JP4232626B2 - Antenna device - Google Patents

Description

  The present invention relates to an antenna device used for a mobile communication device and the like, and more particularly to an antenna device used as a built-in antenna when transmitting and receiving radio waves in two different frequency bands.

  Many antenna devices used in mobile communication devices have been proposed. For example, Patent Literature 1 and Patent Literature 2 describe techniques for widening the frequency band of transmission and reception. In the case of the technique described in Patent Document 1, a series resonance circuit composed of an inductance element and a capacitance element is provided on the antenna base, and the reactance of the antenna main body is canceled by this series resonance circuit to widen the bandwidth. . In the case of the technique described in Patent Document 2, a wide band is realized by providing a capacitively loaded electrode on the other principal surface of the substrate so as to face the radiation electrode formed on one principal surface of the dielectric substrate. is doing.

  However, the technologies described in Patent Documents 1 and 2 are both technologies that provide an inductor component and an electrode serving as a capacitive component on the surface of a substrate to widen the frequency band, and are designed to resonate in a plurality of different frequency bands. It is not a technology to resonate.

  On the other hand, Patent Document 3 describes an antenna device that transmits and receives radio waves in two different frequency bands. As shown in FIG. 22, for example, the antenna device 1 includes an antenna conductor 2, an LC parallel resonant circuit 3, a matching circuit 4, and a transmission / reception circuit 5, and includes two different frequency bands (for example, an 800 MHz band and a 1.5 GHz band). ) And is built in a wireless device such as a cellular phone. The LC parallel resonance circuit 3 is connected in series to the feeding side of the antenna conductor portion 2 as shown in FIG. The LC parallel resonance circuit 3 has a characteristic impedance characteristic that exhibits a capacitive impedance characteristic in a frequency region higher than the resonance frequency and exhibits an inductive impedance characteristic in a frequency region lower than the resonance frequency. Utilizing this characteristic, the antenna conductor portion 2 can resonate in two different frequency bands to transmit and receive radio waves.

JP-A-5-347509 JP 2000-68726 A JP 2002-077650 A

  However, in the case of the antenna device 1 described in Patent Document 3, since the LC parallel resonance circuit 3 is added as an external circuit separately from the antenna conductor portion 2, the LC as the external circuit is mounted in addition to the mounting space of the antenna conductor portion 2. Since a space for mounting the parallel resonant circuit 3 is required, there is a problem that a mounting space as the antenna device 1 is increased. In addition, since the frequency adjustment is performed by the LC parallel resonance circuit 3 that is an external circuit, it is difficult to finely adjust the resonance frequency of the antenna.

  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 promote space saving and control the resonance frequency.

An antenna device according to a first aspect of the present invention is an antenna device capable of transmitting and receiving radio waves of two different frequency bands, and a base and an upper surface of the two different frequency bands on the upper surface of the base. An antenna electrode formed with an electrical length of about ¼ of a radio wave wavelength of a set center frequency, and a power feeding electrode formed on the lower surface of the substrate opposite to the antenna electrode, the first electrode of the substrate sides to form a second electrode having a capacitive component to the second aspect of said substrate to form a first electrode having an inductor component, and, between the antenna electrode and the feeding electrode on the surface of said substrate the first to the second electrode constitute a parallel resonance circuit by parallel connection, co the antenna electrodes through said parallel resonant circuit at one of the two different frequency bands And it is characterized in Rukoto is.

  An antenna device according to claim 2 of the present invention is the antenna device according to claim 1, wherein the first electrode extends to the third side surface and / or the fourth side surface of the base. It is a feature.

The antenna device according to claim 3 of the present invention is the antenna device according to claim 1 or 2, wherein the second electrode is comb-toothed downward from the upper end portion of the second side surface of the base. A first comb-like electrode that extends in a shape and is electrically connected to the antenna electrode at the upper end portion, and extends upward from the lower end portion of the second side surface of the base in a comb-like shape, and the power feed at the lower end portion A second comb-like electrode electrically connected to the electrode, and the comb-tooth portions of the first and second comb-like electrodes enter between the comb-tooth portions from above and below. It is characterized by capacitive coupling through the formed gap .

The antenna device according to claim 4 is the invention according to any one of claims 1 to 3, the third side surface and / or the of the second electrode said substrate 4 is extended to the side surface.

An antenna device according to a fifth aspect of the present invention is the antenna device according to any one of the first , third, and fourth aspects, wherein a chip inductor is provided as an inductor component of the first electrode. It is characterized by that.

An antenna device according to a sixth aspect of the present invention is the antenna device according to any one of the first , second, and fifth aspects, wherein a chip capacitor is provided as a capacitive component of the second electrode. It is characterized by that.

An antenna device according to a seventh aspect of the present invention is the antenna device according to any one of the first to sixth aspects, wherein the feeding electrode is formed as a meandering electrode. is there.

An antenna device according to claim 8 of the present invention is characterized in that, in the invention according to any one of claims 1 to 7 , a conductive plate-like auxiliary element is provided on the antenna electrode. It is what.

According to the onset bright, a parallel resonant circuit need not be provided as an external circuit, the antenna device of the mounting space first parallel resonant circuit it is possible to promote the space saving and second electrodes, respectively It is possible to provide a dual band type antenna device capable of controlling the resonance frequency by adjusting the pattern .

  Hereinafter, the present invention will be described based on the embodiment shown in FIGS. FIG. 1 is a view showing one embodiment of the antenna device of the present invention, and FIGS. 2 to 21 are views showing other embodiments of the antenna device of the present invention.

  The antenna device of the present embodiment is configured as a dual-band type antenna device that can transmit and receive radio waves in two different frequency bands (for example, 800 MHz band and 1.5 GHz band), and mobile communication such as a mobile phone. Used in machines. For example, as shown in FIGS. 1A and 1B, an antenna device 10 according to this embodiment includes a rectangular base 11 formed of an insulating material such as a dielectric material or a magnetic material, and the base. 11 is provided with an antenna electrode 12 formed on the upper surface 11A and a feeding electrode 13 formed on the lower surface 11B opposite to the antenna electrode 12. The feeding electrode 13 supplies a high-frequency signal via a matching circuit 14 on the circuit board. Connected to source 15.

  The antenna electrode 12 is formed in a thin film shape with a conductive metal such as copper on the surface of the upper surface of the substrate 11 except for the left and right ends. The antenna electrode 12 has a resonance frequency that is slightly lower than the set center frequency of the upper frequency band among two different frequencies for radio wave transmission and reception set in advance. It is configured to have an electrical length of about ¼ of the wavelength of the radio wave, and resonates at two different frequency bands as will be described later. A plate-like auxiliary element 16 is connected to the antenna electrode 12, and the antenna gain can be increased by the plate-like auxiliary element 16.

  Thus, as shown in FIGS. 1A and 1B, the first electrode 11C having the inductor component (hereinafter referred to as “inductor component electrode”) 17 is provided on the first side surface 11C of the base 11. Is formed in a thin film shape with a conductive metal such as copper, and the second side surface 11D opposite to the first side surface 11C has a second electrode having a capacitive component (hereinafter referred to as “capacitance component electrode”) 18. Is formed in a comb-like shape in a thin film shape by a conductive metal such as copper. The inductor component electrode 17 and the capacitive component electrode 18 are connected in parallel to the antenna electrode 12 and the feeding electrode 13 at positions facing each other, and are configured to have substantially the same function as the LC parallel resonance circuit. Has been.

  That is, as shown in FIGS. 1A and 1B, the inductor component electrode 17 is formed as a meander-like electrode that meanders by changing its direction by 90 ° from the upper end to the lower end of the first side surface 11C. Has been. The inductor component electrode 17 has an upper end electrically connected to the antenna electrode 12 on the upper surface 11 </ b> A and a lower end connected to the feeding electrode 13.

  Further, as shown in FIGS. 1A and 1B, the capacitive component electrode 18 includes first and second comb-shaped electrodes 18A and 18B, and the first comb-shaped electrode 18A has an upper end. A comb-like electrode portion extending downward from the portion is connected to the antenna electrode 12 at its upper end. The second comb-like electrode 18B has a comb-like electrode portion extending upward from the lower end portion, and is connected to the power supply electrode 13 at the lower end portion. The first and second comb-like electrodes 18A and 18B are capacitively coupled via gaps formed by the respective comb-teeth electrode portions entering between the comb-teeth portions from above and below. .

  Therefore, the inductor component electrode 17 and the capacitive component electrode 18 configured substantially as an LC parallel resonant circuit exhibit capacitive impedance characteristics in a frequency region higher than the resonance frequency, and in a frequency region lower than the resonance frequency. The inductive impedance characteristic is shown, and the antenna electrode 12 can resonate in two different frequency bands set in advance as described below.

  The inductor component electrode 17 and the capacitive component electrode 18 exhibit a large inductance value at a frequency slightly lower than the resonance frequency, give a large inductance value to the feeding side of the antenna electrode 12, and are lower than the resonance frequency of the antenna electrode 12. It can resonate at a frequency. The inductor component electrode 17 and the capacitive component electrode 18 are capacitive in the frequency region above the resonance frequency, and have a configuration in which a capacitor is equivalently connected in series on the power feeding side of the antenna electrode 12, depending on the capacitance. As a result, the inductance value of the antenna electrode 12 is reduced and the antenna electrode 12 can be resonated at a frequency higher than the resonance frequency of the antenna electrode 12. In addition, the inductor component electrode 17 and the capacitor component electrode 18 can control two different resonance frequencies by appropriately changing the respective electrode patterns.

As described above, according to the present embodiment, the base body 11, the antenna electrode 12 formed on the upper surface 11 </ b> A of the base body 11, and the feeding electrode 13 formed on the lower surface 11 </ b> B of the base body 11 facing the antenna electrode 12, The inductor component electrode 17 is formed on the first side surface 11C of the base body 11, the capacitive component electrode 18 is formed on the second side surface 11D opposite to the first side surface 11C of the base body 11, and the antenna electrode 12 and Since the inductor component electrode 17 and the capacitive component electrode 18 are connected in parallel between the feeding electrodes 13, the inductor component electrode 17 and the capacitive component electrode 18 substantially function as an LC parallel resonant circuit. The antenna electrode 12 is connected in series on the power feeding side and resonates in two different frequency bands set in advance to increase two different radio waves. Time can be transmitted and received, yet there is no need to provide an external circuit LC parallel resonance circuit on the circuit board as in the prior art, the mounting space of the antenna device 10 can be space saving. The resonant frequency of the antenna electrode 12 can be controlled by appropriately changing and adjusting the electrode patterns of the inductor component electrode 17 and the capacitive component electrode 18.

Next, modifications of the electrode patterns of the inductor component electrode 17 and the capacitive component electrode 18 will be described based on the embodiments shown in FIGS. As shown in FIGS. 2 to 9, it is possible to obtain the same effect as that of the above-described embodiment by changing the electrode patterns of the inductor component electrode 17 and the capacitive component electrode 18, as well as the resonance of the antenna electrode 12. The frequency can be appropriately controlled. In each of the following embodiments, except that the electrode patterns of the inductor component electrode 17 and the capacitive component electrode 18 are changed, each is configured according to the above embodiment. Only the features will be described with the same reference numerals.

In the case of the antenna device 10 shown in FIG. 2, a chip inductor 17 </ b> A is provided as an inductor component of the inductor component electrode 17, and a chip capacitor 18 </ b> C is provided as a capacitance component of the capacitance component electrode 18. That is, the electrode portion 17B of the inductor component electrode 17 is formed across the upper and lower ends of the first side surface 11C of the base 11, the central portion in the vertical direction are Batch. Then, the electrode portion 17B upper and lower ends are respectively connected to the antenna electrode 12 and the feeding electrode 13, the chip inductor 17A in the Batch is part is connected. The resonant frequency of the antenna electrode 12 can be controlled by appropriately setting the inductance value of the chip inductor 17A. Similar to the capacitance component electrode 18 also inductive component electrodes 17, the electrode 18D is connected to the antenna electrode 12 and the feeding electrode 13 in the upper and lower ends, the chip capacitor 18C is connected to the Batch is part. The resonant frequency of the antenna electrode 12 can be controlled by appropriately setting the capacitance of the chip capacitor 18C.

  In the case of the antenna device 10 shown in FIG. 3, the feeding electrode 13 is formed as a meander electrode, and an inductor component is given to the feeding electrode 13. This meandering electrode can strengthen the inductor component for the antenna electrode 12.

  In the case of the antenna device 10 shown in FIG. 4, the inductor component electrode 17 on the first side surface 11C extends from the first side surface 11C to the third side surface 11E on one side, and the extended portion 17C is the upper surface at the upper end. It is connected to the antenna electrode 12 of 11A. Thereby, the inductor component of the inductive component electrode 17 can be strengthened.

  In the case of the antenna device 10 shown in FIG. 5, an electrode 19 having a slit is formed on the fourth side surface 11F adjacent to the first side surface 11C of the base 11, and this electrode 19 is formed on the antenna electrode 12 on the upper surface 11A and the lower surface. 11B is connected to the feeding electrode 13 and the electrode 19 is opposed by a slit to take capacity.

  In the case of the antenna device 10 shown in FIG. 6, the inductor component 17 on the first side surface 11C and the capacitive component electrode 18 on the second side surface 11D of the base 11 are extended to the third side surface 11E, respectively, and the inductor component and Each of the capacitive components is strengthened. Further, as shown in the figure, the extending portion 17C of the inductor component electrode 17 is connected to the antenna electrode 12 on the upper surface 11A at the upper end. Further, the extending portion 18E of the first comb-shaped electrode 18A of the capacitive component electrode 18 is connected to the antenna electrode 12 at the upper end, and the extending portion 18F of the second comb-shaped electrode 18B is connected to the feeding electrode 13 at the lower end. It is connected.

  In the case of the antenna device 10 shown in FIG. 7, the inductor component electrode 17 on the first side surface 11C of the base 11 is extended to the third and fourth side surfaces 11E and 11F on both sides of the first side surface 11C. The extended portions 17C and 17D of the third and fourth side surfaces 11E and 11F are also connected to the antenna electrode 12 on the upper surface 11A at their upper ends. As a result, the inductor component of the inductor component electrode 17 can be strengthened.

  In the case of the antenna device 10 shown in FIG. 8, the capacitive component electrode 18 on the second side surface 11D of the base 11 is extended to the third and fourth side surfaces 11E and 11F. The extending portion 18E of the first comb-shaped electrode 18A is connected to the antenna electrode 12 at the upper end, and the extending portion 18F of the second comb-shaped electrode 18B is connected to the power supply electrode 13 at the lower end. Thus, the capacitance can be further increased by extending the capacitive component electrode 18 to the third and fourth side surfaces 11E and 11F.

  The antenna device 10 shown in FIG. 9 extends the inductor component electrode 17 on the first side surface 11C and the capacitive component electrode 18 on the second side surface 11D to the third and fourth side surfaces 11E and 11F, respectively, Each of the capacitive components is strengthened. The extending portion 17C of the inductor component electrode 17 is connected to the antenna electrode 12 on the upper surface 11A at the upper end at the third and fourth side surfaces 11E and 11F. In addition, in the third and fourth side faces 11E and 11F, the capacitance component electrode 18 is connected to the antenna electrode 12 at the upper end of the extending portion 18E of the first comb-like electrode 18A, and has a second comb-like shape. The extending portion 18F of the electrode 18B is connected to the feeding electrode 13 at the lower end.

  By the way, in the case of the antenna device 10 of each of the embodiments described above, since the reactance component of the capacitive component electrode 18 is smaller than the reactance component of the inductor component electrode 17, the gain on the higher side of the two resonance frequencies is not sufficient. Absent. Therefore, in the antenna device 10 shown in FIGS. 10 to 21, the second capacitive component electrode that takes a capacitance with the inductor component electrode 17 on the first side surface 11 </ b> C is provided to increase the reactance component of the capacitive component, The frequency gain is increased.

  In the case of the antenna device 10 shown in FIGS. 10A and 10B, a third electrode (hereinafter referred to as a capacitive component) that takes a capacitance component with the inductor component electrode 17 formed on the first side surface 11 </ b> C of the base 11. , Which is referred to as “second capacitive component electrode.”) Except for the provision of 20, it is configured in the same manner as the antenna device 10 shown in FIG. That is, the second capacitance component electrode 20 is configured by first and second comb-like electrodes 20A and 20B arranged so as to sandwich the inductor component electrode 17 on both sides of the first side surface 11C. In the first and second comb-shaped electrodes 20A and 20B, each comb-tooth portion enters the bent concave portion of the meander-shaped electrode from the left and right sides of the inductor component electrode 17 to form a gap with the inductor component electrode 17 is doing. The first and second comb-like electrodes 20A and 20B are both connected to the antenna electrode 12 on the upper surface 11A of the base 11, and take up capacitance in the gap between the inductor component electrode 17 and strengthen the reactance component. It is.

  Therefore, in order to observe the effect of increasing the reactance component, the gain (antenna efficiency) of each of the antenna device 10 shown in FIG. 10 and the antenna device 10 shown in FIG. 1 was measured. The measurement results are shown in Tables 1 to 4. Tables 1 and 2 show the measurement results of the antenna efficiency of the antenna device 10 shown in FIG. 10 in the 800 MHz band and 1.5 GHz band, respectively. Tables 3 and 4 show the 800 MHz band of the antenna device 10 shown in FIG. And the measurement result of the antenna efficiency of 1.5 GHz band is shown. As is clear from these results, the antenna device 10 of this embodiment has high antenna efficiency in both the 800 MHz band and the 1.5 GHz band, and in particular, the antenna efficiency in the 1.5 GHz band is higher than that in the 800 MHz band. It turns out that it is high.

  As described above, according to the present embodiment, the base body 11, the antenna electrode 12 formed on the upper surface 11 </ b> A of the base body 11, and the feeding electrode 13 formed on the lower surface 11 </ b> B of the base body 11 facing the antenna electrode 12, The inductor component electrode 17 is formed on the first side surface 11C of the base body 11, the capacitive component electrode 18 is formed on the second side surface 11D opposite to the first side surface 11C of the base body 11, and the antenna electrode 12 is formed. In addition, the inductor component electrode 11 and the capacitor component electrode 18 are connected in parallel between the power supply electrode 13, and the second capacitor component electrode 20 that takes capacitance between the inductor component electrode 17 and the first side surface 11 </ b> C of the base 11. In addition to the effects similar to those of the antenna device 10 shown in FIGS. 1 to 9, the higher frequency band of the two different frequency bands can be used. It is possible to increase the gain.

  The antenna device 10 of FIGS. 11 to 21 is a modification of the electrode pattern of the inductor component electrode 17, the capacitive component electrode 13, and the second capacitive component electrode 20 shown in FIG. 10, except that the electrode pattern is changed. Are configured in the same manner as the antenna device 10 shown in FIG. 10, and can achieve the same effects as the antenna device 10 shown in FIG. In the following, the same or corresponding parts as those in the above embodiment are denoted by the same reference numerals, and only their features will be described.

  In the antenna device 10 shown in FIG. 11, the first comb-shaped electrode 20A of the second capacitive component electrode 20 is connected to the antenna electrode 12 side at the upper end, and the second comb-shaped electrode 20B is connected to the feeding electrode 13 at the lower end. Connected to the side. In the antenna device 10 shown in FIG. 12, the connection form of the second capacitive component electrode 20 shown in FIG. 11 is reversed, and the first comb-like electrode 20A is connected to the feeding electrode 13 side of the lower surface 11B at the lower end. Two comb-shaped electrodes 20B are connected at the upper end to the antenna electrode 12 side of the upper surface 11A. In addition, the antenna device 10 shown in FIG. 13 has the connection form of the second capacitive component electrode 20 opposite to that of the antenna device 10 shown in FIG. 10, and the first and second comb-like electrodes 20A and 20B are both fed. It is connected to the electrode 13 side.

  Further, in the antenna device 10 shown in FIG. 14, the second capacitance component electrode 20 having the chip capacitors 20 </ b> C and 20 </ b> D is used as an inductor component instead of the second capacitance component electrode 20 taking capacitance between the inductor component electrode 17. Except for being provided on both sides of the electrode 17, it is configured in the same manner as the antenna device 10 shown in FIG.

  The antenna device 10 shown in FIG. 15 is configured in the same manner as the antenna device 10 shown in FIG. 10 except that the feeding electrode 12 on the lower surface 11B of the base 11 is formed as a meandering electrode. By configuring the feeding electrode 13 as a meandering electrode, the inductive component can be strengthened.

  The antenna device 10 shown in FIGS. 16 to 21 has an electrode pattern in which the inductor component electrode 17 and the capacitor component electrodes 18 and 20 are respectively extended to the adjacent side surfaces.

  The antenna device 10 shown in FIG. 16 is characterized in that the inductor component electrode 17 and the second capacitance component electrode 20 in the antenna device shown in FIG. 10 are extended from the first side surface 11C to the third side surface 11E, respectively. . That is, on the third side surface 11E, as shown in the drawing, an extension portion 17C of the inductor component electrode 17 and extension portions 20C and 20D of the second capacitance component electrode 20 are formed. The extending portion 20C is connected to the first comb-like electrode 20A, and the extending portion 20D is connected to the second comb-like electrode 20B.

  Further, the antenna device 10 shown in FIG. 17 is characterized in that the capacitive component electrode 18 in the antenna device shown in FIG. 11 extends to the fourth side surface 11F. That is, extended portions 18E and 18F of the capacitive component electrode 18 are formed on the fourth side surface 11F as shown in FIG. The extension 18E is connected to the first comb-shaped electrode 18A, and the extension 18F is connected to the second comb-shaped electrode 18B.

  The antenna device 10 shown in FIG. 18 extends the inductor component electrode 17 and the second capacitance component electrode 20 in the antenna device 10 shown in FIG. 11 to the third side surface 11E and the capacitance component electrode 18 on the second side surface 11D. Is characterized by extending to the third side surface 11E. That is, on the third side surface 11E, as shown in the figure, an extension portion 17C of the inductor component electrode 17 and extension portions 20C and 20D of the second capacitance component electrode 20 are formed, and the extension of the capacitance component electrode 18 is formed. Portions 18E and 18F are formed.

  In the antenna device 10 shown in FIG. 19, the inductor component electrode 17 and the second capacitance component electrode 20 in the antenna device shown in FIG. 10 are extended to the third and fourth side surfaces 11E and 11F, respectively. This is characterized in that extending portions 17C, 20C, and 20D are formed on the side surfaces 11E and 11F, respectively. Further, the antenna device 10 shown in FIG. 20 extends the capacitive component electrode 18 in the antenna device shown in FIG. 13 to the third and fourth side surfaces 11E and 11F, respectively, and the third and fourth side surfaces 11E and 11F, respectively. Is characterized in that the extending portions 18E and 18F are formed. Further, the antenna device 10 shown in FIG. 21 extends the inductor component electrode 17 and the second capacitance component electrode 20 in the antenna device shown in FIG. 10 to the third and fourth side surfaces, respectively, and the second side surface 11D. The capacitance component electrode 18 is extended to the third and fourth side surfaces, and the extending portions 17C, 20C, 20D, 18E, and 18F are formed on the third and fourth side surfaces.

  The present invention is not limited to the above-described embodiments, and each component can be appropriately changed in design without departing from the gist of the present invention.

  The present invention can be suitably used for a dual band type antenna device.

It is a figure which shows one embodiment of the antenna apparatus of this invention, (a) is the perspective view, (b) is the expanded view. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is a figure which shows other this embodiment of the antenna apparatus of this invention, (a) is the perspective view, (b) is the expanded view. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is an expanded view which shows other this embodiment of the antenna apparatus of this invention. It is a schematic diagram which shows an example of the conventional antenna device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Antenna apparatus 11 Base | substrate 11A Upper surface 11B Lower surface 11C 1st side surface 11D 2nd side surface 11E 3rd side surface 11F 4th side surface 12 Antenna electrode 13 Feed electrode 16 Plate-shaped auxiliary element 17 Inductor component electrode (1st electrode)
18 Capacitance component electrode (second electrode)
20 Second capacitive component electrode (third electrode)

Claims (8)

An antenna device capable of transmitting and receiving radio waves in two different frequency bands, wherein the base and an electric power of about ¼ of the radio wave wavelength of the upper set center frequency of the two different frequency bands on the upper surface of the base An antenna electrode formed with a length and a feeding electrode formed on the lower surface of the base opposite to the antenna electrode, and a first electrode having an inductor component is formed on a first side surface of the base. together to form a second electrode having a capacitive component to the second aspect of said substrate, and said first between the antenna electrode and the feeding electrode on the surface of said substrate, connected in parallel a second electrode and a parallel resonant circuit by an antenna device according to claim Rukoto the antenna electrode is resonated in one of the two different frequency bands via the parallel resonant circuit.   The antenna device according to claim 1, wherein the first electrode extends to the third side surface and / or the fourth side surface of the base. The second electrode includes a first comb-like electrode extending downwardly from the upper end of the second side surface of the base in a comb-like shape and electrically connected to the antenna electrode at the upper end, and the base A second comb-like electrode extending upward from the lower end portion of the second side surface of the first side surface and electrically connected to the power supply electrode at the lower end portion, and the first and second combs 3. The antenna device according to claim 1 , wherein the comb-tooth portion of the tooth-like electrode is capacitively coupled through a gap formed by entering between the comb-tooth portions from above and below. . The antenna device according to any one of claims 1 to 3 , wherein the second electrode extends to a third side surface and / or a fourth side surface of the base. 5. The antenna device according to claim 1 , wherein a chip inductor is provided as an inductor component of the first electrode. 6. The antenna device according to claim 1 , wherein a chip capacitor is provided as a capacitance component of the second electrode. 6. The antenna device according to claim 1 , wherein the feeding electrode is formed as a meandering electrode. The antenna device according to claim 1 , wherein a conductive plate-like auxiliary element is provided on the antenna electrode.

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