JP2882928B2 - Slot antenna - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slot antenna suitable for use as an antenna of a portable radio such as a cordless telephone.

[0002]

2. Description of the Related Art FIG. 13 is a perspective view showing a configuration of a conventional half-wavelength slot antenna 101. This slot antenna 101 has a rectangular slot (non-conductor portion) having a length of about 0.5λ and a width of about 0.01λ almost at the center of a thin metal plate 102 having an outer dimension of about 0.75λ × 0.5λ. 103 is formed. Here, λ is the wavelength at the operating frequency f, and is represented by λ = C / f (where C is the speed of light). On one surface of the metal plate 102, S ≒ 0.05λ from one end 103a of the slot 103 in the longitudinal direction.
The end of the outer conductor 104o of the coaxial cable 104 having the characteristic impedance of 50Ω is fixed to the position by soldering or the like. The outer conductor 104o
The inner conductor 104i protruding from the end of the
And connected to the metal plate 102 by means such as soldering. Coaxial cable 10 connected to slot 103
The other end of 4 is a transmitter or a receiver (neither is shown)
, And power is supplied to the slot antenna 101.

[0003] The operation of the slot antenna 101 will be described below, taking as an example the case where the other end of the coaxial cable 104 is connected to a transmitter. When power is supplied from the transmitter to the slot antenna 101 via the coaxial cable 104, an electric field distribution shown by an arrow in FIG. By setting the slot length to about 0.5λ, the slot 103 resonates with a signal having a wavelength corresponding to λ. Here, the input resistance at the center of the slot 103 where the highest electric field strength is obtained is about 500Ω.
In addition, each end 10 of the slot 103 where the electric field intensity is 0
The input resistance at 3a and 103b is 0Ω. Further, a distance S from one end 103a of the slot 103 in the longitudinal direction is set.
The input resistance at the position of ≒ 0.05λ is 50Ω.
Therefore, by connecting the coaxial cable 104 to this position, the impedance of the coaxial cable and the impedance of the slot antenna can be matched. The coaxial cable 10
No. 4 can obtain the same characteristics even when connected to a position separated by a distance S from the other end 103b side. Further, since the slot antenna has reversibility, even when the other end of the coaxial cable 104 is a receiver, exactly the same characteristics as described above can be obtained.

[0004]

[0005] Since vertical polarization is generally used in mobile communication, it is required that the directivity of the vertical polarization in the horizontal plane of the antenna of the portable radio is uniform. When the slot antenna 101 described above is placed parallel to the XZ plane as shown in FIG. 13, vertical polarization having an amplitude in the Z direction is generated.
The radiation directivity in the horizontal plane (XY plane) of vertically polarized waves is
As shown in FIG. For this reason, when the slot antenna 101 is used for the portable wireless device, there is a problem that communication may be impossible depending on the direction of the portable wireless device with respect to the base station. Further, the outer dimensions of the metal plate 102 constituting the slot antenna 101 usually need to be about 0.75λ × 0.5λ, and the outer dimensions become large at the UHF band frequency generally used in portable radios. There is a problem that it is difficult to use it by attaching it to a wireless device. As an example, when the frequency is 900 MHz, the wavelength λ is about 333 mm.
It is about mm × 170 mm. On the other hand, the external shape of a general portable wireless device is about 50 mm wide × 150 mm high × 20 mm deep, and it is difficult to attach such a slot antenna.

A first object of the present invention is to provide a slot antenna having uniform directivity of vertical polarization in a horizontal plane. A second object of the present invention is to provide a small-sized slot antenna that can be used as an antenna of a portable wireless device.

[0006]

According to a first aspect of the present invention, there is provided a slot antenna, comprising: a dielectric substrate; first and second conductive surfaces formed on a front side and a back side of the dielectric substrate; A first and a second non-conductor portion formed on the surface of the dielectric substrate and having a symmetrical Γ shape on the front side and the back side of the dielectric substrate, respectively. It is characterized by being connected to conductor portions on both sides of either the first or second non-conductor portion.

A slot antenna according to a second aspect of the present invention is the slot antenna according to the first aspect of the present invention, wherein the first and second conductor surfaces formed on one end surface of the dielectric substrate are continuous with each other. 3 and a third non-conductive portion continuous with the first and second non-conductive portions formed on the third conductive surface.

According to a third aspect of the present invention, there is provided a slot antenna, comprising: a dielectric substrate; a conductor surface formed on one side of the dielectric substrate; And a non-conductor part having a Γ shape formed so as to reach the side end of the coaxial cable connected to the communication device, the outer conductor and the inner conductor of the coaxial cable connected to the conductor parts on both sides of the non-conductor part, respectively. It is characterized by the following.

According to a fourth aspect of the present invention, there is provided a slot antenna, comprising: a dielectric substrate; a conductor surface formed on a front side of the dielectric substrate; and one end of the conductor surface having one end on either side of the dielectric substrate. A non-conductor part having a Γ shape formed so as to reach an end, and a non-conductor part on the back side of the dielectric substrate, one end of which is connected to a communication device, and the other end of which is on the front side of the dielectric substrate A microstrip line formed so as to be a position symmetrical with a position straddling, and a through hole formed near the non-conductor portion at the other end of the microstrip line, wherein the through hole is The conductor portion on the front side of the dielectric substrate is connected to the microstrip line.

According to a fifth aspect of the present invention, there is provided a slot antenna including a metal plate and a non-conductor portion having a Γ shape formed through the metal plate, and an outer conductor of a coaxial cable connected to a communication device. And an inner conductor connected to the conductor portions on both sides of the non-conductor portion.

According to a sixth aspect of the present invention, there is provided the slot antenna according to any one of the first, second, third, and fifth aspects, wherein the outer conductor and the inner conductor of the coaxial cable transmit and receive the wavelength of λ
In this case, in the vertical portion of the non-conductor portion, the non-conductor portion is connected to both sides at a position of 0.01λ to 0.02λ from the lower end portion.

A slot antenna according to a seventh aspect of the present invention is the slot antenna according to the first or second aspect, wherein a capacitor is formed at an end of a horizontal portion of the non-conductor portion.

An eighth aspect of the present invention is the slot antenna according to the seventh aspect, wherein at least one of the conductor surfaces on the front and back surfaces of the dielectric substrate projects into the Γ-shaped non-conductor portion, Further, the capacitor is formed by forming a conductor portion facing the other conductor surface.

According to a ninth aspect of the present invention, there is provided the slot antenna according to any one of the first to fifth aspects of the present invention, wherein each of the chip capacitors is provided in a conductor portion on both sides of an end of the horizontal portion of the non-conductor portion. The electrode is connected.

[0015]

According to the slot antenna according to the first to ninth aspects of the present invention, the horizontal portion of the 無 -shaped non-conductor portion formed on the conductor surface on the front and / or the back of the dielectric substrate or the metal plate and the same is provided. Vertically polarized waves are emitted from one end. Therefore, uniform radiation directivity can be obtained in each direction in the horizontal plane with respect to vertical polarization.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of a slot antenna 1 according to a first embodiment of the present invention. FIG. 1A is a perspective view of a surface to which a coaxial cable 4 is connected, and FIG.
FIG. 4 is a perspective view of the back surface. The slot antenna uses a dielectric substrate 2 having a thickness of about 0.5 to 1 mm, and both surfaces thereof are conductor surfaces 2a and 2b. Further, one of the four end surfaces around the dielectric substrate 2 is a conductor surface. Conductor surface 2 of dielectric substrate 2
a and 2b have Γ-shaped slots 3a and 3b, respectively.
Are formed by peeling the conductor by a method such as etching so that is matched on the front and back. Here, each slot 3
The horizontal portions (portions extending in the X direction) of a and 3b reach the end face 2c. Further, a slot 3c connecting the slots 3a and 3b is formed on the end face 2c of the dielectric substrate 2, and one continuous slot 3 is formed by the slots 3a, 3b, 3c. Here, the width of each of the slots 3a, 3b, 3c is about 0.01λ. The length of the horizontal portion of each of the slots 3a and 3b is approximately 0.04λ, and the length of the vertical portion (the portion extending in the Z direction) is approximately 0.17λ. Therefore, the total length of the slot 3 is about 0.42λ. The electric field generated in the slot 3 passes through the dielectric substrate 2. Therefore, the slot length corresponding to the transmission / reception wavelength λ can be shortened as compared with the conventional slot antenna 101 not using a dielectric. Moreover, since the slots are formed on both sides of the dielectric substrate 1 and the slots 3a and 3b on each side are formed in a triangle shape, the outer shape can be reduced to 1/30 as compared with the conventional slot antenna 101.

The outer shape of the dielectric substrate 2 may be any size as long as the slot 3 can be formed. Therefore, in this embodiment, the width is 0.06λ × length 0.23λ. The slot width is not limited to about 0.01λ described above,
It can be arbitrarily selected in the range of about 0.003λ to 0.03λ. Further, the widths of the horizontal portions and the vertical portions of the slots 3a and 3b may be different. further,
The other three end faces except the end face 2c of the dielectric substrate 2 may be used as the conductor faces.

On the conductor surface 2a side of the dielectric substrate 2, 0.01λ to 0.02
The coaxial cable 4 is fixed at a position on λ, and the inner conductor 4i and the outer conductor 4o of the coaxial cable 4
a is connected to both sides by means such as soldering. Here, the case where the coaxial cable 4 is connected to the slot 3a is shown, but it may be connected to the slot 3b.

FIG. 2 shows the direction of the electric field in each part in the slot 3 of the slot antenna 1 by arrows.
As shown in this figure, a vertical electric field is generated in each of the horizontal portions of the slots 3a and 3b and the slot 3c.
As a result, vertically polarized waves are emitted. A horizontal electric field is generated in each of the vertical portions of the slots 3a and 3b, and a horizontal polarization is radiated. FIG. 3 shows the radiation directivity of the slot antenna 1 on a horizontal plane (XY plane). In this figure, the solid line P indicates the radiation directivity with respect to the vertical polarization component, and the broken line S indicates the radiation directivity with respect to the horizontal polarization component, and each shows a value normalized by the gain of the half-wavelength dipole antenna. According to the slot antenna 1, the vertical polarization is radiated from the horizontal portions of the slots 3a and 3b and the slot 3c. Therefore, as shown in FIG. 3, the radiation directivity for the vertical polarization component is substantially in the horizontal plane. Become uniform. As described above, since the radiation directivity with respect to the vertically polarized wave becomes substantially uniform (circular) in the horizontal plane, the slot antenna 1 can be applied to mobile communication such as a portable wireless device. Further, since the slot antenna 1 radiates horizontally polarized waves in addition to vertically polarized waves, it is possible to cope with changes in the polarization plane caused by multipath fading that occurs in mobile communications such as portable wireless devices. That is, the slot antenna 1 functions as a kind of polarization diversity antenna. Therefore, if the slot antenna 1 is used, the quality of communication is significantly improved. Specifically, the error rate in digital communication decreases.
According to experiments, the lower end 3 of the vertical portion of the slot 3a
At a position of 0.01λ to 0.02λ from d, the input resistance of the slot antenna 1 is 50Ω, and by connecting a coaxial cable having a characteristic impedance of 50Ω to this position, the impedance of the coaxial cable 4 and the impedance of the slot antenna 1 are matched. It is possible to do.

FIG. 4 shows the configuration of a slot antenna 1a according to a second embodiment of the present invention. FIG. 4 (a) is a perspective view of the surface to which the coaxial cable 4 is connected, and FIG.
(B) is a perspective view of the back surface. In this figure, parts corresponding to those in FIG. 1 described above are denoted by the same reference numerals. This slot antenna 1a uses a dielectric substrate 2 having a thickness of about 0.5 to 1 mm, and leaves conductor projections 5a and 5b on both surfaces 2a and 2b, respectively, and forms ス ロ ッ ト -shaped slots 3a and 3b. Are formed to correspond to the front and back. The width of each of the slots 3a, 3b, 3c is about 0.014λ. The length of the horizontal portion of the slots 3a and 3b is about 0.04λ, and the length of the vertical portion is about 0.08λ. Therefore, the total length of the slot 3 is about 0.24λ. Since the outer shape of the dielectric substrate 2 may be any size as long as the slot 3 can be formed, in the present embodiment, the width is 0.06λ × the length 0.13λ. The slot width is not limited to about 0.014λ, but can be arbitrarily selected from a range of about 0.003λ to about 0.03λ. Further, the widths of the horizontal and vertical portions of the slots 3a and 3b may be different.

FIG. 5 is an expanded view of the conductor protrusions 5a and 5b and the slot 3c. The conductor protrusions 5a and 5b partially overlap each other with the dielectric substrate 2 interposed therebetween, and function as a capacitor. FIG. 6 shows another configuration for forming a capacitor in the slot 3c. In this configuration, a recess is formed in one conductor portion of the slot 3a from the conductor surface 2a to the end surface 2c, and a conductor protrusion 5a is formed so as to enter the recess. Conductor convex part 5
“a” faces the conductor portion above the slot 3b in the conductor surface 2b.

In this embodiment, as in the first embodiment, each horizontal portion of the slots 3a and 3b and the slot 3
The vertical polarization is radiated from c, and the horizontal polarization is radiated from each vertical portion of the slots 3a and 3b. FIG. 7 shows the radiation directivity of the slot antenna 1a on a horizontal plane (XY plane). In this figure, the solid line P indicates the radiation directivity with respect to the vertical polarization component, and the broken line S indicates the radiation directivity with respect to the horizontal polarization component, and each shows a value normalized by the gain of the half-wavelength dipole antenna. As shown in this figure, the radiation directivity of the vertically polarized component is substantially uniform in the horizontal plane. Further, according to this embodiment, since the capacitor is formed by forming the conductor convex portion in the slot 3, the slot length corresponding to the transmission / reception wavelength λ can be shortened. Therefore, according to this embodiment, it is possible to further reduce the size of the slot antenna than in the first embodiment,
The size can be reduced to 1/60 of that of the conventional slot antenna.

FIG. 8 shows a configuration of a slot antenna 1b according to a third embodiment of the present invention. FIG. 8 (a) is a perspective view of a surface to which the coaxial cable 4 is connected, and FIG.
(B) is a perspective view of the back surface. In this figure, parts corresponding to those in FIGS. 1 and 4 described above are denoted by the same reference numerals. In the slot antenna 1b, the slot 3 near the side end of the conductor surface 2a
Each electrode of the chip capacitor 6 is connected to both sides of “a” by means such as soldering. This slot antenna 1b
In the slot antenna 1a of the second embodiment, a chip capacitor 6 is attached instead of the conductor protrusions 5a and 5b, and the thickness of the dielectric substrate 2, the width and length of the slots 3a and 3b, The conditions such as the connection point of the coaxial cable 4 are the same as in the second embodiment. Therefore, also in this embodiment, the same effects as in the second embodiment can be obtained.
Note that the chip capacitor 6 is not limited to the 2a surface of the dielectric substrate 2 and may be attached to the 2b surface or 2c surface. The number of chip capacitors 6 is not limited to one, and a plurality of chip capacitors 6 may be attached.

FIG. 9 shows a configuration of a slot antenna 1c according to a fourth embodiment of the present invention. FIG. 9 (a) is a perspective view showing a surface to which the coaxial cable 4 is connected.
(B) is a perspective view of the back surface. In this figure, the same reference numerals are given to portions corresponding to FIG. 1 described above. This slot antenna 1c is equivalent to the one in which no conductor is formed on the end face 2c of the slot antenna 1 of the first embodiment shown in FIG.

In the electric field distribution of the slot 3 of the first embodiment shown in FIG. 2, the magnitude is not shown only in the direction of the electric field, but the position where the electric field intensity is minimum is at the lower end of each of the vertical portions of the slots 3a and 3b. 3d, and the position where the electric field intensity is maximum is the horizontal portion of the slot 3c and the slots 3a and 3b in the vicinity thereof. As in the conventional example, the input resistance of the slot antenna 1 at the position of the maximum electric field strength is about 500.
Ω. In other words, the position where the electric field intensity is minimum can be considered to be a short circuit state, and the position where the electric field intensity is maximum is almost open, so that the slot 3a and the slot 3b can be electrically separated in the vicinity of the electric field intensity maximum position. . Therefore, in this embodiment, no conductor is formed on the end face 2c. The electric field distribution in the slots 3a and 3b in this case is the same as that in FIG. Then, the potential on each of the conductor surfaces 2a and 2b of the dielectric substrate 2 shown in FIG. 9 becomes the same potential at symmetric coordinate positions on the xz plane. Other operations are the same as in the first embodiment.

Also in this embodiment, since the slots 3a and 3b are formed on both surfaces of the dielectric substrate 2, the capacitor is formed by forming the conductor convex portions in the slots 3a and 3b as in the second embodiment. It is possible to further reduce the size of the slot antenna. Further, as in the third embodiment, by connecting chip capacitors to both sides of the end of the horizontal portion of the slot 3a on the conductor surface 2a of the dielectric substrate 2, it is possible to reduce the size of the slot antenna. . In this case, the chip capacitor is not limited to the conductor surface 2a of the dielectric substrate 2, but may be attached to the conductor surface 2b. The number of chip capacitors is not limited to one, and a plurality of chip capacitors may be attached. In the slot antenna 1c of this embodiment, the slot 3c of the slot antenna as shown in the first, second and third embodiments is used.
, The configuration of the slot antenna is simplified.

FIG. 10 is a perspective view showing a configuration of a slot antenna 1d according to a fifth embodiment of the present invention. In this figure, parts corresponding to those in FIG. 9 described above are denoted by the same reference numerals. Slot antenna 1d according to the present embodiment
Is equal to the configuration of the slot antenna 1c of the fourth embodiment shown in FIG. 9 except for the conductor surface 2b and the slot 3b. In this embodiment, the coaxial cable 4 is connected to the conductor surface 2a and is not attached to the back surface of the dielectric substrate 2. In this case, the mounting position of the coaxial cable 4 is the same as in the first to fourth embodiments.

In addition, a vertically polarized wave is radiated from the horizontal portion of the slot 3a of the present embodiment, and a horizontally polarized wave is radiated from the vertical portion. Other operations are the same as in the first embodiment.
Also in this slot antenna 1d, as in the third embodiment, chip capacitors are connected to both sides of the end of the horizontal portion of the slot 3a on the conductor surface 2a of the dielectric substrate 2, thereby reducing the size of the slot antenna. It is possible to In this case, the number of chip capacitors is not limited to one, and a plurality of chip capacitors may be attached.
In the slot antenna 1d of this embodiment, the slots 3b and / or 3 shown in the first to fourth embodiments are used.
Since it is not necessary to form c, the slot antenna can be configured with a single-sided substrate, and the manufacture is facilitated.

FIG. 11 is a perspective view showing a configuration of a slot antenna 1e according to a sixth embodiment of the present invention. The slot antenna 1e according to the present embodiment is composed of only the thin metal plate 7. In this case, the slot width is the first to fifth.
As in the embodiment, the slot length can be arbitrarily selected in the range of about 0.003λ to 0.03λ.
If no chip capacitor is installed, follow the first embodiment .
It is almost equal to the slot length on one side of the slot antenna 1 .
That is, the slot antenna 1e of this embodiment is
Length of the slot antenna 1 according to the first embodiment.
波長 wavelength, which is almost equal to half of the
Type antenna. However, in this example,
Since the dielectric of the gap portion of the slot 8 is air, slot length, slot A by each first and third embodiments
The length is about 0.01λ longer than the slot length on one side of the antenna . Further, similarly to the first to fifth embodiments, the lower end 8a of the vertical portion of the slot 8 is set at 0.01λ to 0.02λ.
The coaxial cable 9 is connected to the upper position. In this case, the coaxial cable 9 may be attached to either surface of the metal plate 7.

The operation of this embodiment is the same as that of the first embodiment. Also in this slot antenna 1e, a chip capacitor is connected between the metal plates 7 sandwiching the slot 8 near the end of the horizontal portion of the slot 8 as in the third embodiment. 1
e can be further miniaturized. The slot length is almost equal to that of the third embodiment when a chip capacitor is installed. In this case, the chip capacitor may be attached to either surface of the metal plate 7. The number of chip capacitors is not limited to one, and a plurality of chip capacitors may be attached. In this embodiment, since the slot antenna 1e is constituted only by the metal plate 7, it is possible to manufacture the slot antenna using a metal case or the like that shields a high-frequency circuit portion of the portable wireless device. It is effective as a built-in antenna of the machine.

FIG. 12 shows a configuration of a slot antenna 1f according to a seventh embodiment of the present invention.
(A) is a perspective view of the surface on which the conductor surface 2a is formed,
FIG. 12B is a perspective view of the back surface thereof. In the present embodiment, power is supplied by using a microstrip line instead of the coaxial cable in the fifth embodiment. In FIG. 12, the portions corresponding to those in FIG. ing. In the slot antenna 1f according to the present embodiment, a ス ロ ッ ト -shaped slot 3a is formed on the conductor surface 2a on the front side of the dielectric substrate 2, and a microstrip line 10 is formed on the back surface of the dielectric substrate 2. . Here, reference numeral 11 denotes a through hole connecting the conductor surface 2a and the microstrip line 10.

When the characteristic impedance of the microstrip line 10 is 50Ω, the microstrip line 10
Is formed on the back side of the dielectric substrate 2 at a position 0.01 λ to 0.02 λ above the lower end 3 d of the slot 3. Also,
The microstrip line 10 is formed so as to straddle the slot 3 a on the back surface of the dielectric substrate 2, and its end is connected to the vicinity of the slot 3 a by a through hole 11 to be in an electrically short circuit state. Therefore, coupling occurs between the microstrip line 10 and the slot 3a, and the slot 3a is excited.

In this embodiment, as in the third embodiment, a chip capacitor is connected between conductors sandwiching the slot 3 near the end of the horizontal portion of the slot 3a on the conductor surface 2a of the dielectric substrate 2 in the same manner as in the third embodiment. By doing so, it is possible to further reduce the size of the slot antenna. In this case, the number of chip capacitors is not limited to one, and a plurality of chip capacitors may be attached. Slot antenna 1 according to the present embodiment
When f is formed on the dielectric substrate of the high-frequency circuit portion of the portable wireless device, power can be supplied by the microstrip line, and the structure of the power supply system device is simplified. Therefore, this embodiment is effective as a built-in antenna of a portable wireless device.

[0034]

As described above, according to the present invention, the radiation directivity of vertically polarized waves in the horizontal plane of the slot antenna can be made uniform, and the size and weight of the slot antenna can be reduced. it can. Therefore,
There is an effect that a slot antenna suitable for a portable wireless device for mobile communication can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a slot antenna 1 according to a first embodiment of the present invention.

FIG. 2 is a view showing an electric field distribution in a slot 3 in the embodiment.

FIG. 3 is a diagram showing radiation directivity in the example.

FIG. 4 is a perspective view showing a configuration of a slot antenna 1a according to a second embodiment of the present invention.

FIG. 5 is a development view showing a shape near the horizontal portion end of the slot 3 in the embodiment.

FIG. 6 is a development view showing another example of the shape near the horizontal portion end of the slot 3 in the embodiment.

FIG. 7 is a diagram showing radiation directivity in the example.

FIG. 8 is a perspective view showing a configuration of a slot antenna 1b according to a third embodiment of the present invention.

FIG. 9 is a perspective view showing a configuration of a slot antenna 1c according to a fourth embodiment of the present invention.

FIG. 10 is a perspective view showing a configuration of a slot antenna 1d according to a fifth embodiment of the present invention.

FIG. 11 is a perspective view showing a configuration of a slot antenna 1e according to a sixth embodiment of the present invention.

FIG. 12 is a perspective view showing a configuration of a slot antenna 1f according to a seventh embodiment of the present invention.

FIG. 13 is a perspective view showing a configuration of a conventional slot antenna 101.

FIG. 14 is a diagram showing an electric field distribution in a slot 103 in the slot antenna 101.

FIG. 15 is a diagram showing the radiation directivity of the slot antenna 101.

[Explanation of symbols]

 1, 1a-1f Slot antenna 2 Dielectric substrate 2a, 2b Conductor surface 2c End surface 3a-3c, 8 slot 3d, 8a Lower end 4,9 Coaxial cable 4i Internal conductor 4o External conductor 5a, 5b Conductor protrusion 6 Chip capacitor 7 Metal Board 10 microstrip line 11 through hole

Claims (9)

(57) [Claims] A first substrate formed on a front side and a back side of the dielectric substrate;
And a second conductor surface, and first and second non-conductor portions, each of which has a symmetrical Γ shape on the front and back sides of the dielectric substrate formed on the first and second conductor surfaces, respectively. A slot antenna, wherein an outer conductor and an inner conductor of a coaxial cable connected to a communication device are respectively connected to conductor portions on both sides of the first or second non-conductor portion. 2. A third conductor surface continuous to the first and second conductor surfaces formed on one end surface of the dielectric substrate, and the first and second conductor surfaces formed on the third conductor surface. The slot antenna according to claim 1, further comprising a third non-conductive portion continuous with the second non-conductive portion. 3. A dielectric substrate; a conductor surface formed on one side of the dielectric substrate; and one end formed on the conductor surface such that one end reaches one side end of the dielectric substrate. A non-conductor portion having a Γ shape, wherein an outer conductor and an inner conductor of a coaxial cable connected to a communication device are respectively connected to conductor portions on both sides of the non-conductor portion. 4. A dielectric substrate, a conductor surface formed on the front side of the dielectric substrate, and one end formed on the conductor surface such that one end reaches one of the side ends of the dielectric substrate. A non-conductive portion having a Γ shape, on the back side of the dielectric substrate, one end is connected to a communication device, and the other end is a position symmetrical with a position across the non-conductive portion on the front side of the dielectric substrate. And a through-hole formed in the vicinity of the non-conductive portion at the other end of the microstrip line, wherein the through-hole is the conductor on the front side of the dielectric substrate. And a microstrip line connected to the microstrip line. 5. A metal plate, and a single non-conductor portion having a Γ shape formed through the metal plate, and one end of the non-conductor portion is connected to the metal plate.
Wherein the outer conductor and the inner conductor of the coaxial cable to be connected to the communication device are respectively connected to the conductor portions on both sides of the non-conductor portion. 6. An outer conductor and an inner conductor of the coaxial cable, when a wavelength to be transmitted and received is λ, in a vertical portion of the non-conductor portion, from a lower end to 0.01λ to 0.
The slot antenna according to any one of claims 1, 2, 3, and 5, wherein the slot antenna is connected to both sides of a position on 02λ. 7. The slot antenna according to claim 1, wherein a capacitor is formed at an end of the horizontal portion of the non-conductor portion. 8. The capacitor is formed by forming a conductor protruding into the 無 -shaped non-conductor portion and facing the other conductor surface on at least one of the front and back conductor surfaces of the dielectric substrate. The slot antenna according to claim 7, wherein: 9. The slot antenna according to claim 1, wherein each electrode of a chip capacitor is connected to a conductor portion on both sides of an end of the horizontal portion of the non-conductor portion.