JP2016082361A - Antenna and radio communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To miniaturize an antenna.SOLUTION: An antenna 100 includes: an element 101 wound in a coil shape; and a split ring resonator 102 formed of a ring shape and having a slit 102b on a part of the ring with a predetermined gap, and disposed in the inner space of the element 101 to have predetermined capacitance between with the element 101. A base material having predetermined permittivity is provided between the element 101 and the split ring resonator 102. As the base material, for example, a multilayer printed board can be used.SELECTED DRAWING: Figure 2

Description

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

  An antenna for wireless communication provided in a wireless communication device such as a cellular phone terminal is required to have a predetermined reception sensitivity and size reduction. For example, in communication using a mobile phone network, a plurality of antennas are used, for example, by LTE (Long Term Evolution) MIMO (Multiple-Input and Multiple-Output). As a result, the space inside the wireless communication device is limited, so that the antenna must be downsized.

  As a technology for miniaturizing an antenna, there is a metamaterial antenna having a composite structure of a right-handed left-handed system (CRLH-TL: Composite Right and Left Handed Transmission Line). For example, an antenna using a patch and a magnetic dielectric substrate having a split ring resonator (SRR) structure is disclosed. In addition, an antenna is disclosed in which a dielectric formed with a conductive member having an opening is arranged on the side of an inverted L antenna to adjust the resonance frequency (see, for example, Patent Documents 1 and 2 below). ).

Special table 2011-525721 gazette JP 2011-103629 A

  However, according to the conventional technology, for example, an antenna suitable for a frequency (wavelength) of 200 MHz to 710 MHz of multimedia broadcasting (MM) or terrestrial digital broadcasting (DTV) cannot be reduced in size. For example, when a MM or DTV is configured with a rod antenna, a length of 60 mm to 120 mm is required. In addition, since the capacity component is small in the conventional SRR structure, an antenna such as a MM or DTV having a low frequency with respect to the use frequency of the mobile phone network requires an SRR of about 600 mm to 700 mm and cannot be miniaturized.

  In one aspect, an object of the present invention is to reduce the size of an antenna.

  In one proposal, the antenna is formed in a coil shape, and is formed in a ring shape. The antenna has slits with a predetermined interval in a part of the ring, and is disposed in the inner space of the element. And a split ring resonator having a predetermined capacity.

  According to one embodiment, the antenna can be reduced in size.

FIG. 1 is a perspective view illustrating a configuration example of an antenna according to an embodiment. FIG. 2 is a partially enlarged perspective view of FIG. FIG. 3 is a plan view showing a wiring pattern of each layer when the antenna according to the embodiment is formed using a multilayer printed board. FIG. 4 is a diagram illustrating an electrical connection state between layers of the antenna according to the embodiment. FIG. 5 is a diagram illustrating a dimension example of each part of the antenna according to the embodiment. FIG. 6 is a diagram illustrating an equivalent circuit of the antenna according to the embodiment. FIG. 7 is a diagram for explaining the action of the magnetic wall by the SRR of the antenna according to the embodiment. FIG. 8 is a diagram for explaining the magnetic action when no SRR is provided. FIG. 9 is a diagram illustrating an SRR model according to the embodiment. FIG. 10 is a chart illustrating a model example and characteristics of the CRLH according to the embodiment. FIG. 11 is a chart illustrating frequency characteristics of the antenna according to the embodiment. FIG. 12 is a chart showing frequency characteristics by size according to the embodiment. FIG. 13 is a diagram illustrating a state in which the antenna according to the embodiment is mounted on the wireless communication device. FIG. 14 is a perspective view illustrating another configuration example of the antenna according to the embodiment. FIG. 15 is a diagram illustrating a state in which the antenna according to the embodiment is externally attached to the wireless communication device. FIG. 16 is a diagram illustrating another example of the state in which the antenna according to the embodiment is externally attached to the wireless communication device.

(Embodiment)
Hereinafter, preferred embodiments of the disclosed technology will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a configuration example of an antenna according to an embodiment, and FIG. 2 is a partially enlarged perspective view of FIG. In the figure, X is the length direction, Y is the width direction, and Z is the height direction.

  The antenna 100 includes an antenna (element) 101 wound in a coil shape and an annular (ring-shaped) SRR 102 disposed inside the element 101. The element 101 has a configuration wound in a rectangular shape in the illustrated example, but may be a circular shape or a polygonal shape, and has a predetermined diameter (inner diameter). One end 101A of the element 101 is an antenna input terminal, and the other end 101B is open as a free end.

  The rectangular element 101 in FIG. 1 is configured by connecting an upper element 101a, a lower element 101b, and a pair of side elements 101c and 101d. A part of the connection configuration will be described. One end 101aa of the upper element 101a shown in FIG. 2 is connected to one end 101ba of the lower element 101b via the side element 101c. The other end portion 101ab of the upper element 101a is connected to the other end portion 101bb of the lower element 101b via the side element 101d.

  Then, by repeating the connection from the upper element 101a to the side element 101c to the lower element 101b to the side element 101d to the upper element 101a, one coiled element 101 having a predetermined length is formed. become. Note that the element 101 can also be configured by winding a single conductor in a coil shape.

  The SRR 102 is disposed inside the element 101 and is disposed so as not to be in electrical contact with the element 101. The SRR 102 itself is not directly grounded or the like. The SRR 102 has a length equivalent to that of the element 101 and is formed in an annular shape (ring shape) when viewed from above, and a slit that separates a part of the ring from the end portion 102a in the length direction X of the element 101 at a predetermined interval. 102b is formed.

  Element 101 and SRR 102 are made of a material such as conductive metal. A base material having a predetermined dielectric constant is provided between the element 101 and the SRR 102. As the substrate, a printed board such as a glass epoxy resin having a predetermined dielectric constant, Teflon (registered trademark), or the like can be used, and the substrate may be formed by a method of filling the substrate. In addition, most of the region where the substrate is provided can be an air layer (details will be described later, but a fixing member for the SRR 102 is provided in part).

  FIG. 3 is a plan view showing a wiring pattern of each layer when the antenna according to the embodiment is formed using a multilayer printed board. A configuration example in which the element 101 and the SRR 102 are formed using a multilayer printed circuit board (PCB) will be described with reference to FIG.

  In the example shown in FIG. 3, the antenna 100 can be formed by forming a predetermined conductor pattern in each of three layers of a multilayer printed board. Note that the printed circuit board itself is not shown in FIG. For example, a glass epoxy (FR4) material is used for the printed circuit board.

  The conductor pattern of the upper element 101a shown in FIG. 2 is formed on the first layer (upper layer) 301 of the printed board. As shown in the drawing, the upper element 101a is composed of a plurality of conductor patterns inclined at a predetermined angle in the length direction X. The entire length of the upper element 101a is L, and the width is W1.

  A conductor pattern of the SRR 102 shown in FIG. 1 is formed on the second layer (intermediate layer) 302 of the printed board. As shown in the drawing, the SRR 102 is formed in a rectangular ring shape having an opening in the center in the length direction X when seen in a plane, and a slit 102b is formed in one end portion 102a in the length direction X. The size W2 of the SRR 102 in the width direction Y is smaller than the width W1 of the upper element 101a.

  The conductor pattern of the lower element 101b shown in FIG. 2 is formed on the third layer (lower layer) 303 of the printed board. As shown in the drawing, the lower element 101b is composed of a plurality of conductor patterns inclined at a predetermined angle in the length direction X. The inclination direction of the lower element 101b is opposite to the inclination direction of the upper element 101a. The dimension of each part of the lower element 101b is the same as that of the upper element 101a, and the overall length is L and the width is W1.

  The one end 101aa of the upper element 101a of the first layer 301 is connected to the one end 101ba of the lower element 101b of the third layer 303 via the side element 101c described in FIG. The side element 101 c is formed by a through hole (via) provided between the first layer 301 and the third layer 303. Similarly, the other end 101ab of the upper element 101a of the first layer 301 is connected to the other end 101bb of the lower element 101b of the third layer 303 via the side element 101d. This side element 101 d is also formed by a via provided between the first layer 301 and the third layer 303.

  The inclination direction of the lower element 101b is opposite to the inclination direction of the upper element 101a. Then, the upper element 101a and the lower element 101b on the same position in a plan view are electrically connected between the layers via vias of a multilayer printed board. Thereby, the element 101 having a predetermined length wound in the coil shape shown in FIG. 1 and the like can be formed on the multilayer printed board.

  FIG. 4 is a diagram illustrating an electrical connection state between layers of the antenna according to the embodiment. A plurality of conductor patterns are formed on the first layer 301 and the third layer 303, and each conductor pattern has an inductance component L divided in the length direction X. The SRR 102 of the second layer 302 has a predetermined inductance component L in the length direction X. The conductor patterns of the first layer 301 and the third layer 303 have a predetermined capacitance (capacitance component) C of the multilayer printed board at each formation position in the length direction X with respect to the intermediate second layer 302. Connected with. In the figure, d is the thickness of the multilayer printed board.

  FIG. 5 is a diagram illustrating a dimension example of each part of the antenna according to the embodiment. (A) is the first layer 301, (b) is the second layer 302, and (c) is the conductor pattern on the third layer 303. As shown in (a) and (c), the width W1 = 4 mm, the length L = 50 mm, and the thickness H = 0.4 mm in which the conductor pattern is formed on the upper element 101a and the lower element 101b. Further, the width L1 of the conductor pattern is 0.4 mm, the interval L2 is 0.4 mm, and the entire length of the wound element 101 (coil length) is 450 mm. Thus, in the embodiment, a coil length of 450 mm can be obtained using a region on the printed board having a length L = 50 and a width W1 = 4 mm.

  Further, as shown in (b), the SRR 102 has a width W2 = 3 mm, a conductor pattern width W3 = 1 mm, an overall length (ring length) 100 mm of the SRR 102, and a gap G = 0.1 mm between the slits 102b. The length L is 50 mm like the upper element 101a and the lower element 101b. Also, the printed circuit board characteristics are a three-phase board, a board thickness d = 0.4 mm (see FIG. 4), a dielectric constant = 3.95, Tan δ = 0.012, a conductor pattern material = Cu 5.8e7 s / m, a conductor The thickness is 0.018 mm, and the via diameter is 0.06 mm.

  FIG. 6 is a diagram illustrating an equivalent circuit of the antenna according to the embodiment. Between the first layer 301 of one end (input terminal) 101A of the antenna and the third layer 303 of the free end 101B, a parallel circuit of an inductance component L and capacitance C of the upper element 101a and the lower element 101b is formed. . A via inductance component L is directly connected between the input terminal 101A and the free end 101B, and an inductance component L and a slit due to the conductor pattern of the SRR 102 are connected between the parallel circuits of the first layer 301 and the third layer 303, respectively. A parallel circuit of a capacitor C by 102b is connected.

  The conductor pattern of the first layer 301 and the third layer 303 is formed in the above dimension example (see FIG. 5), and the antenna (element) 101 wound in a coil shape is formed by via connection between these layers. Is done. In addition, the SRR 102 is formed in the second layer 302 between the first layer 301 and the third layer 303. The principle of the right-handed left-handed medium (CRLH) is realized using the SRR 102. The parallel circuit of the inductance component L and the capacitor C formed by the SRR 102 shown in FIG. 6 functions as a magnetic wall for the upper element 101a and the lower element 101b.

  FIG. 7 is a diagram for explaining the action of the magnetic wall by the SRR of the antenna according to the embodiment. The distance between the upper element 101a of the first layer 301 and the lower element 101b of the third layer 303 shown in FIG. 7 is about a thin substrate thickness d (0.4 mm). In the antenna of the embodiment, since the printed circuit board is thin, the upper element 101a and the lower element 101b are arranged close to each other.

  Here, in the embodiment, since the SRR 102 is provided between the upper element 101a and the lower element 101b, the magnetic fluxes of the upper element 101a and the lower element 101b follow the SRR 102 as indicated by arrows in the figure. Flowing. Thereby, a magnetic field can be generated in the element 101, and a current can be passed through the element 101.

  FIG. 8 is a diagram for explaining the magnetic action when no SRR is provided. FIG. 8 differs from FIG. 7 in that the SRR 102 is not provided. Thus, when the element 101 is formed of a thin printed board and the SRR 102 is not provided, the magnetic flux of the upper element 101a and the magnetic flux of the lower element 101b collide and cancel each other, so that no current flows through the element 101.

  As described above, in the embodiment, when the upper element 101a of the first layer 301 and the lower element 101b of the third layer 303 are close to each other using a printed circuit board or the like, the phenomenon that the magnetic fluxes cancel each other by providing the SRR 102 is provided. It is shut off.

  The resonance frequency of the coiled antenna 100 can be controlled by changing the constants of the inductance component L and the capacitance C of the SRR 102. Since the SRR 102 becomes a magnetic wall, the magnetic flux of the upper element 101a and the magnetic flux of the lower element 101b are separated. As a result, even when the element 101 is formed with a conductor pattern on a thin printed circuit board, the effect of canceling out the magnetic flux from above and below can be attenuated, and the effect that the inductance amount of the element 101 does not change can be obtained.

  As described above, as the SRR 102, the basic single (single layer) SRR 102 in accordance with the principle of CRLH is used, and the SRR 102 is simply formed by forming a conductor pattern on the second layer 302 of the printed circuit board. it can. The SRR 102 is provided in the second layer 302 of the coiled antenna 100 surrounded by the first layer 301 and the upper and lower elements 101 and the third layer 303 and vias, thereby improving the transmission / reception sensitivity while reducing the size of the antenna 100. become able to.

  Further, by forming the SRR 102 in double (two layers), the capacitance component C can be further increased, and the antenna 100 can be further downsized. The SRR 102 may be provided in an intermediate layer located between the upper layer and the lower layer in which the element 101 of the multilayer printed board is formed. For example, using a four-layer printed circuit board, the element 101 is formed using the first layer (upper layer) and the fourth layer (lower layer), and the second layer located between the first layer and the fourth layer. The SRR 102 may be formed in each of the third layer (intermediate layer).

  FIG. 9 is a diagram illustrating an SRR model according to the embodiment. As shown in FIG. 9, the SRR 102 is formed in a substantially C shape by forming a conductor (conductor pattern) on a printed circuit board 901 in a ring shape and dividing it by a slit 102b. The ring-shaped conductor pattern has an inductance component L, and the slit 102b portion has a predetermined capacitance component C corresponding to the interval G. In the figure, d is the substrate width and shows an example of a square substrate.

  When a perpendicular magnetic field component is incident on the ring (conductor pattern surface) of the SRR 102, a repulsive magnetic field that cancels the incident magnetic field is created on the ring, an induced current is induced according to the principle of electromagnetic induction, and the current is cut off by the slit 102b. The Electric charges are accumulated depending on the width of the slit 102b, and this capacitance becomes a current in the reverse direction, thereby forming a closed circuit of the LC resonator. The resonance frequency f0 of the antenna 100 is based on the following formula (1) based on the inductance component L (the coil length of the element 101 and the total length of the SRR 102) and the capacitance C (capacitance between the element 101 and the SRR 102) of the element 101 and the SRR 102. Determined. f0 is set to a desired frequency of the MM or DTV.

  f0 = 1 / 2π√CL (1)

  Due to the reverse induced current of the SRR 102, the magnetic permeability μ changes in the repulsive magnetic field, and the incident electromagnetic wave of the SRR 102 resonates with the SRR 102 and is absorbed. The absorbed action is an effect of changing the magnetic permeability μ. Therefore, the magnetic field absorption effect has an effect of making the magnetic permeability μ negative, which satisfies the fact that the refractive index n as a definition of the metamaterial is negative, and the SRR 102 has a metamaterial structure.

Relational expression of SRR102 Dielectric constant ε and permeability μ Dielectric constant ε = n / z, permeability μ = nz
About refractive index n and impedance z

S ₁₁ is the reflection coefficient when the metamaterial (SRR102) is irradiated with a plane wave, and S ₂₁ is the transmission coefficient.

  For constants k and d, k = 2πf / C, d = substrate width of SRR102

  FIG. 10 is a chart illustrating a model example and characteristics of the CRLH according to the embodiment. The CRLH line is represented by a unit element model in which a series capacitance and series inductance circuit of an ideal left-handed line and a parallel inductance and a parallel capacitance are inserted. In CRLH, the length Δz of the circuit section is handled as a section of unit elements having a lattice constant a.

  In the dispersion characteristics, ω is an angular frequency, and β is a phase constant (wave number). The CRLH line is a line having Δz as a periodic structure with a finite ground and having a periodicity of a propagation wave, having a left-handed transmission band on the low frequency side and a right-handed transmission band on the high frequency side. The characteristics of the CRLH line change depending on the frequency, and have the characteristics of a high-pass cutoff, a left-handed propagation band, a band gap, a right-handed propagation band, and a low-pass cutoff in order from the low frequency side to the high frequency side. The low-pass cutoff and the high-pass cutoff are caused by a finite number of unit elements. The cutoff wave number of a one-dimensional CRLH line having a periodic structure is π / a, which corresponds to a Bragg reflection condition.

For the phase velocity (v _p ), group velocity (v _g ), and characteristic impedance, a homogeneous medium approximation is established when the absolute value of β is small, and an effective dielectric constant and permeability can be defined, but the absolute value of β When is large, the wave is treated as a periodic structure because the effect as a Bloch wave increases. In the case of this periodic structure, the characteristic impedance of the line is not uniquely determined, but the impedance Z _B for the Bloch wave in the periodic structure is calculated as shown. Z _L = (L _L / C _L ) ^1/2

  FIG. 11 is a chart illustrating frequency characteristics of the antenna according to the embodiment. The horizontal axis represents the frequency, and the vertical axis represents the voltage standing wave ratio (VSWR: Voltage Standing Wave Ratio). As shown in the figure, according to the above dimension example (the coil length of the element 101 = 450 mm), the antenna 100 having a resonance frequency in the vicinity of 211 MHz suitable for the MM frequency band can be obtained.

  FIG. 12 is a chart showing frequency characteristics by size according to the embodiment. The horizontal axis represents frequency, and the vertical axis represents voltage standing wave ratio (VSWR). The resonance frequency in each coil length when changing the coil length of the element 101 between 450 mm (refer FIG. 11)-90 mm is shown.

  The lowest resonance frequency f0 = 211 MHz when the coil length is 450 mm, f0 = 263 MHz when the coil length is 360 mm, f0 = 340 MHz when the coil length is 180 mm, and f0 = 430 MHz when the coil length is 90 mm. Thus, as the coil length is shortened, f0 moves to the high frequency side. That is, an arbitrary f0 can be obtained by setting the coil length of the element 101 that matches the desired f0. This coil length can be obtained by changing the length L of the element 101 on the printed circuit board.

  FIG. 13 is a diagram illustrating a state in which the antenna according to the embodiment is mounted on the wireless communication device. The wireless communication device is a smartphone, for example, and a multilayer printed circuit board 1301 is provided inside the housing 1300. The multilayer printed board 1301 has, for example, 10 layers, and a wireless communication circuit (not shown) is mounted. The antenna 100 is provided at an upper position of the multilayer printed board 1301.

  The antenna 100 is used, for example, as the above-described MM antenna. The antenna 100 includes the upper element 101a, the SRR 102, and the lower element 101b by using three layers (the first layer 301 to the third layer 303 shown in FIG. 3) of the multilayer printed board 1301. The antenna 100 can be formed in a small size with a length L = 50 mm and a width W1 = 4 mm in the above dimension example, and does not take a mounting space on the multilayer printed board 1301. Further, since the antenna 100 is small, the antenna 100 having a size suitable for a frequency band to be used (for example, DTV) can be further provided on the multilayer printed board 1301.

  FIG. 14 is a perspective view illustrating another configuration example of the antenna according to the embodiment. In the illustrated example, a multilayer Teflon is used as the base material 1401. In the example shown in FIG. 14, the heights of the side elements 101c and 101d (corresponding to vias) are made smaller than in FIG. As described above, the coil-shaped element 101 may have a predetermined coil length corresponding to the resonance frequency f0, and the height, width, and length can be arbitrarily changed.

  Further, the portion of the base material 1401 can be an air layer without providing the base material 1401 itself. In the case of an air layer, the upper element 101a, the lower element 101b, and the side elements 101c and 101d constituting the element 101 are configured by a conductor (conductor) or the like that can stand on its own. Further, the SRR 102 is also composed of a conductor (conductive wire) or the like, and a fixing member such as an insulating filler is provided at a part of the both ends of the element 101 so that the SRR 102 is located in the internal space formed by the element 101. And supported by SRR102.

  FIG. 15 is a diagram illustrating a state in which the antenna according to the embodiment is externally attached to the wireless communication device. For example, the antenna 100 can be externally attached to the outside of the housing 1300 of the wireless communication apparatus. In the illustrated example, the antenna 100 is connected to the antenna terminal of the housing 1300 via the RF coaxial cable 1501. In this manner, by using the antenna 100 as an external configuration, the antenna 100 can be installed at an arbitrary place and the receiving sensitivity can be improved. In addition, it is possible to cope with a configuration example in which the smartphone includes only the antenna necessary for the basic communication function and the antenna 100 for MM or DTV application operation is externally attached.

  FIG. 16 is a diagram illustrating another example of the state in which the antenna according to the embodiment is externally attached to the wireless communication device. In the illustrated example, the antenna 100 is provided in the upper position of the housing 1300. In the illustrated antenna 100, the SRR 102 is formed on a rod-shaped substrate. Then, the element 101 is wound around the substrate of the SRR 102 in a coil shape using a metal conductor (conductive wire). The cross section of the antenna 100 (element 101) can be, for example, circular. The metal conductor which is the element 101 is covered with an outer skin having a predetermined dielectric constant and is electrically insulated from the SRR 102.

  The antenna 100 can be fixed to the housing 1300 or detachable via an antenna terminal. For example, the antenna 100 can be attached to the housing 1300 and used only when an MM or DTV application is operating. Note that the antenna 100 may be provided inside the housing 1300 of the wireless communication device (see FIG. 13), and the antenna 100 in another frequency band or the like may be externally connected.

  According to the embodiment described above, the antenna structure is provided in which the SRR using the principle of CRLH is provided in the internal space of the coiled element. The SRR is formed in a ring shape and has a predetermined inductance, and has a predetermined capacity due to a slit formed at one end. When the magnetic flux from the element enters the SRR, a repulsive magnetic field that cancels the incident magnetic field is created on the ring of the SRR, the induced current is induced according to the principle of electromagnetic induction, and the current is cut off by the slit. Electric charges are accumulated at the interval of the slits, and this capacitance causes a reverse current to form a closed circuit of the LC resonator. Due to the reverse induced current, the permeability changes in the repulsive magnetic field, and the incident electromagnetic wave of the SRR resonates with the SRR and is absorbed. The absorbed action is an effect of changing the magnetic permeability. The magnetic field absorption effect is an effect that the permeability is negative, the refractive index that defines the metamaterial is negative, and the SRR has a metamaterial structure. This SRR acts as a magnetic wall that separates the magnetic flux generated by the current flowing through the element.

  For example, the conductor pattern of the element can be formed on the first layer and the third layer of the multilayer printed circuit board, and the predetermined coil length can be formed in a small space by connecting vias between the elements of the first layer and the third layer. An SRR can be formed in the intermediate second layer. Thus, even if an antenna element is formed with a conductive pattern on a thin printed circuit board, the SRR can attenuate the action of canceling the magnetic force due to the magnetic flux from the upper and lower layers, and the effect of not changing the inductance amount of the element Have Further, by using a multilayer printed circuit board, the reception sensitivity can be improved despite being small, and an antenna can be formed at low cost.

  The resonance frequency of the antenna is determined based on the inductance component L (element coil length and total length of SRR) and capacitance C (capacity between the element and SRR) of the element and SRR. Since these elements and SRR are formed on the same printed circuit board, an arbitrary resonance frequency can be easily obtained by changing the region (length and width) of the conductor pattern formed on the printed circuit board. be able to. In particular, a relatively low frequency antenna for MM and DTV can be provided in a small space on the printed circuit board.

  And the radio | wireless communication apparatus of embodiment is applicable to various radio | wireless communication apparatuses, such as communication apparatuses, such as a smart phone and a mobile telephone terminal, and a computer apparatus. Even when a relatively low-frequency antenna is provided in the wireless communication apparatus, the antenna can be provided inside the device due to downsizing. As a result, even if the wireless communication apparatus has a configuration in which a large number of antennas are built in accordance with the communication frequency band, a plurality of low frequency band antennas such as MM and DTV can be provided inside the apparatus.

  Even when the antenna according to the embodiment is configured to be externally attached to the outside of the wireless communication device, the antenna itself can be reduced in size, so that it can be handled easily. Also, the installation location can be arbitrarily set by external attachment, and the communication performance can be improved.

  The following additional notes are disclosed with respect to the embodiment described above.

(Supplementary note 1) an element wound in a coil shape;
A split ring resonator which is formed in a ring shape, has slits at predetermined intervals in a part of the ring and is arranged in the internal space of the element, and has a predetermined capacity with the element;
An antenna comprising:

(Supplementary note 2) The antenna according to supplementary note 1, wherein a base material having a predetermined dielectric constant is provided between the element and the split ring resonator.

(Additional remark 3) The said base material is a multilayer printed circuit board,
The coil-shaped element comprises a conductor pattern formed on each of an upper layer and a lower layer of the printed circuit board, and vias connecting ends of the conductor patterns of the upper layer and the lower layer,
The antenna according to appendix 2, wherein the split ring resonator includes a conductor pattern formed in an intermediate layer of the printed circuit board.

(Supplementary note 4) The antenna according to supplementary note 3, wherein the split ring resonator includes conductor patterns respectively formed on a plurality of intermediate layers of the printed circuit board.

(Supplementary note 5) The antenna according to Supplementary note 3 or 4, wherein a predetermined resonance frequency is obtained based on a length of the conductor pattern of the element formed on the printed circuit board and the split ring resonator.

(Supplementary note 6) The supplementary notes 3 to 5, wherein the element and the split ring resonator are provided using a plurality of layers in a partial region of a multilayer printed board on which a predetermined electronic circuit is mounted. The antenna as described in any one.

(Supplementary note 7) The antenna according to any one of supplementary notes 2 to 6, wherein the base material is formed of a multilayer Teflon.

(Additional remark 8) Let the part of the said base material be an air layer,
The antenna according to appendix 2, wherein the element and the split ring resonator are formed by conducting wires, and a fixing member for holding a part of the split ring resonator is provided in the internal space of the element.

(Supplementary note 9) A conductor pattern of the split ring resonator is formed on the base material,
The antenna according to appendix 2, wherein the element made of a conductive wire covered with an outer skin having a predetermined dielectric constant is wound in a coil shape on the base material.

(Supplementary note 10) The antenna according to any one of supplementary notes 1 to 9, wherein the antenna can be externally connected to an antenna terminal of a wireless communication device.

(Supplementary note 11) A wireless communication device comprising the antenna described in any one of supplementary notes 1 to 10 and a wireless communication circuit capable of performing wireless communication via the antenna.

100 antenna 101 element 101A one end (input terminal)
101a Upper element 101b Lower element 101c, 101d Side element 102 Split ring resonator (SRR)
102b Slit 301 First layer 302 Second layer 303 Third layer

Claims (10)

An element wound in a coil;
A split ring resonator which is formed in a ring shape, has slits at predetermined intervals in a part of the ring and is arranged in the internal space of the element, and has a predetermined capacity with the element;
An antenna comprising:   The antenna according to claim 1, wherein a base material having a predetermined dielectric constant is provided between the element and the split ring resonator. The substrate is a multilayer printed circuit board;
The coil-shaped element comprises a conductor pattern formed on each of an upper layer and a lower layer of the printed circuit board, and vias connecting ends of the conductor patterns of the upper layer and the lower layer,
The antenna according to claim 2, wherein the split ring resonator includes a conductor pattern formed in an intermediate layer of the printed circuit board.   The antenna according to claim 3, wherein the split ring resonator is formed of a conductor pattern formed on each of a plurality of intermediate layers of the printed circuit board.   5. The antenna according to claim 3, wherein a predetermined resonance frequency is obtained based on a length of the conductor pattern of the element formed on the printed circuit board and the split ring resonator. 6.   6. The element and the split ring resonator are provided using a plurality of layers in a partial region of a multilayer printed board on which a predetermined electronic circuit is mounted. Antenna described in one. The base portion is an air layer,
The antenna according to claim 2, wherein the element and the split ring resonator are formed by conducting wires, and a fixing member for holding a part of the split ring resonator is provided in the internal space of the element. A conductor pattern of the split ring resonator is formed on the substrate,
3. The antenna according to claim 2, wherein the element made of a conductive wire covered with an outer skin having a predetermined dielectric constant is wound on the base material in a coil shape.   The antenna according to any one of claims 1 to 8, wherein the antenna can be externally connected to an antenna terminal of the wireless communication device.   A wireless communication apparatus comprising: the antenna according to claim 1; and a wireless communication circuit capable of performing wireless communication via the antenna.

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