JP6935192B2 - Radar device - Google Patents

Description

The present invention relates to a radar device.

In Patent Document 1, a transmitting antenna and a receiving antenna that transmit and receive radio waves in frequency bands that are the same as or close to each other are arranged on the same antenna substrate, and the radio wave radiation surface is covered with a radome for transmission. A technique for improving isolation by providing a radio wave absorber on an antenna substrate between an antenna and a receiving antenna is disclosed.

Further, in Patent Document 2, a high-frequency circuit is mounted on one surface, and a patch array antenna, a feeding line distributed and connected to the patch array antenna, and a high-frequency connection line connected to the high-frequency circuit are formed on the other surface. Disclosed is a technique for reducing the influence of noise due to unnecessary radiation by providing a dielectric substrate and a shield member provided on the other surface side of the dielectric substrate and covering at least a part of a feeding line and a high-frequency connection line. Has been done.

Further, Patent Document 3 includes an antenna unit that transmits and receives radar waves, a high-frequency circuit unit that handles high-frequency signals, and a low-frequency circuit unit that handles low-frequency signals. It includes a plate-shaped main printed circuit board having an area on which the high-frequency circuit section and the low-frequency circuit section can be mounted on the main surface, and a plate-shaped sub-printed circuit board having an area on which the high-frequency circuit section can be mounted on the front surface. Therefore, a technique capable of handling a signal having a higher frequency is disclosed by using an insulating material necessary for suppressing dielectric loss only on a secondary printed circuit board.

Further, Patent Document 4 discloses a structure of a wide-angle antenna and a technique of reducing radio waves propagating on the substrate by a periodic structure on the surface of the substrate. In particular, in the case of polarized waves propagating TM waves between the transmitting antenna and the receiving antenna on the substrate surface, it is disclosed that the component propagating on the substrate surface is large, and propagation from the transmitting antenna to the receiving antenna becomes a problem. ..

Japanese Unexamined Patent Publication No. 04-140905 JP-A-2007-13531 Japanese Unexamined Patent Publication No. 2014-202098 Re-table 2011-118462

By the way, the technique disclosed in Patent Document 1 has a problem that it is difficult to increase the density because the space on the substrate is occupied by the radio wave absorber. Further, also in the case of the technique disclosed in Patent Document 2, there is a problem that it is difficult to increase the density because the shield is arranged on the substrate.

Further, the technique disclosed in Patent Document 3 has a problem that the apparatus becomes large in size because the number of substrates is two.

Further, in order to realize radar detection at a very close distance, it is necessary to secure the isolation between the transmitting antenna and the receiving antenna. Especially when the TM wave propagates between the transmitting antenna and the receiving antenna on the substrate surface, the transmitted signal is transmitted. Since it is easy to propagate on the surface of the substrate, sufficient consideration must be given to ensuring isolation. A simple high-density arrangement aimed at miniaturization is disadvantageous in the above functions and performance.

The present invention has been made in view of the above points, and provides a radar device capable of miniaturizing a device by increasing the density of elements arranged on a circuit board while ensuring functions and performance. The purpose is.

In order to solve the above problems, the present invention comprises a radar device having a transmitting antenna and a receiving antenna, in which a high frequency circuit for transmitting a high frequency signal via the transmitting antenna and the receiving antenna and a frequency lower than the high frequency signal are used. A circuit board including a low-frequency circuit that handles signals is provided, and the transmitting antenna and the receiving antenna are provided apart from each other in a predetermined direction on a first surface of the circuit board, and are a part of the low-frequency circuit. Is provided between the transmitting antenna and the receiving antenna on the first surface of the circuit board.
According to such a configuration, it is possible to miniaturize the device by increasing the density of the elements arranged on the circuit board while ensuring the function and performance. Further, since the low frequency circuit has different frequencies of the transmitting antenna, the receiving antenna, and the transmission signal, they do not interfere with each other and can be used as a buffer region for separating the transmitting antenna and the receiving antenna, which contributes to the improvement of isolation.

Further, in the present invention, on the second surface, which is the back surface of the first surface of the circuit board, one region in which the high frequency circuit is formed and the low frequency circuit are formed in a direction orthogonal to the predetermined direction. The other region formed is arranged in a row, and the other region is provided with a connector for connecting to an external device.
According to such a configuration, by shortening the signal line between the connector and the low frequency circuit, it is possible to achieve high density and to make the EMC characteristics suitable. In addition, the existing area of the connector pin can also be used as a buffer area for separating the transmitting antenna and the receiving antenna, which contributes to the improvement of isolation.

Further, the present invention is characterized in that the transmitting antenna and the receiving antenna are array antennas having polarization in a direction parallel to the predetermined direction.
According to such a configuration, isolation between the transmitting antenna and the receiving antenna can be ensured while having a wide-angle beam characteristic in a predetermined direction.

Further, the present invention is characterized in that an electromagnetic wave absorbing member is arranged in the vicinity of the receiving antenna on the first surface.
According to such a configuration, the isolation between the transmitting antenna and the receiving antenna can be improved. Further, by arranging it in the vicinity of the receiving antenna, the propagation component on the substrate particularly involved in the receiving antenna can be absorbed more, so that the angle detection characteristic of the receiving antenna can be improved.

Further, in the present invention, in the low frequency circuit arranged on the first surface, a signal line is arranged in a region near the receiving antenna, and the electromagnetic wave absorbing member is arranged so as to cover the signal line. It is characterized by being.
According to such a configuration, since the electromagnetic wave absorbing member absorbs radio waves only for high frequency components, the isolation between the transmitting antenna and the receiving antenna is improved without affecting the signal transmission on the signal line in the low frequency circuit. Can be made to. As a result, the above two functions can be overlapped in a limited area of the substrate, and higher density can be achieved.

Further, the present invention is characterized in that the low frequency circuit includes a power supply circuit for supplying power, and at least a part of the power supply circuit is arranged on a second surface which is a back surface of the first surface.
According to such a configuration, the EMC characteristics can be ensured by arranging the power supply circuit on a surface having a relatively strong ground that can be connected to a shield or the like as compared with the surface.

Further, the present invention is characterized in that the capacitors constituting the power supply circuit are arranged on the second surface which is the back surface of the first surface.
According to such a configuration, the influence on the characteristics of the antenna can be reduced by arranging the capacitor in the power supply circuit, which is relatively tall in the radar component, on the second surface.

Further, in the present invention, the low frequency circuit includes a power supply circuit for supplying power, a communication circuit for communicating with other devices, and a signal processing circuit for processing a signal supplied from the high frequency circuit.
The communication circuit is provided between the transmitting antenna and the receiving antenna on the first surface, and the power supply circuit and the signal processing circuit are arranged on the second surface which is the back surface of the first surface. do.
According to such a configuration, the signal line between the high frequency circuit and the signal processing circuit can be minimized, and the device can be miniaturized by increasing the density of the elements arranged on the circuit board.

According to the present invention, it is possible to miniaturize an apparatus by increasing the density of elements arranged on a circuit board while ensuring functions and performance.

It is a figure which shows the schematic structure example of the circuit board which the radar apparatus which concerns on embodiment of this invention has. It is a block diagram which shows the electrical structure of the radar apparatus which concerns on embodiment of this invention. It is a figure which shows the specific structural example of the circuit board which the radar apparatus which concerns on embodiment of this invention has. It is a figure which shows the structural example of the back surface of the circuit board shown in FIG. It is a figure which shows the configuration example which arranged the electromagnetic wave absorption member on the circuit board shown in FIG. It is a figure which shows the relationship between the viewing angle of the antenna shown in FIG. 3 and a circuit element.

Next, an embodiment of the present invention will be described.

(A) Explanation of Configuration Example of Embodiment of the Present Invention FIG. 1 is a diagram showing a schematic configuration example of a circuit board included in the radar device according to the embodiment of the present invention. The radar device according to the present embodiment is attached to a vehicle, for example, and detects an object (another vehicle, a pedestrian, etc.) existing around the vehicle. FIG. 1 (A) shows the front surface on which the antenna of the circuit board of the radar device is formed, and FIG. 1 (B) shows the back surface thereof. As shown in FIG. 1A, the surface 10a of the circuit board 10 included in the radar device of the present embodiment has a connector 20, a low frequency circuit area 30a, a transmitting antenna area 50, a receiving antenna area 60, and electromagnetic wave absorption. The member 70 is arranged. Further, as shown in FIG. 1B, a connector 20, a high-frequency circuit region 40, and a low-frequency circuit region 30b are arranged on the back surface 10b of the circuit board 10.

Here, the circuit board 10 is formed of, for example, a dielectric substrate such as a glass epoxy substrate, and a circuit pattern made of copper foil or the like is formed on the front surface 10a and the back surface 10b, and circuit elements are arranged. Further, the circuit patterns of the front surface 10a and the back surface 10b are connected via through holes as needed.

The connector 20 includes, for example, a power supply line that supplies power from a battery (not shown), which is a power source, a vehicle communication line with an ECU (Electric Control Unit) (not shown), and a power supply circuit and vehicle communication provided on the circuit board 10. It is a connection part for connecting to each circuit. Since the circuit board 10 is arranged when the connector 20 is accessible from the outside when it is housed in a housing (not shown), a connector (not shown) corresponding to the connector 20 is inserted and electrically coupled. be able to.

The low frequency circuit region 30a is an region in which a circuit that handles a signal (for example, a kHz band to a MHz band) having a frequency lower than that of a high frequency signal (for example, a GHz band) handled in the high frequency circuit region 40 described later is formed. As a specific example, for example, it is connected to the ECU for circuit operation in the high frequency circuit region 40 and the low frequency circuit region 30b, including the vehicle communication circuit for communicating with the ECU via the connector 20 and the communication line. This is an area where drive signal lines and circuits are also formed. Further, elements such as chip components and ICs (Integrated Circuits) are mounted on this circuit.

The transmitting antenna region 50 is, for example, an region in which a transmitting antenna that transmits a high-frequency signal as an electromagnetic wave toward an object is arranged.

The receiving antenna area 60 is, for example, an area in which a receiving antenna that receives electromagnetic waves transmitted from the transmitting antenna area 50 and reflected by an object is arranged.

The electromagnetic wave absorbing member 70 is composed of, for example, a sheet-shaped member made of resin or rubber to which metal powder is added, and is arranged in the vicinity of the receiving antenna. Further, as will be described later, the electromagnetic wave absorbing member 70 is arranged so as to cover, for example, a region in which a plurality of signal lines of the low frequency circuit region 30a are arranged.

Further, the high-frequency circuit region 40 on the back surface 10b of the circuit board 10 shown in FIG. 1B is a circuit for processing a high-frequency signal transmitted from the transmitting antenna and a circuit for processing the high-frequency signal received by the receiving antenna. Is the area where is placed.

The low-frequency circuit region 30b is an region in which a circuit that handles a signal having a frequency lower than that of the high-frequency signal handled in the high-frequency circuit region 40 is arranged. As a specific example, for example, it is a region in which a signal processing circuit for processing information about an object obtained by the high-frequency circuit region 40 and a power supply circuit for supplying power supply power to each part of the radar device are formed.

Next, with reference to FIG. 2, an example of an electrical configuration of the radar device according to the embodiment of the present invention will be described. As shown in FIG. 2, the radar device has a connector 20, a low frequency circuit 130, and a high frequency circuit 140 as main components.

Here, the connector 20 corresponds to the connector 20 shown in FIG. 1. For example, a power supply line for supplying power from a battery (not shown), which is a power source, a communication line with an ECU (not shown), and a circuit board 10. It is a connection part for connecting the power supply line and the communication line provided in the above.

The low frequency circuit 130 includes, for example, a power supply circuit 131, a vehicle communication circuit 132, and a signal processing circuit 133.

Here, the power supply circuit 131 is a circuit that steps down (or boosts) the DC power supply supplied from a battery (not shown) via the power supply line and the connector 20 to a predetermined voltage and supplies it to each part. The vehicle communication circuit 132 is a circuit that communicates with an ECU or the like (not shown) via a communication line and a connector 20. The signal processing circuit 133 is a circuit that processes a signal supplied from the high frequency circuit 140 to detect an object and notifies the ECU or the like of the detection result via the vehicle communication circuit 132.

As an example, the power supply circuit 131 is arranged in the low frequency circuit region 30b shown in FIG. 1 (B), and the vehicle communication circuit 132 is arranged in the low frequency circuit region 30a shown in FIG. 1 (A) for signal processing. The circuit 133 is arranged in the low frequency circuit region 30b shown in FIG. 1 (B).

The high frequency circuit 140 includes, for example, an MMIC (Monolithic Microwave Integrated Circuits) 141, a high frequency circuit 142, a transmitting antenna 150, and a receiving antenna 160.

Here, the MMIC 141 is configured by integrating an active element and a passive element, supplies a high frequency signal (for example, a high frequency pulse signal) to the transmitting antenna 150 via the high frequency circuit 142, and receives the receiving antenna via the high frequency circuit 142. The high-frequency signal supplied from the 160 is subjected to, for example, down-conversion processing, orthogonal conversion processing, and the like, and supplied to the low-frequency circuit 130.

The high frequency circuit 142 is composed of, for example, an amplifier and a filter, and filters and amplifies the high frequency signal supplied from the MMIC 141 and supplies the high frequency signal to the transmitting antenna 150. Further, the high frequency circuit 142 amplifies and filters the high frequency signal supplied from the receiving antenna 160 and supplies it to the MMIC 141.

The transmitting antenna 150 is composed of, for example, an array antenna or the like, and transmits a high frequency signal supplied from the high frequency circuit 142 as an electromagnetic wave toward an object.

The receiving antenna 160 is composed of, for example, an array antenna or the like, receives an electromagnetic wave transmitted from the transmitting antenna 150 and reflected by an object, converts it into a high frequency signal, and supplies it to the high frequency circuit 142.

As an example, the MMIC 141 and the high-frequency circuit 142 are arranged in the high-frequency circuit region 40 shown in FIG. 1 (B), the transmitting antenna 150 is arranged in the transmitting antenna region 50 shown in FIG. 1 (A), and the receiving antenna 160. Is arranged in the receiving antenna area 60 shown in FIG. 1 (A).

FIG. 3 is a diagram showing a more detailed configuration example of the surface 10a of the circuit board 10. The circuit board 10 shown in FIG. 3 corresponds to FIG. 1A, and a transmitting antenna region 50, a low frequency circuit region 30a, and a receiving antenna region 60 are formed on the surface 10a of the circuit board 10 from the left side. Has been done. Further, a ground pattern 11 is formed around the surface 10a of the circuit board 10, and screw holes 12 for fixing the circuit board 10 to the housing are formed at the four apex portions of the circuit board 10 by screws. ing.

The boundary between the transmitting antenna region 50 and the low frequency circuit region 30a is divided by the ground pattern 13, and the boundary between the low frequency circuit region 30a and the receiving antenna region 60 is divided by the ground pattern 14.

In the transmitting antenna region 50, a transmitting antenna 150 composed of an array antenna in which a plurality of patch antennas are connected by a microstrip line is formed. Further, in the receiving antenna region 60, a receiving antenna 160 is formed in which a plurality of array antennas in which a plurality of patch antennas are connected by a microstrip line are arranged. The transmitting antenna 150 and the receiving antenna 160 have polarization in a direction parallel to the left-right direction in FIG.

A low-frequency circuit such as a vehicle communication circuit 132 is formed in the low-frequency circuit region 30a. In the example of FIG. 3, passive elements such as resistance elements, capacitor elements, and coil elements, active elements such as transistors and ICs, and signal lines connecting these passive elements and active elements to each other are arranged. Further, a connector 20 is arranged in the lower part of the low frequency circuit region 30a (lower part in FIG. 3).

FIG. 4 is a diagram showing a more detailed configuration example of the back surface 10b of the circuit board 10. The circuit board 10 shown in FIG. 4 corresponds to FIG. 1 (B), the back surface 10b of the circuit board 10 is divided in the vertical direction, and the upper region formed by the division is the high frequency circuit region 40. The lower region is the low frequency circuit region 30b. Further, a ground pattern 15 is formed around the back surface 10b of the circuit board 10, and screw holes 12 for fixing the circuit board 10 to the housing are formed at the four apex portions of the circuit board 10 by screws. There is.

The boundary between the high frequency circuit region 40 and the low frequency circuit region 30b is divided by the ground pattern 16.

In the high-frequency circuit region 40, active elements, passive elements, and the like constituting the MMIC 141 and the high-frequency circuit 142 are arranged, and signal lines for connecting them are formed.

In the low frequency circuit region 30b, active elements and passive elements constituting the signal processing circuit 133 and the power supply circuit 131 are arranged, and a signal line for connecting them is formed. Further, a connector 20 is arranged in the lower part of the low frequency circuit region 30b (lower part in FIG. 4).

FIG. 5 is a diagram showing a state in which the electromagnetic wave absorbing member 70 is arranged on the surface 10a of the circuit board 10 shown in FIG. In the example of FIG. 5, for example, a metal powder or the like is applied to rubber so as to cover the plurality of signal lines (a plurality of signal lines provided in the vicinity of the receiving antenna 160) in the low frequency circuit region 30a shown in FIG. A rectangular electromagnetic wave absorbing member 70 obtained by processing the added material into a sheet shape is arranged.

FIG. 6 is a cross-sectional view taken along the line AA shown in FIG. In FIG. 6, on the back surface 10b, the display of circuit elements, signal lines, and the like is omitted in order to simplify the drawing. The transmitting antenna 150 has a maximum viewing angle of approximately 150 degrees (see the alternate long and short dash line) and a viewing angle of approximately 120 degrees of the main visual field (see the alternate long and short dash line) centered in the Y direction of FIG. Similarly, the receiving antenna 160 also has a maximum viewing angle of approximately 150 degrees (see the alternate long and short dash line) and a viewing angle of approximately 120 degrees of the main visual field (see the alternate long and short dash line) centered on the Y direction in FIG. There is. Although this proposal provides a radar capable of wide-angle detection, the angular characteristics of the antenna opening area inevitably reduce the amplitude and angle detection performance in the wide-angle direction, and the minimum detection is performed at the maximum viewing angle for quality. Detection with increased value shall be performed in the main viewing angle range.

In the present embodiment, as shown in FIG. 6, the arrangement of the circuit elements is determined so that the circuit elements are not located within the viewing angles of the transmitting antenna 150 and the receiving antenna 160. That is, the circuit element (IC in this example) 61 shown in FIG. 6 has a constant height in the Y direction, but its arrangement position is determined so that the entire circuit element 61 does not enter at least within the main viewing angle. NS. With such an arrangement, as shown by the circuit element 62 shown by the broken line in FIG. 6, unnecessary electromagnetic wave scattering due to the circuit element 62 entering the main viewing angle can be prevented. In the example of FIG. 6, the electromagnetic wave absorbing member 70 is also arranged so as not to be within the main viewing angle of the receiving antenna 160, thereby ensuring the detection quality. On the other hand, for the purpose of absorbing the components propagating on the surface of the substrate, it is more preferable to arrange the electromagnetic wave absorbing member 70 with a relatively large area including the immediate vicinity of the receiving antenna. Therefore, when ensuring the isolation between the transmitting antenna and the receiving antenna, the electromagnetic wave absorbing member 70 is not arranged at least within the main viewing angle, but is arranged within the maximum viewing angle range to detect the main viewing angle. It can be said that both quality and isolation guarantee can be achieved at the same time.

(B) Description of Effect of Embodiment of the Present Invention Conventionally, a circuit is arranged on a surface (surface 10a in the example of FIG. 1) on which a transmitting antenna 150 and a receiving antenna 160 shown in FIG. 1A are arranged. It was common not to. This is because it was considered that the design would be complicated because the characteristics of the transmitting antenna 150 and the receiving antenna 160 would be affected if the circuit elements and signal lines were arranged on the same surface as the transmitting antenna 150 and the receiving antenna 160. ..

The inventor of the present application has considered daringly arranging the circuit element on the same surface as the transmitting antenna 150 and the receiving antenna 160, in spite of the above-mentioned common general technical knowledge. As a result, the transmitting antenna 150 and the receiving antenna 160 are arranged at both ends of the circuit board 10 in the left-right direction, and a low-frequency circuit is arranged between them on the same surface as the transmitting antenna 150 and the receiving antenna 160. Therefore, it was found that the device can be miniaturized without affecting the characteristics of the transmitting antenna 150 and the receiving antenna 160. Further, by arranging a low frequency circuit between the transmitting antenna 150 and the receiving antenna 160 on the same surface, the isolation of the transmitting antenna 150 and the receiving antenna 160 is improved by the scattering action of the electromagnetic wave by the circuit element. We also found that it had the unexpected effect of being able to do it.

Further, the back surface 10b of the circuit board 10 is divided into a direction (vertical direction in FIG. 1) orthogonal to the direction in which the transmitting antenna 150 and the receiving antenna 160 are arranged (horizontal direction in FIG. 1), and the connector 20 is arranged. The region (lower region in FIG. 1) is defined as a low frequency circuit region, and the upper region is defined as a high frequency region. As a result, the signal line between the connector 20 and the low frequency circuit can be minimized. Further, the high frequency circuit that affects the characteristics of the transmitting antenna 150 and the receiving antenna 160 is arranged on the back surface 10b to minimize the influence on the characteristics of the transmitting antenna 150 and the receiving antenna 160 and is arranged on the front surface 10a. By connecting the transmitting antenna 150 and the receiving antenna 160 through a through hole, it is possible to supply power to the transmitting antenna 150 and receive power from the receiving antenna 160.

The circuit board 10 is arranged in a housing made of metal or the like, and is fixed by inserting a screw (not shown) into the screw hole 12. In addition, a radome made of resin or the like is arranged on the upper part of the housing. Therefore, since the back surface 10b has a smaller thermal resistance than the front surface 10a, heat can be dissipated more efficiently. Therefore, as a method of arranging the low frequency circuit, for example, by arranging the circuit element that generates a lot of heat on the back surface 10b, the temperature rise of the circuit element can be suppressed. Further, as shown in FIG. 6, the circuit element having a high height in the Y direction is arranged on the back surface 10b so that it can be arranged at a free position without considering the viewing angles of the transmitting antenna 150 and the receiving antenna 160. be able to. Further, by arranging the signal processing circuit 133 that exchanges signals with and from the MMIC 141 on the back surface 10b, the signal line between the signal processing circuit 133 and the MMIC 141 arranged in the high frequency circuit region 40 can be minimized.

From the above viewpoint, in the present embodiment, in order to dissipate heat by heat conduction by a shield or the like in a component that requires heat dissipation (a situation where the actual temperature is tight with respect to the allowable component temperature), which is difficult to deal with only by natural convection. It is preferable to arrange it on the back surface. Further, the power supply circuit 131 having many circuit elements such as tall capacitors is avoided from being mounted on the surface from the viewpoint of securing the antenna field of view, and from the viewpoint of EMC, it is relatively stronger than the surface by connecting with a shield or the like. It is preferable to arrange it on the back surface 10b having a ground. The signal processing circuit 133, which is desirable to send and receive signals to and from the MMIC 141 in the shortest time, is also arranged on the back surface 10b, and the vehicle communication circuit 132, which generates less heat and has few tall circuit elements, is arranged on the front surface 10a. ..

As shown in FIG. 5, an electromagnetic wave absorbing member 70 is placed on the plurality of signal lines (a plurality of signal lines provided in the vicinity of the receiving antenna 160) in the low frequency circuit region 30a shown in FIG. It is arranged.

(D) Description of Modified Embodiments It goes without saying that each of the above embodiments is an example, and the present invention is not limited to the cases described above.

For example, in the configuration example shown in FIG. 1, the connector 20 is provided on the lower side, but the connector 20 may be provided on the upper side. In that case, the high-frequency circuit region 40 shown in FIG. 1B may be arranged on the lower side, and the low-frequency circuit region 30b may be arranged on the upper side. However, from the viewpoint of ensuring waterproofness and ensuring robustness to prevent the ingress of moisture, when the circuit board 10 shown in FIG. 1 is mounted on a vehicle, the connector 20 is placed on the lower side (ground side) in the vertical direction. It is desirable to arrange it so that it is located.

Further, the arrangement example of the electromagnetic wave absorbing member 70 shown in the configuration example shown in FIG. 1 is an example, and it goes without saying that the electromagnetic wave absorbing member 70 may be arranged at a position other than this.

Further, in the above-described embodiment, the power supply circuit 131 and the signal processing circuit 133 are arranged on the back surface 10b, and the vehicle communication circuit 132 is arranged on the front surface 10a. However, other arrangement methods may be adopted. Needless to say.

Further, it goes without saying that the arrangement of the circuit patterns and circuit elements shown in FIGS. 3 to 5 is an example, and the present invention is not limited to the arrangement shown in FIGS. 3 to 5.

10 Circuit board 10a Surface (first surface)
10b back side (second side)
20 Connector 30a Low frequency circuit area 30b Low frequency circuit area 40 High frequency circuit area 50 Transmission antenna area 60 Reception antenna area 70 Electromagnetic wave absorbing member 130 Low frequency circuit 131 Power supply circuit 132 Vehicle communication circuit 134 Signal processing circuit 140 High frequency circuit 141 MMIC
142 High frequency circuit 150 Transmit antenna 160 Receive antenna

Claims (6)

In a radar device having a transmitting antenna and a receiving antenna
It has a circuit board including a high frequency circuit for transmitting a high frequency signal via the transmitting antenna and the receiving antenna, and a low frequency circuit for handling a signal having a frequency lower than the high frequency signal.
The transmitting antenna and the receiving antenna are provided so as to be separated from each other in a predetermined direction on the first surface of the circuit board.
A part of the low frequency circuit is provided between the transmitting antenna and the receiving antenna on the first surface of the circuit board.
The receiving antenna has a plurality of array antenna are arranged in a plurality in parallel with the predetermined direction,
Electromagnetic wave absorbing member is not disposed in the vicinity of the transmitting antenna, which is placed in the vicinity of the receiving antenna of the first surface,
In the low frequency circuit arranged on the first surface, an element including at least a chip component is mounted in a region near the transmitting antenna, and a signal line is arranged in a region near the receiving antenna.
The electromagnetic wave absorbing member is arranged so as to cover the signal line .
The signal received by the receiving antenna is used for measuring the angle of the object.
On the second surface, which is the back surface of the first surface of the circuit board, one region in which the high frequency circuit is formed and the other region in which the low frequency circuit is formed are formed in a direction orthogonal to the predetermined direction. Are arranged in a row, and a connector for connecting to an external device is provided at the lower end of the circuit board in the other region.
The low frequency circuit is formed on the surface of the first surface on which the connector is provided.
A radar device characterized by that. The claim is characterized in that the electromagnetic wave absorbing member extends in a direction orthogonal to the predetermined direction in a region near the receiving antenna and is arranged so as not to be within the main viewing angle of the receiving antenna. Item 1. The radar device according to item 1. The radar device according to claim 1 or 2, wherein the transmitting antenna and the receiving antenna are array antennas having polarization in a direction parallel to the predetermined direction. The low frequency circuit includes a power supply circuit that supplies power.
The radar device according to any one of claims 1 to 3, wherein at least a part of the power supply circuit is arranged on a second surface which is a back surface of the first surface. The radar device according to claim 4, wherein the capacitors constituting the power supply circuit are arranged on the second surface, which is the back surface of the first surface. The low frequency circuit includes a power supply circuit that supplies power, a communication circuit that communicates with other devices, and a signal processing circuit that processes a signal supplied from the high frequency circuit.
The communication circuit is provided between the transmitting antenna and the receiving antenna on the first surface, and the power supply circuit and the signal processing circuit are arranged on the second surface which is the back surface of the first surface. The radar device according to any one of claims 1 to 5.

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