JP2000244219A - Incorporated antenna for radio communication terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an incorporated antenna for radio communication terminal, which has little effect on a human body and a high gain. SOLUTION: A base plate 101 is fitted so that it becomes almost parallel to a surface (vertical face) where an operation key, a display and a speaker, which are not illustrated, are installed in a radio communication terminal. A loop antenna 102 is fitted so that the loop face becomes almost vertical to a face where the display and the speaker are installed and becomes almost parallel to the upper face (horizontal face) of the radio communication terminal. A balance/non-balance conversion circuit 103 is a conversion circuit having the impedance conversion ratio of one to one or (n) to one ((n) is integer) and it is fitted to the feeding terminal of the loop antenna.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna used for a radio, a portable terminal, and the like, and more particularly, to a built-in antenna.

[0002]

2. Description of the Related Art In recent years, miniaturization of wireless communication terminals has been promoted in order to improve portability. Along with this, miniaturization of built-in antennas used in wireless communication terminals is also required. As a conventional built-in antenna for coping with this, there is an antenna using a plate-shaped inverted-F antenna. Hereinafter, a built-in antenna used in a conventional wireless communication terminal will be described.

FIG. 32 is a schematic diagram showing a configuration of a built-in antenna used in a conventional wireless communication terminal. Although each element shown in FIG. 1 is mounted in the housing of the wireless communication terminal, an overall view of the wireless communication terminal is omitted for simplicity of description. As shown in FIG. 1, a conventional wireless communication terminal generally includes a plate-shaped inverted-F antenna 12 and a ground plane 11. Note that X, Y and Z are
Each coordinate axis is shown.

[0004] The above-mentioned conventional built-in antenna is also used as a diversity antenna for coping with fluctuations in received electric field strength due to multipath of radio waves. FIG. 33 is a schematic diagram showing a configuration of a diversity antenna used in a conventional wireless communication device. As shown in FIG. 33, a monopole antenna 21 is provided as an external antenna in addition to the above-mentioned conventional plate-shaped inverted F-shaped antenna 12. Diversity reception is performed by two antennas, the plate-shaped inverted-F antenna 12 which is an internal antenna and the monopole antenna 21 which is an external antenna, and stable communication is performed.

[0005]

However, the plate-shaped inverted-F type antenna used in the conventional wireless communication apparatus has an excitation that excites the ground plane 11 rather than the plate-shaped inverted-F antenna 12 itself operating as an antenna. It will work as a container. Therefore, an antenna current flows through the ground plane 11, and the ground plane becomes dominant as an antenna. As a result, the plate-shaped inverted-F antenna 12 used in the conventional wireless communication terminal has a problem that the gain is reduced due to the influence of the human body of the user of the wireless communication terminal.

Now, a specific example of the reception characteristics of the inverted inverted F-shaped antenna 12 used in the above-mentioned conventional radio communication terminal will be described with reference to FIGS. 34 (a) and 34 (b). FIGS. 34 (a) and 34 (b) are diagrams showing measured values of the reception characteristics of a plate-shaped inverted-F antenna used in a conventional wireless communication device. The size of the main plate 11 is 120 ×
36 mm and the frequency is 2180 MHz.

First, FIG. 34 (a) is a diagram showing a reception characteristic on a horizontal plane (XY plane) in a free space of a plate-shaped inverted-F antenna 12 used for a conventional wireless communication terminal. As shown in FIG. 34A, since the ground plane 11 operates as an antenna, the plate-shaped inverted-F type antenna 12 is almost non-directional.

On the other hand, FIG. 34 (b) is a diagram showing a reception characteristic on a horizontal plane (XY plane) of the inverted inverted F-shaped antenna 12 used in the conventional radio communication terminal in a talking state.
Here, it is assumed that the wireless communication terminal is used in a state as shown in FIG. That is, as shown in FIG. 35, the wireless communication terminal 35 provided with the inverted inverted F-shaped antenna 12 and the monopole antenna 21 is used for a telephone call by the user 32.

As is apparent from FIG. 34 (b), the gain of the inverted inverted F-shaped antenna 12 is reduced during a call. That is, the decrease in the gain of the plate-shaped inverted F-type antenna 12 is caused by the influence of the human body, for example, the radio wave is cut off by the user's head or hand, as shown in FIG. 34 (a) and FIG. 34 (b). It is evident that this is due to the influence of

As described above, the plate-shaped inverted-F antenna 12 used in the conventional wireless communication terminal has a problem that the gain is reduced due to the influence of the human body.

Further, the same problem as described above occurs in the diversity antenna used in the above-mentioned conventional radio communication terminal when the plate-shaped inverted-F antenna 12 operates.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a high-gain built-in antenna for a radio communication terminal which is less affected by a human body.

[0013]

According to the present invention, there is provided a built-in antenna for a radio communication terminal, comprising: a ground conductor forming a plate-like surface; An antenna element provided such that a loop surface is substantially perpendicular to a plate-like surface of the ground conductor, the antenna element having a peripheral length of about one wavelength or less of a received wave, the other end of the antenna element, and the feeding means; And a balance-unbalance conversion unit that converts impedance between the balanced signal and the unbalanced signal.

According to this configuration, during a call, the loop surface of the antenna element is positioned so as to be substantially perpendicular to the human body. Can be increased. At the same time, since the antenna element is provided so that the peripheral length of the antenna element is substantially equal to or less than one wavelength of the reception wave, the directivity crack due to the phase inversion of the current flowing through the antenna element is suppressed, and the reception characteristic of the antenna element is reduced. Deterioration can be suppressed. Furthermore, the impedance matching between the antenna element and the feeding means is appropriately performed by the balanced / unbalanced conversion means, and the unbalanced signal from the transmission circuit is converted into a balanced signal and supplied to the antenna element. The current flowing through the conductor is minimized. This prevents the ground conductor from acting as an antenna. Therefore, it is possible to provide a high gain built-in antenna for a wireless communication terminal which is less affected by a human body.

Further, according to this configuration, the loop surface of the antenna element is positioned so as to be substantially parallel to the horizontal plane during a call, so that the signal transmitted from the communication partner mainly includes the horizontally polarized wave. Will match. As a result, it is possible to prevent gain deterioration due to the fact that the polarization plane of the signal transmitted from the communication partner does not match.

Furthermore, according to this configuration, the loop surface of the loop antenna is positioned so as to be substantially perpendicular to the horizontal plane during a call, so that the signal transmitted from the communication partner mainly has a vertical polarization. Will match the waves. As a result, it is possible to prevent gain deterioration due to the fact that the polarization plane of the signal transmitted from the communication partner does not match.

The built-in antenna for a radio communication terminal according to the present invention comprises:
In the above-described built-in antenna for a wireless communication terminal, a configuration is adopted in which the loop surface is provided so as not to intersect the plate-like surface of the ground conductor.

According to this configuration, during a call, the loop surface does not intersect the plate-like surface of the ground conductor, so that the human body operates as a reflector. This makes it possible to provide a built-in antenna for a wireless communication terminal having directivity in a direction opposite to the direction of the human body.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
In the above-mentioned built-in antenna for a wireless communication terminal, a configuration is adopted in which the loop surface is formed of surfaces orthogonal to each other.

According to this configuration, the loop surface of the antenna element is positioned so as to be substantially parallel and substantially perpendicular to the horizontal plane during a call, so that only the horizontal polarization of the signal sent from the communication partner is included. But also the vertical polarization. As a result, it is possible to more reliably prevent the gain from being deteriorated due to the inconsistency of the polarization plane with the signal sent from the communication partner.

The built-in antenna for a radio communication terminal according to the present invention comprises:
In the above-mentioned built-in antenna for a wireless communication terminal, a configuration is adopted in which the antenna element includes impedance changing means for changing the impedance of the antenna element.

According to this configuration, an impedance equivalent to a large antenna element can be obtained by changing the impedance of the antenna element, so that the antenna element can be reduced in size or widened.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
In the above-described built-in antenna for a wireless communication terminal, a configuration is adopted in which the impedance changing unit includes at least one reactance element.

According to this configuration, since the current distribution of the antenna element is changed by the reactance element, the impedance of the antenna element can be changed. Thus, the same impedance characteristics as those of a large antenna can be obtained. Further, by changing the position and size of the reactance element, the impedance, radiation pattern, and resonance condition of the antenna element can be changed. Therefore, the size and the bandwidth of the loop antenna can be reduced.

The built-in antenna for a radio communication terminal according to the present invention comprises:
The above-mentioned built-in antenna for a wireless communication terminal adopts a configuration in which the impedance changing means includes at least one capacitive element.

According to this configuration, flexible impedance matching can be achieved by changing the capacitance element used. Therefore, the size and the bandwidth of the loop antenna can be reduced.

The built-in antenna for a radio communication terminal according to the present invention comprises:
In the above-mentioned built-in antenna for a wireless communication terminal, a configuration is adopted in which the impedance changing unit includes at least one switching unit.

According to this configuration, when a plurality of capacitive elements are loaded on the antenna element, the impedance of the antenna element can be more flexibly changed by operating the switching means. Therefore, the size and the bandwidth of the loop antenna can be reduced.

The built-in antenna for a radio communication terminal according to the present invention comprises:
In the above-described built-in antenna for a wireless communication terminal, a configuration is adopted in which at least a part of the antenna element is formed in a comb blade shape.

According to this configuration, at least a part of the antenna element is formed in a comb-shape, so that the frequency band can be changed. Therefore, the size of the loop antenna can be reduced.

The built-in antenna for a radio communication terminal according to the present invention comprises:
In the above-mentioned built-in antenna for a wireless communication terminal, a configuration is adopted in which at least a part of the antenna element is formed of a plate.

According to this configuration, since at least a part of the antenna element is formed of a plate-like body, the frequency change of the impedance is reduced, so that the antenna element has a wide band. Therefore, the band of the loop antenna can be widened.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
A grounding conductor forming a plate-like surface, a dipole antenna connected to the grounding conductor and the feeding means, impedance matching between the dipole antenna and the feeding means, and a balanced signal and an unbalanced signal. And a balance-unbalance conversion means for performing the above-mentioned conversion.

According to this configuration, the impedance matching between the antenna element and the feeding means is appropriately performed by the balanced / unbalanced conversion means, and the unbalanced signal from the transmission circuit is converted into a balanced signal, and , The current flowing through the ground conductor is suppressed as much as possible. This prevents the ground conductor from acting as an antenna. Therefore, it is possible to provide a high gain built-in antenna for a wireless communication terminal which is less affected by a human body.

The built-in antenna for a radio communication terminal according to the present invention comprises:
In the above-described built-in antenna for a wireless communication terminal, a configuration is adopted in which the dipole antenna is provided so as not to intersect the plate-shaped surface of the ground conductor.

According to this configuration, during a call, the dipole antenna does not intersect the plate-like surface of the ground conductor, so that the human body operates as a reflector. This makes it possible to provide a built-in antenna for a wireless communication terminal having directivity in a direction opposite to the direction of the human body.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
In the above-described built-in antenna for a wireless communication terminal, a configuration is adopted in which the dipole antenna is provided so that a major axis direction is substantially parallel to a longitudinal direction of the ground conductor.

According to this configuration, the long axis direction of the dipole antenna is positioned so as to be substantially perpendicular to the horizontal plane during a call, so that the signals transmitted from the communication partner mainly include the vertical polarization. Will match. As a result, it is possible to prevent gain deterioration due to the fact that the polarization plane of the signal transmitted from the communication partner does not match.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
In the above-mentioned built-in antenna for a wireless communication terminal, a configuration is adopted in which the dipole antenna is provided so that the major axis direction is substantially perpendicular to the longitudinal direction of the ground conductor.

According to this configuration, the major axis direction of the dipole antenna is positioned so as to be substantially parallel to the horizontal plane during a call, so that the signals transmitted from the communication partner mainly include the horizontal polarization. Will match. As a result, it is possible to prevent gain deterioration due to the fact that the polarization plane of the signal transmitted from the communication partner does not match.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
The said built-in antenna for radio | wireless communication terminals WHEREIN: The said dipole antenna employ | adopts the structure whose long-axis direction mutually orthogonally crosses.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
In the above-mentioned built-in antenna for a wireless communication terminal, a configuration is adopted in which the antenna element of the dipole antenna is formed in an L shape.

According to these configurations, the long axis direction of the dipole antenna is positioned so as to be substantially parallel and substantially perpendicular to the horizontal plane during a call, so that the signals transmitted from the communication partner have a horizontal deviation. It will coincide not only with waves but also with vertical polarization. As a result, it is possible to more reliably prevent the gain from being deteriorated due to the inconsistency of the polarization plane with the signal sent from the communication partner.

The built-in antenna for a radio communication terminal according to the present invention comprises:
In the above built-in antenna for a wireless communication terminal, the dipole antenna adopts a configuration in which at least a part is formed in a comb blade shape.

According to this structure, at least a part of the antenna element is formed in a comb-tooth shape, so that the frequency band can be changed. Therefore, the size of the dipole antenna can be reduced.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
In the above-described built-in antenna for a wireless communication terminal, the dipole antenna has a configuration in which at least a part is formed in a spiral shape.

According to this configuration, at least a part of the antenna element is formed in a spiral shape, so that the frequency band can be changed. Therefore, the size of the dipole antenna can be reduced.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
In the above-mentioned built-in antenna for a wireless communication terminal, the dipole antenna is configured by arranging two comb-shaped dipole antenna elements in parallel with each other, and the folded dipole antenna has a configuration in which impedance is loaded at the tips of the two antenna elements. Is adopted.

According to this configuration, since the antenna element is formed by two comb-shaped wires, the impedance is stepped up, so that impedance matching can be easily performed.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
In the above built-in antenna for a wireless communication terminal, the dipole antenna is a folded dipole antenna having a configuration in which two helical dipole antenna elements are arranged in parallel with each other, and an impedance is loaded at the tips of the two antenna elements. Take a certain configuration.

According to this configuration, since the antenna element is formed by two spiral wires, the impedance is stepped up, so that impedance matching can be easily performed.

The built-in antenna for a wireless communication terminal of the present invention
In the above-described built-in antenna for a wireless communication terminal, a configuration is adopted in which the dipole antenna element includes impedance changing means for changing the impedance of the antenna element.

According to this configuration, an impedance equivalent to a large antenna element can be obtained by changing the impedance of the antenna element, so that the antenna element can be reduced in size or widened.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
In the above-described built-in antenna for a wireless communication terminal, a configuration is adopted in which the impedance changing unit includes at least one reactance element.

According to this configuration, the current distribution of the antenna element is changed by the reactance element, so that the impedance of the antenna element can be changed. Thus, the same impedance characteristics as those of a large antenna can be obtained. Further, by changing the position and size of the reactance element, the impedance, radiation pattern, and resonance condition of the antenna element can be changed. Therefore, it is possible to reduce the size and the bandwidth of the dipole antenna.

The built-in antenna for a wireless communication terminal according to the present invention comprises:
The above-mentioned built-in antenna for a wireless communication terminal adopts a configuration in which the impedance changing means includes at least one capacitive element.

According to this configuration, flexible impedance matching can be achieved by changing the capacitance element used. Therefore, it is possible to reduce the size and the bandwidth of the dipole antenna.

The built-in antenna for a radio communication terminal according to the present invention comprises:
In the above-mentioned built-in antenna for a wireless communication terminal, a configuration is adopted in which the impedance changing unit includes at least one switching unit.

According to this configuration, when a plurality of capacitance elements are loaded on the antenna element, the impedance of the antenna element can be changed more flexibly by operating the switching means. Therefore, it is possible to reduce the size and the bandwidth of the dipole antenna.

The radio communication terminal device of the present invention employs a configuration having a diversity antenna composed of the above-mentioned radio communication terminal built-in antenna and an antenna different from the radio communication terminal built-in antenna.

The wireless communication terminal device of the present invention employs a configuration in which, in the above wireless communication terminal device, the built-in antenna for the wireless communication terminal is used for reception, and the different antennas are used for transmission and reception.

[0062] The wireless communication terminal device of the present invention employs a configuration in which the built-in antenna for the wireless communication terminal is used for transmission and reception, and the different antenna is used for reception.

[0063] The wireless communication terminal device of the present invention, in the above wireless communication terminal device, adopts a configuration in which at least a part of the different antenna is formed in a comb blade shape.

The wireless communication terminal of the present invention has a configuration in which, in the above wireless communication terminal, the different antenna is a monopole antenna.

[0065] The wireless communication terminal of the present invention employs a configuration in which, in the above-mentioned wireless communication terminal, the different antenna is a helical antenna.

According to these configurations, since a high-gain built-in antenna for a radio communication terminal that is less affected by a human body is mounted, it is possible to provide a radio communication terminal device that realizes good communication. Further, according to these configurations, since the miniaturized built-in antenna for the radio communication terminal is mounted, the miniaturization of the communication terminal device can be realized.

The built-in antenna for a radio communication terminal according to the present invention
In the above-mentioned built-in antenna for a wireless communication terminal, the dipole antenna has a configuration provided on a circuit board of a wireless terminal device.

According to this configuration, since the dipole antenna and the circuit board are integrated, stable characteristics can be obtained.

The built-in antenna for a radio communication terminal of the present invention
The above-mentioned built-in antenna for a wireless communication terminal adopts a configuration in which the dipole antenna is provided on an inner surface of a housing case of the wireless terminal device.

According to this configuration, since a space for providing a dipole antenna is not required, the communication terminal can be downsized.

The wireless communication terminal apparatus of the present invention employs a configuration including the above-described built-in antenna for wireless communication terminals.

The base station apparatus of the present invention employs a configuration for performing wireless communication with the above-mentioned wireless communication terminal apparatus.

[0073]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first gist of the present invention is that a loop surface of a loop antenna is provided so as to be substantially perpendicular to a human body, and that the circumference of the loop antenna is one wavelength or less. And providing power to the loop antenna via a balanced-unbalanced conversion circuit having an impedance conversion function.

A second gist of the present invention is that power is supplied to a dipole antenna via a balun conversion circuit having an impedance conversion function.

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

(Embodiment 1) FIG. 1 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to Embodiment 1 of the present invention. Although each element shown in FIG. 1 is mounted in the housing of the wireless communication terminal, an overall view of the wireless communication terminal is omitted for simplicity of description.
The built-in antenna for a wireless communication terminal according to the present embodiment has a configuration including a ground plane 101, a loop antenna 102, and a balance-unbalance conversion circuit 103. In addition,
X, Y and Z indicate respective coordinate axes. Hereinafter, each component will be described.

The base plate 101 is a plate-like ground conductor, and is attached so as to be substantially parallel to a surface (vertical surface) of the wireless communication terminal on which operation buttons (not shown), a display, a speaker, and the like are provided.

The loop antenna 102 has its loop surface substantially perpendicular to the surface on which the display, the speaker and the like are provided, and its loop surface is substantially parallel to the upper surface (horizontal plane) of the wireless communication terminal. Attached to.
As a result, the loop antenna 102 is provided such that the loop surface is substantially perpendicular to the human body during a call. Thereby, the intensities of the virtual and actual magnetic fields on the loop surface are in phase, so that the gain of the loop antenna 102 is increased.

The loop antenna 102 is mounted such that the loop surface is substantially parallel to the upper surface (horizontal surface) of the wireless communication terminal. As a result, the loop antenna 102 is provided such that the loop surface is substantially parallel to the horizontal plane. As a result, the loop antenna 102 mainly receives horizontal polarization parallel to the loop surface in free space. Further, in a call state, the human body operates as a reflector, so that the loop antenna 102 has directivity in the direction opposite to the human body direction, that is, directivity in the front direction on the paper of FIG.

Further, the loop antenna 102 is provided such that its circumference is substantially equal to or less than one wavelength of the received wave. By the way, in the case of a loop antenna having a perimeter longer than one wavelength of a received wave, the directivity is broken due to the inversion of the phase of the current flowing through the loop antenna. Therefore, the loop antenna 102 according to the present embodiment is provided so that the peripheral length is substantially equal to or less than one wavelength of the received wave, so that the directivity is prevented from being broken.

The balance-unbalance conversion circuit 103 is a conversion circuit having an impedance conversion ratio of 1 to 1 or n to 1 (n is an integer), and is attached to the feeding end of the loop antenna. More specifically, one terminal of the balance-unbalance conversion circuit 103 is connected to a transmission / reception circuit (not shown).
The other terminal is attached to base plate 101.
As a result, since the balance-unbalance conversion circuit 103 performs impedance conversion between the loop antenna 102 and the transmission circuit, impedance matching between the two can be properly achieved. Further, the balance-unbalance conversion circuit 103
Since the unbalanced signal of the transmission circuit is converted into a balanced signal and supplied to the loop antenna 102, the current flowing through the ground plane 101 can be suppressed as much as possible. Thereby, the main plate 10
1 is prevented from functioning as an antenna, so that a decrease in the gain of the loop antenna 102 due to the influence of the human body can be suppressed.

Next, the operation of the built-in antenna for a wireless communication terminal having the above configuration will be described. The unbalanced signal from the transmission circuit is converted to a balanced signal by the balanced-unbalanced conversion circuit 103, and then sent to the loop antenna 102. The loop antenna 102 fed in this way mainly receives horizontal polarized waves parallel to the loop plane. In free space, horizontal polarized waves from all directions around the loop antenna are received.Also, during a call, the human body becomes a reflector as described above. Horizontal polarization from the opposite direction is mainly received.

The above-described signal (balanced signal) received by the loop antenna 102 is converted into a balanced-unbalanced conversion circuit 1
The signal is sent to the above-mentioned transmission circuit via the transmission circuit 03. Here, since the current flowing through the ground plane 101 is suppressed as much as possible by the above-described balance-unbalance conversion circuit 103, the antenna operation by the ground plane 101 is prevented. As a result, a decrease in gain due to the influence of the human body is minimized.

Here, the reception characteristics of the built-in antenna for a radio communication terminal having the above configuration will be described with reference to FIG.
FIG. 2 is a diagram showing measured values of reception characteristics of the built-in antenna for a wireless communication device according to Embodiment 1 during a call. The size of the ground plane 101 is 120 × 36 mm, the size of the loop antenna 102 is 63 × 5 mm, the distance of the loop antenna 102 from the human body surface is 5 mm, and the frequency is 2
180 MHz. Also, in FIG. 2, the direction of 270 degrees from the origin corresponds to the loop antenna 10 in FIG.
This corresponds to the direction of the human body as viewed from 2.

As is apparent from FIG. 2, the loop antenna 102 has directivity in the direction opposite to the direction of the human body due to the influence of the human body acting as a reflector, and has the directivity for the above-described reason. Not only is prevented, but also has a high gain characteristic in which the deterioration of the gain is suppressed as compared with the conventional example shown in FIG.

As described above, according to the present embodiment, loop antenna 102 is provided so that the loop surface of loop antenna 102 is substantially perpendicular to the human body.
And the circumference of the loop antenna 102 is provided so as to be approximately one wavelength or less.
Since the directivity of the loop antenna 102 is prevented from being broken and the antenna current flowing through the ground plane 101 can be minimized by the balance-unbalance conversion circuit 103, the gain of the loop antenna 102 due to the influence of the human body can be reduced. Can be suppressed. Therefore, it is possible to provide a high gain built-in antenna for a wireless communication terminal which is less affected by a human body.

(Embodiment 2) Embodiment 2 is an embodiment in which the method of attaching loop antenna 102 in Embodiment 1 is changed. The second embodiment is the same as the first embodiment except for a method of attaching the loop antenna 102, and thus a detailed description is omitted. Hereinafter, differences of the antenna with a built-in wireless communication terminal according to the present embodiment from Embodiment 1 will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

FIG. 3 is a schematic diagram showing the configuration of a radio communication terminal built-in antenna according to the second embodiment. The loop antenna 301 is configured such that the loop surface is substantially perpendicular to a surface of the wireless communication terminal on which operation buttons, a display, a speaker, and the like (not shown) are provided, and the loop surface is a side surface (vertical surface) of the wireless communication terminal. It is attached so that it may become substantially parallel. That is, the present embodiment is provided in that the loop antenna 301 is attached so that the loop surface thereof is substantially parallel to the side surface (vertical surface) of the wireless communication terminal.
This is different from the first embodiment. As a result, the loop antenna 301 is provided so that the loop surface is substantially perpendicular to the human body and substantially parallel to the vertical plane during a call.

As a result, the loop antenna 301 can suppress the deterioration of the gain for the above-described reason and can receive mainly the vertically polarized wave parallel to the loop plane. By the way, the signal sent from the communication partner is
Due to various factors such as reflection, vertical polarization and horizontal polarization are mixed. Therefore, when there are many vertical polarizations, the antenna for a built-in wireless communication terminal according to the present embodiment matches the polarization plane of the signal transmitted from the communication partner, so that the reception gain can be increased.

As described above, according to the present embodiment, loop antenna 301 has a configuration in which the loop surface is substantially perpendicular to the human body and the loop surface is substantially parallel to the side surface of the radio communication terminal. As a result, it is possible not only to suppress gain deterioration due to the influence of the human body but also to receive mainly vertically polarized waves. Therefore, it is possible to provide a high-gain built-in antenna for a wireless communication terminal that can prevent a gain deterioration due to a mismatch of a polarization plane with a signal from a communication partner and is less affected by a human body.

(Embodiment 3) Embodiment 3 is an embodiment in which the method of attaching loop antenna 102 in Embodiment 1 is changed. The third embodiment is the same as the first embodiment except for a method of attaching the loop antenna 102, and thus a detailed description is omitted. In the following, differences between the first embodiment and the second embodiment in the wireless communication terminal according to the present embodiment will be described with reference to FIG. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description is omitted.

FIG. 4 is a schematic diagram showing a configuration of a radio communication terminal built-in antenna according to the third embodiment. As shown in the drawing, the loop antenna 401 is different from the loop antenna 102 of the first embodiment in that, of the four sides forming the loop surface, the side facing the feeding end is bent at an intermediate point, and each of the bent sides is bent. It has a configuration in which sides form an angle of 90 degrees with each other.

The loop antenna 401 having the above configuration is arranged so that it is substantially perpendicular to a surface (vertical surface) of the wireless communication terminal on which operation buttons, a display, a speaker, and the like (not shown) are provided, and that each of the bent sides is formed. Each wireless communication device is attached so as to be substantially parallel to the upper surface (horizontal surface) and the side surface (vertical surface). That is, the present embodiment is different from the first embodiment in that loop antenna 401 is attached such that the loop surface of the loop antenna 401 is substantially parallel to the upper surface and side surfaces of the wireless communication terminal. As a result, as in the first embodiment, the loop surface of the loop antenna 401 is substantially perpendicular to the human body during a call, and at the same time, the loop surface is formed on the upper surface (horizontal plane) and the side surface (horizontal plane) of the wireless communication terminal. That is, it is provided so as to be substantially parallel to the circular face.

Thus, for the above-described reason, the loop antenna 401 can suppress the deterioration of the gain, and can mainly receive not only the horizontally polarized wave parallel to the loop surface but also the vertically polarized wave. . By the way, as described above, a signal transmitted from a communication partner is a mixture of vertical polarization and horizontal polarization due to various factors such as reflection.
Therefore, the antenna with a built-in wireless communication terminal according to the present embodiment matches the polarization plane of the signal transmitted from the communication partner, so that the gain can be further increased as compared with the first and second embodiments.

As described above, according to the present embodiment, loop antenna 401 has its loop surface substantially perpendicular to the human body, and the loop surface is substantially the same as the top and side surfaces of the radio communication terminal. Being installed in parallel, it not only suppresses gain deterioration due to the influence of the human body, but also can receive both horizontal and vertical polarization, so further increase the gain Can be. Therefore, it is possible to provide a high-gain built-in antenna for a wireless communication terminal with less influence of a human body, which can more reliably prevent a gain deterioration due to a mismatch with a polarization plane of a signal from a communication partner.

(Embodiment 4) In Embodiments 4 to 6, the impedance is changed to the above loop antenna in order to reduce the size or widen the band of the loop antenna in Embodiments 1 to 3. This is a mode in which various means for loading are loaded.

Embodiment 4 is an embodiment in which a reactance element is used as one of the impedance changing means in order to reduce the size and the bandwidth of the loop antenna. Hereinafter, a built-in antenna for a wireless communication terminal according to Embodiment 4 will be described with reference to FIGS. 5 (a) and 5 (b).

FIG. 5A is a schematic diagram showing a configuration of a first built-in antenna for a wireless communication terminal according to the fourth embodiment. In FIG. 5A, a reactance element 502 is mounted at an intermediate point of a side of the loop antenna element 501 facing the power supply end.

FIG. 5B is a schematic diagram showing the configuration of the second built-in antenna for a radio communication terminal according to the fourth embodiment. In FIG. 5B, a reactance element 502 is loaded at an intermediate point between two sides of the loop antenna element 501 that are perpendicular to the feeding end.

As described above, the loop antenna element 501
The current distribution of the loop antenna element 501 changes by loading the reactance element 502 at the midpoint of each side forming the loop surface in the above, so that the impedance of the feeding end of the loop antenna element 501 can be changed. Thus, even when the loop antenna element 501 is made smaller, the impedance characteristic similar to that of a large loop antenna can be obtained by changing the impedance by the reactance element 502.
Therefore, by loading the reactance element 502, the size of the loop antenna 501 can be reduced.

Further, in the loop antenna element 501, the position at which the reactance element 502 is loaded is changed, or the magnitude of the reactance of the reactance element 502 is changed, thereby changing the impedance, radiation pattern, and resonance condition of the feeding end. be able to. Thus, the band of the loop antenna 501 can be widened by changing the loading condition of the reactance element 502.

As described above, according to the present embodiment, since the reactance element is loaded on the loop antenna element,
The impedance characteristic of the loop antenna element can be changed. Therefore, it is possible to provide a small and broadband built-in antenna for a wireless communication terminal.

(Embodiment 5) Embodiment 5 is an embodiment in which a variable capacitance element is used as one of the impedance changing means in order to reduce the size and the bandwidth of the loop antenna. Hereinafter, a built-in antenna for a wireless communication terminal according to Embodiment 5 will be described with reference to FIG.

FIG. 6 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to the fifth embodiment. In FIG. 6, a variable capacitance element 602 is loaded on a feeding end of a loop antenna element 601.

By the way, in the case where the loop antenna element is miniaturized and the perimeter is reduced to substantially half a wavelength or less, the reactance of the impedance of the loop antenna becomes inductive. Therefore, in the present embodiment, the impedance of the loop antenna can be matched by loading a capacitive variable capacitance element 602 on the feeding end of the loop antenna element 601 and changing the capacitance of the variable capacitance element 602. It becomes possible. That is, when the size of the loop antenna element 601 is reduced, impedance matching can be achieved for a wide range of frequencies by changing the capacitance of the variable capacitance element 602.

As described above, according to the present embodiment, the variable capacitance element 602 is connected to the feeding end of the loop antenna element 601.
Is loaded, by changing the capacitance of the variable capacitance element 602, flexible impedance matching becomes possible. Therefore, it is possible to provide a small and broadband built-in antenna for a wireless communication terminal.

(Embodiment 6) Embodiment 6 is an embodiment in which a tuning element and a switching element are used as impedance changing means in order to reduce the size and the bandwidth of the loop antenna. Hereinafter, a built-in antenna for a wireless communication terminal according to Embodiment 6 will be described with reference to FIG.

FIG. 7 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to the sixth embodiment. In FIG. 7, a circuit in which a tuning element 702 and a switching element 703 are connected in series is inserted into a feed end of a loop antenna element 701 such that only one set or a plurality of sets are parallel to each other.

In the radio communication terminal built-in antenna having the above configuration, when all the switching elements 703 are opened, the antenna can be used at the original tuning frequency of the loop antenna. When one switching element 703 is closed, it means that the tuning element 702 connected to this switching element 703 is inserted in parallel, so that tuning is performed to a frequency different from the original tuning frequency. Similarly, when the plurality of switching elements 703 are closed, the tuning elements 702 connected to these switching elements 703 are connected.
Are tuned in parallel, so that the frequency is tuned to the frequency corresponding to the total number of connected tuning elements 702.

As described above, in the built-in antenna for a wireless communication terminal having the above configuration, the frequency band can be changed by the switching operation of each switching element 703, so that tuning corresponding to various frequency bands can be performed. . As a result, even when the size of the loop antenna is reduced, a wider band can be achieved.

As described above, according to the present embodiment, a frequency band can be switched by performing a switching operation of a plurality of switching elements inserted into loop antenna element 701, and thus a small and wide-band wireless communication terminal is provided. A built-in antenna can be provided.

(Embodiment 7) Embodiment 7 is an embodiment in which the shape of the loop antenna element is changed in order to reduce the size of the loop antenna. Hereinafter, the built-in antenna for a wireless communication terminal according to the seventh embodiment will be described with reference to FIG.

FIG. 8 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to the seventh embodiment. In FIG. 8, the loop antenna element 801 is formed so that a part or the whole thereof has a zigzag shape. Accordingly, the built-in antenna for a wireless communication terminal having the above configuration can flexibly change the frequency band, and is equivalent to a small antenna.

As described above, according to the present embodiment, since a part or the whole of the elements constituting the loop antenna is formed in a zigzag shape, a small antenna can be realized.

(Embodiment 8) Embodiment 8 is an embodiment in which the shape of the loop antenna element is changed in order to widen the band of the loop antenna. Hereinafter, a built-in antenna for a wireless communication terminal according to Embodiment 8 will be described with reference to FIG.
This will be described with reference to FIG.

FIG. 9 is a schematic diagram showing a configuration of a built-in antenna for a radio communication terminal according to the eighth embodiment. In FIG. 9, the loop antenna element 901 is formed so that a part or the whole thereof has a plate shape. By the way, an antenna in which a linear antenna element is formed in a plate shape has a wide band because the frequency change of impedance is small. Therefore, in the built-in antenna for a wireless communication terminal having the above configuration, a wider band can be achieved.

As described above, according to the present embodiment, since a part or the whole of the element constituting the loop antenna is formed in a plate shape, a wideband antenna can be realized.

(Embodiment 9) Embodiments 9 to 11 are embodiments in which a diversity antenna is realized by using the built-in antenna for a radio communication terminal according to Embodiments 1 to 3. .

Embodiment 9 is an embodiment in which a diversity antenna is realized by using the built-in antenna for a radio communication terminal in Embodiment 1. Hereinafter, regarding the diversity antenna for wireless communication terminal according to the present embodiment,
This will be described with reference to FIG. In addition, about the structure similar to Embodiment 1, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

FIG. 10 is a schematic diagram showing a configuration of a diversity antenna for a radio communication terminal according to the ninth embodiment.
In FIG. 10, a monopole antenna 1001 is provided for the built-in antenna for a wireless communication terminal according to the first embodiment.

Here, one of the antennas constituting the diversity antenna is used as the loop antenna 102 in the first embodiment for reception only. The other antenna constituting the diversity antenna is used as a monopole antenna 1001 for both transmission and reception.

In the diversity antenna for a radio communication terminal having the above configuration, the monopole antenna 10
01 operates, and the loop antenna 102
Then, the monopole antenna 1001 operates to perform diversity reception.

As described above, according to the present embodiment, since loop antenna 102 of Embodiment 1 is used as a diversity antenna, it is possible to provide a high-gain diversity antenna for a radio communication terminal that is less affected by a human body. Can be.

(Embodiment 10) Embodiment 10 is an embodiment in which a diversity antenna is realized by using the built-in antenna for a radio communication terminal in Embodiment 2 and the monopole antenna in Embodiment 9. Less than,
A diversity antenna for a wireless communication terminal according to the present embodiment will be described using FIG. Note that the same components as those of the second and ninth embodiments are denoted by the same reference numerals, and detailed description is omitted.

FIG. 11 is a schematic diagram showing a configuration of a diversity antenna for a radio communication terminal according to the tenth embodiment. 11, a monopole antenna 1001 is provided for the built-in antenna for a wireless communication terminal according to the second embodiment.

Here, one of the antennas constituting the diversity antenna is used as a loop antenna 301 in the second embodiment for reception only. Further, the other antenna constituting the diversity antenna is used as a monopole antenna 1001 in the ninth embodiment for transmission and reception.

In the diversity antenna for a radio communication terminal having the above configuration, the monopole antenna 10
01 operates, and the loop antenna 301
Then, the monopole antenna 1001 operates to perform diversity reception.

As described above, according to the present embodiment, since loop antenna 301 in Embodiment 2 is used as a diversity antenna, gain deterioration due to inconsistency of the polarization plane with the signal from the other party of communication is obtained. It is possible to provide a high-gain diversity antenna for a wireless communication terminal that can prevent the occurrence of the influence of the human body.

(Embodiment 11) Embodiment 11 is an embodiment in which a diversity antenna is realized by using the built-in antenna for a radio communication terminal in Embodiment 3 and the monopole antenna in Embodiment 9. Less than,
A diversity antenna for a wireless communication terminal according to the present embodiment will be described using FIG. In addition, about the structure similar to Embodiment 3 and Embodiment 9, the same code | symbol is attached | subjected and detailed description is abbreviate | omitted.

FIG. 12 is a schematic diagram showing a configuration of a diversity antenna for a radio communication terminal according to the eleventh embodiment. 12, a monopole antenna 1001 is provided for the built-in antenna for a wireless communication terminal according to the third embodiment.

Here, one of the antennas constituting the diversity antenna is used as a loop antenna 401 in the third embodiment for reception only. Further, the other antenna constituting the diversity antenna is used as a monopole antenna 1001 in the ninth embodiment for transmission and reception.

In the diversity antenna for a radio communication terminal having the above configuration, the monopole antenna 10
01 operates, and the loop antenna 401
Then, the monopole antenna 1001 operates to perform diversity reception.

As described above, according to the present embodiment, since loop antenna 401 in Embodiment 3 is used as the diversity antenna, the gain deterioration caused by the fact that it does not match the polarization plane of the signal from the communication partner is eliminated. It is possible to provide a high-gain built-in antenna for a wireless communication terminal which can be more reliably prevented and has less influence of the human body.

In the above embodiment, the base plate,
The case where the distance and the frequency of the loop antenna from the human body surface and the loop antenna are set as described above has been described, but the present invention is not limited to this, and can be changed as appropriate.

(Embodiment 12) FIG.
FIG. 2 is a diagram illustrating a configuration of a built-in antenna for a wireless communication terminal according to the present embodiment, including a balanced-unbalanced conversion circuit 103 and a dipole antenna 1002. As shown in this figure, dipole antenna 1002 is formed in a comb blade shape, and is mounted so that the axial direction is substantially parallel to the side surface (vertical surface) of the wireless communication terminal. As a result of the attachment, the dipole antenna 1002 is provided so that the axial direction is substantially parallel to the vertical plane during a call.

According to this configuration, a vertically polarized small dipole antenna can be realized, impedance matching between the antenna and the circuit can be easily performed by impedance conversion, and the antenna flowing to the ground plane 101 by the balance-unbalance conversion circuit 103 can be realized. Current can be suppressed, and a high-gain antenna with little influence of a hand or a human body can be realized with a wireless device carried.

Here, the reception characteristics of the built-in antenna for a wireless communication terminal having the above configuration will be described with reference to FIG. FIG. 15 is a diagram illustrating measured values of reception characteristics of the built-in antenna for a wireless communication apparatus according to Embodiment 12 in a call state. The size of the main plate 101 is 120 × 36
mm, the size of the dipole antenna 1002 is 63 × 5
mm, the distance of the dipole antenna 1002 from the human body surface is 5 mm, and the frequency is 2180 MHz. FIG.
5, the direction of 270 degrees from the origin corresponds to the direction of the human body as viewed from the dipole antenna 1002. As apparent from FIG. 15, the dipole antenna 1002
Is affected by the human body acting as a reflector, has directivity in the direction opposite to the human body direction,
For the above-described reason, not only the directivity is prevented from being broken, but also a high gain characteristic in which the deterioration of the gain is suppressed as compared with the conventional example shown in FIG.

(Embodiment 13) Embodiment 13 is an embodiment in which the method of mounting dipole antenna 1002 in Embodiment 12 is changed. FIG.
FIG. 2 is a diagram showing a configuration of a wireless communication terminal built-in antenna according to the present embodiment including a ground plane 101, a balance-unbalance conversion circuit 103, and a dipole antenna 1002. As shown in this figure, dipole antenna 1002 is mounted such that the axial direction is substantially parallel to the upper surface (horizontal plane) of the wireless communication terminal. As a result of this attachment, the dipole antenna 1002 is provided so that the axial direction is substantially parallel to the horizontal plane during a call.

In this configuration, the antenna can realize a small horizontally-polarized dipole antenna 1002, further facilitate impedance matching between the antenna and the circuit by impedance conversion, and flow to the ground plane 101 by the balance-unbalance conversion circuit 103. An antenna current can be suppressed, and a high-gain antenna with little influence of a hand or a human body can be realized with a wireless device carried.

(Embodiment 14) Embodiment 14 is an embodiment in which the mounting method of dipole antenna 1002 is changed in Embodiment 13. FIG.
FIG. 2 is a diagram showing a configuration of a wireless communication terminal built-in antenna according to the present embodiment including a ground plane 101, a balance-unbalance conversion circuit 103, and a dipole antenna 1002. As shown in this figure, the dipole antenna 1002 is such that the axial direction of one antenna element is the side surface (vertical surface) of the wireless communication terminal.
And the other antenna element is mounted such that the axial direction of the other antenna element is also substantially parallel to the upper surface (horizontal plane) of the wireless communication terminal.

With this configuration, a small dipole antenna 1002 having both horizontal and vertical polarization can be realized.
In addition, impedance conversion between the antenna and the circuit can be easily performed by impedance conversion, and the antenna current flowing through the ground plane 101 can be suppressed by the balance-unbalance conversion circuit 103, so that the hand and the human body are less affected by the portable radio. A high gain antenna can be realized.

(Embodiment 15) Embodiment 15 is a mode in which the mounting method of dipole antenna 1002 in Embodiment 14 is changed. FIG.
FIG. 2 is a diagram showing a configuration of a wireless communication terminal built-in antenna according to the present embodiment including a ground plane 101, a balance-unbalance conversion circuit 103, and a dipole antenna 1002. According to this figure, the dipole antenna 1002 is
Are bent in the direction of both sides from the upper surface of the wireless communication terminal, the axial direction is substantially parallel to the side surface (vertical surface) of the wireless communication terminal, and the axial direction is the upper surface (horizontal plane) of the wireless communication terminal.
It is attached so that it is also substantially parallel.

According to this configuration, dipole antenna 1
002 has two vertical polarizations having a horizontal polarization and an interval between both side surfaces of the main plate 101.

(Embodiment 16) FIG.
FIG. 3 is a diagram showing a configuration of a built-in antenna for a wireless communication terminal including a balanced-unbalanced conversion circuit 103, a monopole antenna 1001, and a dipole antenna 1002. The dipole antenna 1002 is used only for reception, and the monopole antenna 1001 is used for both transmission and reception. As shown in this figure, dipole antenna 1002 is formed in a comb blade shape, and is mounted so that the axial direction is substantially parallel to the side surface (vertical surface) of the wireless communication terminal. As a result of the attachment, the dipole antenna 1002 is provided so that the axial direction is substantially parallel to the vertical plane during a call.

According to this configuration, even when diversity is executed, a small vertically polarized dipole antenna 1002 can be realized. Further, impedance matching between the antenna and the circuit can be easily achieved by impedance conversion, and a balance can be obtained. Ground plate 1 by unbalance conversion circuit 103
01 can be suppressed, and a high-gain antenna with little influence of a hand or a human body can be realized with a wireless device carried.

(Embodiment 17) FIG.
FIG. 2 is a diagram illustrating a configuration of a built-in antenna for a wireless communication terminal including a balanced-unbalanced conversion circuit 103, a monopole antenna 1003, and a dipole antenna 1002. As shown in this figure, the monopole antenna 1002 is formed in a comb blade shape. The dipole antenna 1002 is used only for reception, and the monopole antenna 1002 is used for both transmission and reception.

According to this configuration, the external antenna (monopole antenna) can be reduced in size, and even when diversity is performed, a small vertically polarized dipole antenna 1002 can be realized. And the circuit can be easily impedance-matched, and the antenna current flowing through the ground plane 101 can be suppressed by the balance-unbalance conversion circuit 103, realizing a high-gain antenna with little effect on the hand or human body while carrying the radio. can do.

(Embodiment 18) FIG.
FIG. 2 is a diagram illustrating a configuration of a built-in antenna for a wireless communication terminal including a balanced-unbalanced conversion circuit 103, a monopole antenna 1004, and a dipole antenna 1002. The monopole antenna 1001 is formed in a spiral shape. The dipole antenna 1002 is used only for reception, and the monopole antenna 1001 is used for both transmission and reception.

According to this configuration, the external antenna (monopole antenna) can be reduced in size, and even when diversity is performed, a small vertically polarized dipole antenna 1002 can be realized. And the circuit can be easily impedance-matched, and the antenna current flowing through the ground plane 101 can be suppressed by the balance-unbalance conversion circuit 103, realizing a high-gain antenna with little effect on the hand or human body while carrying the radio. can do.

(Embodiment 19) FIG.
FIG. 3 is a diagram illustrating a configuration of a built-in antenna for a wireless communication terminal including a balancer / unbalance converter 103, a dipole antenna 1002, and a dipole antenna 1005. The dipole antenna 1002 is used only for reception, and the dipole antenna 1005 is used for both transmission and reception. Note that the dipole antenna 1005 may be used only for reception, and the dipole antenna 1002 may be used for both transmission and reception.

According to this configuration, the external antenna (dipole antenna) can be reduced in size, and a small vertically-polarized dipole antenna 1002 can be realized when performing diversity and transmitting. And the circuit can be easily impedance-matched, and the antenna current flowing through the ground plane 101 can be suppressed by the balance-unbalance conversion circuit 103, realizing a high-gain antenna with little effect on the hand or human body while carrying the radio. I can do it.

(Embodiment 20) Embodiment 20 is an embodiment in which the mounting method of dipole antenna 1005 in Embodiment 19 is changed. FIG.
Ground plate 101, balance-unbalance conversion circuit 103, dipole antenna 1002, dipole antenna 1005
FIG. 3 is a diagram showing a configuration of a built-in antenna for a wireless communication terminal including the following. The dipole antenna 1002 is used only for reception, and the dipole antenna 1005 is used for both transmission and reception. Note that the dipole antenna 1005 may be used only for reception, and the dipole antenna 1002 may be used for both transmission and reception.

According to this configuration, it is possible to reduce the size of the external antenna (dipole antenna) and to realize a small-sized dipole antenna 1002 having both vertical and horizontal polarizations when transmitting while performing diversity. In addition to making impedance matching between the antenna and the circuit easy by impedance conversion, the antenna current flowing to the ground plane 101 can be suppressed by the balance-unbalance conversion circuit 103, and the influence of the hand or human body while carrying the wireless device can be suppressed. A high-gain antenna with less noise can be realized.

(Embodiment 21) Embodiment 21 is an embodiment in which the mounting method of dipole antenna 1005 in Embodiment 20 is changed. FIG.
Ground plate 101, balance-unbalance conversion circuit 103, dipole antenna 1002, dipole antenna 1005
FIG. 3 is a diagram showing a configuration of a built-in antenna for a wireless communication terminal including the following. The dipole antenna 1002 is used only for reception, and the dipole antenna 1005 is used for both transmission and reception. As shown in this figure, as shown in this figure,
In the dipole antenna 1005, the axial direction of one antenna element is substantially parallel to the side surface (vertical surface) of the wireless communication terminal, and the axial direction of the other antenna element is substantially parallel to the upper surface (horizontal plane) of the wireless communication terminal. It is attached to become. Note that the dipole antenna 1005 may be used only for reception, and the dipole antenna 1002 may be used for both transmission and reception.

According to this configuration, it is possible to reduce the size of the external antenna (dipole antenna) and to realize a small-sized dipole antenna 1002 having both horizontal polarization and vertical polarization when transmitting while performing diversity. In addition to making impedance matching between the antenna and the circuit easy by impedance conversion, the antenna current flowing to the ground plane 101 can be suppressed by the balance-unbalance conversion circuit 103, and the influence of the hand or human body while carrying the wireless device can be suppressed. It is possible to realize a high-gain antenna with less noise.

(Embodiment 22) Embodiment 22 is an embodiment in which the mounting method of dipole antenna 1002 in Embodiment 21 is changed. FIG.
Ground plate 101, balance-unbalance conversion circuit 103, dipole antenna 1002, dipole antenna 1005
FIG. 3 is a diagram showing a configuration of a diversity antenna including The dipole antenna 1002 is used only for reception, and the dipole antenna 1005 is used for both transmission and reception. As shown in this figure, dipole antenna 1002
In the dipole antenna 1005, the axial direction of one antenna element is substantially parallel to the side surface (vertical surface) of the wireless communication terminal, and the axial direction of the other antenna element is substantially parallel to the upper surface (horizontal plane) of the wireless communication terminal. It is attached so that it becomes.

According to this configuration, it is possible to reduce the size of the external antenna (dipole antenna) and to realize a small-sized dipole antenna 1002 having both horizontal polarization and vertical polarization when transmitting while performing diversity. In addition to making impedance matching between the antenna and the circuit easy by impedance conversion, the antenna current flowing to the ground plane 101 can be suppressed by the balance-unbalance conversion circuit 103, and the influence of the hand or human body while carrying the wireless device can be suppressed. It is possible to realize a high-gain antenna with less noise.

(Twenty-third Embodiment) FIG. 25 shows two comb-shaped dipole antenna elements described in the twelfth to twenty-second embodiments arranged in parallel, and the ends of the two dipole antenna elements are short-circuited. FIG. 4 is a diagram showing a configuration of a folded dipole antenna. With the configuration shown in FIG. 25, the impedance can be stepped up, and impedance matching can be easily performed.

(Twenty-fourth Embodiment) FIG. 26 shows two comb-shaped dipole antenna elements described in the twelfth to twenty-second embodiments arranged in parallel, and an impedance at the tip of the two dipole antenna elements. FIG. 3 is a diagram showing a configuration of a folded dipole antenna loaded with. FIG.
According to the configuration shown in FIG. 6, a wider band can be achieved, and the length of the antenna can be further reduced.

(Twenty-Fifth Embodiment) FIG. 27 is a diagram showing a configuration of a dipole antenna in which the comb-shaped dipole antenna element described in the twelfth to twenty-second embodiments is formed by a spiral antenna element. . With the configuration shown in FIG. 27, the length of the antenna element can be further reduced.

(Twenty-Sixth Embodiment) FIG. 28 shows a folded dipole antenna in which two helical dipole antenna elements described in the twenty-fifth embodiment are arranged in parallel and the ends of the two antenna elements are short-circuited. FIG. With the configuration shown in FIG. 28, the same effects as in the twenty-fifth embodiment can be obtained, and the length of the antenna element can be further reduced as compared with the twenty-fifth embodiment.

(Twenty-Seventh Embodiment) FIG. 29 shows a folded dipole antenna in which two spiral dipole antenna elements described in the twenty-fifth embodiment are arranged in parallel, and impedance is loaded at the tips of the two antenna elements. FIG. With the configuration shown in FIG. 29, a wider band can be achieved, and the length of the antenna element can be further reduced as compared with the twenty-sixth embodiment.

(Embodiment 28) FIG. 30 shows that a comb-shaped dipole antenna 1002 is mounted on a circuit board 300.
FIG. 2 is a diagram showing a configuration of a wireless communication terminal built-in antenna arranged in a pattern on 1. According to this configuration, since the dipole antenna 1002 and the circuit board 3001 are integrated, stable characteristics can be obtained.

(Embodiment 29) FIG. 31 shows a case in which a dipole antenna 1002 formed in a comb blade shape is
FIG. 11 is a diagram showing a configuration of a wireless communication terminal built-in antenna arranged in a pattern 02. According to this configuration, since a space for providing the dipole antenna 1002 is not required, the communication terminal can be downsized.

It should be noted that Embodiments 12 to 29
The dipole antenna 1002 shown in (1) does not need to have a comb-blade shape, and can take a linear shape according to the size and frequency of a radio used.

[0166]

As described above, according to the present invention,
The loop surface of the antenna element is provided so as to be substantially perpendicular to the human body, and the perimeter of the antenna element is provided to be substantially equal to or less than one wavelength of the received wave, and impedance matching between the antenna element and the feeding means is provided. Therefore, it is possible to provide a high gain built-in antenna for a wireless communication terminal which is less affected by a human body.

Further, since the power is fed to the dipole antenna via the balun conversion circuit having an impedance conversion function, it is possible to provide a high gain built-in radio communication terminal antenna which is less affected by the human body. .

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing actually measured values of reception characteristics of the built-in antenna for a wireless communication apparatus according to Embodiment 1 in a call state;

FIG. 3 is a schematic diagram showing a configuration of a wireless communication terminal built-in antenna according to a second embodiment;

FIG. 4 is a schematic diagram showing a configuration of a wireless communication terminal built-in antenna according to a third embodiment;

5A is a schematic diagram illustrating a configuration of a first built-in antenna for a wireless communication terminal according to a fourth embodiment. FIG. 5B is a diagram illustrating a configuration of a second built-in antenna for a wireless communication terminal according to the fourth embodiment. Pattern diagram

FIG. 6 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to a fifth embodiment.

FIG. 7 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to a sixth embodiment.

FIG. 8 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to a seventh embodiment.

FIG. 9 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to an eighth embodiment.

FIG. 10 is a schematic diagram showing a configuration of a diversity antenna for a wireless communication terminal according to a ninth embodiment.

FIG. 11 is a schematic diagram showing a configuration of a diversity antenna for a wireless communication terminal according to a tenth embodiment.

FIG. 12 is a schematic diagram illustrating a configuration of a diversity antenna for a wireless communication terminal according to an eleventh embodiment.

FIG. 13 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 12 of the present invention.

FIG. 14 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 13 of the present invention.

FIG. 15 is a diagram showing measured values of reception characteristics of the built-in antenna for a wireless communication terminal according to Embodiment 12 in a call state.

FIG. 16 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 14 of the present invention.

FIG. 17 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 15 of the present invention.

FIG. 18 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 16 of the present invention.

FIG. 19 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 17 of the present invention.

FIG. 20 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 18 of the present invention.

FIG. 21 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 19 of the present invention.

FIG. 22 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 20 of the present invention.

FIG. 23 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 21 of the present invention.

FIG. 24 is a schematic diagram showing a configuration of a built-in antenna for a wireless communication terminal according to Embodiment 22 of the present invention.

FIG. 25 is a schematic diagram showing a configuration of a dipole antenna element in a built-in antenna for a wireless communication terminal according to Embodiment 23 of the present invention.

FIG. 26 is a schematic diagram showing a configuration of a dipole antenna element in a built-in antenna for a wireless communication terminal according to Embodiment 24 of the present invention.

FIG. 27 is a schematic diagram showing a configuration of a dipole antenna element in a built-in antenna for a wireless communication terminal according to Embodiment 25 of the present invention.

FIG. 28 is a schematic diagram showing a configuration of a dipole antenna element in a built-in antenna for a wireless communication terminal according to Embodiment 26 of the present invention.

FIG. 29 is a schematic diagram showing a configuration of a dipole antenna element in a built-in antenna for a wireless communication terminal according to Embodiment 27 of the present invention.

FIG. 30 is a schematic diagram showing a configuration of a radio communication terminal built-in antenna in which a dipole antenna according to a twenty-eighth embodiment of the present invention is patterned and arranged on a circuit board.

FIG. 31 is a schematic diagram showing a configuration of a wireless communication terminal built-in antenna in which a comb-shaped dipole antenna according to a twenty-ninth embodiment of the present invention is arranged in a pattern on a housing case.

FIG. 32 is a schematic diagram showing a configuration of a built-in antenna used in a conventional wireless communication terminal.

FIG. 33 is a schematic diagram showing a configuration of a diversity antenna used in a conventional wireless communication device.

FIG. 34 (a) is a diagram showing reception characteristics in a free space of a planar inverted-F antenna used for a conventional wireless communication terminal. (B) Talk state of the planar inverted-F antenna used for a conventional wireless communication terminal. Diagram showing reception characteristics at the time

FIG. 35 is a schematic diagram showing a state of a conventional wireless communication terminal in a call state;

[Explanation of symbols]

101 Ground plate 102, 301, 401, 501, 601, 701, 8
01, 901 Loop antenna 103 Balance-unbalance conversion circuit 502 Reactance element 602 Variable capacitance element 702 Tuning element 703 Switching element 1001, 1003, 1004 Monopole antenna 1002, 1005 Dipole antenna 3001 Circuit board 3002 Case

Claims (33)

[Claims] 1. A grounding conductor forming a plate-like surface, one end of which is connected to the grounding conductor and the other end of which is connected to a power supply means, and a loop surface to be formed is substantially equal to a plate-like surface of the grounding conductor. An antenna element provided so as to be at a right angle and having a peripheral length of about one wavelength or less of a received wave, and impedance matching between the other end of the antenna element and the feeding means,
A built-in antenna for a wireless communication terminal, comprising: a balanced-to-unbalanced converting means for converting between a balanced signal and an unbalanced signal. 2. The built-in antenna for a wireless communication terminal according to claim 1, wherein the loop surface is provided so as not to intersect with a plate-like surface of the ground conductor. 3. The built-in antenna for a wireless communication terminal according to claim 2, wherein said loop surface is formed of surfaces orthogonal to each other. 4. The built-in antenna for a wireless communication terminal according to claim 2, wherein said antenna element includes impedance changing means for changing the impedance of said antenna element. 5. The built-in antenna for a wireless communication terminal according to claim 4, wherein said impedance changing means includes at least one reactance element. 6. The built-in antenna for a wireless communication terminal according to claim 4, wherein said impedance changing means includes at least one capacitive element. 7. The built-in antenna for a wireless communication terminal according to claim 6, wherein said impedance changing means includes at least one switching means. 8. The built-in antenna for a wireless communication terminal according to claim 2, wherein at least a part of said antenna element is formed in a comb blade shape. 9. The built-in antenna for a wireless communication terminal according to claim 2, wherein the antenna element is at least partially formed of a plate. 10. A grounding conductor forming a plate-like surface, a dipole antenna connected to the grounding conductor and the feeding means, and impedance matching between the dipole antenna and the feeding means, and a balanced signal A built-in antenna for a wireless communication terminal, comprising: a balanced-to-unbalanced conversion unit that converts between a signal and an unbalanced signal. 11. The built-in antenna for a wireless communication terminal according to claim 10, wherein the dipole antenna is provided so as not to intersect with a plate-shaped surface of the ground conductor. 12. The wireless communication terminal according to claim 10, wherein the dipole antenna is provided such that a major axis direction of the antenna element is substantially parallel to a longitudinal direction of the ground conductor. Built-in antenna. 13. The wireless communication terminal according to claim 10, wherein a major axis direction of the dipole antenna is provided substantially at right angles to a longitudinal direction of the ground conductor. Built-in antenna. 14. The built-in antenna for a wireless communication terminal according to claim 10, wherein a major axis direction of the dipole antenna is orthogonal to each other. 15. The built-in antenna for a wireless communication terminal according to claim 10, wherein said dipole antenna has an L-shaped antenna element. 16. The dipole antenna according to claim 1, wherein at least a part of the dipole antenna is formed in a comb blade shape.
An internal antenna for a wireless communication terminal according to any one of claims 0 to 15. 17. The dipole antenna according to claim 1, wherein at least a part of the dipole antenna is formed in a spiral shape.
An internal antenna for a wireless communication terminal according to any one of claims 0 to 15. 18. The folded dipole antenna according to claim 18, wherein the dipole antenna is configured by arranging two comb-shaped dipole antenna elements in parallel with each other, and has a configuration in which impedance is loaded at the tips of the two antenna elements. The built-in antenna for a wireless communication terminal according to any one of claims 10 to 15, wherein: 19. The dipole antenna is a folded dipole antenna having a configuration in which two spiral dipole antenna elements are arranged in parallel with each other, and an impedance is loaded at the tip of the two antenna elements. The built-in antenna for a wireless communication terminal according to any one of claims 10 to 15. 20. The built-in antenna for a wireless communication terminal according to claim 18, wherein said dipole antenna element includes impedance changing means for changing an impedance of said antenna element. 21. The built-in antenna for a wireless communication terminal according to claim 20, wherein said impedance changing means includes at least one reactance element. 22. The apparatus according to claim 2, wherein said impedance changing means includes at least one capacitive element.
0 built-in antenna for a wireless communication terminal. 23. The apparatus according to claim 2, wherein said impedance changing means includes at least one switching means.
0 built-in antenna for a wireless communication terminal. 24. A diversity antenna comprising the built-in antenna for a wireless communication terminal according to any one of claims 1 to 23, and an antenna different from the built-in antenna for the wireless communication terminal. Wireless communication terminal device. 25. The wireless communication terminal device according to claim 24, wherein the built-in antenna for the wireless communication terminal is used for reception, and the different antenna is used for transmission and reception. 26. The wireless communication terminal device according to claim 24, wherein the built-in antenna for the wireless communication terminal is used for transmission and reception, and the different antenna is used for reception. 27. The wireless communication terminal device according to claim 24, wherein at least a part of said different antenna is formed in a comb blade shape. 28. The system according to claim 24, wherein the different antenna is a monopole antenna.
8. The wireless communication terminal device according to any one of 7. 29. The method according to claim 24, wherein the different antenna is a helical antenna.
The wireless communication terminal device according to any one of the above. 30. The built-in antenna for a wireless communication terminal according to claim 16, wherein the dipole antenna is provided on a circuit board of a wireless terminal device. 31. The built-in antenna for a wireless communication terminal according to claim 16, wherein the dipole antenna is provided on an inner surface of a housing case of the wireless terminal device. 32. Claims 1 to 23 and 30.
32. A wireless communication terminal device comprising the wireless communication terminal built-in antenna according to claim 31. 33. A base station apparatus for performing wireless communication with the wireless communication terminal apparatus according to claim 30.