JP2015154328A - Antenna device and radio communication apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna device which can be relatively small-sized in comparison with a wavelength of a subjected frequency.SOLUTION: A balun 400 is provided between a feeding point 300 of a circuit board 310 in which a transceiver circuit is provided, and first and second antenna elements 302-1 and 302-2. The first antenna element 302-1 and the second antenna element 302-2 operate as dipole antennas. The circuit board 310 between the first antenna element 302-1 and the second antenna element 302-2 is floating in a high frequency manner by means of the balun 400.

Description

  The present invention relates to an antenna device and a wireless communication device for wireless communication.

  2. Description of the Related Art Conventionally, for example, in cellular phones, antenna structures for dealing with different frequency bands in order to perform communication for multibands (for example, 800 MHz band, 1.5 GHz band, and 2 GHz band) have been proposed. ing.

  For example, Patent Document 1 discloses an antenna device including a dielectric substrate, a feeding unit, a monopole antenna, a parallel circuit, an antenna element, and a parasitic element as a multi-frequency shared antenna device. In this antenna device, the monopole antenna operates alone at the frequency f1 and suppresses leakage current to the dielectric substrate. The monopole antenna, the parallel circuit, and the antenna element have a length that is about 1/4 of the wavelength of the frequency f2, resonates at the frequency f2, and operates as an antenna device at the frequency f2. Since the monopole antenna used at the frequency f1 is also used at the frequency f2, the antenna device can be downsized.

  On the other hand, a lower frequency such as a 200 MHz band is used as a frequency band for multimedia broadcasting. Since the ½ wavelength in the 200 MHz band is 70 cm or more, it is required that the antenna on the mobile body side when carrying out mobile communication in such a frequency band should be small in size to be carried.

  In order to meet such demands, Patent Document 2 discloses a folding antenna device that is compact when carried and can receive radio waves in a plurality of frequency bands when actually used as an antenna. In this antenna device, a first housing to which a first antenna is attached, a second housing to which a second antenna is attached, and a hinge portion that can fold these two housings are provided. The first and / or second antenna takes two states, a state in which the antenna is housed in the housing and a state in which the antenna is extended from the housing, receives the first frequency band in the housed state, and is expanded. In this state, radio waves in the second frequency band can be received.

  Furthermore, in recent years, with the tightening of frequencies, as one means for improving frequency utilization efficiency, there is an effective utilization of a frequency band that is free in space and time.

  Further, Non-Patent Document 1 discloses a wideband discrete OFDM (Orthogonal Frequency Division Multiplexing) communication method as one of methods for effectively using frequency bands.

  In general, a frequency band of 1 GHz or less is suitable for wireless communication from the viewpoint of propagation characteristics. As frequency bands used by the mobile communication system, frequencies of 700 MHz band and 900 MHz band have been added by frequency reorganization associated with the stoppage of analog terrestrial television broadcasting.

  However, it is very difficult to secure a new vacant frequency band that can accommodate high-speed wireless transmission in a frequency band of 1 GHz or less.

  On the other hand, when the actual frequency usage state of 1 GHz or less is seen, there is a discrete but vacant frequency band between the bands of the existing communication systems. Although the usage situation fluctuates temporally and geographically, there is a possibility that a bandwidth capable of realizing high-speed wireless transmission can be secured if these small vacant frequency bands are flexibly bundled and used.

  For this purpose, unlike existing communication systems, it is necessary to develop a communication technique that can flexibly cope with transmission band division and transmission in a plurality of frequency bands. The OFDM (Orthogonal Frequency Division Multiplexing) communication method is a method of multiplexing and transmitting information on a plurality of relatively narrow-band carriers (subcarriers) orthogonal to each other. In a transceiver, IFFT (Inverse Fast By performing digital signal processing using Fourier Transform (Fast Fourier Transform) / FFT (Fast Fourier Transform), transmission band division is relatively easy. Using this OFDM method, discrete OFDM (Non-Contiguous OFDM) that realizes high-speed transmission by arranging subcarriers in free frequency bands that exist discretely as described above and bundling those subcarriers to form a transmission line ) Technology is being considered.

  FIG. 15 is a diagram showing the basic concept of such discrete OFDM.

  In discrete OFDM, communication can be performed without interference by arranging subcarriers so as not to interfere with signals of other existing communication systems.

  As a conventional antenna used in a frequency band of 1 GHz or less, for example, there is a biconical antenna. With such an antenna, for example, a signal of 200 MHz to 1000 MHz can be transmitted and received. However, also here, the maximum size is 440 mm, and miniaturization is difficult.

Japanese Patent Application Laid-Open No. 2006-67234 Japanese Patent Application Laid-Open No. 2014-3549

Takashiki Keiji, Hasegawa Goro and Shibata Tatsuo, "Study on Wideband Discrete OFDM Technology", IEICE Tech. 113, no. 57, SR2013-16, pp. 83-89, May 2013

  That is, in the terminal device that is a mobile station, although it is necessary to perform reception or transmission of a frequency of about 200 to 300 MHz, it is not easy to downsize the antenna as described above. .

  In recent years, tablet computers have been frequently used as portable communication terminals. Here, at the frequency of the 200 MHz band as described above, the ½ wavelength exceeds twice the length of the long side of a normal tablet computer. On the other hand, a tablet-type computer requires a thin housing as much as possible from the viewpoint of ease of use, and it is difficult to provide a folding structure and a rod antenna as disclosed in Patent Document 2 in terms of device design. .

  That is, the demand for small-sized wireless communication devices such as mobile phones continues to increase, and there are wireless systems using various frequencies. A small wireless communication device has a small volume, and an area where an antenna space can be installed is limited. Furthermore, when the size of the small wireless device itself is too small with respect to the wavelength of the frequency to be used, there is a problem that it is difficult to ensure the antenna characteristics.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an antenna device that can be relatively miniaturized as compared with the wavelength of the target frequency. .

  Another object of the present invention is to provide an antenna device capable of downsizing a wireless communication device.

  According to one aspect of the present invention, an antenna device for a wireless communication device having a housing, the conductive component group extending in the long side direction and the short side direction in the housing, and the conductive component group A circuit board on which at least a part of the circuit board is mounted, a power feeding portion provided on the circuit board, an antenna length longer than the long side of the circuit board, and a dipole antenna having a shape extending from the long side direction to the short side direction And a balanced-unbalanced converter provided between the power feeding unit and the antenna, and the dipole antenna receives power from the power feeding unit via the balanced-unbalanced converter at a substantially central portion.

  Preferably, the power feeding unit is provided on the short side of the circuit board, and the dipole antenna is at least a predetermined distance from the circuit board and extends in the short side direction of the circuit board along the first long side direction of the circuit board. A circuit extending along the second long side direction of the circuit board at least a predetermined distance from the first antenna element and the circuit board, which bends and extends at one corner and is coupled to the balanced-unbalanced converter A second antenna element that bends and extends at the other corner in the short side direction of the substrate and is coupled to the balanced-unbalanced converter.

  Preferably, the first and second antenna elements are metal layers formed on the outer surface of the housing.

  According to another aspect of the present invention, a wireless communication device includes a housing, a conductive component group extending in a long side direction and a short side direction in the housing, and a conductive component provided in the housing. A circuit board on which at least a part of the group is mounted; a transmission / reception unit provided on the circuit board for performing transmission processing or reception processing of a signal for wireless communication; a power feeding unit provided on the circuit board; A dipole antenna having an antenna length longer than the long side and having a shape extending from the long side direction to the short side direction, and a balanced-unbalanced converter provided between the power feeding unit and the antenna, The dipole antenna receives power from the power feeding unit through a balanced-unbalanced converter at a substantially central portion.

  Preferably, the power feeding unit is provided on the short side of the circuit board, and the dipole antenna is at least a predetermined distance from the circuit board and extends in the short side direction of the circuit board along the first long side direction of the circuit board. A circuit extending along the second long side direction of the circuit board at least a predetermined distance from the first antenna element and the circuit board, which bends and extends at one corner and is coupled to the balanced-unbalanced converter A second antenna element that bends and extends at the other corner in the short side direction of the substrate and is coupled to the balanced-unbalanced converter.

  Preferably, the first and second antenna elements are metal layers formed on the outer surface of the housing.

  According to the present invention, the antenna device can be relatively downsized as compared with the wavelength of the target frequency.

  Also, the wireless communication device can be relatively downsized as compared with the wavelength of the target frequency.

It is a figure for demonstrating the structure of the dipole antenna of this Embodiment. It is a conceptual diagram which shows the ideal state by providing the balun 400 about the dipole antenna 302. FIG. It is a conceptual diagram which shows the structure of a monopole antenna. It is a figure which shows the simulation result of the frequency dependence of the voltage standing wave ratio (VSWR) of the monopole antenna shown in FIG. It is a conceptual diagram which shows the problem of monopole antenna 302-1 '. It is a conceptual diagram for demonstrating the antenna characteristic of a monopole antenna and an ideal dipole antenna. It is a conceptual diagram for demonstrating the operation state of the actual dipole antenna 302-1. It is a figure which shows the simulation result of the frequency dependence of the voltage standing wave ratio (VSWR) of the monopole antenna 302-1 'which operate | moves in the state close | similar to reality. It is a figure which shows the simulation result of the frequency dependence of the voltage standing wave ratio (VSWR) when the dipole antenna 302 operate | moves in an ideal state. It is a figure which shows the simulation result of the frequency dependence of the voltage standing wave ratio (VSWR) when the dipole antenna 302 operate | moves in the state where the circuit board 310 exists. 3 is a circuit diagram showing an example of a configuration of a balun 400. FIG. 1 is a diagram illustrating an appearance of a wireless communication device 1000. FIG. It is a conceptual diagram which shows the structure which provides the 1st antenna element 302-1 and the 2nd antenna element 302-2 about the radio | wireless communication apparatus 1000. FIG. It is the elements on larger scale of the area | region PB in the XIII-XIII 'cross section of FIG.13 (b). It is a figure which shows the basic concept of discrete OFDM.

  Hereinafter, a wireless communication device using the antenna device according to the embodiment of the present invention will be described as an example. In the following embodiments, components and processing steps given the same reference numerals are the same or equivalent, and the description thereof will not be repeated unless necessary.

  FIG. 1 is a diagram for explaining a configuration of a dipole antenna according to the present embodiment.

  In addition, the dimension in a figure is an example and is a thing when the frequency band of 200-300 MHz is assumed as object. The dimensions are not necessarily limited to those shown.

  FIG. 1 is a conceptual diagram illustrating a configuration in which an antenna device 100 that operates as a λ / 2 dipole antenna is formed on a circuit board 310 having a thickness of 1 mm and an area of 150 × 200 mm.

  The circuit board 310 is provided in the housing of the wireless communication apparatus, and as shown in FIG. 1, basically, the upper surface shape is basically assumed to be a rectangular shape. However, as long as it is a substantially rectangular shape, a part of the rectangle may be missing, or a part may protrude. Further, there may be a plurality of circuit boards, which may form a substantially rectangular shape as a whole, or the circuit board and another conductive component group provided outside the circuit board may be integrated into one approximately one. A rectangular shape may be formed. On the circuit board, an electronic circuit or an electronic component is mounted as a part of the conductive component group. Examples of the other conductive component group include a camera, a speaker, a microphone, a metal chassis, a power switch, and various types. Such as a sensor. In this way, the circuit board in the housing and the other conductive component group are electrically connected or capacitively coupled, so that, as a whole, when viewed from the antenna side, substantially in terms of high frequency. Will show an integral behavior. In such a substantially rectangular shape, a direction along the long side is referred to as a “long side direction”, and a direction along the short side is referred to as a “short side direction”. Therefore, for example, “P extends along the long side direction” means that P has a shape along the same direction as the long side direction regardless of whether or not P exists on the substrate. It means that you are doing.

  The antenna device 100 extends at a predetermined distance (for example, 20 mm) from the circuit board 310 and bends at one corner in the short side direction of the circuit board 310 along the first long side direction of the circuit board 310. The first antenna element 302-1 and the circuit board 310 are spaced apart from each other by a predetermined distance (for example, 5 mm) and bent along the long side direction of the circuit board 310 at the other corner in the short side direction of the circuit board 310. And a second antenna element 302-2 extending. The first antenna element 302-1 and the second antenna element 302-2 constitute a dipole antenna 302.

  A power feeding unit 300 for the dipole antenna 302 is provided in the vicinity of the short side of the circuit board 310. Here, it is assumed that the power feeding unit 300 is provided on the short side and near the long side. One end of the first antenna element 302-1 and the second antenna element 302-2 are coupled to the power feeding unit 300 via the balanced-unbalanced converter 400. In the following, the balanced-unbalanced converter is simply referred to as “Balun”. Here, on the circuit board 310, a transmission / reception circuit for performing transmission processing (encoding processing, modulation processing, etc.) and reception processing (demodulation processing, decoding processing, etc.) in wireless communication is provided. On the circuit board 310, since the signal is transmitted in an unbalanced state, a balun 400 is provided between the circuit board 310 and the dipole antenna 300 operating in the balanced state.

  Here, at least the first antenna element 302-1 may be provided on the circuit board 310. Regarding the point of forming the antenna on the substrate, for example, the above-mentioned Patent Document 1 also discloses. Or the structure provided in the outer surface of the housing | casing of a radio | wireless communication apparatus may be sufficient as the 1st antenna element 302-1 and the 2nd antenna element 302-2 so that it may demonstrate later.

  Although it does not specifically limit as a board | substrate, For example, a low-temperature co-fired ceramic substrate, a glass epoxy board | substrate, a composite board | substrate etc. can be used, As mentioned above, the circuit of a radio | wireless communication apparatus is formed on a board | substrate.

  In FIG. 1, the hatched area is actually an area where an electronic circuit including an RF circuit is formed, but functions as a ground when viewed from the antenna element.

  FIG. 2 is a conceptual diagram showing an ideal state of the dipole antenna 302 due to the provision of the balun 400.

  That is, if balanced-unbalanced conversion is performed by the balun 400 and the dipole antenna 302 can be said to be in a completely balanced state, the circuit board 310 is effectively electrically grounded for the dipole antenna 302. The first antenna element 302-1 and the second antenna element 302-2 do not function, and one of them operates as if it is the other ground.

  As a result, when the circuit board 310 functions as the ground, the distance between the first antenna element 302-1 and the second antenna element 302-2 is 20 mm and 5 mm, respectively. In this state, it is equivalent to having an interval of 175 mm.

  As a result, it is possible to effectively reduce capacitive coupling between the first antenna element 302-1 and the second antenna element 302-2.

  In addition, it is good also as a structure which shortens physical length by inserting a coil (a loading coil, an extension coil) in the middle of an antenna element.

(Contrast of dipole antenna and monopole antenna)
In order to examine the effectiveness of the dipole antenna 302 shown in FIG. 1 and FIG. 2, only the first antenna element 302-1 ′ is provided and compared with a monopole antenna that operates with the circuit board 310 as the ground. explain.

  FIG. 3 is a conceptual diagram showing the configuration of the monopole antenna.

  The monopole antenna 302-1 'is fed from a feeding unit 300' on the circuit board 310 '. It is assumed that the monopole antenna 302-1 'and the circuit board 310' have a clearance (spatial distance) of 20 mm.

  The outer dimensions of the circuit board 310 ′ are equivalent to the outer dimensions of the circuit board 310.

  FIG. 4 is a diagram showing a simulation result of the frequency dependence of the voltage standing wave ratio (VSWR) of the monopole antenna shown in FIG.

  As shown in FIG. 4, the resonance frequency is 340 MHz, and VSWR is about 9.

  FIG. 5 is a conceptual diagram showing a problem of the monopole antenna 302-1 ′.

  First, the physical length AL of the antenna is AL = 200 mm which is substantially equal to the long side of the circuit board 310. As a result, the antenna physical length that can be secured is limited by the size of the wireless communication device.

  Second, the clearance between the monopole antenna 302-1 ′ and the circuit board 310 ′ is CL = 20 mm. As the target wavelength increases, capacitive coupling between the ground and the antenna element increases and the impedance decreases. It will be said that.

  Therefore, when the size of the wireless communication apparatus is given, it is necessary to secure a large antenna physical length and a large clearance from the ground to the antenna element when the frequency is low. Therefore, this means that the antenna volume becomes large, and it is difficult to reduce the size of the antenna.

  FIG. 6 is a conceptual diagram for explaining antenna characteristics of a monopole antenna and an ideal dipole antenna.

  FIG. 6A is a diagram schematically showing a current flowing between the antenna and the ground during the antenna operation in the monopole antenna 302-1 ′ as shown in FIG.

  In the monopole antenna 302-1 ′, currents flowing through the circuit board 310 ′ serving as the ground and the monopole antenna 302-1 ′ facing the circuit board 310 ′ are in opposite directions. For this reason, the currents flowing to each other are in opposite phases and cancel each other, and when viewed from a distance, this is equivalent to the suppression of the current flowing through the antenna, and the characteristics of the antenna deteriorate.

  FIG. 6B is a diagram schematically showing a current flowing in the antenna during the antenna operation in a state where the dipole antenna 302-1 is ideally operated as shown in FIG.

  In the dipole antenna 302-1, since the first antenna element 302-1 and the second antenna element 302-2 maintain a sufficient clearance across the feeding portion, the first antenna element 302-1 is maintained. Since the cancellation of the current flowing through the second antenna element 302-2 and the current flowing through the second antenna element 302-2 are reduced, the antenna characteristics are improved as compared with FIG.

  FIG. 7 is a conceptual diagram for explaining the operating state of the actual dipole antenna 302-1.

  Unlike the ideal state shown in FIG. 6B, actually, between the circuit board 310 and the first antenna element 302-1 and between the circuit board 310 and the second antenna element 302-2. There is capacitive coupling.

  However, since the circuit board 310 existing between the first antenna element 302-1 and the second antenna element 302-2 is in a state of floating at a high frequency, the first antenna element 302-1 and the second antenna element 302-1 The induced current induced in the circuit board 310 by the current flowing through the second antenna element 302-2 has the same phase. For this reason, current cancellation is reduced and antenna characteristics are improved as compared with FIG.

  FIG. 8 is a diagram illustrating a simulation result of the frequency dependence of the voltage standing wave ratio (VSWR) of the monopole antenna 302-1 ′ operating in a state close to reality.

  That is, the shape of the circuit board 310 is made closer to the actual shape by providing a notch or the like, and the resonance frequency is changed by providing a top load at the tip of the monopole antenna 302-1 ′. doing.

  FIG. 9 is a diagram showing a simulation result of the frequency dependence of the voltage standing wave ratio (VSWR) when the dipole antenna 302 of the present embodiment operates in an ideal state (the presence of the circuit board 310 can be ignored). It is.

  FIG. 10 is a diagram illustrating a simulation result of the frequency dependence of the voltage standing wave ratio (VSWR) when the dipole antenna 302 of the present embodiment operates in a state where the circuit board 310 is present.

  In the monopole antenna 302-1 'of FIG. 8, the resonance frequency is 240 MHz and VSWR is 9.5. In the ideal state of FIG. 9, the resonance frequency is 240 MHz and VSWR is 2.5. In the state of the present embodiment, the resonance frequency is 240 MHz and VSWR is 4.

  Therefore, the configuration of the dipole antenna 302 of this embodiment can improve the VSWR and improve the antenna characteristics as compared with the case of the monopole antenna. That is, the antenna device can be relatively downsized as compared with the wavelength of the target frequency.

  FIG. 11 is a circuit diagram showing an example of the configuration of the balun 400.

  Referring to FIG. 11, balun 400 includes an inductor L402 provided between power feeding unit 300 and first antenna element 302-1, a coupling node between inductor L402 and first antenna element 302-1 and a ground. A capacitor C402 provided between the power supply unit 300 and the second antenna element 302-2, a coupling node between the capacitor C404 and the second antenna element 302-2, and the ground. And an inductor L404 provided between the two.

  As described above, the balun 400 supplies the unbalanced input on the power feeding unit 300 side to the dipole antenna 302 side as a balanced output.

  As the balun, a narrow band balun configured with a lumped constant as shown in FIG. 11 is illustrated, but the balun is not limited to such a configuration, and the balun may be of a distributed constant type.

  FIG. 12 is a diagram illustrating an appearance of the wireless communication apparatus 1000.

  As an example, the wireless communication device 1000 is a tablet terminal, and a housing 1010 and a touch-type liquid crystal panel 1020 are provided as a display device and an input device.

  FIG. 13 is a conceptual diagram illustrating a configuration in which the first antenna element 302-1 and the second antenna element 302-2 are provided in the wireless communication apparatus 1000.

  FIG. 13B shows a state where the circuit board 310 and the like are seen through the housing 1010, and FIG. 13A is a partially enlarged view of a region surrounded by an ellipse PA in FIG. 13B. It is.

  As shown in FIG. 13A, a power feeding unit 300 is provided on a circuit board 310, and a balun 400 is provided between the power feeding unit 300 and the first antenna element 302-1 and the second antenna element 302-2. Is provided.

  In addition, as shown in FIG. 13B, the first antenna element is formed on the outer surface of the casing 1010 from the first long side of the rectangular casing 1010 to a part of the short side on the side where the balun 400 exists. 302-1 is provided. Further, the second antenna element 302-is formed on the outer surface of the housing 1010 from the second long side facing the first long side of the rectangular housing 1010 to a part of the short side on the side where the balun 400 exists. 2 is provided.

  Here, if the dimension of the circuit board 310 is, for example, 130 mm × 200 mm × 1 mm, and the outer dimension of the upper surface of the housing is 150 mm × 200 mm, the circuit board 310 and the first long side The clearance can be 20 mm.

  FIG. 14 is a partially enlarged view of the region PB in the XIII-XIII ′ cross section of FIG.

  Referring to FIG. 14, liquid crystal panel 1020 includes a surface glass 1020-1, a liquid crystal display unit and touch sensor 1020-2, and a liquid crystal holding unit and control unit 1020-3.

  Further, the circuit board 310 is supported by the housing 1010 by being fitted into a recess formed in a resin constituting the housing 1010. A mounting component 312 is mounted on the circuit board 310.

  A second antenna element 302-2 is provided on the outer surface of the housing 1010. A method for forming such an antenna element is not particularly limited. For example, the antenna element can be configured by vapor-depositing or printing a metal pattern on the outside of the housing. Such a configuration can be similarly applied to the first antenna element 302-1.

  By configuring the antenna element in this way, the distance between the circuit board 310 and the metal pattern of the antenna element can be secured without affecting the housing size. For example, in the example shown in FIG. 14, it is possible to secure 5 mm of the clearance size as described in the present embodiment.

  Embodiment disclosed this time is an illustration of the structure for implementing this invention concretely, Comprising: The technical scope of this invention is not restrict | limited. The technical scope of the present invention is shown not by the description of the embodiment but by the scope of the claims, and includes modifications within the wording and equivalent meanings of the scope of the claims. Is intended.

  DESCRIPTION OF SYMBOLS 100 antenna apparatus, 300 electric power feeding part, 302 dipole antenna, 302-1 1st antenna element, 302-2 2nd antenna element, 310 circuit board, 400 balun, 1000 wireless communication apparatus, 1010 housing | casing, 1020 liquid crystal panel.

Claims (6)

An antenna device for a wireless communication device having a housing,
In the housing, a group of conductive parts extending in the long side direction and the short side direction,
A circuit board on which at least a part of the conductive component group is mounted;
A power feeding unit provided on the circuit board;
A dipole antenna having an antenna length longer than the long side of the circuit board and having a shape extending from the long side direction to the short side direction;
A balanced-unbalanced converter provided between the feeding unit and the antenna;
The dipole antenna is an antenna device that receives power from the power feeding unit via the balance-unbalance converter at a substantially central portion. The power feeding unit is provided on the short side of the circuit board,
The dipole antenna is
At least a predetermined distance from the circuit board, and bends and extends at one corner in the short side direction of the circuit board along the first long side direction of the circuit board, and the balanced-unbalanced converter, A first antenna element to be coupled;
The balanced-unbalanced converter extends at a predetermined distance from the circuit board, bent along the second long side direction of the circuit board and bent at the other corner in the short side direction of the circuit board. The antenna device according to claim 1, further comprising: a second antenna element coupled to the antenna device.   The antenna device according to claim 2, wherein the first and second antenna elements are metal layers formed on an outer surface of the casing. A wireless communication device,
A housing,
In the housing, a group of conductive parts extending in the long side direction and the short side direction,
A circuit board provided in the housing and mounting at least a part of the conductive component group;
A transmission / reception unit provided on the circuit board for transmitting or receiving a signal for wireless communication; and
A power feeding unit provided on the circuit board;
A dipole antenna having an antenna length longer than the long side of the circuit board and having a shape extending from the long side direction to the short side direction;
A balanced-unbalanced converter provided between the feeding unit and the antenna;
The dipole antenna is a wireless communication device that receives power from the power feeding unit via the balance-unbalance converter at a substantially central portion. The power feeding unit is provided on the short side of the circuit board,
The dipole antenna is
At least a predetermined distance from the circuit board, and bends and extends at one corner in the short side direction of the circuit board along the first long side direction of the circuit board, and the balanced-unbalanced converter, A first antenna element to be coupled;
The balanced-unbalanced converter extends at a predetermined distance from the circuit board, bent along the second long side direction of the circuit board and bent at the other corner in the short side direction of the circuit board. The wireless communication apparatus according to claim 4, further comprising: a second antenna element coupled to the antenna.   The wireless communication device according to claim 5, wherein the first and second antenna elements are metal layers formed on an outer surface of the housing.