used as a main communication circuit used in

The receiving circuit 17 performs a predetermined demodulation process on the radio wave received from the base station received by the sub-antenna 18, converts it into digital received data, and outputs it to the control unit 10.
The receiving circuit 16 is mainly used for high-speed data communication corresponding to “1xEV-DO”, which is an extended specification of “CDMA2000 1x”.

  The main antenna 16 is a transmission / reception antenna used in the transmission circuit 14 and the reception circuit 15.

  The sub-antenna 18 is a reception-dedicated antenna used in the reception circuit 17. This detailed configuration will be described later with reference to FIG.

  The audio processing unit 19 performs signal processing such as amplification, analog-digital conversion, and encoding on the audio signal input from the microphone 21, converts the audio signal into digital audio data, and outputs the digital audio data to the control unit 10. In addition, the audio data input from the control unit 10 is subjected to signal processing such as decoding, digital-analog conversion, and amplification to be converted into an analog audio signal, which is output to the ringer speaker 20.

  The microphone 21 converts the user's voice into an electrical signal and inputs it to the voice processing unit 19 mainly during a voice call.

The linger speaker 20 converts an electrical signal supplied from the audio processing unit 19 into a voice and outputs it, for example, at the time of an incoming call. In particular, the ringer speaker 20 requires a high output such as a ring tone or a hands-free voice. This is an audio output speaker.
The ear speaker 22 converts an electrical signal of a call voice supplied from the voice processing unit 19 into a voice and outputs the voice, for example, during a voice call.

FIG. 2 is a diagram illustrating an example of the structure of the ringer speaker 20.
For example, as shown in FIG. 2, the ringer speaker 20 includes a conductive frame 201, a diaphragm 205, a coil 202 for vibrating the diaphragm 205, and a constant magnetic field around the coil 202. It has a magnet 206 and speaker terminals 203 and 204 for supplying power to the coil 202.

The frame 201 has a shape in which a circular conductor is curved toward the center and a cylindrical depression is provided at the center. Similarly to the frame 201, the diaphragm 205 has a shape in which a circular diaphragm is curved toward the center, and is configured to cover the opening of the frame 201. A disc-shaped magnet 206 having a circular groove is disposed at the bottom of the cylindrical portion of the frame 201, and the coil 202 is fitted in the groove with a gap. The coil 202 is bonded to the center of the curved portion of the diaphragm 205, and is configured such that an electromagnetic force acting on the coil 202 drives the diaphragm 205.
Since the magnetic circuit composed of the magnet 206 and the coil 202 is covered with the conductive frame 201, the magnetic force of the magnetic circuit is kept uniform.

  The speaker terminals 203 and 204 are disposed on the outer wall at the bottom of the cylindrical portion provided in the center of the frame 201, and are constituted by, for example, spring contacts. By pressing the spring contacts against electrodes 31 and 32 described later, the circuit and the coil 202 are connected, and power is supplied to the coil 202.

  Next, a detailed configuration of the sub antenna 18 will be described.

FIG. 3 is a diagram showing a configuration example of the sub-antenna 18, and the same reference numerals in FIGS. 1 and 2 and FIG. 3 indicate the same components.
As shown in FIG. 3, the sub-antenna 18 is configured using a frame 201 of the ringer speaker 20. That is, the sub-antenna 18 is configured by connecting the frame 201 and the receiving circuit 17 via the matching antennas 181 and 182.

The matching antennas 181 and 182 are antennas for matching the resonance frequency to a predetermined value.
The matching antenna 181 is connected between a high-frequency signal input terminal of the receiving circuit 17 and one end of the frame 201.
The matching antenna 182 is connected between the other end of the frame 201 and the ground line GND.

  The matching antennas 181 and 182 are constituted by, for example, microstrip antennas. The two microstrip antennas have, for example, the same length.

For example, the connection point P1 between the matching antenna 181 and the frame 201 and the connection point P2 between the matching antenna 182 and the frame 201 are provided at positions where the electrical distance between them is farthest. In the example of FIG. 3, connection points P <b> 1 and P <b> 2 are provided at the edge of the circular opening portion of the frame 201, separated by a half circumference of the circle.
By making the electrical distance between the connection points P1 and P2 as long as possible, the length of the microstrip line in the matching antennas 181 and 182 can be shortened.

  The matching antennas 181 and 182 can be formed on, for example, a flexible printed board.

  The differential amplifier 191 and the high frequency attenuation circuits 192 and 193 shown in FIG. 3 are constituent elements included in the audio processing unit 19.

  The differential amplifier 191 is an embodiment of the drive circuit of the present invention, and outputs a differential signal for driving the coil 202 of the ringer speaker 20.

The high frequency attenuation circuit 192 is inserted in a wiring connecting one output terminal of the differential amplifier 191 and the speaker terminal 203, and attenuates a predetermined high frequency component propagating to the wiring.
The high frequency attenuation circuit 193 is inserted in a wiring connecting the other output terminal of the differential amplifier 191 and the speaker terminal 203, and attenuates a predetermined high frequency component propagating through this wiring.

FIG. 4 is a diagram illustrating an example of the configuration of the high-frequency attenuation circuits 192 and 193.
The high frequency attenuation circuits 192 and 193 are configured by a parallel resonance circuit of a capacitor C1 and an inductor L1, for example, as shown in FIG. By making this resonance frequency equal to the frequency of the radio wave transmitted from the main antenna 16, for example, it is possible to suppress a high frequency component propagating from the main antenna 16 to the differential amplifier 191.

  FIG. 5 is a diagram illustrating an example in which the differential amplifier 191, the high frequency attenuation circuits 192 and 193, and the ringer speaker 20 are mounted on a common substrate.

The board 30 is, for example, a two-layer printed board, and a differential amplifier 191 and high-frequency attenuation circuits 192 and 193 are mounted on one surface thereof, and the ringer speaker 20 is mounted on the other surface.
In the portion of the substrate 30 where the ringer speaker 20 is mounted, an area AR1 in which a ground potential pattern is cut out is provided in order to prevent interference with the frame 202 operating as an antenna. In this area AR1, electrodes 31 and 32 for pressing and contacting the two speaker terminals 203 and 204 are formed. The electrodes 31 and 32 are connected to wiring on the back surface of the substrate 30 through contact wiring that penetrates the substrate. These wirings are connected to the differential amplifier 191 through the high frequency attenuation circuits 192 and 193.

Conductive shields 33 and 34 grounded to the ground potential are formed on the surface of the substrate 30 interposed between the frame 201 of the ringer speaker 20 and the high frequency attenuation circuits 192 and 193. The conductive shields 33 and 34 are formed on the same surface of the substrate 30 as the electrodes 31 and 32 for supplying power to the speaker terminals 203 and 204.
By providing the conductive shields 33 and 34, it is possible to prevent the high frequency signals of the high frequency attenuation circuits 192 and 193 from adversely affecting the characteristics of the sub antenna 18 through the frame 201.

FIG. 6 is a diagram illustrating an example of mounting positions of the receiving circuit 17 and the ringer speaker 20.
For example, as shown in FIG. 6A, the mobile terminal device according to the present embodiment includes two casings 41 and 42 that are connected to each other through a connecting portion so as to be opened and closed. The receiving circuit 17 and the ringer speaker 20 are both contained in the housing 42.
FIG. 6B shows a state where the two casings 41 and 42 are folded. In this state, a hole 43 for releasing the sound of the ringer speaker 20 to the outside is provided on the surface of the housing 42 opposite to the surface folded inward.

  As described above, according to the mobile terminal device according to the present embodiment, the sub-antenna 18 is configured by connecting the frame 201 of the ringer speaker 20 and the receiving circuit 17 via the matching antennas 181 and 182. ing. Thereby, since the frame 201 operates as an antenna, the size of the antenna can be reduced as compared with the case where the antenna is configured by only the strip line.

  For example, in order to construct a quarter wavelength (λ / 4) antenna that receives signals in the 800 MHz band, a conductor having a length of about 95 mm is required. If the frame 201 is regarded as a disk conductor having a diameter of 20 mm, the matching antennas 181 and 182 may have a total length of 75 mm. That is, the length of the matching antennas 181 and 182 can be shortened by the length of the frame 201. Therefore, the length of the stripline can be shortened and the antenna can be downsized as compared with the case where the antenna is configured with only the stripline without using the frame 201.

  Further, according to the above example, the area of a disk conductor having a diameter of 20 mm is 314 mm 2, whereas the area when a 95 mm antenna is configured by a strip line having a width of 1 mm is 95 mm 2. In other words, according to the present embodiment, by using the frame 201 as an antenna, the radiation area of the antenna can be widened as compared to the case where the antenna is configured with only strip lines. Thereby, the gain of the antenna can be increased and the reception sensitivity can be improved.

  In particular, in recent years, there is a tendency to increase the size of the diaphragm and the magnetic circuit in order to increase the ringtone, and the size of the frame that accommodates these has also increased. Therefore, according to the present embodiment in which the speaker frame is operated as an antenna, it is possible to achieve both improvement of the output performance of the speaker and miniaturization of the antenna.

  Further, according to the mobile terminal device according to the present embodiment, the high frequency attenuation circuits 192 and 193 are inserted in the wiring connecting the differential signal output terminal of the differential amplifier 191 and the speaker terminals 203 and 204. The propagation of high frequency components to the differential amplifier 191 can be suppressed.

When the transmission power emitted from the transmission circuit 14 through the main antenna 16 is received by the sub-antenna 18 configured using the frame 201, the electrostatic coupling between the coil 202 and the frame 201 disposed in proximity to each other is performed. Is transmitted to the speaker terminals 203 and 204. If the high-frequency attenuation circuits 192 and 193 are not provided, the transmission power propagated to the speaker terminals 203 and 204 is propagated to the differential amplifier 191 as it is. Since the semiconductor element inside the differential amplifier 191 receives this transmission power and generates a minute noise signal, this noise signal is superimposed on the differential signal supplied from the differential amplifier 191 to the ringer speaker 20. It will be. Since the noise signal has a frequency that does not exist in the original sound, it causes deterioration in sound quality.
According to the present embodiment, by providing the high frequency attenuation circuits 192 and 193, unnecessary high frequency components picked up by the sub antenna 18 can be attenuated before reaching the differential amplifier 191. It is possible to suppress deterioration of the sound quality of the ringer speaker 20 while operating as an antenna.

Further, according to the portable terminal device according to the present embodiment, the conductive shields 33 and 34 are grounded to the ground potential on the surface of the substrate 30 interposed between the high frequency attenuation circuits 192 and 193 and the frame 201 of the ringer speaker 20. Is formed. Thereby, since the high frequency attenuation circuits 192 and 193 are electromagnetically shielded from the frame 201 by the conductive shields 33 and 34, the influence of the operation of the high frequency attenuation circuits 192 and 193 on the characteristics of the sub antenna 18 can be reduced. it can.
In addition, in the substrate 30, the conductive shields 33 and 34 are formed on the same surface as the electrodes 31 and 32. Therefore, these can be easily formed by a process using the same mask, so that the manufacturing process can be simplified.

  Furthermore, according to the mobile terminal device according to the present embodiment, in the structure having the two casings 41 and 42 that are openably and closably connected via the connecting portion, the receiving circuit 17 and the matching antenna are provided in the same casing 42. 181 and 182, and a ringer speaker 20 are included. Therefore, it becomes possible to connect each component of the subantenna 18 without using the wiring passing through the connecting portion of the housing. Usually, since a large number of wirings are concentrated in the connecting portion of the housing, the wiring passing therethrough is easily subjected to unnecessary signal interference and the like. Therefore, the antenna performance can be prevented from being deteriorated by configuring the antenna 18 so as to avoid the connecting portion.

In the mobile terminal device according to the present embodiment, the transmission circuit 14 and the main antenna 16 connected to the transmission circuit 14 are provided independently of the reception circuit 17 and the sub-antenna 18 connected thereto. Functions as a receive-only antenna.
In general, most of the time when the speaker is not used is waiting for an incoming call, and it is highly possible that the speaker is used when transmission is performed. Further, when the speaker frame is used as an antenna, a more stable operation as an antenna can be expected when the speaker body is not used than when it is used. Therefore, as in this embodiment, for example, when processing such as diversity reception is performed using a plurality of antennas, by selecting a reception-specific sub-antenna as an antenna using a speaker frame, higher performance as an antenna is exhibited. Can be made.
In particular, the mobile terminal device of the present invention performs voice communication using “CDMA2000 1x” that does not require diversity reception, and performs data communication using “1xEVDO” that requires diversity reception. Basically, diversity reception is performed so that it can immediately shift to “1xEVDO” at the time of standby. However, when voice communication is started, communication is switched to “CDMA2000 1x” which does not require diversity reception. Accordingly, since diversity reception is not performed during a voice call using the speaker, the receiving circuit 17 is not used, and the ringer speaker 20 is not used as an antenna. On the other hand, diversity reception is performed during standby or data communication. In this case, since a speaker is rarely used, there is almost no inconvenience even when the ringer speaker 20 is used as an antenna.

  As mentioned above, although one Embodiment of this invention was described, this invention is not limited only to said form, Various variations are included.

In the sub-antenna 18 shown in FIG. 3, the matching antenna 182 is inserted between the frame 201 and the ground line GND, but the present invention is not limited to this. For example, as shown in FIG. 7, the frame 201 and the ground line GND may be directly connected.
In general, the speaker is often arranged at a position close to the outside of the housing, and since a sound emitting hole as shown in FIG. 6B is provided in the vicinity thereof, electrostatic discharge from the human body or the like. It is in the state where it is easy to receive. Therefore, when the frame 201 and the ground line GND are directly connected as shown in FIG. 7, the electrostatic discharge energy to the ringer speaker 20 can be released to the ground line GND, so that the circuit reliability can be improved. it can.
When the matching antenna 182 is deleted as shown in FIG. 7, the line length of the microstrip formed on the matching antenna 181 needs to be made, for example, about twice as long as that shown in FIG. .

  In the example of the substrate wiring pattern shown in FIG. 5, the conductive shields 33 and 34 are provided in the area AR1 in which the ground potential pattern is cut out, but the present invention is not limited to this. For example, as shown in FIG. 8, by arranging the high-frequency attenuation circuits 192 and 193 outside the area AR1, a ground pattern outside the area AR1 can be used as a conductive shield. Further, by disposing the high-frequency attenuation circuits 192 and 193 away from the frame 201, it is possible to reduce the interference between them and eliminate the need for a conductive shield.

  The substrate 30 may be a two-layer substrate or a multilayer substrate having three or more layers. In that case, the electrodes 31 and 32 and the conductive shields 33 and 34 are preferably formed on the same surface or layer. The high-frequency attenuation circuits 192 and 193 are preferably formed on a different surface or layer from the electrodes 31 and 32 and the conductive shields 33 and 34.

  The high frequency attenuation circuits 192 and 193 may be formed on a multilayer substrate as shown in FIGS. 5 and 8, or may be formed on a flexible printed circuit board.

  In the above-described embodiment, an example in which a microstrip antenna is used as the matching antenna is described. However, the present invention is not limited thereto, and a coil or the like may be used, for example.

  In the above-described embodiment, an example in which a speaker frame having a relatively large aperture is used as an antenna is given. However, the present invention is not limited to this, and the present invention can be realized using a frame such as an ear receiver.

  The mobile terminal device of the present invention is not limited to a mobile phone. For example, the present invention can be widely applied to portable terminal devices having a communication function such as PDA (personal digital assistants).

It is a figure which shows the structural example of the portable terminal device which concerns on this invention. It is a figure which shows an example of the structure of a speaker. It is a figure which shows the structural example of a subantenna. It is a figure which shows an example of a structure of a high frequency attenuation circuit. It is the figure which illustrated the example which mounts a differential amplifier, a high frequency attenuation circuit, and a speaker on a common board | substrate. It is a figure which shows the example of the mounting position of a receiving circuit and a speaker. It is a figure which shows the other structural example of a subantenna. It is the figure which illustrated the other example which mounts a differential amplifier, a high frequency attenuation circuit, and a speaker on a common board | substrate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Control part, 11 ... Memory, 12 ... Display part, 13 ... Key operation part, 14 ... Transmission circuit, 15, 17 ... Reception circuit, 16 ... Main antenna, 18 ... Subantenna, 19 ... Audio | voice processing part, 20 ... Ringer speaker, 21 ... microphone, 22 ... ear speaker, 201 ... frame, 202 ... coil, 203, 204 ... speaker terminal, 205 ... diaphragm, 206 ... magnet, 181, 182 ... matching antenna, 191 ... differential amplifier, 192, 193: High frequency attenuation circuit, C1: Capacitance, L1: Inductor, 31, 32: Electrode, 33, 34: Conductive shield, 41, 42: Case, 43: Hole for speaker

Claims (9)

A mobile terminal device having a receiving circuit and a receiving antenna connected to the receiving circuit,
A speaker unit having a conductive frame, a diaphragm, a coil that vibrates the diaphragm, and a speaker terminal that supplies power to the coil;
A drive circuit for outputting a drive signal for the coil;
A high-frequency attenuation circuit that is inserted into a wiring connecting the output terminal of the driving signal of the driving circuit and the speaker terminal and attenuates a predetermined high-frequency component propagating through the wiring;
The antenna is configured by connecting the frame and the receiving circuit via at least one matching antenna for matching a resonance frequency to a predetermined value. A board on which the high-frequency attenuation circuit, the drive circuit, and the speaker unit are mounted;
The portable terminal device according to claim 1, wherein a conductive shield grounded to a predetermined reference potential is formed on a layer or surface of the substrate interposed between the high-frequency attenuation circuit and the frame. An electrode for supplying power to the speaker terminal is formed on the same layer or surface of the substrate as the conductive shield,
The portable terminal device according to claim 2, wherein the high-frequency attenuation circuit is mounted on a layer or a surface of the substrate different from the conductive shield and the electrode. The portable terminal device according to any one of claims 1, 2, and 3, wherein the frame is grounded to a predetermined reference potential. Having a plurality of casings that are openably and closably connected via a connecting portion;
The mobile terminal device according to any one of claims 1, 2, 3, and 4, wherein the receiving circuit, the matching antenna, and the speaker unit are included in the same casing. A transmission circuit;
The mobile terminal device according to claim 1, further comprising a transmission antenna connected to the transmission circuit. The portable terminal device according to any one of claims 1, 2, 3, 4, 5, 6 or 7, wherein the matching antenna includes a microstrip antenna. An antenna used by being connected to a receiving circuit of a portable terminal device having a speaker having a conductive frame,
Having a matching antenna for matching the resonance frequency to a predetermined value;
An antenna comprising: the receiving circuit and the frame connected through the matching antenna. The antenna according to claim 8, wherein the matching antenna includes a microstrip antenna.

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