JP2002064325A - Element antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an element antenna, which is thin and has broadband characteristics, concerning an element antenna provided with a cavity for radiation in a single direction. SOLUTION: In the element antenna having a flare slot having broadband characteristics and the cavity, a flare cavity is composed of a base conductor, which is parallel with the flare slot, having almost the same form and almost the same area and a side face conductor for electrically connecting the flare slot and the base conductor so that a thin and broadband characteristic antenna can be provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an element antenna having a cavity for radiating in a single direction and having a thin and wide band characteristic.

[0002]

2. Description of the Related Art FIG. 12 is an external view showing a conventional antenna device. This is an IEEE Trans. AP. Vo
l. AP-35, No. 8 is an example. FIG. 13 is a diagram illustrating the reflection characteristics of the conventional antenna device, and FIG. 14 is a diagram illustrating the radiation patterns of the electric field surface (a) and the magnetic field surface (b) in the conventional antenna device.

In FIG. 12, reference numeral 47 denotes a dielectric substrate;
8 is a copper foil on the dielectric substrate 47, 49 is a copper foil 48
The vertically polarized slot 50 provided on the copper foil 48 by etching is provided above the vertically polarized slot 50.
9 is a slot for horizontal polarization provided by etching so as to be orthogonal to the center at 9;
9 and the horizontal polarization slot 50, a flare type slot 52, a vertical polarization microstrip feed line 52 for feeding the vertical polarization slot 49 from the end using the copper foil 49 as a base plate, and 53 The copper foil 49 is used as a ground plane, and the horizontal polarization slot 50 is fed from the end. The horizontal polarization microstrip feed line 54 is connected to the copper foil 48 by the vertical polarization microstrip feed line 52.
And a cavity having a circular bottom provided on the side of the microstrip feed line 53 for horizontal polarization.

Next, the operation will be described. For example, in the vertical polarization slot 49, the position of the short-circuited state returning from the open end of the vertical polarization microstrip line 52 to the approximately １ ／ wavelength power supply side and approximately 1 / The electromagnetic wave energy input to the vertically polarized microstrip line 52 by crossing the position of the open state four wavelengths away is supplied to the vertically polarized slot 49 by a wide-band coupling characteristic. Vertical polarization slot 4
9 has a gap gradually widening from the position where it is opened, and the electromagnetic wave radiates an electromagnetic wave having a frequency corresponding to a half wavelength to free space while propagating through the gap. Then, it continues to radiate while propagating from the center of the vertically polarized slot 49 while the gap becomes narrower, and is reflected at the other short-circuited end and radiates electromagnetic waves of the same condition while propagating again. Shows broadband radiation characteristics.

At this time, if the longitudinal direction of the vertically polarized slot 49 is made horizontal to the ground, the electric field is orthogonal to the longitudinal direction, so that vertically polarized waves can be obtained. Further, when the slots having the same dimensions as the vertical polarization slots 49 are orthogonal to each other at the center, the flared slots 51 are formed. Less coupling.

Therefore, if electromagnetic wave energy is supplied through the horizontal polarization microstrip feed line 53, the slot orthogonal to the vertical polarization slot 49 is similar to the vertical polarization slot 49 because the longitudinal direction is perpendicular to the ground. Operates as a horizontally polarized slot 50 for a wide band. Therefore, the flare type slot can obtain vertical and horizontal polarizations in a wide band. In addition, by supplying electromagnetic wave energy of equal amplitude and 90 degrees phase difference to the vertical polarization microstrip feed line 52 and the horizontal polarization microstrip feed line 53, circular polarization can be obtained.

In the above configuration, the flared slot radiates in both directions from the copper foil 48. Therefore, as shown in FIG. 12, a cavity 54 having a depth of one wavelength at the center frequency of the band to be used is provided on one side of the copper foil as a reflector.
Since an absorber is inserted into the cavity 54 to suppress unnecessary reflection in the cavity 54, a broadband reflection characteristic as shown in FIG. 13 is exhibited. By providing the cavity 54, as shown in FIGS. 14A and 14B, a radiation pattern having a beam only in the front direction is drawn.

[0008]

Since the conventional antenna device is configured as described above, the external dimensions of the antenna device are determined by the external dimensions of the cavity. The length of the cavity in the depth direction can be determined as a reflector, but if the length in the depth direction is shortened, generally the impedance becomes low, the band becomes narrow, and it becomes difficult to reduce the thickness. There was a problem. Further, although the shape of the bottom surface of the cavity is arbitrary, there is a problem that the size of the cavity cannot be easily reduced because it affects the characteristics as a cavity resonator.
Furthermore, since there is one feeding point for one slot and it is offset from the line of symmetry of the slot shape, there is a problem that the beam on the magnetic field surface is inclined and it is difficult to obtain a symmetric radiation pattern. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to realize a wide-band antenna device with a small and small cavity having a small area. Another object of the present invention is to reduce the tilt angle of the beam and obtain a symmetrical unidirectional radiation pattern.

[0010]

According to a first aspect of the present invention, there is provided an element antenna provided on a conductor plate, the length of which is approximately half a wavelength at a first frequency of a used band. A first slot having a width gradually reduced so as to have a width sufficiently narrower than a wavelength of a high frequency band from the center toward both ends to a position of approximately 1/4 wavelength, and the first slot described above. A second slot having the same shape and the same area as the slot, and being provided on the conductor plate so as to be orthogonal to the first slot at the center thereof;
Four rectangular slots respectively connected to both ends of the slot at a second frequency and having a length of about 1/4 wavelength at the second frequency;
A flared slot comprising the first slot, the second slot, and the rectangular slot; a bottom conductor parallel to the conductor plate and having substantially the same shape and substantially the same area as the flared slot; And a side conductor for electrically connecting the bottom conductor, and a flare-shaped cavity having a power supply means for supplying power in the vicinity of a connection between the first slot or the second slot and the rectangular slot. Things.

An element antenna according to a second aspect of the present invention is provided with a conductor plate and a length provided on the conductor plate, wherein the width near the center is substantially half a wavelength at the first frequency of the operating band. And a first slot whose width is gradually reduced so as to be sufficiently narrower than a wavelength of a high frequency from the first to the both ends to a position of approximately 1/4 wavelength, and the same shape as the first slot. A second slot which has the same area and is provided on the conductor plate so as to be orthogonal to the first slot at the center.
And a circular slot connected to both ends of the first slot and the second slot, and having a size such that the circumference thereof is approximately a half wavelength of the second frequency.
A flared slot comprising the first slot, the second slot, and the circular slot; a bottom conductor parallel to the conductor plate and having substantially the same shape and substantially the same area as the flared slot; A flare-shaped cavity comprising a side conductor electrically connecting the slot and the bottom conductor, and having a feeding means for feeding power near a connection between the first slot or the second slot and the circular slot. Things.

In the element antenna according to a third aspect of the present invention, the feeding means is provided in the groove provided on the conductor plate, and further provided inside the groove in parallel with the groove, and the end is connected to the boundary of the flared slot. A coplanar line made of a strip-shaped conductor is provided.

Further, in the element antenna according to a fourth aspect of the present invention, the feeding means is disposed at a position parallel to the conductor plate and between the conductor plate and the bottom conductor, the outer conductor is grounded to the side conductor, and the inner conductor is The side conductor is connected to the side opposite to the ground portion of the side conductor across the first slot or the second slot.

According to a fifth aspect of the present invention, in the element antenna, the feeding means includes a second conductor plate including a bottom conductor and parallel to the conductor plate;
A strip conductor parallel to the conductor plate and positioned between the second conductor plate at a lower portion of the conductor plate, and a width direction of the strip conductor at a portion where the strip conductor crosses a side conductor. A window opened in parallel with the second frequency at a size of about half a wavelength or more and the strip-shaped conductor are connected to a side conductor at a position opposite to the window to form a triplate line structure.

Further, in the element antenna according to a sixth aspect of the present invention, the feeding means is placed below the bottom conductor in parallel with the side conductor.
An outer conductor is grounded to the bottom conductor, and an inner conductor is bent to use a coaxial feed line connected to the bottom conductor.

An element antenna according to a seventh aspect of the present invention is provided on a dielectric substrate, a metal foil such as a copper foil provided on both surfaces of the dielectric substrate, and a metal foil on one of the metal foils. ,
The width near the center has a length that is approximately a half wavelength at the first frequency of the used band, and is approximately 1 from the center toward both ends.
A first slot whose width is gradually reduced so as to have a width sufficiently smaller than a wavelength of a high frequency band up to the position of / 4 wavelength, and a first slot having the same shape and the same area as the first slot; A second slot provided on the conductive plate so as to be orthogonal to the first slot at the center is connected to both ends of the first slot and the second slot, respectively. Four rectangular slots having a length of four wavelengths, a flared slot comprising the first slot, the second slot and the rectangular slot, a metal foil provided with the flared slot, and another metal A flare-shaped cavity comprising a connection conductor for electrically connecting a foil and having a power supply means for supplying power near a connection between the first slot or the second slot and the rectangular slot. A.

In the element antenna according to an eighth aspect of the present invention, the feeding means is a first feeding line, and the center of the first slot or the second slot is line-symmetric or rotationally symmetric with the first feeding line. To the second feeder line
In-phase or out-of-phase signals having the same amplitude are input to the first feed line and the second feed line, respectively.

In the element antenna according to a ninth aspect of the present invention, in the second feed line, the connection position between the flare type slot and the connection portion between the second slot portion and the fifth slot portion or the second slot portion may be changed. This is a connection portion between the portion and the sixth slot portion, and signals having equal amplitudes and a phase difference of 90 degrees from each other are input to the first and second power supply lines.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is a top view (a) and a perspective perspective view (b) showing an element antenna according to the first embodiment, FIG. 2 is an enlarged view around a coaxial feed line (a) for explaining the operation principle, and AA ′. FIG. 3 is a perspective view (a), a radiation pattern diagram (b), and a reflection characteristic diagram (c) for explaining the characteristics. .

In the figure, reference numeral 1 denotes a conductor plate, and 2 is provided on the conductor plate 1. The width near the center has a length of about a half wavelength at the first frequency and is smaller than the wavelength of the higher frequency band. The first slot 3 has the same shape as the first slot 2 and has a shape which is symmetrical at the center from the center to the both ends so as to have a sufficiently small width and has a width gradually reduced to a position of about 1/4 wavelength. And second slots 4 and 4 having the same area and provided on the conductor plate 1 so as to be orthogonal to the first slots 2.
Are connected to both ends of the first slot 2 and the second slot 3, respectively, and are connected to the first slot 2 or the second slot 2.
Four rectangular slots having the same width as both ends of the slot 3 and having a length of about 1/4 wavelength at the second frequency, 5 being the first slot 2, the second slot 3 and the rectangular slot. 4, a flared slot 6; an outer conductor 6; an inner conductor 7; a connection point 8 of the inner conductor 7 to the conductor plate 1; a coaxial feed line 9 consisting of the outer conductor 6 and the inner conductor 7; Reference numeral 10 denotes a bottom conductor which is parallel to the conductor plate 1 and has substantially the same shape and substantially the same area as the flared slot 5, and 11 denotes the flared slot 5 and the bottom conductor 10.
Is a flare-shaped cavity composed of the flared slot 5, the bottom conductor 10, and the side conductor 11, 13 is a current flowing through the inner conductor 7, and 14 is induced by the current 13. Magnetic field, 15
Is the short-circuited end of the rectangular slot 4 connected to the first slot 2, 16 is the electric field distribution inside the first slot 2, 17 is the electric field vector inside the flare type cavity 12, and 18 is the electric field vector 17 , 19 is the propagation direction of the traveling wave inside the flare type cavity 12,
20 is the propagation direction of the reflected wave from which the traveling wave 19 is reflected at the other end of the first slot 2, and 21 is the electric field in the flare type cavity 12.

Next, the operation of the element antenna will be described. In FIG. 2A, a current 13 flowing through the inner conductor 7 induces a magnetic field 14 around it. When the coaxial feed line 9 is installed so as to straddle the inner conductor 7 at a quarter wavelength from one short-circuit end 15 of the rectangular slot 4 in a direction orthogonal to the first slot 2, as shown in FIG. The electric field vector 17 generated in the first slot 2 is orthogonal to the magnetic field 14, and the induced electric field has an electric field distribution 16 as shown in FIG. become. Therefore, the electromagnetic wave energy from the coaxial feed line 9 is efficiently converted to the flared slot 5 and supplied.

As shown in FIGS. 2B and 2C, the supplied electromagnetic wave energy propagates through the first slot 2 in the traveling direction 19 of the traveling wave as guided by the waveguide. . At this time, the gap of the first slot 2 is gradually widened, and the electromagnetic wave energy propagates through the gap.
Electromagnetic waves having a frequency whose width is substantially equal to a half wavelength are radiated to free space. The electromagnetic wave of the same condition while continuing to radiate while propagating while the gap of the first slot 2 is being narrowed, and being reflected by the other short-circuited end and propagating again in the direction of propagation 20 of the reflected wave. Radiates broadband radiation characteristics.

As an example of the radiation pattern, an electric field plane (zy plane) and a magnetic field plane (zx plane) represented by a coordinate system shown in FIG. Since the electric field distribution in the direction of the electric field plane is symmetric with respect to the center of the first slot 2, the radiation pattern of the electric field plane is symmetric with respect to the front direction. In the direction of the magnetic field, the radiation pattern is a combined radiation pattern of a traveling wave and a reflected wave. After the first slot 2 gradually widens along the traveling wave propagation direction 19, the width gradually narrows from the vicinity of the center, and an electromagnetic wave having a frequency at which the width becomes substantially half a wavelength is emitted. ), The reflection characteristic becomes broader.

As described above, the flare-shaped cavity 12 and the flare-shaped slot 5 are formed by tapering the open-ended waveguide.
By configuring the element antenna as described above, the radio wave absorber is not required, and the effect of high efficiency, thin shape, and wide band can be obtained.

Embodiment 2 FIG. 4 is a top view (a) and a perspective perspective view (b) of an element antenna device according to Embodiment 2 of the present invention. In the second embodiment, instead of the rectangular slot 4 connected to the first slot 2 and the second slot 3, a circular slot 22 having a perimeter of approximately half a wavelength is provided. 2 (b) and 2 (c), respectively, and FIG. 3 (b) shows a radiation pattern diagram and a reflection characteristic diagram, respectively. ) And (c).

As described above, according to the element antenna of the second embodiment, good radiation characteristics and reflection characteristics can be obtained over a wide band on the same principle as that of the first embodiment. Further, the provision of the circular slot 27 having a perimeter of a half wavelength makes it possible to obtain an effect that the electromagnetic field energy from the coaxial feed line 9 to the flared slot 5 can be converted and supplied over a wider band.

Embodiment 3 FIG. 5 is a top view (a) showing an element antenna according to a third embodiment of the present invention, and an enlarged view (b) showing the vicinity of a feeder. A groove 23 provided on the conductor plate 1 at the ground portion of the outer conductor 6 of the coaxial power supply line 9 in place of the coaxial power supply line 9;
And a coplanar line composed of a strip-shaped conductor 24 whose end is connected to the connection point 8 of the flared slot 5 on the conductor plate 1. The schematic diagram of the electric field mode pattern in the slot according to the third embodiment is the same as FIG. 2C, and the radiation pattern diagram and the reflection characteristic diagram are the same as FIG. 3B and FIG. 3C, respectively.

As described above, according to the element antenna of the third embodiment, the groove 23 shown in FIG.
And the electromagnetic wave energy applied between the band-shaped conductor 24 propagates upward in the figure and is supplied to the flared slot 5,
It looks like an electric field 25 in the slot. The principle of the subsequent electromagnetic wave radiation is the same as in the first embodiment. Unlike the case where the feed circuit is formed by the coaxial feed line, the feed circuit can be formed only by the plate-shaped conductor, and an effect that a thin broadband element antenna excellent in mass productivity can be obtained is obtained.

Embodiment 4 FIG. 6 is a top view (a) of an element antenna according to a fourth embodiment of the present invention and an enlarged view (b) of the vicinity of a power supply unit. In the fourth embodiment, the outer conductor 6 is placed on the coaxial feed line 9 in a position parallel to the conductor plate 1 and between the bottom conductor 10 and the lower portion of the conductor plate 1.
To the side conductor 11 and the inner conductor 7 to the first slot 2
Is connected to the connection point 8 on the side opposite to the grounding portion of the side conductor 11. The schematic diagram of the electric field mode pattern in the slot according to the fourth embodiment is shown in FIG.
(C), the radiation pattern diagram and the reflection characteristic diagram are respectively shown in FIG.
Same as (b) and (c).

As described above, in the element antenna according to the fourth embodiment, the electromagnetic wave energy is supplied from the coaxial feed line 9 as the current 13 flowing through the inner conductor 7. The magnetic field 14 induced by the current 13 produces orthogonal electric field vectors 17. The principle of the subsequent electromagnetic wave radiation is the same as in the first embodiment. If the positions of the outer conductor 6 and the connection point 8 are located between the conductor plate 1 and the bottom conductor 10, and the flare-shaped cavity 12 is a waveguide, the ground point of the outer conductor 6 is brought closer to the bottom conductor 10. The impedance seen from the side looks lower than when the conductor plate 1 is grounded. Therefore, the input impedance can be controlled by the ground position. The principle of the subsequent electromagnetic wave radiation is the same as in the first embodiment. As described above, the effect that the input impedance can be controlled can be obtained by connecting the coaxial feed line 9 at a position near the bottom conductor 10 from the conductor plate 1 provided with the slot.

Embodiment 5 FIG. 7 is a top view (a) of an element antenna according to a fifth embodiment of the present invention and an enlarged view (b) of the vicinity of a feeder for explaining the operation principle. In the fifth embodiment, instead of the coaxial feed line 9, the second conductor plate 27 including the bottom conductor 10 and being parallel to the conductor plate 1 is provided.
Parallel to the conductor plate 1 and the second
A band-like conductor 26 placed at a position between the conductor plate 27 and
A window 28 opened at a portion where the band-shaped conductor 26 intersects with the side-surface conductor 11 in a direction parallel to the width of the band-shaped conductor 26 at a first frequency with a size of about half a wavelength or more, and the band-shaped conductor 26 It is connected to the side conductor 11 at a position opposite to the window 28 at a connection point 29 to form a triplate line structure. The schematic diagram of the electric field mode pattern in the slot according to the fifth embodiment is the same as FIG. 2C, and the radiation pattern diagram and the reflection characteristic diagram are the same as FIGS. 3B and 3C, respectively.

As described above, in the element antenna according to the fifth embodiment, the electromagnetic wave energy passes through the window 28 by the triplate line composed of the conductor plate 1, the second conductor plate 27 and the band conductor 26, It is supplied as a current 13 flowing on 26. The magnetic field 14 induced by the current 13 produces orthogonal electric field vectors 17. The principle of the subsequent electromagnetic wave radiation is the same as in the first embodiment. Unlike the case where the power supply circuit is formed by the coaxial power supply line 9, the power supply circuit can be formed only by the plate-shaped conductor, so that the connection structure with the radio circuit such as the transmission / reception device can be integrated, and the connection portion between the element antenna and the transmission / reception device can be small. The effect that can be obtained is obtained.

Embodiment 6 FIG. FIG. 8 is a top view (a) of an element antenna and an enlarged view (b) of the vicinity of a feeder according to a sixth embodiment of the present invention. In the sixth embodiment, the outer conductor 31 is grounded to the bottom conductor 10, the inner conductor 30 is bent, and the bottom conductor 10 is connected to the bottom conductor 10. Coaxial feed line 32
Is used. The schematic diagram of the electric field mode pattern in the slot according to the sixth embodiment is shown in FIG.
The radiation pattern diagram and the reflection characteristic diagram are shown in FIG.
Same as (c).

As described above, in the element antenna according to the sixth embodiment, the electromagnetic wave energy is supplied into the flare type cavity 12 by the coaxial feed line 9 as the current 13 flowing on the inner conductor 30. Although the magnetic field 14 is induced by the current 13, the length of the bent inner conductor 30 is sufficiently smaller than the wavelength, and the magnetic fields 14 induced by the current 13 flowing in the portion parallel to the side conductor 11 cancel each other out. Only the magnetic field 14 induced by the current 13 flowing in the portion parallel to the conductor 10 is obtained. This magnetic field 14 induces a current vector 17 in the flared cavity 12. The principle of the subsequent electromagnetic wave radiation is the same as in the first embodiment. Since the coaxial feed line 9 can be provided perpendicular to the bottom conductor 10, there is an effect that the impedance can be controlled while reducing the occupied area as viewed from the top surface of the flare type slot 5 including the coaxial feed line 32.
Although the inner conductor 30 is bent in a rectangular shape in the drawing, a similar effect can be obtained by bending the inner conductor 30 in a circular shape.

Embodiment 7 FIG. FIG. 9 is a top view (a) and a perspective perspective view (b) of an element antenna according to a seventh embodiment of the present invention. In the seventh embodiment, the conductor plate 1 and the bottom conductor 10 or the second conductor plate 27 including the bottom conductor 10 are provided.
Instead, a dielectric substrate 35 having a metal foil, for example, a copper foil 33 on both sides, is used, and the side conductor 11 and the side conductor 1 are used.
The conductor parallel to 1 is replaced by a connection conductor 34 in a dielectric substrate 35. The electric field mode pattern in the slot according to the seventh embodiment is schematically shown in FIG.
The radiation pattern diagram and the reflection characteristic diagram are shown in FIG.
Same as (c).

As described above, in the element antenna according to the seventh embodiment, instead of the conductor plate 1 and the bottom conductor 10 or the second conductor plate 27 including the bottom conductor 10, copper foils 33 are provided on both surfaces. Using the dielectric substrate 35, the side conductor 11 and the conductor parallel to the side conductor 11 are replaced with connection conductors 34 (for example, through holes) in the dielectric substrate 35. Since the intervals between the connection conductors 34 are arranged at intervals of approximately half a wavelength or less of the first frequency, electromagnetic waves cannot pass between the connection conductors 34. Therefore, the same effect as that of the conductor wall can be obtained. Further, since the dielectric substrate 35 is used, the flare type slot 5 and the flare type cavity 12 can be reduced in size due to the wavelength shortening effect. Further, by replacing the entire configuration with the dielectric substrate 35, there is an effect that manufacturing can be performed using a substrate processing technique. Although a plurality of columnar connection conductors 34 are continuously arranged in the drawing, a similar effect can be obtained by processing a plurality of connection conductors into one longitudinal hole by router processing or the like.

Embodiment 8 FIG. FIG. 10 is a top view (a) and a pattern diagram (b) of an element antenna according to Embodiment 8 of the present invention. In the eighth embodiment, a coaxial feed line, a coplanar line, or a triplate line is used.
One feed line 36, in addition to the first feed line 36,
A second power supply line 37 is connected to the center of the first slot 2 or the second slot 3 at a position symmetrical with the first power supply line 36, and the first power supply line 36 and the second power supply line 36 are connected to each other. In-phase signals are input to the line 37 at the same amplitude. 2 (b) and 2 (c), respectively, and FIG. 3 (b) is a radiation pattern and reflection characteristic diagram, respectively. , (C).

As described above, the element antenna according to the eighth embodiment includes the first feed line 36 and the first feed line 36.
The second feed line 37 is connected to the center of the slot 2 or the second slot 3 with respect to the first feed line 36 at a position symmetric or rotationally symmetric with the first feed line 36.
By inputting in-phase or out-of-phase signals with equal amplitude to the second feed line 37 and the second feed line 37, electromagnetic wave energy supplied from each feed line is radiated according to the same principle as in the first embodiment. The radiation patterns are shown in FIG.
The beam tilts as shown in FIG. Then, the electromagnetic waves supplied from the two feeding lines are radiated and added, and the radiation pattern becomes symmetric with respect to the front direction as indicated by 40 in FIG. 10B.

Embodiment 9 FIG. 11 is a top view (a) of an element antenna and a diagram (b) of an electric field pattern in a slot according to a ninth embodiment of the present invention. Embodiment 9
Is a rectangular slot connected from the first slot 2 to the second slot 3 or from the second slot 3 to one end of the first slot 2. Move to the vicinity of the connection with
In this example, signals having the same amplitude and a phase difference of 90 degrees from each other are input to the feeder line 41 and the second feeder line. 2B and 2C, respectively, and FIG. 3B shows a radiation pattern and a reflection characteristic diagram, respectively. , (C).

As described above, in the element antenna according to the ninth embodiment, the connection position between the second feed line 42 and the flared slot 5 is changed from the first slot 2 to the second slot 3 or the second slot 3. By moving from the slot 3 to the vicinity of the connection with the rectangular slot 4 connected to one end of the first slot 2, as shown in FIG. An electric field 45 is generated by the first feed line 42, and the direction of polarization 44 by the first feed line 41 and the direction of polarization 46 by the second feed line 42 are orthogonal to each other. Therefore, horizontal and vertical polarization can be shared. Further, the first and second power supply lines 4
When signals having the same amplitude and a phase difference of 90 degrees are input to the first and the second 42, the above polarization directions 44 and 46 are excited with the same amplitude and a phase difference of 90 degrees. Polarization can be obtained.

[0041]

According to the first aspect of the present invention, there is provided an element antenna having a flare-shaped slot and a cavity, wherein a bottom conductor parallel to the flare-shaped slot and having substantially the same shape and substantially the same area; Since the flare-type cavity and the side conductor that electrically connects the slot and the bottom conductor are formed, a radio wave absorber is not required, and an effect that a highly efficient, thin, and wide-band element antenna can be realized is obtained.

According to the second aspect of the present invention, in the element antenna having the flare-shaped slot and the cavity, the slot of the connecting portion of the coaxial feed line is formed in a circular shape having a peripheral length of substantially a half wavelength at the second frequency. A flare-shaped cavity comprising a bottom conductor parallel to the flare-shaped slot, having substantially the same shape and substantially the same area, and a side conductor electrically connecting the flare-shaped slot and the bottom conductor. In addition to the broadband radiation characteristics, an effect that the connection with the feed line can be widened can be obtained.

According to the third aspect of the invention, in the element antenna having the flare type slot and the cavity, a thin broadband element antenna excellent in mass productivity can be obtained by using a coplanar line instead of the coaxial feed line. The effect is also obtained.

According to the fourth aspect of the invention, in the element antenna having the flared slot and the cavity, the input impedance is reduced by connecting the coaxial feed line from the conductor plate provided with the slot at a position close to the bottom conductor. The effect of being able to control is also obtained.

According to the fifth aspect of the present invention, in the antenna device having the flare type slot and the cavity, the side surface conductor of the flare type cavity is provided with a window, and the power is supplied by the triplate line. The connection structure of the transmission / reception device and the wireless circuit can be integrated, and the effect of miniaturizing the connection structure between the element antenna and the transceiver can be obtained.

According to the sixth aspect of the present invention, in the element antenna having the flare-shaped slot and the cavity, the inner conductor of the coaxial feed line connected to the bottom conductor is bent and connected to the bottom conductor. There is also an effect that the impedance can be controlled while reducing the occupied area as viewed from the upper surface of the flare type cavity including the feed line.

According to the seventh aspect, in the element antenna having the flared slot and the cavity, the slot and the bottom conductor are formed of, for example, a copper-clad dielectric substrate, and the side conductor and the conductor parallel to the side conductor are formed of the connection conductor. This has an effect that the multi-layer substrate can be easily manufactured by a processing technique, and mass productivity can be improved. In addition, there is an effect that the size can be reduced due to the wavelength shortening effect of the dielectric.

According to the eighth aspect of the present invention, in the element antenna having the flared slot and the cavity,
By connecting the first feed line and the first feed line at a line symmetric or rotationally symmetric position from the center of the slot and feeding power in the same or opposite phases, a radiation pattern symmetric in the front direction can be obtained. There is also.

According to the ninth aspect, in the element antenna having the flare type slot and the cavity, the second feed line is connected to the position orthogonal to the first feed line and the slot, so that the horizontal and vertical polarization can be achieved. There is also an effect that a circularly polarized wave can be obtained by inputting signals having the same amplitude and a phase difference of 90 degrees in response to common use.

[Brief description of the drawings]

FIG. 1 is a first embodiment of an antenna device according to the present invention;
3A and 3B are a top view and a perspective perspective view, respectively.

FIG. 2 is an enlarged view around a coaxial feed line, an AA ′ cross-section and a perspective view, and a schematic view of an electric field mode pattern in a slot for explaining an operation principle.

FIG. 3 is a perspective view, a radiation pattern diagram, and a reflection characteristic diagram for explaining characteristics.

FIG. 4 is a second embodiment of the antenna device according to the present invention;
3A and 3B are a top view and a perspective perspective view, respectively.

FIG. 5 is a third embodiment of the antenna device according to the present invention;
FIG. 5A is a top view showing the power supply unit, and FIG.

FIG. 6 is a fourth embodiment of the antenna device according to the present invention;
FIG. 5A is a top view showing the power supply unit, and FIG.

FIG. 7 is a fifth embodiment of the antenna device according to the present invention;
FIG. 5A is a top view showing the power supply unit, and FIG.

FIG. 8 is a sixth embodiment of the antenna device according to the present invention;
FIG. 5A is a top view showing the power supply unit, and FIG.

FIG. 9 is a seventh embodiment of the antenna device according to the present invention;
3A and 3B are a top view and a perspective perspective view, respectively.

FIG. 10 is a top view and a radiation pattern diagram showing an eighth embodiment of the antenna device according to the present invention.

FIG. 11 is a top view showing an embodiment 9 of the antenna device according to the present invention and a diagram of an electric field pattern in a slot for explaining an operation principle.

FIG. 12 is a perspective view showing a conventional antenna device.

FIG. 13 is a diagram showing reflection characteristics of a conventional antenna device.

FIG. 14 is a diagram showing a radiation pattern of an electric field surface and a magnetic field surface of a conventional antenna device.

[Explanation of symbols]

1 conductor plate, 2 first slot, 3 second slot,
4 rectangular slot, 5 flare type slot, 6 outer conductor, 7
Inner conductor, 8 connection points, 9 coaxial feed line, 10 bottom conductor, 11 side conductor, 12 flared cavity, 15
Short-circuit end, 22 circular slot, 23 groove, 24 band conductor, 26 band conductor, 27 second conductor plate, 28 window,
29 connection point, 30 inner conductor, 31 outer conductor, 32 coaxial feed line, 33 copper foil, 34 connection conductor, 35 dielectric multilayer substrate, 36 first feed line, 37 second feed line, 4
1 1st feed line, 42 2nd feed line, 47 dielectric substrate, 48 copper foil, 49 slot for vertical polarization, 50 slot for horizontal polarization, 51 flared slot, 52 microstrip feed for vertical polarization Line, 53 Microstrip feed line for horizontal polarization, 54 cavities.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Teruo Furuya 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term in Mitsubishi Electric Corporation (reference) 5J045 AA02 AA21 DA03 EA05 HA06

Claims (9)

[Claims] 1. A conductor plate, provided on said conductor plate, having a length in which a width near a center is substantially a half wavelength at a first frequency of a use band, and is approximately 1 / from the center toward both ends.
A first slot whose width is gradually reduced so as to be sufficiently narrower than the wavelength of the high frequency band up to the position of four wavelengths;
A second slot having the same shape and the same area as the first slot and provided on the conductor plate so as to be orthogonal to the first slot at the center, and the first slot and the second slot; Four rectangular slots respectively connected to both ends of the slot and having a length of about 1/4 wavelength at a second frequency; and a flared slot comprising the first slot, the second slot, and the rectangular slot. A bottom conductor parallel to the conductor plate and having substantially the same shape and substantially the same area as the flared slot; and a side conductor electrically connecting the flared slot and the bottom conductor. An element antenna comprising a flare-shaped cavity provided with a feeding means for feeding power in the vicinity of a connection between the slot or the second slot and the rectangular slot. 2. A conductor plate, provided on the conductor plate, having a length in which a width near a center is substantially a half wavelength at a first frequency of a use band, and is approximately 1 from the center toward both ends.
A first slot whose width is gradually reduced so as to have a width sufficiently smaller than a wavelength of a high frequency band up to the position of / 4 wavelength, and a first slot having the same shape and the same area as the first slot; A second slot provided on the conductor plate so as to be orthogonal to the first slot at the center is connected to both ends of the first slot and the second slot, and the circumference thereof is the second frequency. The first slot, the second slot, and the second slot.
And a bottom conductor having the same shape and substantially the same area as the flared slot parallel to the conductor plate and electrically connecting the flared slot to the bottom conductor. And the first slot or the second slot
An element antenna comprising a flare-shaped cavity provided with a power supply means for supplying power near a connection between the circular slot and the circular slot. 3. A coplanar line having a band-shaped conductor provided inside a groove provided on a conductor plate in parallel with the groove and having an end connected to a boundary portion of the flared slot. The element antenna according to claim 1 or 2, wherein: 4. The power supply means is placed parallel to the conductor plate and at a position between the conductor plate and the bottom conductor, the outer conductor is grounded to the side conductor, and the inner conductor is the first slot or the second conductor. 3. The element antenna according to claim 1, wherein the side surface conductor is connected to a side opposite to the ground portion of the side conductor across the slot. 5. A power supply device comprising: a second conductor plate including a bottom conductor and parallel to a conductor plate; and a second conductor plate parallel to the conductor plate and below the conductor plate. A band-shaped conductor placed at a position, a window opened at a portion where the band-shaped conductor intersects with the side conductor, at a second frequency and at least a half wavelength or more at a second frequency in parallel with the width direction of the band-shaped conductor; The element antenna according to claim 1 or 2, wherein a conductor is connected to the side conductor at a position facing the window to form a triplate line structure. 6. A coaxial power supply line in which the power supply means is placed below the bottom conductor in parallel with the side conductor, the outer conductor is grounded to the bottom conductor, and the inner conductor is bent to connect to the bottom conductor. The element antenna according to claim 1, wherein the element antenna is configured by: 7. A dielectric substrate, a metal foil such as a copper foil provided on both surfaces of the dielectric substrate, and a metal foil provided on one of the metal foils and having a width near the center. Band 1
Has a length that is approximately a half wavelength at the frequency of, and gradually narrows the width from the center to both ends to approximately 1/4 wavelength, so that it is sufficiently narrower than the wavelength of the high frequency band. A first slot, a second slot having the same shape and the same area as the first slot, and provided on the conductor plate so as to be orthogonal to the first slot at the center thereof; Four rectangular slots respectively connected to both ends of the second slot and the second slot and having a length of about 1/4 wavelength at a second frequency; and
A flare-type slot comprising the second slot and the rectangular slot; a connection conductor for electrically connecting a metal foil provided with the flare-type slot to another metal foil; and the first slot Alternatively, an element antenna comprising a flare-shaped cavity provided with a power feeding means for feeding power near a connection between the second slot and the rectangular slot. 8. The power supply device according to claim 1, wherein the power supply means is a first power supply line.
The second feed line or the second feed line is symmetrically or rotationally symmetric with respect to the center of the second feed slot or the second feed slot.
The element antenna according to any one of claims 1 to 7, wherein the first feed line and the second feed line are connected to each other, and signals having the same phase or the opposite phase with the same amplitude are input to the first feed line and the second feed line, respectively. 9. In the second power supply line, the second power supply line
Is moved from the first slot to the second slot or from the second slot to the vicinity of the connection with the rectangular slot connected to one end of the first slot. 10. The element antenna according to claim 9, wherein signals having equal amplitudes and having a phase difference of 90 degrees are input to the second feeder lines.