JP2015142340A - Antenna unit having variable antenna effective length - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna unit preventing damage when fallen to the ground, and capable of coping with a wide frequency band by only one antenna.SOLUTION: The antenna unit, to be mounted inside or outside the housing of a communication device, includes: an antenna part for transmitting or receiving a radio wave; and a conductive antenna contact part, contacting to a predetermined conductive part of the antenna part, for making conduction of a high frequency signal between the antenna part and a predetermined radio circuit. The antenna unit is configured to have a variable antenna effective length by the slide of the antenna contact part to the longitudinal direction of the antenna part, in a state of electrically contacting to the antenna part. An effective length as an antenna is adjusted according to a radio wave band through which transmission or reception is made by the self-antenna unit.

Description

  The present invention relates to an antenna unit capable of adjusting an effective length of an antenna according to a band of a radio wave to be transmitted or received.

  In the prior art, there is an antenna unit of a portable terminal that can operate in a wide frequency band by combining an external antenna that can be stored at a high frequency and an external antenna and an internal antenna at a low frequency (for example, Patent Documents). 1).

  However, when using a product using an extendable external antenna as in the prior art, the external antenna may be accidentally dropped to the ground with the external antenna extended, and the external antenna may be damaged. If this is an external antenna with a protrusion shape, the stress applied when falling from the protrusion-shaped part increases, and if it is an extensible external antenna, the risk of damage when falling when extended is even greater. Become. If the external antenna is damaged, the operation performance as an antenna cannot be satisfied. In addition, in the case of communication using an external antenna as in the prior art, only two types of frequencies at the time of expansion and shortening can be handled. Therefore, for example, when a plurality of wireless circuits are mounted, it is inconvenient because a number of antennas corresponding to the number of wireless circuits must be prepared.

JP 2005-176302 A

  The present invention has been made in view of the above problems, and by preventing the antenna from projecting or expanding outside the housing, the antenna can be prevented from being damaged due to falling on the ground, and a wide frequency band can be obtained with only one antenna. It is to provide an antenna unit that can handle the above.

  In order to solve the above-described problems, the present invention provides an antenna unit that is mounted inside or outside a housing of a communication device, and an antenna unit that transmits or receives radio waves, and a predetermined portion having conductivity of the antenna unit. A conductive antenna contact portion that conducts a high-frequency signal between the antenna portion and a predetermined wireless circuit in contact with the antenna portion, and the contact structure between the antenna contact portion and the antenna portion is the antenna contact The structure is such that the effective length as an antenna is variable by sliding in the length direction of the antenna unit while the unit is in electrical contact with the antenna unit, and the band of the radio wave transmitted or received by the own antenna unit The effective length of the antenna is adjusted according to the above.

  ADVANTAGE OF THE INVENTION According to this invention, the antenna unit which can prevent the damage of the antenna by the fall to the ground, and can respond to a wide frequency band only with one antenna can be provided.

It is a structural example of the antenna part and movable part at the time of using a helical antenna. It is an example of operation | movement of a movable part at the time of using a helical antenna. It is the block diagram which showed the detail of the movable part. It is an example of a structure of the antenna part and movable part at the time of using a meander line antenna. It is an example of operation | movement of a movable part at the time of using a meander line antenna.

  Hereinafter, the embodiment of the present invention will be described by dividing into two examples of the case where a helical antenna is used and the case where a meander line antenna is used. First, an example using a helical antenna will be described.

  FIG. 1 is a configuration example of an antenna unit and a movable unit when a helical antenna is used. A helical antenna (101-A) made of a metal object, a helical antenna tip (102) that is an open portion at the tip of the helical antenna (101-A), and a movable part made of a conductor including metal ( 103-A).

  Here, the helical antenna (101-A) has a spiral shape, and the directivity differs depending on the relationship between the diameter of one turn of the helical portion and the interval between the turns. If the helical portion is equal to or longer than the wavelength λ, the helical antenna (101-A) has directivity in the extending direction, and if the helical portion is sufficiently reduced, it is vertically polarized like a monopole antenna. It has a characteristic that becomes omnidirectional. When used in a cordless telephone or the like, it is desirable to use an antenna that is omnidirectional with respect to vertical polarization.

  The antenna tip (102), which is the tip of the helical antenna (101-A), is not in contact with the movable part (103-A) and is always open.

  FIG. 2 is an example of the operation of the movable part when a helical antenna is used. The range of movement of the helical antennas (101-B), (101-C) and the movable parts (103-B), (103-C) within the casings (104-A), (104-B) It is. The housing (104-A) is in a state where the helical antenna (101-B) and the movable portion (103-B) are contracted, and the housing (104-B) is in a state where the helical antenna (101-C) and the movable portion (103 -C) shows a stretched state.

  The state in which the helical antenna (101-B) and the movable part (103-B) shown in the housing (104-A) contract is the maximum usable frequency, and the helical antenna shown in the housing (104-B). The state where (101-C) and the movable part (103-C) are extended corresponds to the lowest usable frequency. By combining the lengths of the helical antennas (101-A to 101-C) and the movable portions (103-A to 103-C), a usable frequency range can be obtained during expansion and contraction.

  Here, the length of the antenna differs depending on the frequency to be used, and the required antenna length can be obtained from the wavelength of the frequency. The calculation formula is: wavelength λ [m] = light speed c [m / s] / frequency f [ Hz], and a length that is 1/4 times the wavelength λ [m] obtained from the calculation formula is a length necessary for the antenna.

  FIG. 3 is a configuration diagram showing details of the movable part. The details of the movable part (103) are shown. In order to connect to the helical antenna (101), the antenna contact part (105) made of a highly conductive conductor that conducts a high-frequency signal is matched with the impedance of the antenna. Impedance matching unit (106), an operation unit (107) for arbitrarily operating the movable unit (103) from the outside of the housing (104), and a coaxial corresponding to flexible movement of the movable unit (103) It comprises a cable (108), a board connector (109) for connecting the helical antenna (101) and the board of the housing (104).

  The antenna contact portion (105) is a portion that forms an antenna together with the helical antenna (101) in the movable portion (103), and the antenna contact portion (105) is combined with the antenna contact portion (105). The antenna length is a usable frequency.

  The antenna contact portion (105) is not limited to a high rigidity and may be configured using a highly flexible shape as long as it is a conductor and has a low electrical resistance.

  Here, it is assumed that the operation portion (107) can be operated from the outside of the housing (104), and the convex portion does not protrude when the operation portion (107) is incorporated in the housing (104).

  Next, an embodiment using a meander line antenna will be described.

  FIG. 4 is a configuration example of an antenna unit and a movable unit when a meander line antenna is used. A meander line antenna (110-A) composed of a metal object, a meander line antenna tip portion (111) that is an open portion at the leading end portion of the meander line antenna (110-A), and a movable portion composed of a conductor containing metal. Part (103-E) is shown. The meander line antenna (110) is formed into a crank shape by bending a conducting wire.

  FIG. 5 is an example of the operation of the movable part when a meander line antenna is used. The movable range of the meander line antennas (110-B) and (110-C) and the movable parts (103-F) and (103-G) in the casings (104-C) and (104-D) is shown. Is. The housing (104-C) is in a state where the meander line antenna (110-B) and the movable portion (103-F) are contracted, and the housing (104-D) is connected to the meander line antenna (110-C). The movable part (103-G) has shown the extended state.

  A state where the meander line antenna (110-B) and the movable part (103-F) shown in the housing (104-C) contracts becomes the maximum usable frequency, and the meander shown in the housing (104-D). The state in which the line antenna (110-C) and the movable part (103-G) are extended corresponds to the lowest usable frequency. By combining the lengths of the meander line antennas (110-A to 110-C) and the movable parts (103-E to 103-G), a usable frequency range can be obtained during expansion and contraction.

    Here, the required antenna length can be similarly obtained from the wavelength λ [m] = light velocity c [m / s] / frequency f [Hz], and a value of ¼ is the antenna length.

  Each embodiment has been described above.

  In this embodiment, by fixing the helical antenna (101) and the meander line antenna (110) inside the housing (104), it is possible to prevent the antenna from being damaged when dropped and to improve the quality of the product. Become. In addition, by changing the length of the antenna easily by the movable part (103), the usable frequency is changed and the user needs to make fine adjustments due to the influence of the surrounding environment. Can be arbitrarily adjusted.

Further, the present invention is not limited to the embodiment described above, and can be modified without departing from the spirit. For example, although the present embodiment has been described with the configuration in which the antenna is fixed inside the housing (104), a structure in which the antenna is mounted outside in a shape that does not protrude.

  101: Helical antenna, 102: Helical antenna tip, 103: Movable part, 104: Housing, 105: Antenna contact part, 106: Impedance matching part, 107: Operation part, 108: Coaxial cable, 109: Board connection connector, 110: meander line antenna, 111: tip of meander line antenna

Claims (1)

In the antenna unit that is mounted inside or outside the housing of the communication device,
An antenna unit that transmits or receives radio waves; and a conductive antenna contact unit that contacts a predetermined conductive portion of the antenna unit and conducts a high-frequency signal between the antenna unit and a predetermined wireless circuit; , And
The contact structure between the antenna contact portion and the antenna portion is variable in effective length as an antenna by sliding in the length direction of the antenna portion in a state where the antenna contact portion is in electrical contact with the antenna portion. An antenna unit having a variable antenna effective length, wherein the antenna effective length is adjusted according to a band of a radio wave transmitted or received by the antenna unit.

Images