JPH09246849A - Taper slot antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a reflecting characteristic over a broad band by forming a notch that is formed by removing a ground conductor in a shape to have a bent in nearly axis symmetry with respect to a rotation symmetrical axis at a position of a taper slot line on a ground conductor face in nearly axis symmetry with respect to the rotation symmetrical axis. SOLUTION: At a lower frequency band where a width W of an open end of a taper slot line 6a is less than 1/2 wavelength, a current path along a line 6a is extended up to an end of a notch 7a via a folded part from an open end of the line 6a so as to concentrate a current not attenuated in the vicinity of the open end of the line 6a onto a folded part of the notch 7a and to attenuate sufficiently the current at the end of the notch 7a thereby forming a traveling wave current distribution along the vicinity of a line 6a. Thus, a current flowing along the vicinity of the line 6 on a ground conductor plane 3a is not attenuated in the vicinity of the line 6a but attenuated at the end via a bent of the notch 7a. That is, the bent acts like an antenna.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a taper slot antenna used in an antenna device which requires good reflection characteristics over a wide band.

[0002]

2. Description of the Related Art FIG. J. Gibso
n, "The Vivaldi aerial," in
Proc. 9th European Micro
aveConf. Brighton, U .; K. , 19
79, pp. 101-105. And S. N. Pra
sad and S. Mahapatra, "A no
vel mic slot-line antenne
a, "in Proc. 9th European M
icrowave Conf. , Brighton,
U. K. , 1979, pp. 120-124. FIG. 7 is a perspective view of a conventional tapered slot antenna shown in FIG. In the figure, 1h is a dielectric substrate, 2f is the dielectric substrate 1
The feeding line 3i formed on one surface of h is a ground conductor surface formed on the surface of the dielectric substrate 1h opposite to the surface on which the feeding line 2f is formed, and 4e is the feeding line 2f and the ground conductor. The microstrip feed line 5h formed by the surface 3i is a slot line formed on the ground conductor surface 3i so as to be orthogonal to the microstrip feed line 4e, and 6h is a slot width gradually connected to one end of the slot line 5h. Taper slot line that spreads over the wire, 8 is an exciting current flowing on the feed line 2f, and 9 is the exciting current 8
The magnetic field 10 induced by the slot line 5h is caused by the taper slot line 6 through the slot line 5h.
An electric field propagating in h, 11 is the tapered slot line 6h
And 20 is the width W of the open end of the tapered slot line 6h in the vicinity of the current flowing through the ground conductor surface 3i.

Next, the operation will be described. Slot line 5h is 1/4 from the open end of microstrip line 4e
Assuming that they intersect at the wavelength, the amplitude of the excitation current 8 flowing in the feed line 2f becomes maximum, the maximum magnetic field 9 is coupled to the slot line 5h, and the slot line 5h and the tapered slot line 6h form an electric field 10. Propagate. The electric field 10 propagating through the tapered slot line 6h is efficiently radiated into the space from the open end of the tapered slot line 6h and operates as an antenna if the width of the tapered slot line 6h is at least ½ wavelength or more. If it has two wavelengths or less, it operates as a transmission line. Here, when the electric field 10 propagates through the tapered slot line 6h, the current 11 is applied to the ground conductor surface 3
It flows on i along the vicinity of the tapered slot line 6h.
When the frequency is high, the current 11 is sufficiently attenuated at the open end of the tapered slot line 6h to form a traveling wave current distribution, but when the frequency is low, it is not sufficiently attenuated and the ground conductor surface 3i on both sides of the open end is formed. Is reflected at the end of, and a standing wave current distribution is formed.

[0004]

In the conventional tapered slot antenna, the width W of the open end of the tapered slot line is 1 or less.
If the frequency is low, the width W of the open end must be increased and the length of the taper slot line must be increased when the frequency is low, which causes a problem that the antenna size becomes large. On the contrary, at a low frequency such that the width W of the open end of the taper slot line is equal to or less than 1/2 wavelength, the taper slot line operates as a transmission line, so that the current near the taper slot line at the open end is sufficiently attenuated. However, the reflection characteristics at the input end of the antenna are deteriorated by being reflected by the ground conductor surfaces on both sides of the open end, that is, VSWR.
There is also a problem that (voltage standing wave ratio) deteriorates.

The present invention has been made in order to solve the above-mentioned problems, and even in a low frequency band where the width W of the open end of the tapered slot line is 1/2 wavelength or less, the antenna is Reflection characteristics at the input end, that is, V
It is an object of the present invention to obtain a taper slot antenna having a wide band reflection characteristic without reducing the deterioration of SWR and increasing the antenna size.

[0006]

A taper slot antenna according to a first aspect of the present invention comprises a ground conductor provided on one surface of a dielectric substrate and a strip conductor provided on the other surface. A microstrip feed line, a slot line formed on the ground conductor surface, a conversion means for converting the microstrip feed line into a slot line,
A tapered slot line is provided which is connected to one end of the slot line that is electromagnetically coupled and fed via the conversion means, and the slot width of which gradually widens, and on the ground conductor surface on both outer sides in the vicinity of the widened open end of the tapered slot line. A notch in which the ground conductor is removed is provided in a position having a substantially symmetrical axis of symmetry with respect to the rotational symmetry axis at a position that is substantially axially symmetric with respect to the rotational symmetry axis of the tapered slot line.

According to a second aspect of the present invention, there is provided a taper slot antenna having a first grounding conductor and a second grounding conductor which are provided on outer surfaces of the first and second dielectric base materials, respectively, which are superposed on each other. A ground conductor and a strip conductor provided on the inner surface of the triplate feed line, and the first ground conductor surface and the second ground conductor surface each having substantially the same shape. Slot line and second slot line, conversion means for converting the triplate feed line into the first slot line and second slot line, and the first slot line electromagnetically coupled and fed through the conversion means And a second taper slot line respectively connected to one ends of the first taper slot line and the second taper slot line, the slot width of which gradually increases, and the first taper slot line and the second taper slot line are provided.
Of the first taper slot line and the second taper slot line on both outer sides in the vicinity of the widening open end of the taper slot line of FIG. Notches in which the first ground conductor and the second ground conductor are removed are provided at symmetrical positions in a shape having a bent portion that is substantially axially symmetric with respect to the rotational symmetry axis.

A taper slot antenna according to a third aspect of the present invention is formed on a ground conductor provided on one surface of a dielectric substrate, a coplanar feed line provided on the ground conductor surface, and the ground conductor surface. Slot line, a conversion means for converting the coplanar feeder line into a slot line,
A tapered slot line is provided which is connected to one end of the slot line that is electromagnetically coupled and fed via the conversion means, and the slot width of which gradually widens, and on the ground conductor surface on both outer sides in the vicinity of the widened open end of the tapered slot line. A notch in which the ground conductor is removed is provided in a position having a substantially symmetrical axis of symmetry with respect to the rotational symmetry axis at a position that is substantially axially symmetric with respect to the rotational symmetry axis of the tapered slot line.

A taper slot antenna according to a fourth aspect of the present invention is the taper slot antenna according to any one of the first to third aspects, wherein a boundary between the taper slot line and ground conductors on both outer sides of the taper slot line forms a taper shape. At least one pair of metal pieces extending from the boundary to the slot and forming a pair in a shape substantially axisymmetric with respect to the rotational symmetry axis are provided at positions substantially axisymmetric with respect to the rotational symmetry axis of the taper slot line. It is a thing.

A taper slot antenna according to a fifth aspect of the present invention is the taper slot antenna according to any one of the first to fourth aspects, in which the widened open end of the taper slot line is on the same plane as the taper slot line. In the taper slot line, a plurality of non-excited conductors having a shape substantially axisymmetrical to the rotational symmetry axis are provided at positions substantially axisymmetrical to the rotational symmetry axis.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment of the Invention 1 is a perspective view of a tapered slot antenna having a notch showing a first embodiment of the present invention. FIG. 2 is an explanatory diagram for explaining the effect of improving the reflection characteristic of the tapered slot antenna having the cutout according to the first embodiment of the present invention. In FIG. 1, 1 to 6 and 8 to 11 are the same as the conventional taper slot antenna shown in FIG. 7a is a ground conductor surface 3a
The ground conductor surface 3a is removed so as to have an axially symmetric shape at a position axially symmetric with respect to the rotationally symmetric axis of the tapered slot line 6a, and is, for example, a notch provided with a bent portion as shown in the drawing. . The taper slot line 6a
Is, for example, a Vivaldi shape in which the slot width exponentially expands.

Next, the operation will be described. Assuming that the slot line 5a crosses the open end of the microstrip feed line 4a at a quarter wavelength, the amplitude of the exciting current 8 flowing through the feed line 2a becomes maximum, and the maximum magnetic field 9 causes the slot line 5a. And the electric field 10 propagates through the slot line 5a and the tapered slot line 6a. The electric field 10 propagating through the tapered slot line 6a is efficiently radiated into the space from the open end of the tapered slot line 6a as long as the width of the tapered slot line 6a is at least ½ wavelength or more. To work as. In addition, the width W of the open end of the tapered slot line 6a
In a low frequency band in which is less than or equal to 1/2 wavelength, the current path along the tapered slot line 6a has a cutout 7a from the open end of the tapered slot line 6a through a bent portion.
The current that is extended to the end of the notch 7a and that is not attenuated in the vicinity of the open end of the tapered slot line 6a can be concentrated in the bent portion of the notch 7a, and can be sufficiently attenuated at the end of the notch 7a. It is possible to form a traveling wave current distribution along the vicinity of the tapered slot line 6a. Since the tapered slot line 6a operates as a transmission line in this way, the current 11 flowing along the vicinity of the tapered slot line 6a on the ground conductor surface 3a is not attenuated in the vicinity of the tapered slot line 6a and the cutout 7a bends. Through the portion, it is sufficiently damped at the end of the notch 7a. That is, a strong current distribution is formed in the bent portion, and this bent portion operates as an antenna. That is, by providing the notch 7a, the tapered slot line 6a is provided in a low frequency band where the width W of the open end is equal to or less than 1/2 wavelength.
Operates as a transmission line, and the bent portion of the cutout 7a operates as an antenna.

FIG. 2 shows that the width W of the open end of the tapered slot line 6a is about 15 GHz and the half wavelength (10 mm).
7 is an experimental result showing the frequency characteristics of VSWR (voltage standing wave ratio) at the input end of the microstrip feed line 4a with and without the notch 7a in the tapered slot antenna. From this figure, the width W of the open end
It can be seen that the VSWR is improved by providing the cutout 7a in the frequency band lower than 15 GHz, where is less than or equal to 1/2 wavelength.

Embodiment 2 of the Invention 3 is a configuration diagram of a taper slot antenna according to Embodiment 2 of the present invention,
FIG. 3A is a perspective view, and FIGS. 3B and 3C are exploded views thereof. In this embodiment, the stacked dielectric substrates 1
On both ground conductor surfaces 3b and 3c outside b and 1c, the slot lines 5b and 5c, the taper slot lines 6b and 6c, and the axially symmetrical positions with respect to the rotational symmetry axes of the taper slot lines 6b and 6c are provided. The ground conductor surfaces 3b and 3c are removed so as to form a symmetrical shape, and for example, notches 7b and 7c provided with a bent portion as shown in the drawing are provided, respectively, and further, the ground conductor surfaces 3b and 3c and the feed line 2b are formed. A common triplate feed line 12 has a triplate structure in which two slot lines 5b and 5c are electromagnetically coupled and fed.

The basic operation of providing the notch is the same as that of the first embodiment of the present invention, and the description thereof is omitted.

In this case, since the tri-plate feed line 12 electromagnetically couples and feeds the two slot lines 5b and 5c in the same phase, the ground conductor surface 3b of the conversion portion composed of the triplate feed line 12 and the slot lines 5b and 5c. And 3
The normal direction component of the electric field with respect to c can be canceled and the cross polarization component can be suppressed. Therefore, it is possible to obtain a tapered slot antenna having a good VSWR over a wide band and a low cross polarization characteristic without changing the dimensions of the antenna.

Third Embodiment of the Invention FIG. 4 is a perspective view showing the configuration of the tapered slot antenna according to the third embodiment of the present invention. As shown in FIG. 4, the tapered slot line 6d
The ground conductor surfaces 3d and 3e are removed so as to have an axially symmetric shape on the ground conductor surfaces 3d and 3e outside of and at positions axially symmetric with respect to the rotational symmetry axis of the tapered slot line 6d. Notch 7 with such a bent portion
d, and further, the center conductor 13 and the ground conductor surfaces 3d and 3e
Power is supplied to the slot line 5d by the coplanar power supply line 14 including.

The basic operation by providing the notch is the same as that of the first embodiment of the present invention, and the description thereof will be omitted.

In this case, since the coplanar feeder line 14, the slot line 5d, and the ground conductor surfaces 3d and 3e can be formed on the same plane, a via hole or the like is not used when connecting a semiconductor element or the like to the center line 13. In addition, semiconductor elements and the like can be easily arranged on the same plane. Further, since they can all be configured on the same plane, they can be manufactured with a single-sided printed circuit board, and a tapered slot antenna having a good VSWR over a wide band and a low cross polarization characteristic without changing the dimensions of the antenna can be obtained. It can be realized at a low price.

Fourth Embodiment of the Invention FIG. 5 is a perspective view showing the structure of the tapered slot antenna according to the fourth embodiment of the present invention. In this embodiment, the taper slot line 6e
On the ground conductor surface 3f on the outside of the taper slot line 6
The ground conductor surface 3f is removed at an axially symmetric position with respect to the rotational symmetry axis of e so as to form an axially symmetric shape, and a notch 7e having a bent portion as shown in the drawing is provided, and the tapered slot line is further provided. 6a and a ground conductor surface 3f, and a pair of metals having a shape that is substantially axisymmetric with respect to the rotational symmetry axis at a boundary portion that forms a taper shape and at a position that is axially symmetric with respect to the rotational symmetry axis of the tapered slot line 6e. At least one pair of pieces 15 is provided. Also, this metal piece 15
May be formed by arranging several pieces, and in this case, the susceptance equivalent to being connected in parallel to the taper slot line described below can be easily adjusted.

The basic operation by providing the notch is the same as that of the first embodiment of the present invention, and the description thereof will be omitted.

In this case, the metal piece 15 provided on the tapered boundary between the tapered slot line 6e and the ground conductor surface 3f is equivalent to the susceptance connected in parallel to the tapered slot line 6e, and the metal piece 15 By changing the size or the like, the normalized admittance of the open end of the tapered slot line 6e from the metal piece 15 can be set to 1 at a specific frequency, that is, matching can be achieved. As a result, it is possible to realize a good VSWR at a desired frequency while having a good reflection characteristic over a wide band. Further, by providing a plurality of metal pieces 15 forming a pair at different intervals, it is possible to obtain a relatively good V at a desired plurality of frequencies.
SWR can be realized.

The embodiment of the present invention can be combined with any of the first to third embodiments of the present invention.
It goes without saying that the same effect as described above can be obtained.

Fifth Embodiment of the Invention 6 is a perspective view showing the configuration of a tapered slot antenna according to the fifth embodiment of the present invention. In this embodiment, the taper slot line 6f
And 6g outside the ground conductor surfaces 3g and 3h, and at positions axially symmetric with respect to the rotational symmetry axes of the tapered slot lines 6f and 6g, the ground conductor surface 3 is formed so as to have an axially symmetric shape.
g and 3h are removed, for example, cutouts 7f and 7g provided with a bent portion as shown in the drawing are provided, and further the front of the widened open end of the tapered slot lines 6f and 6g on the same plane as the tapered slot lines 6f and 6g, respectively. And the two taper slot lines 6f and 6g are respectively provided with two non-exciting conductors 16a and 16b and non-exciting conductors 16c and 16d which are axially symmetric with respect to the rotational symmetry axes. A plurality of arrays are arranged in an array. Note that FIG. 6 illustrates two cases for the sake of simplicity. Further, here, 17 and 18 are non-excitation conductors 16a and 16b and non-excitation conductor 16c, respectively.
And 16d are not present, and the coupling electromagnetic field C0 from the tapered slot line 6f to the tapered slot line 6g and the coupling electromagnetic fields C1 and 19 are the non-exciting conductors 16a and 16b,
It is a coupling electromagnetic field C2 from the taper slot line 6f when there are non-excitation conductors 16c and 16d to the non-excitation conductors 16a and 16b and the non-excitation conductors 16c and 16d.

The basic operation by providing the notch is the same as that of the first embodiment of the present invention, and the description thereof will be omitted.

Here, when the non-excited vibrators 16a and 16b and the non-excited conductors 16c and 16d are not provided, the coupling electromagnetic field C is obtained.
0 couples from the tapered slot line 6f to the tapered slot line 6g at a strong level, but the parasitic conductors 16a and 1
6b and the non-exciting conductors 16c and 16d are divided into a coupling electromagnetic field C1 and a coupling electromagnetic field C2, and the coupling electromagnetic field C1 to the tapered slot line 6g is smaller than the coupling electromagnetic field C0. That is, the non-exciting conductors 16a and 16
b, by providing the non-exciting conductors 16c and 16d, mutual coupling between the tapered slot lines 6f and 6g can be suppressed. Therefore, when a plurality of taper slot antennas having the cutouts 7 are arranged and used in an array, it is possible to maintain the broadband reflection characteristics of the taper slot antennas having the cutouts without deteriorating.

The embodiment of the present invention can be combined with any of the first to fourth embodiments of the present invention.
It goes without saying that the same effect as described above can be obtained.

[0028]

Since the present invention has the above-described structure, the following effects can be obtained.

According to the invention of claim 1, in the low frequency band in which the width of the open end of the taper slot line is shorter than 1/2 wavelength, the taper slot line is operated as a transmission line,
The bent portion of the notch can be operated as an antenna, and the effect of improving the reflection characteristic in a low frequency band can be obtained without increasing the width of the open end of the tapered slot line, that is, the antenna size.

According to the second aspect of the present invention, since the tapered slot antenna with the cutout of the triplate feed structure is used, the direction of the normal to the ground conductor plane generated at the conversion part from the triplate feed line to each slot line is generated. The electric field component can be canceled out, the effect of suppressing the cross polarization component can be obtained, and the effect of improving the reflection characteristic in the low frequency band can be obtained.

According to the third aspect of the invention, since the tapered slot antenna with the notch of the coplanar coplanar feeding structure is used, the semiconductor element and the like can be easily arranged on the same plane without using a via hole or the like. Since they can all be configured on the same plane, they can be manufactured on an inexpensive single-sided printed circuit board, and the effect that a taper slot antenna with improved reflection characteristics in a low frequency band can be realized at low cost can be obtained.

According to the fourth aspect of the present invention, the boundary between the tapered slot line and the ground conductors on both outer sides of the boundary is located at a position substantially axisymmetric with respect to the rotational symmetry axis of the tapered slot line. To the slot and has a notched tapered slot antenna provided with at least one pair of metal pieces which are paired in a shape substantially axisymmetric with respect to the rotational symmetry axis. The effect that the susceptance can be easily formed is obtained, and since it is possible to connect in multiple stages, it is possible to obtain the effect that a relatively good reflection characteristic is obtained at a plurality of desired frequencies, and at the same time, the reflection characteristic in a low frequency band can be obtained. The effect that can be improved is obtained.

According to the fifth aspect of the present invention, the rotation of the taper slot line on the same plane as that of the taper slot line is substantially axisymmetric with respect to the rotational symmetry axis of the taper slot line in front of the widening open end of the taper slot line. Since a tapered slot antenna with notches is provided with a plurality of non-excited conductors that are approximately axisymmetric with respect to the axis of symmetry, when multiple tapered slot antennas are arranged in an array, the coupling electromagnetic between the tapered slot lines is A part of the field can be coupled to the non-excited conductor, the effect of reducing the coupling amount between the tapered slot lines can be obtained, and the deterioration of the reflection characteristics in the low frequency band can be reduced even when beam scanning is performed. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a tapered slot antenna having a cutout showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a reflection characteristic in the first embodiment of the present invention.

FIG. 3 is a perspective view of a tapered slot antenna having a notch showing a second embodiment of the present invention.

FIG. 4 is a perspective view of a tapered slot antenna having a notch showing a third embodiment of the present invention.

FIG. 5 is a perspective view of a tapered slot antenna having a notch showing a fourth embodiment of the present invention.

FIG. 6 is a perspective view showing a fifth embodiment of the present invention in which tapered slot antennas having notches are arranged in an array.

FIG. 7 is a perspective view of a conventional taper slot antenna.

[Explanation of symbols]

1 dielectric substrate, 2 feed line, 3 ground conductor surface, 4
Microstrip feed line, 5 slot line, 6
Taper slot line, 7 notches, 8 excitation current, 9
Magnetic field, 10 electric field, 11 current, 12 triplate feed line, 13 center conductor, 14 coplanar feed line, 15 metal piece, 16 non-excited conductor, 17 coupling electromagnetic field C0, 18 coupling electromagnetic field C1, 19 coupling electromagnetic field C
2, 20 Width W at the open end.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] June 5, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

Title of invention Tapered slot antenna

[Claims]

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a taper slot antenna used in an antenna device which requires good reflection characteristics over a wide band.

[0002]

2. Description of the Related Art FIG. J. Gibso
n, "The Vivaldi aerial," in
Proc. 9th European Micro
aveConf. Brighton, U .; K. , 19
79, pp. 101-105. And S. N. Pra
sad and S. Mahapatra, "A no
vel mic slot-line antenne
a, "in Proc. 9th European M
icrowave Conf. , Brighton,
U. K. , 1979, pp. 120-124. FIG. 7 is a perspective view of a conventional tapered slot antenna shown in FIG. In the figure, 1h is a dielectric substrate, 2f is the dielectric substrate 1
The feeding line 3i formed on one surface of h is a ground conductor surface formed on the surface of the dielectric substrate 1h opposite to the surface on which the feeding line 2f is formed, and 4e is the feeding line 2f and the ground conductor. The microstrip feed line 5h formed by the surface 3i is a slot line formed on the ground conductor surface 3i so as to be orthogonal to the microstrip feed line 4e, and 6h is a slot width gradually connected to one end of the slot line 5h. Taper slot line that spreads over the wire, 8 is an exciting current flowing on the feed line 2f, and 9 is the exciting current 8
The magnetic field 10 induced by the slot line 5h is caused by the taper slot line 6 through the slot line 5h.
An electric field propagating in h, 11 is the tapered slot line 6h
And 20 is the width W of the open end of the tapered slot line 6h in the vicinity of the current flowing through the ground conductor surface 3i.

Next, the operation will be described. Slot line 5h is 1/4 from the open end of microstrip line 4e
Assuming that they intersect at the wavelength, the amplitude of the excitation current 8 flowing in the feed line 2f becomes maximum, the maximum magnetic field 9 is coupled to the slot line 5h, and the slot line 5h and the tapered slot line 6h form an electric field 10. Propagate. The electric field 10 propagating through the tapered slot line 6h is efficiently radiated into the space from the open end of the tapered slot line 6h and operates as an antenna if the width of the tapered slot line 6h is at least ½ wavelength or more. If it has two wavelengths or less, it operates as a transmission line. Here, when the electric field 10 propagates through the tapered slot line 6h, the current 11 is applied to the ground conductor surface 3
It flows on i along the vicinity of the tapered slot line 6h.
When the frequency is high, the current 11 is sufficiently attenuated at the open end of the tapered slot line 6h to form a traveling wave current distribution, but when the frequency is low, it is not sufficiently attenuated and the ground conductor surface 3i on both sides of the open end is formed. Is reflected at the end of, and a standing wave current distribution is formed.

[0004]

In the conventional tapered slot antenna, the width W of the open end of the tapered slot line is 1 or less.
If the frequency is low, the width W of the open end must be increased and the length of the taper slot line must be increased when the frequency is low, which causes a problem that the antenna size becomes large. On the contrary, at a low frequency such that the width W of the open end of the taper slot line is equal to or less than 1/2 wavelength, the taper slot line operates as a transmission line, so that the current near the taper slot line at the open end is sufficiently attenuated. However, the reflection characteristics at the input end of the antenna are deteriorated by being reflected by the ground conductor surfaces on both sides of the open end, that is, VSWR.
There is also a problem that (voltage standing wave ratio) deteriorates.

The present invention has been made in order to solve the above-mentioned problems, and even in a low frequency band where the width W of the open end of the tapered slot line is 1/2 wavelength or less, the antenna is Reflection characteristics at the input end, that is, V
It is an object of the present invention to obtain a taper slot antenna having a wide band reflection characteristic without reducing the deterioration of SWR and increasing the antenna size.

[0006]

A taper slot antenna according to a first aspect of the present invention comprises a ground conductor provided on one surface of a dielectric substrate and a strip conductor provided on the other surface. A microstrip feed line, a slot line formed on the ground conductor surface, a conversion means for converting the microstrip feed line into a slot line,
A tapered slot line is provided which is connected to one end of the slot line that is electromagnetically coupled and fed via the conversion means, and the slot width of which gradually widens, and on the ground conductor surface on both outer sides in the vicinity of the widened open end of the tapered slot line. the position where the paired Shi axisymmetric to the rotation symmetry axis of the tapered slot line, is provided with a notch the ground conductor shape is removed having a bent portion axisymmetric to the axis of rotational symmetry.

According to a second aspect of the present invention, there is provided a taper slot antenna having a first grounding conductor and a second grounding conductor which are provided on outer surfaces of the first and second dielectric base materials, respectively, which are superposed on each other. a ground conductor, triplate feed line, the first formed in each same shape on the first ground conductor surface and the second ground conductor surface comprising a strip conductor provided on the inner surface Slot line and second slot line, conversion means for converting the triplate feed line into the first slot line and second slot line, and the first slot electromagnetically coupled and fed through the conversion means. A first taper slot line and a second taper slot line, which are respectively connected to one ends of the line and the second slot line and whose slot width gradually increases, and the first taper slot line and the second taper slot line are provided. Widening the open end near both outer sides of the first
The position where the paired Shi axisymmetric to the rotation symmetry axis of the ground conductor surface and the second of the first on the ground conductor face of the tapered slot line and a second tapered slot lines, bending axisymmetric to the axis of rotational symmetry The first grounding conductor and the second grounding conductor.
The ground conductor is removed to provide a notch.

A taper slot antenna according to a third aspect of the present invention is formed on a ground conductor provided on one surface of a dielectric substrate, a coplanar feed line provided on the ground conductor surface, and the ground conductor surface. Slot line, a conversion means for converting the coplanar feeder line into a slot line,
A tapered slot line is provided which is connected to one end of the slot line that is electromagnetically coupled and fed via the conversion means, and the slot width of which gradually widens, and on the ground conductor surface on both outer sides in the vicinity of the widened open end of the tapered slot line. the position where the paired Shi axisymmetric to the rotation symmetry axis of the tapered slot line, is provided with a notch the ground conductor shape is removed having a bent portion axisymmetric to the axis of rotational symmetry.

A taper slot antenna according to a fourth aspect of the present invention is the taper slot antenna according to any one of the first to third aspects, wherein a boundary between the taper slot line and ground conductors on both outer sides of the taper slot line forms a taper shape. of the position where the paired Shi axisymmetric to the rotation symmetry axis of the tapered slot line extends from the boundary to the slot, provided at least one pair of metal pieces paired in the form of pairs Shi axisymmetric to the axis of rotational symmetry It is a thing.

A taper slot antenna according to a fifth aspect of the present invention is the taper slot antenna according to any one of the first to fourth aspects, in which the widened open end of the taper slot line is on the same plane as the taper slot line. of the position where the paired Shi axisymmetric to the rotation symmetry axis of the tapered slot line, is provided with a plurality of parasitic conductor in the form of pairs Shi axisymmetric to the axis of rotational symmetry.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. 1 is a perspective view of a tapered slot antenna having a notch showing a first embodiment of the present invention. FIG. 2 is an explanatory diagram for explaining the effect of improving the reflection characteristic of the tapered slot antenna having the cutout according to the first embodiment of the present invention. In FIG. 1, 1 to 6 and 8 to
Reference numeral 11 is the same as the conventional tapered slot antenna shown in FIG. Further, 7a is located on the ground conductor surface 3a and at a position axially symmetric with respect to the rotational symmetry axis of the tapered slot line 6a, so that the ground conductor surface 3 has an axially symmetric shape.
a is a notch in which a is removed and a bent portion as illustrated is provided. The tapered slot line 6a has, for example, a Vivaldi shape in which the slot width exponentially expands.

Next, the operation will be described. Assuming that the slot line 5a crosses the open end of the microstrip feed line 4a at a quarter wavelength, the amplitude of the exciting current 8 flowing through the feed line 2a becomes maximum, and the maximum magnetic field 9 causes the slot line 5a. And the electric field 10 propagates through the slot line 5a and the tapered slot line 6a. The electric field 10 propagating through the tapered slot line 6a is efficiently radiated into the space from the open end of the tapered slot line 6a as long as the width of the tapered slot line 6a is at least ½ wavelength or more. To work as. In addition, the width W of the open end of the tapered slot line 6a
In a low frequency band in which is less than or equal to 1/2 wavelength, the current path along the tapered slot line 6a has a cutout 7a from the open end of the tapered slot line 6a through a bent portion.
The current that is extended to the end of the notch 7a and is not attenuated in the vicinity of the open end of the tapered slot line 6a can be concentrated at the bent portion of the notch 7a, and this portion is radiated.
It is possible to contribute to . Since the tapered slot line 6a operates as a transmission line in this way, the current 11 flowing along the vicinity of the tapered slot line 6a on the ground conductor surface 3a is not attenuated in the vicinity of the tapered slot line 6a and the cutout 7a bends. Excite the club. That is, a strong current distribution is formed in the bent portion, and this bent portion operates as an antenna. That is, by providing the notch 7a, the taper slot line 6a operates as a transmission line in the low frequency band where the width W of the open end is equal to or less than 1/2 wavelength, and the bent portion of the notch 7a is Operates as an antenna.

FIG. 2 shows that the width W of the open end of the tapered slot line 6a is about 15 GHz and the half wavelength (10 mm).
7 is an experimental result showing the frequency characteristics of VSWR (voltage standing wave ratio) at the input end of the microstrip feed line 4a with and without the notch 7a in the tapered slot antenna. From this figure, the width W of the open end
It can be seen that the VSWR is improved by providing the cutout 7a in the frequency band lower than 15 GHz, where is less than or equal to 1/2 wavelength.

Embodiment 2. 3 is a configuration diagram of a taper slot antenna according to Embodiment 2 of the present invention.
FIG. 3A is a perspective view, and FIGS. 3B and 3C are exploded views thereof. In this embodiment, the superposed dielectric substrates 1b are used.
And 1c on both ground conductor surfaces 3b and 3c on the outside, axially symmetric with respect to the rotationally symmetrical axes of the slot lines 5b and 5c, the tapered slot lines 6b and 6c, and the tapered slot lines 6b and 6c. The ground conductor surfaces 3b and 3c are removed so as to have the shape of, and cutouts 7b and 7c provided with bent portions as shown in the drawing are provided, respectively, and the ground conductor surfaces 3b and 3c and the feed line 2b are common. The tri-plate feed line 12 has a triplate configuration in which two slot lines 5b and 5c are electromagnetically coupled and fed.

The basic operation of providing the notch is the same as that of the first embodiment of the present invention, and the description thereof is omitted.

In this case, since the tri-plate feed line 12 electromagnetically couples and feeds the two slot lines 5b and 5c in the same phase, the ground conductor surface 3b of the conversion portion composed of the triplate feed line 12 and the slot lines 5b and 5c. And 3
The normal direction component of the electric field with respect to c can be canceled and the cross polarization component can be suppressed. Therefore, it is possible to obtain a tapered slot antenna having a good VSWR over a wide band and a low cross polarization characteristic without changing the dimensions of the antenna.

Embodiment 3. FIG. 4 is a perspective view showing the configuration of the tapered slot antenna according to the third embodiment of the present invention. As shown in FIG. 4, the ground conductor is formed on the ground conductor surfaces 3d and 3e outside the taper slot line 6d at a position axially symmetric with respect to the rotational symmetry axis of the taper slot line 6d so as to have an axially symmetric shape. Faces 3d and 3e are removed,
For example, a notch 7d having a bent portion as shown in the drawing is provided, and the slot line 5d is fed by the coplanar feed line 14 including the center conductor 13 and the ground conductor surfaces 3d and 3e.

The basic operation by providing the notch is the same as that of the first embodiment of the present invention, and the description thereof will be omitted.

In this case, since the coplanar feeder line 14, the slot line 5d, and the ground conductor surfaces 3d and 3e can be formed on the same plane, a via hole or the like is not used when connecting a semiconductor element or the like to the center line 13. In addition, semiconductor elements and the like can be easily arranged on the same plane. Further, since they can all be configured on the same plane, they can be manufactured with a single-sided printed circuit board, and a tapered slot antenna having a good VSWR over a wide band and a low cross polarization characteristic without changing the dimensions of the antenna can be obtained. It can be realized at a low price.

Fourth Embodiment FIG. 5 is a perspective view showing the structure of the tapered slot antenna according to the fourth embodiment of the present invention. In this embodiment, the ground conductor surface 3f is formed on the ground conductor surface 3f outside the taper slot line 6e and at a position axially symmetric with respect to the rotational symmetry axis of the taper slot line 6e so as to have an axially symmetric shape. For example, a notch 7e having a bent portion as shown in the drawing is removed, and a tapered boundary portion between the tapered slot line 6e and the ground conductor surface 3f is formed and the axis of rotation is symmetrical with respect to the rotational symmetry axis of the tapered slot line 6e. to be symmetrical position, in which the at least one pair provided with forming the metal strip 15 in a pair in the shape of axial pairs <br/> referred to with respect to the axis of rotational symmetry. The metal piece 15 may be formed by arranging several pieces, and in this case, the susceptance equivalent to being connected in parallel to the taper slot line described below can be easily adjusted.

The basic operation by providing the notch is the same as that of the first embodiment of the present invention, and the description thereof will be omitted.

In this case, the metal piece 15 provided on the tapered boundary between the tapered slot line 6e and the ground conductor surface 3f is equivalent to the susceptance connected in parallel to the tapered slot line 6e, and the metal piece 15 By changing the size or the like, the normalized admittance of the open end of the tapered slot line 6e from the metal piece 15 can be set to 1 at a specific frequency, that is, matching can be achieved. As a result, it is possible to realize a good VSWR at a desired frequency while having a good reflection characteristic over a wide band. Further, by providing a plurality of metal pieces 15 forming a pair at different intervals, it is possible to obtain a relatively good V at a desired plurality of frequencies.
SWR can be realized.

The embodiment of the present invention can be combined with any of the first to third embodiments of the present invention.
It goes without saying that the same effect as described above can be obtained.

Embodiment 5. 6 is a perspective view showing the configuration of a tapered slot antenna according to the fifth embodiment of the present invention. In this embodiment, the tapered slot lines 6f and 6 are
The ground conductor surfaces 3g and 3h are removed so as to have an axially symmetric shape on the ground conductor surfaces 3g and 3h outside of g and at positions that are axially symmetric with respect to the rotational symmetry axes of the tapered slot lines 6f and 6g. For example, cutouts 7f and 7g provided with a bent portion as shown in the drawing are provided, and further, in front of the widening open end of the tapered slot lines 6f and 6g on the same plane as the tapered slot lines 6f and 6g and the tapered slot line 6f and Two non-excited conductors 1 each having an axially symmetric shape at positions axially symmetric with respect to the 6g rotationally symmetric axis.
6a and 16b, and tapered slot antenna in which a parasitic conductor 16c and 16d is obtained by arranged the A array shape. Note that FIG. 6 illustrates two cases for the sake of simplicity. Further, here, 17 and 18 are the coupling electromagnetic field C0 and the coupling electromagnetic field C from the tapered slot line 6f to the tapered slot line 6g with and without the non-exciting conductors 16a and 16b and the non-exciting conductors 16c and 16d, respectively.
Reference numerals 1 and 19 denote non-excitation conductors 16a and 16b, and non-excitation conductor 1
It is a coupling electromagnetic field C2 from the taper slot line 6f when there are 6c and 16d to the non-exciting conductors 16a and 16b and the non-exciting conductors 16c and 16d.

The basic operation by providing the notch is the same as that of the first embodiment of the present invention, and the description thereof will be omitted.

Here, when the non-excited vibrators 16a and 16b and the non-excited conductors 16c and 16d are not provided, the coupling electromagnetic field C is obtained.
0 couples from the tapered slot line 6f to the tapered slot line 6g at a strong level, but the parasitic conductors 16a and 1
6b and the non-exciting conductors 16c and 16d are divided into a coupling electromagnetic field C1 and a coupling electromagnetic field C2, and the coupling electromagnetic field C1 to the tapered slot line 6g is smaller than the coupling electromagnetic field C0. That is, the non-exciting conductors 16a and 16
b, by providing the non-exciting conductors 16c and 16d, mutual coupling between the tapered slot lines 6f and 6g can be suppressed. Therefore, when a plurality of taper slot antennas having the cutouts 7 are arranged and used in an array, it is possible to maintain the broadband reflection characteristics of the taper slot antennas having the cutouts without deteriorating.

The embodiment of the present invention can be combined with any of the first to fourth embodiments of the present invention.
It goes without saying that the same effect as described above can be obtained.

[0028]

Since the present invention has the above-described structure, the following effects can be obtained.

According to the invention of claim 1, in the low frequency band in which the width of the open end of the taper slot line is shorter than 1/2 wavelength, the taper slot line is operated as a transmission line,
The bent portion of the notch can be operated as an antenna, and the effect of improving the reflection characteristic in a low frequency band can be obtained without increasing the width of the open end of the tapered slot line, that is, the antenna size.

According to the second aspect of the present invention, since the tapered slot antenna with the cutout of the triplate feed structure is used, the direction of the normal to the ground conductor plane generated at the conversion part from the triplate feed line to each slot line is generated. The electric field component can be canceled out, the effect of suppressing the cross polarization component can be obtained, and the effect of improving the reflection characteristic in the low frequency band can be obtained.

According to the third aspect of the invention, since the tapered slot antenna with the notch of the coplanar coplanar feeding structure is used, the semiconductor element and the like can be easily arranged on the same plane without using a via hole or the like. Since they can all be configured on the same plane, they can be manufactured on an inexpensive single-sided printed circuit board, and the effect that a taper slot antenna with improved reflection characteristics in a low frequency band can be realized at low cost can be obtained.

According to the invention of claim 4, the position where the paired Shi axisymmetric to the rotation symmetry axis of the boundary of the tapered slot line forming the tapered shape of the tapered slot line and its outer sides of the ground conductor, the boundary from extending into the slot, since the at least one pair provided with notches tapered slot antenna metal pieces paired in the form of pairs Shi axisymmetric to the axis of rotational symmetry, parallel for matching the tapered slot line The effect of easily forming susceptance is obtained,
In addition, since the connection can be made in multiple stages, the effect of obtaining a relatively good reflection characteristic at a plurality of desired frequencies and the effect of improving the reflection characteristic in a low frequency band can be obtained.

According to the invention of claim 5, the position where the tapered slot line pair Shi axisymmetric to the rotation symmetry axis of the front of the tapered slot line widening the open end of the tapered slot line on the same plane, the rotation since you are Shi pair symmetry axis axisymmetric plurality of notched tapered slot antenna in which a parasitic conductor shape, when an array of tapered slot antenna plurality array form, electromagnetically coupled between the tapered slot line A part of the field can be coupled to the non-excited conductor, the effect of reducing the coupling amount between the tapered slot lines can be obtained, and the deterioration of the reflection characteristics in the low frequency band can be reduced even when beam scanning is performed. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a tapered slot antenna having a cutout showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram for explaining a reflection characteristic in the first embodiment of the present invention.

FIG. 3 is a perspective view of a tapered slot antenna having a notch showing a second embodiment of the present invention.

FIG. 4 is a perspective view of a tapered slot antenna having a notch showing a third embodiment of the present invention.

FIG. 5 is a perspective view of a tapered slot antenna having a notch showing a fourth embodiment of the present invention.

FIG. 6 is a perspective view showing a fifth embodiment of the present invention in which tapered slot antennas having notches are arranged in an array.

FIG. 7 is a perspective view of a conventional taper slot antenna.

[Explanation of reference numerals] 1 dielectric substrate, 2 feed line, 3 ground conductor surface, 4
Microstrip feed line, 5 slot line, 6
Taper slot line, 7 notches, 8 excitation current, 9
Magnetic field, 10 electric field, 11 current, 12 triplate feed line, 13 center conductor, 14 coplanar feed line, 15 metal piece, 16 non-excited conductor, 17 coupling electromagnetic field C0, 18 coupling electromagnetic field C1, 19 coupling electromagnetic field C
2, 20 Width W at the open end.

Front page continuation (72) Inventor Kazushi Nishizawa 2-3-3 Marunouchi, Chiyoda-ku, Tokyo Sanryo Electric Co., Ltd.

Claims (5)

[Claims] 1. A microstrip feed line comprising a ground conductor provided on one surface of a dielectric substrate and a strip conductor provided on the other surface, and a slot line formed on the ground conductor surface. A conversion means for converting the microstrip feed line into a slot line; and a taper slot line connected to one end of the slot line that is electromagnetically coupled and fed through the conversion means, the slot width gradually increasing, the taper slot The ground is formed on the ground conductor surface on both sides in the vicinity of the widened open end of the line at a position substantially axisymmetric with respect to the rotational symmetry axis of the taper slot line on the ground conductor surface. A taper slot antenna characterized in that a notch with a conductor removed is provided. 2. A first dielectric substrate and a second which are superposed on each other.
Of the dielectric substrate, a triplate feed line comprising a first ground conductor and a second ground conductor provided on the outer surface of each of the dielectric base materials, and a strip conductor provided on the inner surface thereof.
A first slot line and a second slot line formed in substantially the same shape on the ground conductor surface and the second ground conductor surface, respectively, and the triplate feed line to the first slot line and the second slot line. To the first slot line and the second slot line, which are electromagnetically coupled and fed via the conversion unit, respectively, and are connected to one ends of the first slot line and the second slot line, respectively, and the first taper slot line and the Two taper slot lines, and the first ground conductor surface and the first ground conductor surface on the second ground conductor surface on both outer sides in the vicinity of the widened open ends of the first taper slot line and the second taper slot line. The taper slot line and the second taper slot line have a bent portion that is substantially axisymmetrical to the rotational symmetry axis at a position that is substantially axisymmetrical to the rotational symmetry axis. Grounding Tapered Slot Antenna, characterized in that the body is provided with a notch removed. 3. A ground conductor provided on one surface of a dielectric substrate, a coplanar feeder line provided on the ground conductor surface, a slot line formed on the ground conductor surface, and the coplanar feeder line as a slot. Conversion means to convert to track,
A tapered slot line is provided which is connected to one end of the slot line that is electromagnetically coupled and fed via the conversion means, and the slot width of which gradually widens, and on the ground conductor surface on both outer sides in the vicinity of the widened open end of the tapered slot line. A notch in which the ground conductor is removed is provided in a position having substantially axisymmetrical symmetry with respect to the rotational symmetry axis at a position approximately axisymmetrical with respect to the rotational symmetry axis of the tapered slot line. Tapered slot antenna. 4. The taper slot antenna according to claim 1, wherein a tapered boundary between the taper slot line and ground conductors on both sides of the taper slot line is provided on a rotational symmetry axis of the taper slot line. A taper slot antenna, characterized in that at least one pair of metal pieces that extend from the boundary to the slot and are paired in a shape that is substantially axisymmetric with respect to the axis of rotational symmetry are provided at positions that are substantially axisymmetric with respect to the axis. 5. The tapered slot antenna according to claim 1, wherein the tapered slot line has a rotational symmetry axis in front of the widened open end of the tapered slot line on the same plane as the tapered slot line. A taper slot antenna characterized in that a plurality of non-exciting conductors having a shape substantially axisymmetric with respect to the rotational symmetry axis are provided at positions substantially axisymmetric to each other.