Antenna, sensor, and in-vehicle system

FIGS. 1 and 2A are structural diagrams of a flat beam generating array antenna according to an example of the invention.

In the antenna illustrated in FIGS. 1 and 2A , a first radiating portion 110 a and a second radiating portion 110 b are formed on a first surface of a dielectric substrate 100 . A first conductor portion 120 a is formed on the first surface of the dielectric substrate 100 and a second conductor portion 130 a is formed on a second surface opposite to the first surface of the dielectric substrate 100 . In addition, a through hole 400 a is formed for electrically connecting the conductor on the first surface of the dielectric substrate 100 and the conductor on the second surface. First horns 200 a , at least inner surfaces of which are formed of the conductor, is attached on the first face side of the dielectric substrate 100 , and a first dielectric lens 300 a is disposed in the vicinity of a radiation-side opening portion of each first horn 200 a . With such a configuration, the antenna of Example 1 radiates radio waves substantially in parallel with a first optical axis D 1 a -D 1 a ′ and a second optical axis D 1 b -D 1 b ′ of the first dielectric lenses 300 a.

A first imaginary line (longitudinal center line) A 1 -A 1 ′ is a line passing through centers of the radiation-side opening portions of the first horns 200 a in the shortest length. A second imaginary line (transverse center line) B 1 -B 1 ′ is a line passing through the center of the first imaginary line A 1 -A 1 ′ and perpendicular to the first imaginary line A 1 -A 1 ′.

In the antenna of the example, one half of the first imaginary line A 1 -A 1 ′ (that is, the length of one radiation-side opening portion in the A 1 -A 1 ′ direction) is longer than the second imaginary line B 1 -B 1 ′. That is, in the example, the radiation-side opening portion of the first horn 200 a has a rectangular shape in which a direction (longitudinal direction) of the first imaginary line A 1 -A 1 ′ is longer than a direction of the second imaginary line B 1 -B 1 ′ (transverse direction).

A third imaginary line C 1 -C 1 ′ is a line passing through the intersection of the first imaginary line A 1 -A 1 ′ and the second optical axis D 1 b -D 1 b ′ and perpendicular to the first imaginary line A 1 -A 1 ′.

(A) of FIG. 1 illustrates a shape of the antenna of the example as seen from a radiation-side opening portion side of the first horn 200 a . (B) of FIG. 1 illustrates a cross-sectional shape of the antenna of the example along the first imaginary line A 1 -A 1 ′. (C) of FIG. 1 illustrates a cross-sectional shape of the antenna of the example along the third imaginary line C 1 -C 1 ′.

FIG. 2A illustrates a shape of the dielectric substrate 100 as seen from a first surface side.

On the first surface of the dielectric substrate 100 , the first conductor portion 120 a is formed to surround the first radiating portion 110 a and the second radiating portion 110 b leaving a certain distance from the first radiating portion 110 a and the second radiating portion 110 b . The first conductor portion 120 a is electrically connected to the second conductor portion 130 a formed on the second surface of the dielectric substrate 100 via the through hole 400 a . As a result, the first conductor portion 120 a and the second conductor portion 130 a function as reference potential planes of the first radiating portion 110 a and the second radiating portion 110 b and each of the first radiating portion 110 a and the second radiating portion 110 b operates as a patch antenna, and thus an electromagnetic wave is radiated from the first surface side of the dielectric substrate 100 .

Furthermore, radiation-source-side opening portions which are positioned on a side opposite to the radiation-side opening portions of the first horns 200 a in a radio wave travelling direction are disposed on the first surface side of the dielectric substrate 100 so as to involve the first radiating portion 110 a and the second radiating portion 110 b respectively. That is, the first horns 200 a have two left-right symmetric horn shapes symmetrical with the second imaginary line B 1 -B 1 ′ as an axis.

As described above, the antenna of the example is constituted of the first radiating portion 110 a , the second radiating portion 110 b , and two first horns 200 a.

It is preferable that the interval at which the through holes 400 a are arranged be set to be shorter than the length of a quarter of the wavelength of an electromagnetic wave to be used within the dielectric substrate 100 .

Further, the potential of the first horn 200 a can be made equal to the reference potential of the first radiating portion 110 a and the second radiating portion 110 b by electrically connecting the first horn 200 a to the first conductor portion 120 a , and thus the electromagnetic waves radiated from the first radiating portion 110 a and the second radiating portion 110 b can be efficiently transmitted to the first horns 200 a.

Furthermore, the first dielectric lens 300 a having a convex shape in the direction of the radiation-source-side opening portion is arranged in the radiation-side opening portion of the first horn 200 a , in such a manner that the length of the first horn 200 a from the radiation-source-side opening portion to the radiation-side opening portion can be shortened, and thus the size of the antenna can be reduced. Further, first dielectric lenses are formed in consecutive convex shapes in the direction of the first imaginary line A 1 -A 1 ′, the number of the consecutive convex shape and the number of the radiating portions 110 a and 110 b being the same. That is, two first dielectric lenses 300 a of the antenna of the example are consecutively arranged in the direction of the first imaginary line A 1 -A 1 ′ and has a left-right symmetric convex shape with respect to the second imaginary line B 1 -B 1 ′ as an axis. Further, the first radiating portion 110 a and the second radiating portion 110 b are arranged at positions approximately corresponding to the focal position of the first dielectric lens 300 a . The diameter of the convex shape constituting the first dielectric lens 300 a is longer than the dimension of the first horn 200 a in a direction along the third imaginary line C 1 -C 1 ′ in the plane of the radiation-side opening portion.

According to the structure described above, the diameter of the first dielectric lens 300 a is shortened to one-half of that of a case where the first dielectric lens 300 a has one convex shape. In this case, the diameter of the dielectric lens and the focal length are substantially proportional to each other in general, and thus the focal length of the first dielectric lens 300 a is shortened to approximately one-half. Therefore, the size thereof can be reduced in the electromagnetic wave radiation direction (direction of the first optical axis D 1 a -D 1 a ′ or the second optical axis D 1 b -D 1 b ′).

Further, the first dielectric lens 300 a is formed into a cylindrical shape having a hyperbolic shape in the direction of the first imaginary line A 1 -A 1 ′ and a linear shape in the direction of the second imaginary line B 1 -B 1 ′, in such a manner that side lobes in the direction of the first imaginary line A 1 -A 1 ′ and the direction of the second imaginary line B 1 -B 1 ′ of the beam radiated from the first dielectric lens 300 a can be reduced.

Further, it is preferable that, in the direction of the first imaginary line A 1 -A 1 ′, the center of the first radiating portion 110 a is located at the intersection of the first optical axis D 1 a -D 1 a ′ of the first dielectric lens 300 a and the first surface of the dielectric substrate 100 , and the center of the second radiating portion 110 b is located at the intersection of the second optical axis D 1 b -D 1 b ′ of the first dielectric lens 300 a and the first surface of the dielectric substrate 100 .

Next, the operation of the antenna of the example will be described. The spherical electromagnetic wave radiated from the first radiating portion 110 a propagates in the first horn 200 a , is input to the first dielectric lens 300 a , and propagates in the first dielectric lens 300 a , and then the electromagnetic wave is radiated to the space. During the propagation, the first horn 200 a and the first dielectric lens 300 a convert the spherical wave into the plane wave. Similarly, a spherical electromagnetic wave radiated from the second radiating portion 110 b propagates in the first horn 200 a and the electromagnetic wave is converted from the spherical wave to the plane wave by the first horn 200 a and the first dielectric lens 300 a during the propagation.

Further, the plane electromagnetic wave originated in the first radiating portion 110 a and radiated from the first horn 200 a , and the plane electromagnetic wave originated in the second radiating portion 110 b and radiated from the first horn 200 a are synthesized in a space outside the radiation-side opening portion of the first horn 200 a and radiated as plane electromagnetic waves.

By such operation, the antenna of the example can radiate a beam having directivity in a desired direction.

Further, the antenna of the example has a structure in which two horns are in a row in the longitudinal direction, and half (the length of the radiation-side opening portion of one horn in the direction of the first imaginary line A 1 -A 1 ′) of the first imaginary line A 1 -A 1 ′ is longer than the second imaginary line B 1 -B 1 ′. That is, in one dielectric lens 300 a (a part of the dielectric lens corresponding to one radiating portion) provided on the radiation side of the antenna, the length in the direction of the first imaginary line A 1 -A 1 ′ is longer than the length in the direction of the second imaginary line B 1 -B 1 ′. In the antenna of the example, the first imaginary line A 1 -A 1 ′ is arranged in the longitudinal direction and the second imaginary line B 1 -B 1 ′ is arranged in the transverse direction. Therefore, regarding the shape of the beam radiated from the first horn 200 a , a flat beam in which the width in the direction (transverse direction) of the second imaginary line B 1 -B 1 ′ is greater than the width in the direction (longitudinal direction) of the first imaginary line A 1 -A 1 ′ is generated.

It is preferable that the electric field plane direction (B plane direction) of electromagnetic waves radiated from the first radiating portion 110 a and the second radiating portion 110 b be arranged in parallel to the first imaginary line A 1 -A 1 ′, in such a manner that the shape of the beam radiated from the first horn 200 a is likely to be narrowed in the first imaginary line A 1 -A 1 ′ direction.

FIGS. 2B and 2C are structural diagrams of a flat beam generating array antenna according to an example of the invention and illustrate shapes as viewed from the first surface side of the dielectric substrate 100 . Variations of a feed line are illustrated in the second example.

In the antenna illustrated in FIGS. 2B and 2C , the first radiating portion 110 a is connected to a first feed line 140 a and the second radiating portion 110 b is connected to the second feed line 140 b . The first conductor portion 120 a is formed to surround the first radiating portion 110 a and the second radiating portion 110 b leaving a certain distance from the first radiating portion 110 a and the second radiating portion 110 b . Also, the first conductor portion 120 a is formed leaving a certain distance from the first feed line 140 a and the second feed line 140 b.

With such a configuration, energy for electromagnetic waves to be radiated is supplied to the first radiating portion 110 a via the first feed line 140 a . Similarly, energy for electromagnetic waves to be radiated is supplied to the second radiating portion 110 b via the second feed line 140 b . The antenna gain can be improved by a structure where the first radiating portion 110 a is connected to the first feed line 140 a and the second radiating portion 110 b is connected to the second feed line 140 b.

In the antenna illustrated in FIG. 2B , the first feed line 140 a is connected to the first radiating portion 110 a from a downward direction and the second feed line 140 b is connected to the second radiating portion 110 b from an upper direction. On the other hand, in the antenna illustrated in FIG. 2C , the first feed line 140 a is connected to the first radiating portion 110 a from the downward direction and the second feed line 140 b is connected to the second radiating portion 110 b from the downward direction. Therefore, the phases of the signals supplied from the first feed line 140 a and the second feed line 140 b are different in the antenna illustrated in FIG. 2B and in phase in the antenna illustrated in FIG. 2C . In this manner, signals are supplied, in such a manner that the beam radiated from the radiation-side opening portion of the first horn 200 a through the first dielectric lens 300 a can be synthesized so that the gain is maximized in the front direction (direction perpendicular to the radiation-side opening portion). The maximum direction of the gain of the radiated beam can be set in an arbitrary direction by controlling the phases of the signals supplied from the first feed line 140 a and the second feed line 140 b.

FIGS. 3A, 3B, and 4 are structural diagrams of a flat beam generating array antenna according to an example of the invention. FIGS. 3A and 3B illustrate shapes as viewed from the radiation-side opening portion side of the first horn 200 a . Example 3 is different from the examples described above in the horn shape.

In the antenna illustrated in FIG. 3A , the shape of the radiation-side opening portion of the first horn 200 a is formed such that the direction of the first imaginary line A 1 -A 1 ′ is longer than the direction of the third imaginary line C 1 -C 1 ′ and four corners are formed in a curved shape (rounded-corner rectangle shape).

Further, in the antenna illustrated in FIG. 3B , the shape of the radiation-side opening portion of the first horn 200 a is formed into an elliptical shape in which a long side in the direction of the first imaginary line A 1 -A 1 ′ is longer than a short side in the direction of the third imaginary line C 1 -C 1 ′.

The shape of the radiation-side opening portion of the first horn 200 a of the antenna of the invention may be selected from either a rectangular shape illustrated in FIG. 1 or a shape including a curved portion illustrated in FIG. 3A or 3B in accordance with ease of manufacturing and a radiation pattern of the flat beam to be generated. Also, in accordance with the radiation pattern of the flat beam to be generated, it may be in a shape of a horn having a ridge at the radiation-side opening portion or the radiation-source-side opening portion.

In the antenna illustrated in FIG. 4 , a side surface shape of a second horn 200 b has a curved shape. The other points are the same as those of the antennas of the examples described above. Further, the side surface shape of the horn of the antenna of the invention may be a shape other than a linear shape ( FIG. 1 ) like the first horn 200 a or a curved shape ( FIG. 4 ) like the second horn 200 b (for example, a shape with irregularities). Even when the shape is selected in accordance with the radiation pattern of the flat beam to be generated, the effects of the flat beam generating array antennas of the invention are the same.

FIG. 5 is a structural diagram of a flat beam generating array antenna according to an example of the invention. The flat beam generating array antenna of Example 4 includes an electromagnetic wave shielding portion instead of a horn.

(A) of FIG. 5 illustrates a shape of the antenna of the example as seen from the radiation-side opening portion side. (B) of FIG. 5 illustrates a cross-sectional shape of the antenna of the example along the first imaginary line A 1 -A 1 ′. (C) of FIG. 5 illustrates a cross-sectional shape of the antenna of the example along the third imaginary line C 1 -C 1 ′.

The antenna illustrated in FIG. 5 includes a first electromagnetic wave shielding portion 210 a and a second electromagnetic wave shielding portion 210 b . The first electromagnetic wave shielding portion 210 a includes a first opening portion having the same shape as the radiation-side opening portion of the first horn 200 a and the first dielectric lens 300 a is arranged in the first opening portion. The second electromagnetic wave shielding portion 210 b is arranged in between the first radiating portion 110 a , the second radiating portion 110 b , and the first dielectric lens 300 a , in a direction parallel to the second imaginary line B 1 -B 1 ′. In the example, the cross-sectional shape of the second electromagnetic wave shielding portion 210 b in a case of cutting with a plane parallel to the direction of the first imaginary line A 1 -A 1 ′ is a triangle. However, other shapes may be used.

Structures other than those described above are the same as those in Examples 1 to 3.

The electromagnetic waves radiated from the first radiating portion 110 a and the second radiating portion 110 b are converted from the spherical wave to the plane wave by the first dielectric lens 300 a and radiated from opening surfaces of the first dielectric lenses 300 a on a side opposite to the first radiating portion 110 a and the second radiating portion 110 b . In the antenna of the example, the radiation of electromagnetic waves is limited by the shape of the first opening portion of the first electromagnetic wave shielding portion 210 a . In other words, the shape of an electromagnetic wave to be radiated, that is, the beam, is a flat beam of which the width in the direction of the first imaginary line A 1 -A 1 ′ is narrower than the width in the direction of the second imaginary line B 1 -B 1 ′.

Since a horn is unnecessary for the antenna of the example, the structure can be simplified and the cost can be reduced.

Also, the electromagnetic waves radiated from the first radiating portion 110 a pass a path along the first optical axis D 1 a -D 1 a′ by arranging the second electromagnetic wave shielding portion 210 b as described above and the electromagnetic wave radiated from the second radiating portion 110 b passes a path along the second optical axis D 1 b -D 1 b ′. That is, electromagnetic waves radiated from mutually different optical axes are shielded with the second electromagnetic wave shielding portion 210 b , in such a manner that it is possible to reduce side lobes of electromagnetic waves, that is, beams, radiated through the first dielectric lens 300 a.

FIG. 6 is a block diagram of a transmitting side of a sensor including the flat beam generating array antenna according to Examples 1 to 4 described above. In Example 5, an example of the transmitting side of the sensor including the flat beam generating array antenna will be described.

A sensor illustrated in FIG. 6 includes a flat beam generating array antenna 10 and a first transmission circuit 510 a . The first transmission circuit 510 a includes a first terminal 511 a connected to the first radiating portion 110 a and a second terminal 512 a connected to the second radiating portion 110 b . The phases of the signals output from the first terminal 511 a and the second terminal 512 a are determined by a direction of an electric field plane generated in the first radiating portion 110 a and the second radiating portion 110 b and may be differential or same.

Next, the operation of a transmitting unit of the sensor of the example will be described. The signal output from the first terminal 511 a of the first transmission circuit 510 a is input to the first radiating portion 110 a and radiated from the first dielectric lens 300 a as an electromagnetic wave. Similarly, the signal output from the second terminal 512 a of the first transmission circuit 510 a is input to the second radiating portion 110 b and radiated from the first dielectric lens 300 a as an electromagnetic wave.

The transmitting unit of the sensor including the flat beam generating array antenna of the example can be applied to a sensor for measuring a distance to an obstacle or the like, and a relative speed of an obstacle or the like.

FIG. 7 is a block diagram of a transmitting side of a sensor having the flat beam generating array antenna according to Examples 1 to 4 described above. In Example 6, an example of the transmitting side of the sensor in which electricity is supplied to the flat beam generating array antenna via a distributer will be described.

The sensor illustrated in FIG. 7 includes the flat beam generating array antenna 10 , a second transmission circuit 510 b , and a first distributer 500 a . The second transmission circuit 510 b includes a third output terminal 513 a for outputting a signal. The first distributer 500 a includes a first terminal 501 a , a second terminal 502 a , and a third terminal 503 a.

The third terminal 503 a of the first distributer 500 a is connected to the third output terminal 513 a of the second transmission circuit 510 b , the first radiating portion 110 a is connected to the first terminal 501 a of the first distributer 500 a , and the second radiating portion 110 b is connected to the second terminal 502 a of the first distributer 500 a . The phases of the signals output from the first terminal 501 a and the second terminal 502 a are determined by the direction of the electric field plane generated in the first radiating portion 110 a and the second radiating portion 110 b and may be differential or same.

Next, the operation of a transmitting unit of the sensor of the example will be described. The signals output from the third output terminal 513 a of the second transmission circuit 510 b are input to the third terminal 503 a of the first distributer 500 a , adjusted to the desired phase and amplitude at the first distributer 500 a , and output from the first terminal 501 a and the second terminal 502 a . The signal output from the first terminal 501 a is input to the first radiating portion 110 a and radiated from the first dielectric lens 300 a as an electromagnetic wave. Similarly, the signal output from the second terminal 502 a is input to the second radiating portion 110 b and radiated from the first dielectric lens 300 a as an electromagnetic wave.

The transmitting unit of the sensor including the flat beam generating array antenna of the example can be applied to a sensor for measuring a distance to an obstacle or the like, and a relative speed of an obstacle or the like.

FIG. 8 is a block diagram of a receiving side of a sensor including the flat beam generating array antenna according to Examples 1 to 4 described above. In Example 7, an example of the receiving side of the sensor including the flat beam generating array antenna will be described.

The sensor illustrated in FIG. 8 includes the flat beam generating array antenna 10 , a first reception circuit 520 a , and a second reception circuit 520 b . The first reception circuit 520 a includes a first input terminal 521 a connected to the first radiating portion 110 a and the second reception circuit 520 b includes a second input terminal 521 b connected to the second radiating portion 110 b.

Next, the operation of a receiving unit of the sensor of the example will be described. The electromagnetic wave input to the first dielectric lens 300 a is converted into an electrical signal at the first radiating portion 110 a via the first dielectric lens 300 a , and input to the first input terminal 521 a of the first reception circuit 520 a . Simultaneously, the electromagnetic wave input to the first dielectric lens 300 a is converted into an electrical signal at the second radiating portion 110 b via the first dielectric lens 300 a , and input to the second input terminal 521 b of the first reception circuit 520 a.

The receiving unit of the sensor including the flat beam generating array antenna of the example can be applied to a sensor for measuring a distance to an obstacle or the like, and a relative speed of an obstacle or the like. Further, since the flat beam generating array antenna of the invention generates a flat beam of which a beam width in the longitudinal direction is longer than that in the transverse direction as described above, it can be applied to a sensor which measures a vertical position (angle from a horizontal plane) of an obstacle or the like in a vertical direction (direction of the first imaginary line A 1 -A 1 ′ (not illustrated in FIG. 8 )).

FIG. 9 is a block diagram of a sensor including the flat beam generating array antenna according to the Examples 1 to 4 described above. In Example 8, an example of a sensor in which a transmission unit and a receiving unit are connected to the flat beam generating array antenna via a distributer will be described.

The sensor illustrated in FIG. 9 includes the flat beam generating array antenna 10 , the second transmission circuit 510 b , a third reception circuit 520 c , and a second distributer 500 b . The second transmission circuit 510 b includes the third output terminal 513 a for outputting a signal. The second distributer 500 b includes a first terminal 501 b , a second terminal 502 b , a third terminal 503 b , and a fourth terminal 504 b . The second distributer 500 b synthesizes the signals input to the first terminal 501 b and the second terminal 502 b , and outputs the signals from the third terminal 503 b . The second distributor 500 b distributes the signals input to the fourth terminal 504 b , and outputs the signals from the first terminal 501 b and the second terminal 502 b.

The fourth terminal 504 b of the second distributer 500 b is connected to the third output terminal 513 a of the second transmission circuit 510 b , the third terminal 503 b of the second distributer 500 b is connected to a third input terminal 521 c of the third reception circuit 520 c , the first radiating portion 110 a is connected to the first terminal 501 b of the second distributer 500 b , and the second radiating portion 110 b is connected to the second terminal 502 b of the second distributer 500 b.

Next, the operation of the transmitting unit and the receiving unit of the sensor of the example will be described. The signal output from the third output terminal 513 a of the second transmission circuit 510 b is input to the fourth terminal 504 b of the second distributor 500 b and adjusted to the desired phase and amplitude by the second distributor 500 b , and then the signal is output from the first terminal 501 b and the second terminal 502 b . The signal output from the first terminal 501 b is input to the first radiating portion 110 a , and radiated from the first dielectric lens 300 a as an electromagnetic wave. Similarly, the signal output from the second terminal 502 b is input to the second radiating portion 110 b , and radiated from the dielectric lens 300 a as an electromagnetic wave.

Electromagnetic waves radiated from the first dielectric lens 300 a are reflected by an obstacle or the like. The reflected electromagnetic waves are converted into electric signals at the first radiating portion 110 a and the second radiating portion 110 b via the first dielectric lenses 300 a . Further, the electric signal received at the first radiating portion 110 a is input to the first terminal 501 b of the second distributor 500 b , and the electric signal received at the second radiating portion 110 b is input to the second terminal 502 b of the second distributer 500 b . The second distributor 500 b adjusts the input signal to a desired phase and amplitude, outputs the signal from the third terminal 503 b , and the second distributer 500 b inputs the signal to the third input terminal 521 c of the third reception circuit 520 c.

The transmitting/receiving unit of the sensor including the flat beam generating array antenna of the example can be applied to a sensor for measuring a distance to an obstacle or the like, and a relative speed of an obstacle or the like.

FIG. 10 is a structural diagram of a sensor including the flat beam generating array antenna according to the Example 1 to 4 described above. FIGS. 11A to 11C are block diagrams of the sensor of Example 9. In Example 9, an example of a sensor including a transmitting unit, a transmitting antenna, a receiving unit, and a receiving antenna will be described.

(A) of FIG. 10 illustrates a shape of the flat beam generating array antenna of Example 9 as seen from the radiation-side opening portion side of the first horn 200 a , (B) of FIG. 10 illustrates a cross-sectional shape of the flat beam generating antenna of Example 9 taken along a sixth imaginary line C 2 -C 2 ′, (C) of FIG. 10 illustrates a cross-sectional shape of the flat beam generating antenna of Example 9 taken along a first imaginary line A 1 -A 1 ′, and (D) of FIG. 10 illustrates a shape of the dielectric substrate 100 as seen from the first surface side.

The first radiating portion 110 a , the second radiating portion 110 b , a third radiating portion 110 c , a fourth radiating portion 110 d , a fifth radiating portion 110 e , and a sixth radiating portion 110 f are arranged on the first surface (surface on which horns 200 a , 200 b , and 200 c are arranged) of the dielectric substrate 100 . Each of the radiating portions 110 a to 110 f is connected to a semiconductor element 600 a mounted on the first surface of the dielectric substrate 100 via feed lines 140 a to 140 f.

The semiconductor element 600 a includes the first transmission circuit 510 a , the first reception circuit 520 a , the second reception circuit 520 b , a fourth reception circuit 520 d , and a fifth reception circuit 520 e . The semiconductor element 600 a may be disposed in a gap portion between the first horn 200 a , the second horn 200 b , and the dielectric substrate 100 . The semiconductor element 600 a may be mounted on a second surface of the dielectric substrate 100 . Further, two or more semiconductor elements 600 a may be mounted on one or both of the first surface and the second surface of the dielectric substrate 100 .

On the first surface of the dielectric substrate 100 , the first horn 200 a , the second horn 200 b , and the third horn 200 c are installed. The first to third horns 200 a to 200 c may be connected as the same member or may be integrally formed.

In radiation-side opening portions of the horns 200 a to 200 c , dielectric lenses 300 a to 300 c having a cylindrical shape are respectively installed. The first to third dielectric lenses 300 a to 300 c may be connected as the same member or may be integrally formed.

The first radiating portion 110 a and the second radiating portion 110 b are respectively disposed in each of two radiation-source-side opening portions of the first horns 200 a , and connected to the semiconductor element 600 a by the first conductor portion 120 a and a second conductor portion 120 b . The third radiating portion 110 c and the fourth radiating portion 110 d are respectively disposed in each of two radiation-source-side opening portions of the second horns 200 b , and connected to the semiconductor element 600 a by a third conductor portion 120 c and a fourth conductor portion 120 d . The fifth radiating portion 110 d and the sixth radiating portion 110 f are respectively disposed in each of two radiation-source-side opening portions of the third horns 200 c , and connected to the semiconductor element 600 a by a fifth conductor portion 120 e and a sixth conductor portion 120 f.

The transmitting-side antenna and the receiving-side antenna may have the same size and shape. However, it is preferable for the aspect ratio of the receiving-side antenna be set larger.

As illustrated in FIG. 11A , the first transmission circuit 510 a includes the first terminal 511 a connected to the first radiating portion 110 a and the second terminal 512 a connected to the second radiating portion 110 b . The phases of the signals output from the first terminal 511 a and the second terminal 512 a are determined by the direction of electric field planes generated in the first radiating portion 110 a and the second radiating portion 110 b and may be differential or same.

As illustrated in FIG. 11B , the first reception circuit 520 a includes the first input terminal 521 a connected to the third radiating portion 110 c and the second reception circuit 520 b includes the second input terminal 521 b connected to the fourth radiating portion 110 d.

As illustrated in FIG. 11C , the fourth reception circuit 520 d includes a fourth input terminal 521 d connected to the fifth radiating portion 110 e and the fifth reception circuit 520 e includes a fifth input terminal 521 e connected to the sixth radiating portion 110 f.

Next, the operation of the transmitting unit and the receiving unit of the sensor of the example will be described. The signal output from the first terminal 511 a of the first transmission circuit 510 a is input to the first radiating portion 110 a and radiated from the first dielectric lens 300 a as an electromagnetic wave. Similarly, the signal output from the second terminal 512 a of the first transmission circuit 510 a is input to the second radiating portion 110 b and radiated from the first dielectric lens 300 a as an electromagnetic wave.

Electromagnetic waves radiated from the first dielectric lenses 300 a are reflected by an obstacle or the like. The reflected electromagnetic wave is converted into an electrical signal at the third radiating portion 110 c via the second dielectric lens 300 b , and input to the first input terminal 521 a of the first reception circuit 520 a . Simultaneously, the electromagnetic wave input to the first dielectric lens 300 a is converted into an electric signal at the fourth radiating portion 110 d via the second dielectric lens 300 b , and input to the second input terminal 521 b of the second reception circuit 520 b.

Further, the reflected electromagnetic wave is converted into an electric signal at the fifth radiating portion 110 e via the third dielectric lens 300 c , and input to the fourth input terminal 521 d of the fourth reception circuit 520 d . Simultaneously, the electromagnetic wave input to the third dielectric lens 300 c is converted into an electric signal at the sixth radiating portion 110 f via the third dielectric lens 300 c , and input to the fifth input terminal 521 e of the fifth reception circuit 520 e.

The transmitting/receiving unit of the sensor including the flat beam generating array antenna of the example can be applied to a sensor for measuring a distance to an obstacle or the like, and a relative speed of an obstacle or the like. Further, in the flat beam generating array antenna of the invention, a plurality of radiation-side opening portions are arranged side by side in an up-down direction and a right-left direction, and thus it can be applied to a sensor which measures an up-down position (angle from a horizontal plane) of an obstacle or the like in the up-down direction (direction of the first imaginary line A 1 -A 1 ′) and a right-left position (angle from the front direction) of an obstacle or the like in the right-left direction (direction of the sixth imaginary line C 2 -C 2 ′).

FIG. 12 is a block diagram of another example of a sensor including the flat beam generating array antenna according to Example 9. In Example 10, an example of a sensor including a signal processing circuit 700 will be described.

The signal processing circuit 700 is connected to the first transmission circuit 510 a , the first reception circuit 520 a , the second reception circuit 520 b , the fourth reception circuit 520 d , and the fifth reception circuit 520 e . The signal processing circuit 700 supplies a signal to be transmitted from the antenna to the first transmission circuit 510 a , and processes the signals output from the first reception circuit 520 a , the second reception circuit 520 b , the fourth reception circuit 520 d , and the fifth reception circuit 520 e.

Next, the operation of the transmitting unit and the receiving unit of the sensor of the example will be described. A first transmission signal output from the signal processing circuit 700 and input to the first transmission circuit 510 a is output from the first terminal 511 a of the first transmission circuit 510 a as the second transmission signal, and further input to the first radiating portion 110 a and radiated from the first dielectric lens 300 a as a transmission electromagnetic wave. Similarly, the second transmission signal output from the second terminal 512 a of the first transmission circuit 510 a is input to the second radiating portion 110 b and radiated from the first dielectric lens 300 a as a transmission electromagnetic wave.

Transmission electromagnetic waves radiated from the first dielectric lens 300 a are reflected by an obstacle or the like. The reflected electromagnetic wave is converted into a first reception signal at the third radiating portion 110 c via a second dielectric lens 300 b , and further it is input to the first input terminal 521 a of the first reception circuit 520 a . The first reception signal is output from the first reception circuit 520 a as the fifth reception signal and input to the signal processing circuit 700 .

Simultaneously, the reflected electromagnetic wave is converted into the second reception signal at the fourth radiating portion 110 d via the second dielectric lens 300 b , and further it is input to the second input terminal 521 b of the second reception circuit 520 b . The second reception signal is output from the second reception circuit 520 b as a sixth reception signal and input to the signal processing circuit 700 .

Simultaneously, the reflected electromagnetic wave is converted into a third reception signal at the fifth radiating portion 110 e via the third dielectric lens 300 c , and further it is input to the fourth input terminal 521 d of the fourth reception circuit 520 d . The third reception signal is output from the fourth reception circuit 520 d as a seventh reception signal and input to the signal processing circuit 700 .

Simultaneously, the reflected electromagnetic wave is converted into a fourth reception signal at the sixth radiating portion 110 f via the third dielectric lens 300 c , and further it is input to the fifth input terminal 521 e of the fifth reception circuit 520 e . The fourth reception signal is output from the fifth reception circuit 520 e as the eighth reception signal and input to the signal processing circuit 700 .

The signal processing circuit 700 combines and processes the signals output from the first reception circuit 520 a , the second reception circuit 520 b , the fourth reception circuit 520 d , and the fifth reception circuit 520 e . In other words, the sensor of the example includes one transmission channel and four reception channel, and combines and processes signals of four channels.

The transmitting/receiving unit of the sensor including the flat beam generating array antenna of the example can be applied to a sensor for measuring a distance to an obstacle or the like, and a relative speed of an obstacle or the like. Further, the flat beam generating array antenna of the invention can be applied to a sensor which measures an up-down position (angle from a horizontal plane) of an obstacle or the like in the up-down direction (direction of the first imaginary line A 1 -A 1 ′) and a right-left position (angle from the front direction) of an obstacle or the like in the right-left direction (direction of the sixth imaginary line C 2 -C 2 ′).

FIG. 13 is a block diagram of an example of an in-vehicle system including the sensor including the flat beam generating array antenna according to Example 11.

The in-vehicle system of Example 11 includes the flat beam generating array antennas of Example 1 to 4, the first transmission circuit 510 a , the first reception circuit 520 a , the second reception circuit 520 b , the fourth reception circuit 520 d , the fifth reception circuit 520 e , the signal processing circuit 700 , and a vehicle control circuit 800 .

The signal processing circuit 700 is connected to the first transmission circuit 510 a , the first reception circuit 520 a , the second reception circuit 520 b , the fourth reception circuit 520 d , and the fifth reception circuit 520 e . The signal processing circuit 700 supplies a signal to be transmitted from the antenna to the first transmission circuit 510 a , and processes the signals output from the first reception circuit 520 a , the second reception circuit 520 b , the fourth reception circuit 520 d , and the fifth reception circuit 520 e.

The vehicle control circuit 800 is connected to the signal processing circuit 700 . The connection between the vehicle control circuit 800 and the signal processing circuit 700 may be wired by cable or wireless such as wireless Local Access Network (LAN).

The vehicle control circuit 800 has a function of controlling the operation of a moving body such as a power train control and a vehicle body control according to the signal output from the signal processing circuit 700 .

The operation of the sensor including the flat beam generating array antenna of the example is the same as that of Example 10. The vehicle control circuit 800 recognizes the position of an obstacle or the like, and the distance to an obstacle or the like by the signal output from the signal processing circuit 700 and outputs a control signal to a power train control unit or a vehicle body control unit, in such a manner that the movement of a moving body according to the surrounding situation is controllable. Thus, the in-vehicle system of the example functions as a driving support system.

FIG. 14 is a diagram illustrating an attachment angle of the flat beam generating array antenna of Examples 9 and 10 described above. In Examples 12 and 13, variations of the attachment angle of the antenna will be described.

In Example 12, an antenna (radiation-side opening portion) is arranged such that the first imaginary line A 1 -A 1 ′, a fourth imaginary line A 2 -A 2 ′, and a fifth imaginary line A 3 -A 3 ′ become the vertical direction and a seventh imaginary line E 1 -E 1 ′ passing the center of the first imaginary line A 1 -A 1 ′, the center of the fourth imaginary line A 2 -A 2 ′, and the center of the fifth imaginary line A 3 -A 3 ′ becomes the horizontal direction.

The vertical (direction along the first imaginary line A 1 -A 1 ′, the fourth imaginary line A 2 -A 2 ′, and the fifth imaginary line A 3 -A 3 ′) length of the radiation-side opening portion of each antenna is wider than the horizontal (direction along the seventh imaginary line E 1 -E 1 ′) width thereof. Therefore, in the cross-sectional shape perpendicular to the radiation direction of the beam radiated from the antenna of the example, the direction in the vertical direction is narrow and the horizontal direction is wide. With such an antenna structure, it is possible to realize radar having a wide irradiation angle in the horizontal direction while solving the problem of reducing the load clutter noise.

The sensor including the antenna of Example 12 can be attached to either the front side, the lateral side, or the rear side of a moving body.

FIG. 15 is a view illustrating an attachment angle of the sensor including the flat beam generating array antenna of Example 9 and 10 described above to a moving body. In Example 13, an example in which a long side of an opening portion of the antenna is inclined from the vertical direction will be described.

In Example 13, as illustrated in FIG. 15 , an antenna (radiation-side opening portion) is arranged in a state where the first imaginary line A 1 -A 1 ′ and the seventh imaginary line E 1 -E 1 ′ (horizontal direction) form a polarization angle 50 a . An angle formed by the fourth imaginary line A 2 -A 2 ′ and the seventh imaginary line E 1 -E 1 ′ and an angle formed by the fifth imaginary line A 3 -A 3 ′ and the seventh imaginary line E 1 -E 1 ′ are also the polarization angle 50 a . It is preferable that the polarization angle 50 a is 45°. Since the beam radiated from the antenna of the Example 13 has a polarization angle of 45° with respect to the vertical direction, the influence of the load clutter noise can be reduced.

Further, the sensor including the antenna of Example 13 can be attached to either the front side, the lateral side, or the rear side of the moving body.

Hereinbefore, the preferred modes of the structure and the operation of the flat beam generating array antenna, the sensor including the flat beam generating array antenna, and the in-vehicle system including the sensor of the invention are described using the Examples 1 to 13. The number of radiating portions constituting the flat beam generating array antenna of the invention may be different from those of Examples 1 to 13 and the effect of the flat beam generating array antenna of the invention can be obtained. Furthermore, even when the shape of the radiating portion is different from those of Examples 1 to 13, when the longitudinal direction of one radiation side opening portion is longer than the transverse direction, the effect of the flat beam generating array antenna of the invention can be obtained.

Further, in Examples 1 to 13, the first to third dielectric lenses 300 a to 300 c have convex shapes bulging in the direction of the first to six radiating portions 110 a to 110 f . However, the first to third dielectric lenses 300 a to 300 c may have convex shapes bulging in an opposite direction from the first to sixth radiating portions 110 a to 110 f . In addition, the shape of the first to third dielectric lenses 300 a to 300 c is not a cylindrical shape but may be a convex surface having a rotating dipole shape.

Further, the types and the number of combinations of the flat beam generating array antenna and the sensor including the flat beam generating array antenna may have arbitrary combinations other than those of the examples described above.

Further, the attachment angle of the sensor including the flat beam generating antenna to the moving body and the direction of the beam radiated from the flat beam generating antenna may have arbitrary forms other than those of Examples 12 and 13.

Also, the material constituting the dielectric substrate 100 may be either a resin material, a ceramic material, or a semiconductor material.

As described above, according to the examples of the present invention, there are provided a plurality of radiating portions formed on a substrate, and a plurality of dielectric lenses respectively converting the spherical wave radiated from each radiating portion into the plane wave and the dielectric lens is formed in a shape where the cross-sectional surface perpendicular to the beam radiation direction has a shape in which a beam having the second direction narrower than the first direction perpendicular to the second direction is radiated, and further a plurality of dielectric lenses are arranged side by side in the second direction so that the beams radiated from the respective dielectric lenses are synthesized. Thus, it is possible to reduce the size of the dielectric lenses and shorten the focal length. Therefore, it is possible to reduce the size of the flat beam generating antenna. In particular, a length in a depth direction can be reduced.

In addition, the dielectric lens has a shape in which the second direction is longer than the first direction and the dielectric lens is installed so that the first direction becomes a horizontal direction and the second direction becomes a vertical direction. Therefore, the dielectric lens can generate a flat beam with a wide horizontal width.

Furthermore, a plurality of waveguides (horns) propagating radio waves radiated from the radiating portions are provided, and each dielectric lenses are installed in the radiation-side opening portions (opening portions on the opposite side to the radiating portions) of the respective waveguides. Therefore, the gain of the antenna can be improved.

In addition, since the shape of the radiation-side opening portion of the waveguide includes at least four straight sides, it is possible to increase the opening area and improve the gain of the antenna.

In addition, a reference potential portion formed around the radiating portion on the substrate and serving as a reference potential of the radiating portion is provided and the reference potential portion is electrically connected to the waveguide. Therefore, the reflection at the entrance of the horn can be reduced, and thus the gain can be improved by reducing the loss of the antenna.

Further, since the dielectric lens is formed in a convex shape having a thick central portion and a thin peripheral portion, the gain of the antenna can be improved.

In addition, since the dielectric lens is a cylindrical lens having a hyperbolic shape in which the thickness in the first direction (horizontal direction) is constant and the center portion in the second direction (vertical direction) is thick, the gain of the antenna can be improved. In particular, by using the horn and the cylindrical lens together, electromagnetic waves converted into plane waves by the horn will enter the surface of the cylindrical lens, so that a flat beam with reduced beam disturbance can be generated.

In addition, since the plurality of radiating portions and the plurality of dielectric lenses are arranged side by side in the up-down direction and the right-left direction, obstacles can be detected from the horizontal direction and the vertical direction. For example, it is possible to detect an uphill slope ahead and obstacles separately.

The invention is not limited to the examples described above and includes various modification examples and equivalent structures within the scope of the appended claims. For example, the examples described above are described in detail in order to explain the invention in an easy-to-understand manner and the invention is not necessarily limited to those including all the configurations described. In addition, apart of the configuration of one example may be replaced by the configuration of another example. Further, the configuration of one embodiment may be added to the configuration of another embodiment. In addition, other configurations may be added, deleted, or replaced with respect to a part of the configuration of each example.

The configurations, functions, processing units, processing means, and the like described above may be realized by hardware, for example, by designing a part or all of them with an integrated circuit or the like, or realized by software by a processor interpreting and executing a program realizing the respective functions.

Information such as programs, tables, files, and the like which realize the respective functions can be stored in a storage device such as a memory, a hard disk, and a solid state drive (SSD), or a recording medium such as an IC card, an SD card, and a DVD.

Further, control lines and information lines which are considered necessary for the explanation are illustrated and not all control lines and information lines necessary for mounting are illustrated. In fact, it can be thought that almost all configurations are interconnected.