JP4302501B2 - Antenna device for wireless terminal - Google Patents

Description

  The present invention relates to a radio terminal antenna device mounted on, for example, a portable television terminal.

  An antenna device mounted on a wireless terminal is generally required to be small and light. In response to such a demand, there is a conventional one that uses a human body as an antenna. Specifically, for example, an antenna circuit is provided in a door key holder, the antenna circuit and a user's hand are in contact with each other, and a human body is operated as an antenna (see, for example, Patent Document 1). In general, when the size of an antenna is less than a half wavelength, the performance is proportional to the length of the antenna. And since the human body has a height of about 1.5 (m), it is described that it operates as an effective radiation element from a frequency of about several tens (MHz).

Japanese Patent Laid-Open No. 07-042429 (first page, FIG. 1)

  However, the prior art has the following problems. The human body is a medium that is very lossy with respect to high frequencies, and radio wave radiation from the human body is small. Considering the operating environment of an antenna device in a conventional portable device, there is a problem that a loss due to a human body is large because a circuit board as a main radiation source is almost covered with a hand. In order to reduce the loss caused by the human body, it is necessary to lengthen the circuit board, which is the main radiation source, and to enlarge the portion not covered with hands. However, when the circuit board becomes long, depending on the holding state of the terminal, a situation may occur in which the hand and the antenna circuit do not contact each other.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain an antenna device for a wireless terminal that operates an antenna reliably in an antenna that operates by bringing a human body and a conductor piece into contact with each other. To do.

An antenna device for a radio terminal according to the present invention includes a dielectric casing, a conductor plate installed inside the dielectric casing and operating as a radiating element, a conductor piece provided along a side surface of the dielectric casing, A radio terminal antenna device comprising a high frequency power source for applying a high frequency voltage between a conductor plate and a conductor piece, the length of the conductor piece being a conductor on a side surface of a dielectric housing provided with the conductor piece The length of the non-installation portion is set to a length shorter than a predetermined gripping length , and the conductor strip is composed of a plurality of conductor strips provided along one or more side surfaces of the dielectric housing to be gripped. A plurality of high-frequency lines having one end connected to each of the plurality of conductor pieces; a plurality of high-frequency power lines connected to the other end of each of the plurality of high-frequency lines; and a conductor plate One of multiple high-frequency lines to apply a high-frequency voltage between In which further comprising a switch for selecting.
The antenna device for a radio terminal according to the present invention includes a dielectric casing, a conductor plate installed inside the dielectric casing and operating as a radiating element, and a conductor piece provided along a side surface of the dielectric casing. And a high frequency power supply for applying a high frequency voltage between the conductor plate and the conductor piece, wherein the length of the conductor piece is the side surface of the dielectric housing provided with the conductor piece The length of the conductor piece non-installation part is set to a length shorter than a predetermined gripping length, and the conductor piece is formed from a plurality of conductor pieces provided along one or more side surfaces of the dielectric housing to be gripped. Each of the plurality of conductor pieces, further comprising a plurality of high-frequency lines that are connected to the high-frequency power source at the other end, and the conductor pieces corresponding to the high-frequency lines are combined with the high-frequency lines. Each part of electrical length is the wave those which are an integral multiple of λ / 2 with respect to λ.

  According to the present invention, by determining the length of the conductor piece provided on the side surface of the dielectric casing so that the length of the conductor piece non-installation portion is shorter than the predetermined gripping length, The conductor piece and the human body can be reliably brought into contact without depending on the gripped position, and an antenna device for a wireless terminal that can reliably operate the antenna regardless of the gripped state can be obtained.

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

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of an antenna device for a radio terminal according to Embodiment 1 of the present invention. The radio terminal antenna device in FIG. 1 includes a dielectric casing 1 that also serves as an external casing of a radio terminal, a conductor plate 2 that is built in the dielectric casing 1 and operates as a radiating element, and a dielectric casing 1. One conductor piece 3 provided on one side surface and a high frequency power source 4 for applying a high frequency voltage between the conductor plate 2 and the conductor piece 3 are provided.

  The conductor plate 2 corresponds to a ground conductor of a circuit board in a wireless terminal and a shield case that covers the conductor, and the periphery of the conductor plate 2 is covered with a dielectric casing 1. Here, the dielectric housing 1 is a rectangular parallelepiped having the size of a general mobile phone, and in the following description, the size is height (H) 100 × width (W) 40 × depth (D) 20 mm. Assume that.

  The conductor piece 3 is disposed along the longitudinal direction of the dielectric housing 1 and is attached to one side surface of the dielectric housing 1. Furthermore, the conductor piece 3 is connected to a high-frequency power source 4 provided on the conductor plate 2 through wiring inside the dielectric casing 1.

  When using the radio terminal antenna device having the above-described configuration, the user holds the side surface of the dielectric housing 1 by hand. When the dielectric housing 1 is gripped by the user's hand, the conductor piece 3 affixed to the side surface of the dielectric housing 1 and the user's hand (that is, the human body) come into contact with each other, thereby The antenna device operates as an antenna. That is, when the conductor piece 3 comes into contact with the human body, a monopole antenna is formed in which the human body operates as a ground conductor and the conductor plate 2 serves as a radiating element, and radio waves are radiated from the current on the conductor plate 2. In this case, the antenna efficiency is improved in proportion to the length of the conductor plate 2.

  FIG. 2 is a diagram showing a state where the radio terminal antenna apparatus according to Embodiment 1 of the present invention is gripped. FIG. 2 shows a state in which the finger 5 of the user's hand is holding the lower end portion of the dielectric housing 1. On the other hand, FIG. 3 shows a state in which the upper end portion of the dielectric housing 1 is gripped with respect to FIG. That is, FIG. 2 and FIG. 3 show a case where the gripping position on one side surface of the dielectric housing 1 is extreme.

  When the user holds the radio terminal antenna device, it is considered that there are many states in which three or four fingers 5 are in contact with the side surface of the dielectric casing 1. In such a state, the length of the part where the user's finger 5 contacts along the side surface of the dielectric housing 1 is assumed to be about 40 mm (see FIGS. 2 and 3).

  The length of the region portion of the finger 5 that is assumed to be in contact with the dielectric housing 1, that is, the portion corresponding to the length of the four fingers 5 in FIGS. Is defined. The height (H) of the dielectric housing 1 is assumed to be about 100 mm.

  Furthermore, the range of the gripping position of the dielectric housing 1 that may be gripped by the user is a range from the lower end position shown in FIG. 2 to the upper end position shown in FIG. Based on these conditions, it is necessary to determine the length and position of the conductor piece 3 so that the user's finger 5 and the conductor piece 5 come into reliable contact when the user holds the dielectric housing 1. There is.

  Conductor so that the conductor piece 3 wraps to the “grip length” at any position of the “grip length” of 40 mm with respect to the side surface of the dielectric housing 1 having a height (H) of 100 mm. The length and position of the piece 3 are determined. In other words, the length and position of the conductor piece 3 is the part where the conductor piece 3 is not provided on the side surface of the dielectric casing 1 (hereinafter, this part is referred to as “conductor piece non-installation part”). ) Is shorter than the “gripping length”.

  The required length of the conductor piece 3 is also changed by changing the attaching position of the conductor piece 3. Therefore, it is considered to obtain the length of the conductor piece after specifying the position where the conductor piece 3 is attached. In the radio terminal antenna apparatus of FIGS. 2 and 3, the high-frequency power source 4 is provided in the lower part of the dielectric housing 1. Further, the conductor piece 3 is provided at the lower end portion of the dielectric casing portion 1 so as to be close to the high frequency power source 4.

  Therefore, it is considered to determine the length of the conductor piece 3 on the assumption that the conductor piece 3 is attached to the lower end portion of the dielectric casing 1. In this case, the length of the conductor piece 3 is obtained by making the length of the “conductor piece non-installation portion” shorter than the “grip length” of 40 mm in the upper portion of the dielectric casing 1. Since the height (H) of the dielectric casing is 100 mm, the conductor piece 3 may have a length exceeding 60 mm.

  Considering that the high-frequency power source 4 and the conductor piece 3 are connected using a high-frequency line, the conductor piece 3 is not limited to the lower end portion of the side surface of the dielectric casing. It can also be provided in the center. Then, next, the length of the conductor piece 3 in the case where the conductor piece 3 is provided in the central portion of the dielectric housing having a height (H) of 100 mm will be examined. In this case, the “conductor piece non-installation part” is two places, an upper part and a lower part of the dielectric casing 1. Therefore, the length of the conductor piece 3 is obtained by making the lengths of these two locations shorter than the “grip length” of 40 mm. Assuming that the lengths of these two locations are both 35 mm shorter than 40 mm, the length of the conductor piece 3 attached to the central portion of the dielectric housing 1 can be set to 30 mm.

  In the above description, the “grip length” is assumed to be 40 mm as the length of the portion gripped by the finger 5, and the height (H) of the dielectric housing is 100 mm. However, the present invention is not limited to this, and the optimum length and position of the conductor piece can be obtained for various setting conditions. For example, it is conceivable to assume the size of a child's hand or to assume that the number of fingers is one instead of four.

  According to the first embodiment, the position and length of the conductor piece provided on the side surface of the dielectric housing are appropriately selected in consideration of the length of the conductor piece non-installation portion and the gripping length of the dielectric housing. be able to. Thereby, it becomes possible to make a conductor piece and a human body contact reliably, without depending on the position where a user grasps a dielectric case. As a result, the antenna can be reliably operated when using the wireless terminal antenna device regardless of the gripping state of the user.

Embodiment 2. FIG.
FIG. 4 is a configuration diagram of the radio terminal antenna apparatus according to Embodiment 2 of the present invention. The basic configuration is the same as that of the first embodiment, and the same components as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. The following description focuses on the newly added components. In the second embodiment, the plurality of conductor pieces 3 are provided at a plurality of portions on the left and right side surfaces of the dielectric housing 1. Each of the plurality of conductor pieces 3 is connected to the switch 7 via the high-frequency line 6. Further, a high frequency power source 4 is connected between the switch 7 and the ground conductor of the conductor plate 2.

  By switching the switch 7, any one conductor piece 3 is selected from the plurality of conductor pieces 3 provided on the side surface of the dielectric housing 1. The selected conductor piece 3 is connected to the high frequency power source 4 via the switch 7 and is applied with a high frequency voltage.

  The position where the user holds the dielectric housing 1 can be in various states other than the cases shown in FIGS. For example, when the user holds the dielectric housing 1, there are cases where the right hand is used and the left hand is used. Therefore, in the second embodiment, a plurality of conductor pieces 3 are arranged on the left and right side surfaces of the dielectric casing 1.

  In the first embodiment, the length and position of one conductor piece 3 are obtained, but the same concept can be applied to a plurality of conductor pieces 3. That is, even when a plurality of conductor pieces 3 are installed on one side surface of the dielectric housing 1, the lengths of the plurality of “conductor piece non-installation portions” are shorter than the “gripping length”. Thus, the length and position of the plurality of conductor pieces 3 can be determined.

  Furthermore, the plurality of conductor pieces 3 may be provided on one side surface of the dielectric housing 1 or may be provided on a plurality of side surfaces of the dielectric housing 1. By arranging the plurality of conductor pieces 3 at appropriate positions, it is possible to create a state in which at least one of the plurality of conductor pieces 3 and the user's finger 5 are reliably in contact with various gripping states. Become.

  Next, in the configuration of FIG. 4, in order to reliably perform the operation as the antenna of the wireless terminal antenna device, the conductor piece 3 in contact with the user's finger 5 and the high frequency power source 4 are connected. It is necessary to switch the switch 7. This selection of the switching position can be realized, for example, by monitoring the power transmitted from the high-frequency power source 4 and reflected from the conductor piece 3 at the time of transmission, and will be described in detail below.

  FIG. 5 is a diagram showing the load impedance of the conductor piece 3 when the user's hand and the conductor piece 3 are not in contact with each other in Embodiment 2 of the present invention, and FIG. It is the figure which showed the load impedance of the conductor piece 3 in case the user's hand and the conductor piece 3 are contacting in the form 2. FIG. Here, FIGS. 5 and 6 are Smith charts used to schematically determine the impedance of the antenna terminal.

  The Smith chart represents the impedance represented by the XY coordinates in polar coordinates, and represents all the impedances represented by the sum of the resistance component of 0 to + ∞ and the reactance component of −∞ to + ∞. Can do. On the horizontal axis of the Smith chart, the left end represents resistance 0 and the right end represents resistance ∞. Further, on the upper semicircle side, it moves clockwise as the inductance increases, and on the lower semicircle side, it moves counterclockwise as the capacitance increases. The center of polar coordinates corresponds to reflection 0 and the outer periphery corresponds to reflection 1.

  As shown in FIG. 5, the load impedance of the conductor piece 3 when the user's hand and the conductor piece 3 are not in contact is almost in an open state. As a result, the reflection coefficient is close to 1, and most of the electric power input to the conductor piece 3 is reflected. On the other hand, as shown in FIG. 6, the load impedance of the conductor piece 3 when the user's hand and the conductor piece 3 are in contact with each other is not in an open state and has a certain value of impedance. It becomes. As a result, the reflection coefficient becomes smaller than 1, and the reflected power is reduced accordingly.

  Therefore, by monitoring the reflected power of each conductor piece 3 while sequentially switching the switch 7 and detecting the conductor piece 3 having a small reflected power, the conductor piece 3 in contact with the user's hand can be specified. A high frequency voltage is applied from the high frequency power supply 4 to the conductor piece 3 in contact with the user's hand by determining the switching position of the switch 7 at the position where the conductor piece 3 thus identified is connected. It becomes possible. Further, at the time of reception, the same result can be obtained by sequentially switching the switch 7 and specifying the conductor piece 3 having the maximum received power.

  According to the second embodiment, by arranging a plurality of conductor pieces on one or more side surfaces of the dielectric casing, the user's hand and the plurality of pieces can be obtained without depending on the gripping position of the dielectric casing by the user. Any of the conductor pieces can be reliably brought into contact. Furthermore, by individually monitoring each of the electric power reflected from the plurality of conductor pieces in accordance with switching of the switch, the conductor piece in contact with the user's hand can be easily specified. Accordingly, the antenna can be reliably operated when using the wireless terminal antenna device regardless of the gripping state of the user.

Embodiment 3 FIG.
FIG. 7 is a configuration diagram of the radio terminal antenna apparatus according to Embodiment 3 of the present invention. The basic configuration is the same as that of the second embodiment, and the same components as those of the second embodiment are denoted by the same reference numerals and description thereof is omitted. The following description focuses on the newly added components. In the second embodiment, the high frequency power supply 4 and the plurality of conductor pieces 3 are connected via the switch 7. On the other hand, in the third embodiment, all of the plurality of conductor pieces 3 are connected in parallel with the high frequency power supply 4 via the high frequency line 6. For convenience of explanation, a plurality of high-frequency lines 6 in FIG. 7 are connected to the high-frequency power source 4 via connection points 8.

  As described in the second embodiment, the impedance of the conductor piece 3 that is not in contact with the user's hand is in an open state. Therefore, the electrical length of the combined portion of the high-frequency line 6 and the conductor piece 3 is selected so as to be an integral multiple of λ / 2 with respect to the wavelength λ of the transmitted and received radio waves. When such selection is performed, the impedance when the conductor piece 3 that is not in contact with the user's hand is viewed from the connection point 8 is in an open state. Therefore, the conductor piece 3 that is not in contact with the user's hand does not affect the impedance at the connection point 8.

  Although there is a restriction that the wavelength of the radio wave to be transmitted and received is in the vicinity of λ, the impedance characteristic as described above can be obtained, so that the switch 7 interposed between the high frequency power source 4 and the plurality of conductor pieces 3 can be provided. Can be eliminated. Further, along with the necessity of the switch 7, a determination process for specifying the conductor piece 3 in contact with the user's hand is also unnecessary.

  According to the third embodiment, a plurality of conductor pieces are connected in parallel to a high-frequency power source via a high-frequency line, and the electrical length of the combined portion of the high-frequency line and the conductor piece is set to the wavelength λ of the radio wave to be transmitted and received. On the other hand, it is selected to be an integral multiple of λ / 2. Thereby, the impedance of the conductor piece which a user's hand is not contacting can be made into an open state. As a result, power can be transmitted from the high-frequency power source only to the conductor piece in contact with the user's hand, and the antenna can be reliably operated when the wireless terminal antenna device is used.

Embodiment 4 FIG.
FIG. 8 is a configuration diagram of the radio terminal antenna apparatus according to Embodiment 4 of the present invention. The basic configuration is the same as that of the first embodiment, and the same components as those of the first embodiment are denoted by the same reference numerals and description thereof is omitted. The following description focuses on the newly added components. The fourth embodiment is different from the first embodiment in that the conductor piece 3 and the high frequency power supply 4 are connected via a conductor wire 9.

  The antenna of the fourth embodiment is basically the same in that it operates when the conductor piece 3 comes into contact with the user's hand, like the antennas of the first to third embodiments. However, the radio terminal antenna apparatus from the first embodiment to the third embodiment does not operate as an antenna when the conductor piece 3 is not in contact with the user's hand. On the other hand, the antenna device for a radio terminal according to the fourth embodiment is for improving the antenna performance when the conductor piece 3 and the user's hand are not in contact.

  In FIG. 8, the conductor piece 3 and the high-frequency power source 4 are connected via a conductor wire 9. In such a configuration, the conductor wire 9 and the conductor piece 3 are selected so that the electrical length of the combined portion of the conductor wire 9 and the conductor piece 3 is about ¼ of the wavelength of the radio wave to be transmitted and received. Thereby, even when the user's hand is not in contact with the conductor piece 3, the radio terminal antenna device can operate as an antenna. The performance of the antenna in this case is improved as compared with the case where the conductor wire 9 is not provided, although the performance is deteriorated as compared with the case where the hand is in contact.

  In the above description, the conductor wire 9 shows a structure installed inside the dielectric casing 1, but the same effect can be obtained even if it is installed outside the dielectric casing 1.

  According to the fourth embodiment, the conductor length and the high-frequency power source are connected by the conductor wire, and the electrical length of the combined portion of the conductor wire and the conductor piece is about λ / 4 with respect to the wavelength λ of the transmitted / received radio wave It is selected to be. Thereby, the performance of the antenna when the user's hand is not in contact with the conductor piece can be improved.

Embodiment 5 FIG.
FIG. 9 is a configuration diagram of an earphone that is a part of the radio terminal antenna apparatus according to Embodiment 5 of the present invention. The earphone according to the fifth embodiment plays a role as an antenna of an antenna device for a wireless terminal by being connected to the wireless terminal main body, and will be described below.

  A speaker 11 is installed inside the earphone housing 10, and two parallel wires 12 are connected to the speaker 11 as power lines for transmitting audio signals. A cable 13 is connected to the earphone housing 10. Here, the parallel two wires 12 are housed in the cable 13 and have a configuration capable of being connected to the wireless terminal main body. In addition, a conductor piece 14 is arranged in a ring shape on the outer side surface of the earphone housing 10, and one of the parallel two lines 12 is connected to the conductor piece 14.

  The parallel two lines 12 in the normal earphone transmit only the audio signal, but the fifth embodiment assumes a line that can also transmit a high-frequency signal. The cable 13 is used by being connected to the wireless terminal main body. The wireless terminal main body feeds high-frequency signals and audio signals to the parallel two wires 12 inside the cable 13. The sound signal transmitted through the parallel two lines 12 is converted into sound by the speaker 11. On the other hand, the high-frequency signal transmitted through the parallel two lines 12 is transmitted to the conductor piece 14 when one of the parallel two lines 12 is connected to the conductor piece 14, and the conductor piece 14 is excited.

  The conductor piece 14 is provided in a portion that comes into contact with the inside of the ear when the earphone is used. The earphone operates as an antenna when the conductor piece 14 contacts the ear. When the conductor piece 14 comes into contact with the ear, a high-frequency current flowing in the same phase on the parallel two wires 12 is induced, and a monopole antenna is formed in which the human body operates as a ground conductor and the parallel two wires 12 operate as a radiating element. That is, the parallel two wires 12 housed in the cable 13 function the same as the conductor plate 2 in the first embodiment.

  When a high frequency signal is transmitted into the speaker 11, a loss occurs. Therefore, means for blocking the high frequency signal is required inside the speaker 11. This can be easily realized by using an inductor.

  According to the fifth embodiment, an audio signal and a high frequency signal are transmitted by connecting one of the two parallel wires to the conductor piece using the earphone provided with the conductor piece. Thereby, a human body and a conductor piece can be made to contact reliably, and it becomes possible to ensure the stable operation | movement of an antenna by using an earphone.

  In the above description, the position and length of the conductor piece 3 are determined by paying attention only to the length direction. However, the same idea can be applied to a two-dimensional region that takes into account both the length and the width. Based on the region of the “conductor piece non-installation portion” and the “grip region” having the length and width, the dielectric It is also possible to determine the length, width and position of the conductor piece 3 provided on the side surface of the body housing 1.

  In addition, the arrangement location of the conductor piece 3 is not limited to the left and right side surfaces of the dielectric housing 1, and can be disposed on the side surface corresponding to the front surface or the back surface of the dielectric housing 1. In addition, a plurality of buttons are usually installed in the wireless terminal, but it is also possible to arrange the conductor piece 3 on these buttons.

It is a block diagram of the antenna apparatus for radio | wireless terminals which concerns on Embodiment 1 of this invention. It is the figure which showed the state by which the antenna apparatus for radio | wireless terminals which concerns on Embodiment 1 of this invention was hold | gripped. FIG. 3 is a diagram showing a state where the upper end portion of the dielectric housing 1 is gripped with respect to FIG. 2. It is a block diagram of the antenna apparatus for radio | wireless terminals which concerns on Embodiment 2 of this invention. It is the figure which showed the load impedance of the conductor piece 3 in case the user's hand and the conductor piece 3 are not contacting in Embodiment 2 of this invention. It is the figure which showed the load impedance of the conductor piece 3 in case the user's hand and the conductor piece 3 are contacting in Embodiment 2 of this invention. It is a block diagram of the antenna apparatus for radio | wireless terminals which concerns on Embodiment 3 of this invention. It is a block diagram of the antenna apparatus for radio | wireless terminals which concerns on Embodiment 4 of this invention. It is a block diagram of the antenna apparatus for radio | wireless terminals which concerns on Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Dielectric housing | casing, 2 conductor board, 3 conductor pieces, 4 high frequency power supply, 6 high frequency track, 7 switch, 9 conductor wire, 12 parallel 2 wires, 14 conductor piece.

Claims (2)

A dielectric housing;
A conductor plate installed inside the dielectric housing and operating as a radiating element;
A conductor piece provided along a side surface of the dielectric casing;
A radio terminal antenna device comprising: a high frequency power source that applies a high frequency voltage between the conductor plate and the conductor piece;
The length of the conductor piece is set to a length such that the length of the conductor piece non-installation portion on the side surface of the dielectric housing provided with the conductor piece is shorter than a predetermined gripping length ,
The conductor piece is composed of a plurality of conductor pieces provided along one or more side surfaces of the dielectric housing to be gripped,
A plurality of high-frequency lines having one end connected to each of the plurality of conductor pieces;
The plurality of high-frequency lines are connected between the other ends of the plurality of high-frequency lines and the high-frequency power source, and apply a high-frequency voltage between any one of the plurality of conductor pieces and the conductor plate. With a switch to select one of
An antenna device for a wireless terminal , further comprising: A dielectric housing;
A conductor plate installed inside the dielectric housing and operating as a radiating element;
A conductor piece provided along a side surface of the dielectric casing;
A high frequency power source for applying a high frequency voltage between the conductor plate and the conductor piece;
An antenna device for a wireless terminal comprising:
The length of the conductor piece is set to a length such that the length of the conductor piece non-installation portion on the side surface of the dielectric housing provided with the conductor piece is shorter than a predetermined gripping length,
The conductor piece is composed of a plurality of conductor pieces provided along one or more side surfaces of the dielectric housing to be gripped,
One end is connected to each of the plurality of conductor pieces, each of the other ends further comprises a plurality of high-frequency lines connected together to the high-frequency power source,
Each of the electrical lengths of the combined portion of the conductor piece corresponding to the high-frequency line and the high-frequency line is an integral multiple of λ / 2 with respect to the wavelength λ of the radio wave to be transmitted and received. apparatus.

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