JP2009021856A - Radio device and antenna system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress interference with other internal antenna, when a rod-type antenna of a radio device is stored in a case. <P>SOLUTION: An antenna system 10 is equipped with the rod type antenna 13 which is formed into a rod shape and stored in the case of the radio device 1 that includes a case member 11, and configured to be drawn out of the case. Furthermore, the antenna system 10 has an antenna storage member 14, which is formed into a cylindrical shape and disposed on the case member 11 so as to store the rod-type antenna 13, when the rod type antenna 13 is stored in the case of the radio device 1. The antenna storage member 14 is made of, for example, resin and has a magnetic material 15 wound around its circumference into the cylindrical shape, at a position close to the root of the antenna storage member 14 and nearby a bent portion of the rod type antenna 13. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radio apparatus and an antenna apparatus, and more particularly, to a radio apparatus and an antenna apparatus that include a rod-type antenna in the configuration.

  Wireless devices such as cellular phones in recent years include not only so-called cellular mobile communication systems, but also various wireless systems (for example, wireless identification (RFID), terrestrial digital television broadcasting, wireless local area network (WLAN), Functions corresponding to the Global Positioning System (GPS) and others) are installed. This trend will continue to expand, and it is expected that wireless devices will become more versatile and multifunctional.

  Since a wireless device must house antennas required for each of these wireless systems in a small housing, interference between a plurality of antennas may be a problem. For example, for reception of terrestrial digital television broadcasting, a rod-type antenna housed inside the housing is used by being pulled out of the housing. However, when the antenna is housed inside the housing, spatial Interference with other built-in antennas close to the antenna becomes a problem.

  With respect to a rod-type antenna of a wireless device, a technique is known that attempts to reduce unnecessary electromagnetic field radiation or improve radiation efficiency using a radio wave absorber or a magnetic material (see, for example, Patent Document 1).

  The mobile phone disclosed in Patent Document 1 includes a (rod-type) antenna composed of a whip antenna and a helical antenna mainly transmitting and receiving radio waves for communication with a base station, and a metal surface as a substrate ground for the antenna. And a printed circuit board on which electronic components are mounted, a power feeding unit that supplies power to the antenna and the metal surface, and an outer case for increasing the amount of radio waves in a free space during a call It includes at least a magnetic plate made of a magnetic material, and an outer case that houses the printed board, the power feeding unit, and the magnetic plate inside.

  The printed circuit board disclosed in the above-mentioned Patent Document 1 has a multilayer structure, and the magnetic body plate is separated from the substrate ground and is located in the inner layer on the opposite side where the antenna of the printed circuit board is installed. It is configured to be embedded and disposed partly or entirely between the layers.

According to Patent Document 1 described above, since a magnetic board is embedded between arbitrary layers of a multilayer printed board included in the configuration of a mobile phone, the amount of radio waves radiated to the space during a call increases due to the effect of the magnetic board. In addition to obtaining the known effect of improving the radiation efficiency, the outer case can be made thinner by the amount that the gap where the magnetic plate is conventionally disposed is unnecessary, so that further thinning of the mobile phone can be realized. ,Are listed.
JP 2002-232316 A (2nd, 4th, 5th pages, FIG. 3)

  The prior art disclosed in Patent Document 1 described above is intended to improve radiation efficiency by reflecting electromagnetic waves from the rod-shaped antenna toward the human body when reflected by a magnetic plate when talking using a mobile phone. is there. In addition, there is a feature in the configuration of the magnetic plate that contributes to the thinning of the mobile phone. However, no consideration is given to interference with other built-in antennas that may occur when the rod-type antenna is housed in the casing of the mobile phone.

  The present invention has been made to solve the above problems, and a radio apparatus and an antenna capable of suppressing interference with other built-in antennas when the rod-type antenna of the radio apparatus is housed inside the casing of the radio apparatus. An object is to provide an apparatus.

  In order to achieve the above object, a wireless device according to the present invention is configured to be formed in a housing, a rod shape, housed inside the housing, and drawn out of the housing, and A rod-type antenna having a bent portion and a cylindrical shape are formed, and are arranged so as to accommodate the rod-type antenna when the rod-type antenna is accommodated inside the housing. And an antenna housing member formed by winding a magnetic material around the cylindrical shape at a portion located in the vicinity of the bent portion when the rod type antenna is housed inside the housing. It is characterized by.

  The antenna device according to the present invention is configured such that, in an antenna device provided in a wireless device, the antenna device is formed in a rod shape and is housed inside the housing of the wireless device and can be pulled out of the housing. And a rod-shaped antenna having a bent portion and a cylindrical shape, and the rod-shaped antenna is accommodated when the rod-shaped antenna is accommodated inside the housing. And an antenna housing member formed by winding a magnetic material around the cylindrical shape at a portion located near the bent portion when the rod-shaped antenna is housed inside the housing. It is characterized by having.

  According to the present invention, the rod-type antenna is shielded by interposing a magnetic material between a portion of the rod-type antenna of the wireless device having a characteristic shape and another antenna, thereby shielding the rod-type antenna of the housing of the wireless device. When housed inside, interference with other built-in antennas can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In addition, when referring to the following figures, up, down, left, right, horizontal, vertical (vertical) means up, down, left, right, horizontal, vertical (vertical) on the paper on which the figure is represented, unless otherwise specified. . Moreover, the same code | symbol shall represent the same structure between each figure.

  FIG. 1 is a diagram illustrating a configuration of a main part of a wireless device 1 and an antenna device 10 included in the wireless device 1 according to an embodiment of the present invention. In addition to the antenna device 10, the wireless device 1 includes a housing member 11 that constitutes a part of the housing and to which the antenna device 10 is attached, and a loop antenna 12 that is attached to the housing member 11. The loop antenna 12 is an antenna for radio identification (RFID) having a frequency of 13 megahertz (MHz), for example.

  The antenna device 10 is, for example, an antenna for receiving UHF band terrestrial digital television broadcasts. The antenna device 10 is formed in a rod shape, and is housed inside the housing of the wireless device 1 (consisting of the housing member 11 and other members not shown), and can be pulled out of the housing. The rod type antenna 13 is provided.

  The rod-type antenna 13 is composed of, for example, a helical antenna element on the front end (right end) side in the pull-out direction and a monopole antenna element provided in a linear portion. FIG. 1 shows a state in which the rod-type antenna 13 is housed inside the casing of the wireless device 1 and only the tip of the helical antenna element is visible from the outside of the casing of the wireless device 1. At this time, the helical antenna element is connected to a power feeding portion 16 formed of a conductor and provided on the housing member 11, and can feed power to a radio circuit for receiving terrestrial digital television broadcasts (not shown).

  The antenna device 10 has a cylindrical shape, and an antenna disposed on the housing member 11 so as to accommodate the rod antenna 13 when the rod antenna 13 is accommodated inside the housing of the wireless device 1. A housing member 14 is provided. The antenna housing member 14 is made of, for example, resin, and a magnetic material 15 is wound around a cylindrical shape around a part of the antenna housing member 14 near the base (left end).

  The rod-type antenna 13 can be pulled out of the casing of the wireless device 1 by pinching the tip portion. FIG. 2 is a diagram illustrating the same main part of the wireless device 1 as shown in FIG. 1 and the configuration of the antenna device 10 in a state in which the rod-type antenna 13 is pulled out of the casing of the wireless device 1. . At this time, the monopole antenna element of the rod antenna 13 is connected to the power supply unit 16 and can supply power to a radio circuit for receiving terrestrial digital television broadcasts (not shown).

  The rod type antenna 13 has a bent portion 17 on the side closer to the left end. The bent portion 17 is formed in a hinge shape, for example, and the rod type antenna 13 is configured so that the direction can be arbitrarily changed with the bent portion 17 as a fulcrum (the rod type antenna 13 has an orientation represented by a broken line in FIG. Or any other orientation.)

  As shown in FIG. 1, the magnetic material 15 described above has a cylindrical shape of the antenna housing member 14 in a portion located in the vicinity of the bent portion 17 when the rod type antenna 13 is housed inside the housing of the wireless device 1. It is wound around the shape. The effect of winding the magnetic material 15 around the antenna housing member 14 will be described with reference to FIGS. 3 to 8 and a comparison with other examples.

  FIG. 3A is an external view of the antenna housing member 14 (same as shown in FIGS. 1 and 2) around which the magnetic material 15 is wound. FIG. 3B is an external view of the same antenna housing member 14b as the antenna housing member 14 except that the magnetic material is not wound. FIG. 3C is an external view of the antenna housing member 14 c which is the same as the antenna housing member 14 except that a magnetic material 15 c different from the magnetic material 15 is wound. The magnetic member 15c is a cylindrical member of the antenna housing member 14c so as to cover all portions of the rod antenna 13 that are close to the loop antenna 12 when the rod antenna 13 is housed inside the housing of the wireless device 1. It is wound around the shape.

  FIGS. 4A to 4D are views illustrating the structure and shape of the bent portion 17 of the rod antenna 13. The rod-type antenna 13 is divided into a tip-side portion 13U and a root-side portion 13L across the bent portion 17. As shown in the elevation view of FIG. 4 (a), the portion including the lower end of the tip portion 13U is formed by cutting both sides, and the groove formed in the portion including the upper end of the root portion 13L is formed in the groove. It is sandwiched and arranged. 4B is a side view as viewed from the right side in FIG. 4A. As shown in FIG. 4B, the lower end of the tip side portion 13U is the upper end groove and shaft 18 of the root side portion 13L. Are joined together.

  FIG. 4C is a diagram showing a cross section of the rod-type antenna 13 including the broken straight line “c-c” shown in FIG. 4A, and a rectangle hatched in the center is the tip side portion 13U. The cross section of the part containing a lower end is represented, and the half-moon shaped part of both sides represents the part containing the upper end of the part 13L of the root side. FIG. 4D is a diagram showing a cross section of the rod-type antenna 13 including the broken straight line “dd” shown in FIG. 4A, and a rectangle hatched in the center is the tip side portion 13U. The cross section of the part containing a lower end is represented, and the half-moon shaped part of both sides represents the part containing the upper end of the part 13L of the root side. In addition, the reduced scale of FIG.4 (c), (d) is expanded from the reduced scale of FIG.4 (a), (b).

  As shown in FIGS. 4C and 4D, the cross section of the bent portion 17 of the rod type antenna 13 has an uneven contour. When the rod type antenna 13 is housed inside the casing of the wireless device 1, the bent portion 17 having such a cross-sectional shape is close to the loop antenna 12.

  Assuming that the wireless device 1 includes the antenna housing member 14b shown in FIG. 3B instead of the antenna housing member 14, which portion of the cross-section of the bent portion 17 having the concavo-convex shape is a loop antenna. 12 (in other words, in which direction the rod-shaped antenna 13 is housed inside the housing of the wireless device 1 in a plane parallel to the cross section), the characteristics of the loop antenna 12 are affected. there's a possibility that.

  Note that the cross section of the bent portion 17 is not limited to the one having an uneven contour, and any shape other than a perfect circle (for example, an ellipse, a quadrangle, a polygon, a deformed or eccentric circle, etc.) can be used. There is a possibility of affecting the characteristics of the loop antenna 12 depending on which part is closest to the loop antenna 12.

  An example of the experimental result will be described with reference to FIG. 5 regarding the influence of the orientation in the plane parallel to the cross section of the rod antenna 13 described above on the characteristics of the loop antenna 12. In the experiment, one direction in a plane parallel to the cross section of the rod antenna 13 was set to 0 degree, and the resonance frequency of the loop antenna 12 was measured at directions of 0 degree, 45 degrees, 90 degrees, 135 degrees, and 180 degrees. . FIG. 5 is a table showing the measured values of the resonance frequency of the loop antenna 12 in each of the above-described directions for two types of samples (# 1, # 2) of the wireless device 1.

  As shown in FIG. 5, depending on whether the bent portion 17 is shielded by the magnetic material 15 or 15 c, whether the orientation in the plane parallel to the cross section of the rod type antenna 13 affects the resonance frequency of the loop antenna 12 or not. The results were divided. The reason why both the samples # 1 and # 2 have values different from 13.56 MHz for RFID is that the measurement is performed in a state where the absolute value of the resonance frequency has not been adjusted.

  In the case of sample # 1, when the bent portion 17 was not shielded, a change in resonance frequency of 0.0225 MHz at maximum was observed depending on the orientation in the plane parallel to the cross section of the rod type antenna 13. In the case of sample # 2, when the bent portion 17 was not shielded, a change in the resonance frequency of 0.0375 MHz at maximum was observed depending on the orientation in the plane parallel to the cross section of the rod type antenna 13.

  On the other hand, in both samples # 1 and # 2, no change in the resonance frequency of the loop antenna 12 was observed when the bent portion 17 was shielded by the magnetic material 15 or 15c. As this result shows, the influence of the orientation in the plane parallel to the cross section of the rod antenna 13 on the resonance frequency of the loop antenna 12 can be suppressed by shielding the bent portion 17 using the magnetic material 15 or 15c. it can.

  Assuming that the wireless device 1 includes the antenna housing member 14c shown in FIG. 3C instead of the antenna housing member 14, the range in which the magnetic material 15c is close to the loop antenna 12 is longer than that of the magnetic material 15. Therefore, the influence on the inductance characteristics of the loop antenna 12 may be increased.

  An example of the experimental result will be described with reference to FIGS. 6 to 8 regarding the influence on the characteristics of the loop antenna 12 when the magnetic material 15c or the magnetic material 15 is used. FIG. 6 is a diagram illustrating the configuration of the experimental model of the wireless device 1. The experimental model of the wireless device 1 includes a communication antenna 20 disposed in the vicinity of the loop antenna 12. The communication antenna 20 is, for example, an antenna for cellular mobile communication, and is connected to a communication radio circuit (not shown) via a power feeding unit 21. The other configuration is as shown in FIG.

  FIG. 7 shows an experimental model of the wireless device 1 having the configuration shown in FIG. 6, in which an antenna housing member 14c wound with a magnetic material 15c is used instead of the antenna housing member 14 wound with a magnetic material 15. It is a figure showing the measurement example of the voltage standing wave ratio (VSWR) frequency characteristic of the communication antenna 20, and a corresponding Smith diagram. The horizontal axis in the figure represents a frequency in the range of 500 MHz to 2500 MHz in 200 MHz steps. The vertical axis in the figure represents VSWR values from 1 to 11 in one step.

  The radiation efficiency of the communication antenna 20 measured at the same time is -8.6 dB, which is not a good value. As shown in FIG. 7, this is because a parasitic resonance point outside the design is generated around a frequency of 900 MHz. Such a parasitic resonance point is because the influence on the inductance characteristics of the loop antenna 12 is increased by using the magnetic material 15c.

  FIG. 8 shows the VSWR frequency characteristic of the communication antenna 20 and the corresponding Smith diagram in the experimental model of the wireless device 1 having the configuration shown in FIG. 6 (using the antenna housing member 14 wound with the magnetic material 15). It is a figure showing the example of a measurement. The horizontal and vertical axes in the figure are the same as those in FIG.

  The radiation efficiency of the communication antenna 20 measured at the same time was −5.6 dB, which was an improvement of 3 dB compared to the measurement example of FIG. This is because, as shown in FIG. 8, a parasitic resonance point does not occur before and after the frequency of 900 MHz, and the magnetic material 15 in which the shielding portion of the rod type antenna 13 is limited to the magnetic material 15c is used. It is an effect.

  According to the embodiment of the present invention described above, when the rod-type antenna of the wireless device is housed inside the housing of the wireless device, the magnetic material in which the portion including the bent portion of the rod-shaped antenna is wound around the antenna housing member. By shielding with, interference with other built-in antenna can be suppressed.

  In the above description of the embodiments, the system, shape, configuration, connection, shape, arrangement, and the like of each antenna element are merely examples, and various modifications can be made without departing from the scope of the present invention.

The figure showing the structure of the principal part of the radio | wireless apparatus which concerns on the Example of this invention, and the antenna apparatus contained in this radio | wireless apparatus. The figure showing the case where the rod type antenna is pulled out in the configuration shown in FIG. (A) is an external view of an antenna housing member according to an embodiment of the present invention, (b) is an external view of an antenna housing member on which a magnetic material is not wound, and (c) is a magnetic material wound in a longer range than (a). The external view of the rotated antenna accommodating member. (A) is an elevation view illustrating the structure and shape of the bent portion of the rod-type antenna according to the embodiment of the present invention, (b) is a side view, (c) is a sectional view, and (d) is the same ( Sectional drawing in the different cross section from (c). The table | surface of the experimental result showing the response | compatibility of the direction in the surface parallel to the cross section of the rod type antenna which concerns on the Example of this invention, and the resonant frequency characteristic of a loop antenna. The figure showing the structure of the experiment model provided with the antenna for communication of the radio | wireless apparatus which concerns on the Example of this invention. The experimental result showing the characteristic of the antenna for communication at the time of using the antenna accommodating member of FIG.3 (c) in the experimental model of FIG. The experimental result showing the characteristic of the antenna for communication at the time of using the antenna accommodating member of Fig.3 (a) in the experimental model of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Radio | wireless apparatus 10 Antenna apparatus 11 Housing | casing member 12 Loop antenna 13 Rod type antenna 13L Base part 13U Tip side part 14, 14b, 14c Antenna accommodation member 15, 15c Magnetic material 16, 21 Feed part 17 Bending part 18 Axis 20 Communication antenna

Claims (8)

A housing,
A rod-shaped antenna formed in a rod shape and housed inside the housing, configured to be pulled out to the outside of the housing, and having a bent portion;
The rod-shaped antenna is formed so as to accommodate the rod-shaped antenna when the rod-shaped antenna is housed inside the housing, and the rod-shaped antenna is disposed on the housing. A radio apparatus comprising an antenna housing member formed by winding a magnetic material around the cylindrical shape at a portion located in the vicinity of the bent portion when housed inside.   The radio apparatus according to claim 1, further comprising a loop antenna disposed inside the housing so as to be adjacent to the antenna housing member.   The radio apparatus according to claim 1, wherein the bent portion has a contour of a cross section orthogonal to a longitudinal direction of the rod-shaped antenna.   A loop type antenna disposed inside the housing so as to be adjacent to the antenna housing member, and the bent portion has a contour of a cross section perpendicular to a longitudinal direction of the rod type antenna. The wireless device according to claim 1. In the antenna device provided in the wireless device,
A rod-shaped antenna formed in a rod shape and housed inside the housing of the wireless device and configured to be pulled out to the outside of the housing, and having a bent portion;
The rod-shaped antenna is formed so as to accommodate the rod-shaped antenna when the rod-shaped antenna is housed inside the housing, and the rod-shaped antenna is disposed on the housing. An antenna device comprising: an antenna housing member formed by winding a magnetic material around the cylindrical shape at a portion located in the vicinity of the bent portion when housed inside.   The antenna apparatus according to claim 5, wherein the antenna housing member is disposed so as to be adjacent to a loop antenna disposed inside the housing.   The antenna device according to claim 5, wherein the bent portion has a contour of a cross section perpendicular to a longitudinal direction of the rod-shaped antenna.   The antenna housing member is disposed adjacent to a loop antenna disposed on the inner side of the housing, and the bent portion has a contour of a cross section perpendicular to the longitudinal direction of the rod antenna. The antenna device according to claim 5, wherein

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