JP3326889B2 - antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna, and more particularly to, for example, a GPS (Global Positioning System) and the like. The present invention relates to an antenna having a laminated structure, a ground electrode formed on the other surface, and an electrical connection between the first and second radiation electrodes.

[0002]

2. Description of the Related Art As a conventional antenna, there is Japanese Patent Application Laid-Open No. 3-192804, which was filed on Aug. 22, 1991. This is because the dielectric provided between the radiating element of the microstrip antenna or plate-shaped inverted-F antenna and the ground plane and the peripheral part of the radiating element and the ground plane in order to reduce the size and weight of the antenna. The dielectric constant of the dielectric to be used is higher than that of the other dielectrics.

[0003]

However, in such a conventional antenna, when the dielectric having the lower dielectric constant is air, the radiation electrode cannot be formed by screen printing or the like, and a metal plate or the like cannot be formed. It must be attached to a dielectric. For this reason, there is a problem that the resonance frequency, input impedance, and the like of the antenna change depending on the position where the antenna is attached.
On the other hand, if work is performed so that such a problem does not occur, the work time becomes longer.

[0004] Therefore, a main object of the present invention is to provide an antenna capable of easily stabilizing the resonance frequency or the input impedance.

[0005]

According to the present invention, there is provided a dielectric substrate, a first radiation electrode formed on one surface of the dielectric substrate,
An antenna including a plate-shaped second radiation electrode laminated on the first radiation electrode while leaving a part of the first radiation electrode, and an earth electrode formed on the other surface of the dielectric substrate.

[0006]

For example, a ring-shaped first radiation electrode is formed on one side of a doughnut-shaped dielectric substrate by screen printing or the like, and a second radiation electrode having a diameter smaller than the outer diameter of the radiation electrode is formed. For example, a metal plate as an electrode is mounted on the surface of the dielectric substrate so as not to protrude outside the first radiation electrode.

In the case where an engagement piece for engaging with the inner diameter of the donut-shaped dielectric substrate is formed on the metal plate, the metal plate is placed so that the center of the dielectric substrate and the center of the metal plate coincide with each other. Is attached. In addition, for example, 2
If one concave portion is formed as a third engaging portion and the metal plate is formed with, for example, two convex portions engaging with the concave portion as a fourth engaging portion, the metal plate is positioned at a predetermined position on the dielectric substrate. Mounted correctly.

[0008]

According to the present invention, since the first radiation electrode is formed between the second radiation electrode and the dielectric substrate, the resonance frequency of the antenna can be stabilized.
Further, by forming the first and second engaging portions, the metal plate can be easily mounted on the dielectric substrate, and the resonance frequency of the antenna can be stabilized. In addition, the third and fourth
By mounting the second radiation electrode at a predetermined position by the engagement portion, the input impedance of the antenna can be stabilized.

The above objects, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS. 1 to 6, an antenna 10 according to a first embodiment includes a dielectric substrate 12 formed in a donut shape. As can be seen from FIGS. 1 and 2, the dielectric substrate 12
On one main surface, a ring-shaped radiation electrode 14 is formed, and on the other main surface, a ground electrode 16 is formed.

The antenna 10 also includes a metal plate 18 functioning as a radiation electrode as shown in FIGS. 3 and 4, a part of the main surface being punched in a U-shape and being bent toward the other main surface. Thus, a bent piece 20 is formed. Then, as shown in FIGS. 5 and 6, a metal plate 18 is mounted on the dielectric substrate 12, and the peripheral edge of the metal plate 18 and the radiation electrode 14 are fixed by, for example, reflowing a solder paste. Note that the diameter of the metal plate 18 is smaller than the outer diameter of the radiation electrode 14, and the metal plate 18 is mounted on the dielectric substrate 12 so that the periphery does not protrude beyond the outer diameter of the radiation electrode 14. Also, the feeding point, that is, the bent piece 2
0 is connected to the lead wire 22.

Thus, even if the mounting position of the metal plate 18 is slightly shifted, the outer diameter of the entire radiation electrode does not change, so that the resonance frequency of the antenna 10 can be stabilized. Referring to FIGS. 7 to 10, antenna 10 of the second embodiment
Includes the dielectric substrate 12 shown in FIG. 1 and FIG. The metal plate 24 shown in FIGS. 7 and 8 is obtained by forming two engaging pieces 26 on the other main surface of the metal plate 18 shown in FIGS. 9 and FIG.
As can be seen from FIG. 0, the engagement piece 26 is attached to the dielectric substrate 12 so as to engage with the inner diameter of the dielectric substrate 12. Further, a lead wire 22 is connected to the bent piece 20. Thus, the metal plate 24 can be mounted more easily than the antenna 10 of the first embodiment, and the resonance frequency can be stabilized.

However, in the antennas 10 of the first and second embodiments, the resonance frequency is stable, but it is difficult to arrange the feeding point at a predetermined position determined by the pattern of the radiation electrode 14. Therefore, there remains a problem that impedance characteristics and the like change. Therefore, the antennas 10 of the third to fifth embodiments described below are conceivable.

The antenna 10 of the third embodiment shown in FIGS. 11 to 16 includes a dielectric substrate 28 formed in a donut shape. As can be seen from FIGS. 11 and 12, a radiation electrode 30 is formed on one main surface of the dielectric substrate 28.
Inside the radiation electrode 30 on one main surface of the dielectric substrate 28, two concave portions 32 are formed at an angle of 180 degrees from each other.
Is formed. Further, a ground electrode 34 is formed on the other main surface of the dielectric substrate 28.

The antenna 10 is also shown in FIGS.
Are formed on the other main surface of the metal plate 36. An engagement piece 38 that engages with the concave portion 32 is formed. In addition, a part of the main surface of the metal plate 36 is punched in a U-shape, so that a bent piece 40 that is vertically bent toward the other main surface is formed in this portion. Then, as shown in FIGS. 15 and 16, the metal plate 36 is mounted on the dielectric substrate 28 so that the engagement pieces 38 are engaged with the recesses 32, respectively. , For example, by reflowing a solder paste. In addition, the lead wire 4
2 are connected.

The antenna 10 of the fourth embodiment shown in FIGS. 17 to 22 also includes a dielectric substrate 44. FIG. 17 and FIG.
As can be seen from FIG. 7, the dielectric substrate 44 is formed in a disk shape, and a radiation electrode 46 is formed near the periphery on one main surface. In addition, two concave portions 48 are formed on one main surface of the dielectric substrate 44 between the radiation electrode 46 and the peripheral edge at an angle of 180 degrees from each other. The dielectric substrate 44 has a hole 50 penetrating from one main surface to the other main surface on a straight line connecting the concave portion 48 inside the radiation electrode 46. Further, a ground electrode 52 is formed on the other main surface of dielectric substrate 44. The hole 50 is connected to the ground electrode 52.
Also penetrates.

As can be seen from FIGS. 19 and 20, the metal plate 54 of the antenna 10 of this embodiment has, on its periphery, a protrusion on the other main surface so as to engage with the concave portion 48 of the dielectric substrate 44. Thus, two engaging pieces 56 are formed. Further, a part of the metal plate 54 is cut out in a U-shape, and a hole 58 is formed. Then, as shown in FIGS. 21 and 22, the metal plate 54 is mounted on the dielectric substrate 44 so that the engaging pieces 56 are engaged with the concave portions 48, respectively, and the periphery of the metal plate 54 and the radiation electrode 46 are connected. , For example, by solder paste. As shown in FIG. 22, a connector 60 is attached to the dielectric substrate 44 on the side of the ground electrode 52, and the conductor 62 is connected to a feeding point of the metal plate 54 through the hole 58. As a result, a current is supplied to the metal plate 54.

The antenna 10 of the fifth embodiment shown in FIGS. 23 to 28 also includes a dielectric substrate 64 and a metal plate 66. As can be seen from FIGS. 23 and 24, the dielectric substrate 64 is formed in a disk shape, and the radiation electrode 68 is formed thin near the periphery on one main surface. In addition, one concave portion 70 is formed on one main surface of the dielectric substrate 64 from the outside of the radiation electrode 68 to the periphery of the dielectric substrate 64. Further, a hole 72 that does not penetrate to the other main surface is formed at the center of the one main surface, and a hole 74 that penetrates from one main surface to the other main surface extends on the extension of the line connecting the concave portion 70 and the hole 72. It is formed. Furthermore, a ground electrode 76 is formed on one surface of the other main surface of the dielectric substrate 64. The hole 74 also penetrates the ground electrode 76.

As can be seen from FIGS. 25 and 26, engagement pieces 78 and 80 are formed on the other main surface of metal plate 66 so as to engage with recess 70 and hole 72, respectively. A part of 66 is cut out in a U-shape, and a hole 82 is formed. 27 and 28, the engaging pieces 78 and 80 of the metal plate 66 engage with the concave portions 70 and the holes 72 of the dielectric substrate 64, respectively, so that the metal plate 66 It is mounted, and the periphery of the metal plate 66 and the radiation electrode 68 are fixed by, for example, a solder paste. Further, the ground electrode 76
A connector 84 is attached to the surface of the metal plate 66, and the conductor 86 is connected to the feeding point of the metal plate 66 through the hole 82. Thus, current is supplied to the metal plate 66.

In the third to fifth embodiments, since the metal plate is engaged with the concave portion or the hole formed in the dielectric substrate, the distance from the peripheral edge of the radiation electrode to the peripheral edge of the dielectric substrate is uniform. , And the feeding point is also determined at a predetermined position. Therefore, electrical characteristics such as impedance characteristics can be stabilized. Although this embodiment has been described using a stripline antenna, the present invention can of course be applied to an inverted F antenna.

[Brief description of the drawings]

FIG. 1 is an external view showing a dielectric substrate.

FIG. 2 is a cross-sectional view of the dielectric substrate shown in FIG. 1, taken along the line II-II.

FIG. 3 is an external view showing a metal plate.

FIG. 4 is a sectional view taken along line IV-IV of the metal plate shown in FIG. 3;

FIG. 5 is an external view showing a first embodiment of the present invention.

FIG. 6 is a sectional view taken along line VI-VI of the embodiment shown in FIG.

FIG. 7 is an external view showing a metal plate.

FIG. 8 is a sectional view taken along line VIII-VIII of the metal plate shown in FIG. 7;

FIG. 9 is an external view showing a second embodiment of the present invention.

FIG. 10 is a sectional view taken along the line XX of the embodiment shown in FIG. 9;

FIG. 11 is an external view showing a dielectric substrate.

FIG. 12 is a sectional view taken along line XII-XII of the dielectric substrate shown in FIG. 11;

FIG. 13 is an external view showing a metal plate.

FIG. 14 is a sectional view taken along line XIV-XIV of the metal plate shown in FIG.

FIG. 15 is an external view showing a third embodiment of the present invention.

16 is a sectional view taken along line XVI-XVI of the embodiment shown in FIG.

FIG. 17 is an external view showing a dielectric substrate.

18 is a sectional view taken along line XVIII-XVIII in FIG.

FIG. 19 is an external view showing a metal plate.

20 is a sectional view taken along line XX-XX of FIG.

FIG. 21 is an external view showing a fourth embodiment of the present invention.

FIG. 22 is a sectional view taken along line XXII-XXII of FIG. 21.

FIG. 23 is an external view showing a dielectric substrate.

24 is a sectional view taken along line XXIV-XXIV of FIG.

FIG. 25 is an external view showing a metal plate.

26 is a sectional view taken along line XXVI-XXVI of FIG. 25.

FIG. 27 is an external view showing a fifth embodiment of the present invention.

28 is a sectional view taken along line XXVIII-XXVIII in FIG.

[Explanation of symbols]

 10 Antennas 12, 28, 44, 64 Dielectric substrate 14, 30, 46, 68 Radiation electrodes 32, 48, 70 Depressions 16, 34, 52, 76 Earth electrodes 50, 58, 72, 74, 82 ... holes 26, 38, 56, 78, 80 ... engagement pieces

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-219306 (JP, A) JP-A-5-22022 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01Q 13/08

Claims (3)

(57) [Claims] 1. A dielectric substrate, a first radiation electrode formed on one surface of the dielectric substrate, and a plate laminated on the first radiation electrode except for a part of the first radiation electrode An antenna comprising: a second radiating electrode in a shape of an arrow; and a ground electrode formed on the other surface of the dielectric substrate. 2. A first engaging portion is formed on said dielectric substrate such that a center of said dielectric substrate coincides with a center of said second radiation electrode, and said first radiation portion is provided on said second radiation electrode. The antenna according to claim 1, wherein a second engaging portion that engages with the engaging portion is formed. 3. A dielectric substrate having at least two third engagement portions formed thereon, and said second radiation electrode having at least two fourth engagement portions engaged with said third engagement portions. The antenna according to claim 1, wherein the antenna is formed.