JP4833897B2 - Dual frequency antenna - Google Patents

Description

  The present invention relates to a miniaturizable antenna suitable for incorporation in a portable terminal or the like, and more particularly to a dual frequency antenna that uses two frequencies in common.

  Conventionally, with the spread of terminal devices such as mobile phones and the sophistication of their functions, technological development of a multi-frequency shared antenna that can be used at two or more resonance frequencies as a small antenna that can be built into the terminal device has been promoted. It has been. The multi-frequency shared antenna can be roughly classified into two types as follows. The first type multi-frequency shared antenna uses a plurality of modes in one element, and the second type multi-frequency shared antenna has an element branched into a plurality from a common feeding portion. Thus, resonance at a plurality of frequencies can be obtained by a plurality of elements.

  As a first type multi-frequency shared antenna, for example, the one described in Patent Document 1 as shown in FIG. 8 is known. The antenna 900 shown in the figure is provided with a folded portion 901 by being folded so as to be parallel to the longitudinal direction, and by adjusting the line-to-line capacitance of the parallel elements by changing the distance or the like, harmonics (higher order mode) ) Is configured to control. The first type multi-frequency shared antenna configured as described above is advantageous for downsizing since a plurality of resonances can be realized by one element.

  As a second type of multi-frequency shared antenna, for example, the one described in Patent Document 2 as shown in FIG. 9 is known. The antenna 910 shown in the figure is a dual-frequency shared antenna configured to have two resonance frequencies by branching to two antenna elements 911 and 912. In the second type multi-frequency shared antenna configured to realize a plurality of resonances using a plurality of elements, the two frequencies to be used can be controlled to some extent independently.

  On the other hand, in order to improve the performance of an antenna, there is also known an antenna configured to increase the local capacitance using a material having a high dielectric constant. An antenna configured to positively use capacitive coupling is called a dielectric antenna or a chip antenna. For example, those disclosed in Patent Documents 3 and 4 are known.

  In the antenna 920 described in Patent Document 3 shown in FIG. 10, the open end of the radiation electrode 924 and the ground electrode 923 are placed close to each other on the high dielectric substrate 921, and the capacitance is obtained by devising the shape of the open end. The amount of sexual coupling is adjusted, thereby achieving a wider band.

Further, the antenna 930 described in Patent Document 3 shown in FIG. 11 has an open end portion 933a of the radiation electrode 933 and an end portion 935a of the loading electrode 935 connected to the ground electrode 932 on the dielectric substrate 931 so as to face each other. Thus, the capacitive coupling is adjusted, whereby the frequency is lowered and the antenna 930 is reduced in size.
Japanese Patent No. 2898921 JP 2006-196994 A JP 2001-358515 A JP 2005-236624 A

However, the conventional antenna has the following problems.
The first type of multi-frequency shared antenna as disclosed in Patent Document 1 has a problem that the frequency band to be used cannot be controlled independently or that the adjustable range is narrow. The characteristics of an antenna designed in a free space (or a simple system) that does not consider the influence of the surroundings usually change greatly when it is actually built in the casing of a mobile phone. Such changes in antenna characteristics are different in the low frequency band and the high frequency band, and if each cannot be controlled independently, it takes a lot of time for adjustment work after mounting on the housing. End up.

  Further, the second type multi-frequency shared antenna as disclosed in Patent Document 2 has a problem that the size of the antenna becomes large. If this is arranged in a narrow space in order to reduce the antenna size, mutual interference between frequencies becomes prominent, causing problems such as loss of independent controllability and narrowing of the band. For this reason, normally, from the viewpoint of reducing mutual interference, it is necessary to dispose the open ends of the elements at positions away from each other, which makes it difficult to reduce the antenna size.

  Furthermore, as shown in Patent Documents 3 and 4, several examples of antennas having high functionality by providing capacitive coupling between the open end of the main element and the ground electrode connected to the ground are disclosed. However, in the dual-frequency shared antenna having two elements, the conventional technology using capacitive coupling has been used so far in order to achieve high functionality for both the low-frequency band element and the high-frequency band element. Not known to.

  Accordingly, the present invention has been made to solve the above-described problem, and includes a low frequency band element and a high frequency band element so that each frequency band can be easily adjusted and mutual interference can be reduced. An object is to provide a dual-frequency antenna that can be miniaturized.

A first aspect of the dual-frequency antenna according to the present invention is a dual-frequency antenna that includes a conductor pattern branched into a low-frequency band element and a high-frequency band element sharing a circuit connection portion, The frequency band element and the high frequency band element are connected to both ends of the circuit connection portion, extend in substantially opposite directions, respectively, form one or more folded portions, and bring the open ends close to each other. A separation part that separates the two open ends is formed between the two open ends by disposing the intermediate portion of the main path for obtaining resonance of the low frequency band element in a non-contact manner , The band element is folded to form a proximity region, the high frequency band element is folded to form a proximity region, and the low frequency band element and the high frequency band element The distance between the open end and the separating portion of respectively, characterized in that are equipped with capacitive coupling part becomes smaller than the proximity distance of the respective adjacent regions.

  In another aspect of the dual-frequency antenna according to the present invention, the low-frequency band element and the high-frequency band element are folded at approximately 180 degrees in the folded portion.

  Another aspect of the dual-frequency antenna according to the present invention is characterized in that the conductor pattern and the capacitive coupling portion are formed on a three-dimensional surface including a plane.

  According to another aspect of the dual-frequency antenna of the present invention, a short-circuit path is provided in at least one of the folded portion of the low-frequency band element and the folded portion of the high-frequency band element, and resonance in a low-frequency band or a high-frequency band is achieved. It is characterized by adjusting the frequency

  In another aspect of the dual-frequency antenna according to the present invention, a first short-circuit path and a second short-circuit path are provided on at least one of the folded portion of the low-frequency band element and the folded portion of the high-frequency band element, respectively. The low-frequency band resonance frequency is adjusted by the first short-circuit path, and the high-frequency band resonance frequency is adjusted by the second short-circuit path.

  In another aspect of the dual-frequency antenna according to the present invention, the low-frequency band element and the high-frequency band element are such that at least a portion forming the capacitive coupling portion is formed on a dielectric molding. Features.

  Another aspect of the dual-frequency antenna according to the present invention is characterized in that one conductor pattern is provided and the circuit connecting portion is connected to a feeding point.

  Another aspect of the dual-frequency antenna according to the present invention is characterized in that the circuit connection portion further includes a grounding portion.

  In another aspect of the dual-frequency antenna according to the present invention, the conductor patterns are arranged so as to face each other on the front and back of a dielectric plate having a predetermined dielectric constant, and one of the conductor patterns has the circuit connection portion. The power supply point is connected to form a power supply conductor pattern, and the other conductor pattern connects the circuit connection portion to the ground point to form a grounding conductor pattern, and the power supply conductor pattern and The low frequency band elements and the high frequency band elements of each of the grounding conductor patterns are short-circuited in the vicinity of the open end.

  In another aspect of the dual-frequency antenna according to the present invention, a central portion of each of the feeding conductor pattern and the grounding conductor pattern is included in a high dielectric having a dielectric constant higher than that of the dielectric plate. It is characterized by.

  According to the present invention, the separation portion consisting of a part of the low frequency band element is provided between the open end of the low frequency band element and the open end of the high frequency band element, thereby reducing mutual interference and easily Provided is a dual-frequency antenna that can be individually adjusted for each frequency band and can be downsized and widened by simultaneously forming a capacitive coupling portion between each open end and a separation portion. Can do.

  A dual frequency antenna according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. In addition, about each structural part which has the same function, the same code | symbol is attached | subjected and shown for simplification of illustration and description.

  A dual-frequency antenna according to the first embodiment of the present invention will be described below using the plan view shown in FIG. In the dual-frequency antenna 100 of this embodiment, the conductor pattern 102 is branched into a low-frequency band element 110 and a high-frequency band element 120 while sharing the circuit connection portion 101. The circuit connection unit 101 of the present embodiment is a power supply unit connected to a power supply point.

  In each of the low-frequency band element 110 and the high-frequency band element 120, the folded ends 111 and 121 are formed so that the open ends 112 and 122 are brought close to each other. By forming the conductor pattern 102 in this way, the space occupied by the antenna elements 110 and 120 is reduced.

  The folded portions 111 and 121 are preferably formed by folding the low-frequency band element 110 and the high-frequency band element 120 at 180 degrees, whereby the low-frequency band element 110 and the high-frequency band element 120 are respectively folded. , 121 approximately before and after 121, it is possible to reduce the size of the dual-frequency antenna 100.

  If the two open ends 112 and 122 are arranged close to each other, mutual interference becomes obvious and their basic characteristics are greatly disturbed, making it extremely difficult to adjust the respective antenna characteristics. In the dual-frequency shared antenna 100 of the present embodiment, the separation portion 113 that separates the two is formed by disposing the low-frequency band element 110 between the two open ends 112 and 122 via the central portion. I have to.

  By interposing a strong current separating portion 113 between the two open ends 112 and 122, mutual interference between the two can be reduced. Further, since the separation portion 113 is formed by a part of the low frequency band element 110, the dual frequency shared antenna 100 can be wired without increasing the size.

The separation portion 113 and the open ends 112 and 122 are arranged close to each other in parallel by a predetermined length, thereby forming a capacitive coupling 130b between the open end 112 and the separation portion 113. In addition, a capacitive coupling 130 a is also formed between the open end 122 and the separation part 113.

In the dual-frequency antenna 100 formed as described above, in addition to being able to reduce the mutual interference between the low-frequency band element 110 and the high-frequency band element 120 by providing the separation portion 113, The capacitive coupling 130b contributes to the downsizing of the low frequency band element 110, while the capacitive coupling 130a contributes to the widening of the high frequency band as described below.

The low frequency band element 110 has harmonics in the vicinity of the resonance frequency in the high frequency band. By adjusting the capacitive coupling 130a , the higher frequency band can be broadened by incorporating such harmonics. Can be planned. When there is no capacitive coupling, a portion having a high current intensity at the resonance frequency is concentrated in the high frequency band element. By coupling with the low frequency band element via capacitive coupling, a portion with a large current intensity near the resonance frequency spreads to the low frequency band element 110 side through the capacitive coupling section 130a . Further, when a high-order resonance mode exists in the low frequency band element in the vicinity of the resonance frequency of the high frequency band element, a portion having a high current intensity in the resonance state spreads throughout the low frequency band element 110. That is, it is possible to achieve a wide bandwidth.

  The ranges in which the capacitive couplings 130a and 130b are formed, that is, the open end 112 and the separation portion 113 of the low frequency band element 110, and the open end 112 and the separation portion 113 of the high frequency band element 120 are arranged in parallel and close to each other. The length can be adjusted as appropriate in order to reduce the size of the low frequency band element 110 and to increase the bandwidth of the high frequency band.

  FIG. 1 shows an example of the dual-frequency antenna 100 in which the conductor pattern 102 and the capacitive coupling portion 130 are formed in a substantially planar shape. However, the conductor pattern 102 and the capacitive coupling part 130 do not need to be formed on one plane, and can be arbitrarily formed on a three-dimensional plane. As an example, FIG. 2 shows a dual-frequency shared antenna 100 ′ in which the shapes of the conductor pattern 102 and the capacitive coupling portion 130 are three-dimensionally deformed.

  In FIG. 2, the low frequency band element 110 and the high frequency band element 120 are installed substantially vertically, and each has a bent shape. In addition, the open ends 112 and 122 of each element and the separation portion 113 are arranged substantially horizontally, and the capacitive coupling portion 130 is formed in the horizontal direction.

  As described above, the dual-frequency antenna 100 according to the present embodiment may be formed on a plane as shown in FIG. 1 or may be formed three-dimensionally as shown in FIG. The shape of the dual-frequency shared antenna 100 can be determined according to the shape.

  In the dual-frequency shared antenna 100 of this embodiment, a first short-circuit path 114 and a second short-circuit path 124 are provided in the vicinity of the folded portions 111 and 121, respectively, so that the resonance frequency can be adjusted at each installation position. ing. That is, the low-frequency band resonance frequency can be adjusted by adjusting the installation position of the first short-circuit path 114, and the high-frequency band resonance frequency can be adjusted by adjusting the installation position of the second short-circuit path 124. It is configured to be able to. In adjusting the resonance frequency, it is naturally possible to cut and change the open end portion of each element. However, in the portion where the electric field strength is high near the open end, in addition to the length of the element (resonance length), more or less variation due to mutual coupling is added, and it is difficult to adjust with the linearity with respect to the cut portion. In this regard, when the adjustment method as in this embodiment is used, the condition near the open end is constant, and the resonance frequency can be easily adjusted.

  In order to control capacitive coupling in the dual-frequency antenna 100, it is preferable to form the capacitive coupling portion 130 on a dielectric having a high dielectric constant. By making capacitive coupling between the separation unit 113 and the open ends 112 and 122 on the dielectric, it is possible to easily adjust the size and bandwidth of the dual-frequency antenna 100. Further, if the low-frequency element 110 and the high-frequency band element are formed on a dielectric having a high dielectric constant, the size can be reduced by the wavelength shortening effect.

  By adding a grounding portion 103 as shown in FIG. 3 to the dual-frequency antenna 100 of this embodiment, it is possible to perform reverse F-type power feeding. The ground unit 103 is installed in parallel with the circuit connection unit 101 serving as a power feeding unit at a predetermined interval, and the input impedance can be adjusted by adjusting the interval. In other words, depending on the adjustment, alignment is possible even if it is placed close to the ground plane.

  A dual-frequency antenna according to a second embodiment of the present invention will be described below using the plan view shown in FIG. The dual-frequency antenna 200 of this embodiment has a structure in which conductor patterns 202 and 203 are disposed on both surfaces of a dielectric plate 201 having a predetermined dielectric constant, respectively. Here, the conductor pattern disposed on the back side of the dielectric plate 201 is referred to as a power supply conductor pattern 202, and the conductor pattern disposed on the front side of the dielectric plate 201 is referred to as a ground conductor pattern 203.

  Both the feeding conductor pattern 202 and the grounding conductor pattern 203 have the same structure as the dual-frequency antenna 100 of the first embodiment, and the low-frequency band elements 210 and 230 and the high-frequency band element 220, respectively. , 240. The circuit connection portion 204 of the power supply conductor pattern 202 is connected to a power supply point (not shown), and the circuit connection portion 205 of the grounding conductor pattern 203 is connected to a ground point (not shown). At this time, the power supply conductor pattern 202 and the grounding conductor pattern 203 do not have to have the same shape, and the length of the separation portion, the length of the capacitive coupling portion, and the like can be individually set.

  Further, in the dual-frequency antenna 200 of the present embodiment, short-circuit points 215 and 225 are provided in the vicinity of the open ends 212 and 222 of the low-frequency band element 210 and the high-frequency band element 220 of the power supply conductor pattern 202. ing. Similarly, the grounding conductor pattern 203 is also provided with short-circuit points 235 and 245 in the vicinity of the open ends 232 and 242 of the low-frequency band element 230 and the high-frequency band element 240. The short-circuit points 215 and 235 of the low-frequency band elements 210 and 230 are short-circuited, and the short-circuit points 225 and 245 of the high-frequency band elements 220 and 240 are short-circuited.

  In the dual-frequency shared antenna 200 of the present embodiment, it is possible to achieve a wide band by realizing double resonance in each of the low frequency band and the high frequency band. Further, a low posture operation in which the distance from the ground plate 250 is shortened can be achieved. Further, similarly to the first embodiment, the first short circuit path 214 and the second short circuit path 224 provided in the folded portions 211 and 221 of the power supply conductor pattern 202 and the folded portion of the grounding conductor pattern 203 are provided. There are a first short-circuit path 234 and a second short-circuit path 244 provided at 231 and 241. Various characteristic adjustments can be easily realized by adjusting these four short-circuit paths. For example, it is possible to change only the resonance frequency of the low frequency band by changing the positions of the short-circuit path 214 and the short-circuit path 234 by the same amount. The bandwidth (input impedance) of the frequency band can be adjusted. The same applies to the high-frequency band, and a wide adjustment range can be secured not only by the resonance frequency but also by the combination of short-circuit paths.

  A dual-frequency antenna according to a third embodiment of the present invention will be described below using the plan view shown in FIG. The dual-frequency shared antenna 300 of this embodiment is formed so as to cover the central portion of the dual-frequency shared antenna 200 of the second embodiment with a dielectric 301 having a high dielectric constant. In other words, the central portion of each of the feeding conductor pattern 202 and the grounding conductor pattern 203 is enclosed by a high dielectric 301 having a dielectric constant higher than that of the dielectric plate 201.

  The capacitive coupling formed between the separating portion 213 of the power supply conductor pattern 202 and the open ends 212 and 222 and between the separating portion 233 of the ground conductor pattern 203 and the open ends 232 and 242 is high. By being formed inside the dielectric 301, it is possible to reduce the space for forming the capacitive coupling. As a result, it is possible to realize the downsizing of the low frequency band elements 210 and 230 and the widening of the high frequency band as in the first embodiment by capacitive coupling in a limited space.

  The folded portions 211 and 221 of the power supply conductor pattern 202 and the folded portions 231 and 241 of the grounding conductor pattern 203 are both exposed without being covered with the high dielectric 301 within a predetermined range. Thereby, it becomes possible to easily adjust the respective path lengths by changing the installation positions of the short-circuit paths 214, 224, 234, 244 provided in the folded portions 211, 221, 231, 241 respectively. .

  The dual-frequency shared antenna 300 of the present embodiment configured as described above is configured so that the central portions of the feeding conductor pattern 202 and the grounding conductive pattern 203 are covered with a high dielectric 301, thereby allowing the dual-frequency shared antenna 300 to be used. Further reduction in size and enhancement of capacitive coupling can be achieved.

  In the dual frequency antenna according to the present invention, a separation part is provided between the open end of the low frequency band element and the open end of the high frequency band element, and capacitive coupling is formed between each open end and the separation part. Therefore, in any of the first to third embodiments described above, the interference between the low frequency band and the high frequency band can be greatly reduced, and each characteristic can be independently set. It is possible to control.

  As an example of evaluating the independent controllability between the low frequency band and the high frequency band, the positions of the short-circuit paths 214 and 234 of the low frequency band elements 210 and 230 are adjusted in the dual frequency shared antenna 300 of the third embodiment. Then, by adjusting the influence (frequency change) on the high frequency band resonance frequency when the low frequency band resonance frequency is adjusted and the positions of the short-circuit paths 224 and 244 of the high frequency band elements 220 and 240, the high frequency band resonance frequency is adjusted. FIG. 6A shows the influence on the low frequency band resonance frequency when adjusted. For comparison, the result of a conventional parallel two-wire antenna using the same-order higher-order mode is also shown in FIG. In the conventional parallel two-wire antenna, the high-frequency element and the separation band as in the present embodiment are not formed.

  In FIG. 6, the upper case 1 shows the influence on the high frequency band resonance frequency when the low frequency band resonance frequency is adjusted, and the lower case 2 shows the low frequency band resonance frequency when the high frequency band resonance frequency is adjusted. Shows the impact on. From FIG. 6 (a), it is clear that the low frequency band and the high frequency band can be controlled relatively independently in the dual-frequency shared antenna 300 of the present embodiment. On the other hand, in the conventional parallel two-wire antenna using the higher-order mode shown in FIG. 6B, it is difficult to adjust only the low frequency band or only the high frequency band, and the adjustment range is narrow for the high frequency band.

  FIG. 7 shows a comparison of the VSWR (voltage standing wave ratio) of the dual-frequency shared antenna 300 of this embodiment with a conventional parallel two-wire antenna. FIGS. 9A and 9B show a comparison of VSWR in the low frequency band and the high frequency band, respectively. In the low-frequency band 10 and the high-frequency bands 11 and 12 that are the use bands, the VSWR 20 of the dual-frequency shared antenna 300 of the present embodiment is both kept low and exhibits good characteristics.

  The dual-frequency shared antenna 300 of this embodiment is smaller than the conventional parallel two-wire antenna, but the VSWR 20 of the dual-frequency shared antenna 300 in the low frequency band 10 is the same as the VSWR 30 of the conventional parallel two-wire antenna. Compared to this, almost the same characteristics are obtained. From this, it can be seen that the dual-frequency shared antenna 300 of this embodiment can be downsized without degrading the VSWR characteristics.

  Further, in the high frequency bands 11 and 12, the VSWR 20 of the dual frequency shared antenna 300 is kept low over a wide band and shows good characteristics. As described above, in the dual-frequency antenna 300 according to this embodiment, the low frequency band characteristics and the high frequency band special entitlements can be adjusted independently without interfering with each other. Obtainable.

  Note that the description in the present embodiment shows an example of the dual-frequency shared antenna according to the present invention, and the present invention is not limited to this. The detailed configuration and detailed operation of the dual-frequency shared antenna in the present embodiment can be changed as appropriate without departing from the spirit of the present invention.

1 is a plan view of a dual frequency antenna according to a first embodiment of the present invention. It is a top view of the dual-frequency common antenna which concerns on 1st Embodiment from which the shape of this invention differs. It is a top view which shows another Example of the dual frequency shared antenna which concerns on the 1st Embodiment of this invention. It is a top view of the dual frequency antenna according to the second embodiment of the present invention. It is a top view of the dual frequency antenna according to the third embodiment of the present invention. It is a figure which shows the result of having evaluated the adjustment width of a low frequency band and a high frequency band. It is the figure which compared VSWR of the dual frequency shared antenna which concerns on 3rd Embodiment with the conventional parallel 2000 antenna. It is a top view which shows the conventional dual frequency shared antenna. It is a top view which shows the conventional dual frequency shared antenna. It is a perspective view which shows the conventional dual frequency shared antenna. It is a perspective view which shows the conventional dual frequency shared antenna.

Explanation of symbols

100, 200, 300 Dual frequency antenna 101, 204, 205 Circuit connection part 102, 202, 203 Conductor pattern 103 Grounding part 110, 210, 230 Low frequency band element 111, 121, 211, 221, 231, 241 Folding part 112, 122, 212, 222, 232, 242 Open end 113, 213, 233 Separating part 114, 124, 214, 224, 234, 244 Short circuit path 120, 220, 240 High frequency band element 130 Capacitive coupling 201 Dielectric plate 215, 225, 235, 245 Short circuit point 250 Base plate 301 High dielectric

Claims (10)

A dual-frequency antenna having a conductor pattern branched into a low-frequency band element and a high-frequency band element sharing a circuit connection portion,
The low-frequency band element and the high-frequency band element are connected to both ends of the circuit connection part, extend in substantially opposite directions, respectively, form one or more folded parts, and bring the open ends close to each other.
A separation part for separating the two open ends is formed between the two open ends by disposing the intermediate portion in the main path for obtaining resonance of the low frequency band element in a non-contact manner ,
The low frequency band element is folded to form a proximity region,
The high frequency band element is folded to form a proximity region,
2. A capacitive coupling portion in which the distance between the open end of each of the low frequency band element and the high frequency band element and the separation portion is smaller than the proximity distance of each proximity region is provided. Frequency sharing antenna. 2. The dual-frequency antenna according to claim 1, wherein the low-frequency band element and the high-frequency band element are each folded back at approximately 180 degrees in the folded portion. The dual-frequency antenna according to claim 1 or 2 , wherein the conductor pattern and the capacitive coupling portion are formed on a solid surface including a plane. The short frequency path is provided in at least one of the folded portion of the low frequency band element and the folded portion of the high frequency band element to adjust the resonance frequency of the low frequency band or the high frequency band. The dual-frequency antenna according to claim 3 . At least one of the folded portion of the low-frequency band element and the folded portion of the high-frequency band element is provided with a first short-circuit path and a second short-circuit path, respectively. 5. The dual-frequency antenna according to claim 1 , wherein a resonance frequency is adjusted, and a high-frequency band resonance frequency is adjusted by the second short-circuit path. The element and the element for the high frequency band for the low frequency band, one of claims 1 to 3, characterized in that portions to form at least the capacitive coupling portion is formed on a dielectric molded product The dual-frequency antenna according to item 1 . The dual-frequency antenna according to any one of claims 1 to 6 , wherein one of the conductor patterns is provided, and the circuit connection portion is connected to a feeding point. The circuit connection part further comprises a grounding part,
The dual-frequency antenna according to claim 7 . The conductor patterns are arranged facing each other on the front and back of a dielectric plate having a predetermined dielectric constant,
One of the conductor patterns connects the circuit connection portion to the feeding point to form a feeding conductor pattern, and the other conductor pattern connects the circuit connection portion to the grounding point to connect to the grounding conductor pattern. Forming
According claim 1, characterized in that each of the elements to each other and the element to each other for the high frequency band for the low frequency band of the grounding conductor pattern and the feeding conductor pattern, are short-circuited in the vicinity of the open end Item 7. The dual-frequency antenna according to any one of items 6 . 10. The dual frequency sharing according to claim 9 , wherein a central portion of each of the feeding conductor pattern and the grounding conductor pattern is enclosed by a high dielectric having a dielectric constant higher than that of the dielectric plate. antenna.

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