electronic machines

Abstract

To provide an electronic apparatus that increases convenience in an object detection technique such as a millimeter-wave radar.SOLUTION: An electronic apparatus comprises: a first antenna that has directivity in a first direction; a second antenna that has directivity in a second direction including a component in a direction different from the first direction; and a control unit that controls the operation of the first antenna and the second antenna. The control unit controls, in a switchable manner, a first mode for actuating one of the first antenna and the second antenna, and a second mode for actuating both the first antenna and the second antenna.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to electronic devices. [Background technology]

[0002] For example, in fields such as the automobile industry, technology for measuring the distance between a vehicle and a predetermined object has become increasingly important. In particular, in recent years, various RADAR (Radio Detecting and Ranging) technologies have been researched, which measure the distance between a vehicle and an object by transmitting radio waves such as millimeter waves and receiving the waves reflected by the object, such as an obstacle. The importance of such technology for measuring distance is expected to increase in the future along with the development of technologies for assisting drivers in driving and technologies related to autonomous driving, which automates driving partially or completely.

[0003] Various applications of the above-mentioned radar-like technology have been proposed. For example, Patent Document 1 teaches that a forward detection radar mounted on the front of a vehicle can reduce unwanted reflections from the road surface by orienting the antenna's directivity upward to reduce downward gain. Patent Document 2 also proposes a configuration in which antenna spacing is increased to increase antenna aperture while maintaining minimal redundancy in order to obtain good angular accuracy from a forward detection radar mounted on the front of a vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-43080 [Patent Document 2] Special Publication No. 2013-504764 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned radar-like technology, if it were possible to switch the beam direction of the transmitted wave or received wave as well as the width or narrowness of the directivity, convenience would be improved in certain usage situations.

[0006] An object of the present disclosure is to provide an electronic device that improves convenience in object detection technology such as millimeter-wave radar. [Means for solving the problem]

[0007] An electronic device according to one embodiment includes a first antenna, a second antenna, and a control unit. The first antenna has directivity in a first direction. The second antenna has directivity in a second direction that includes a component in a direction different from the first direction. The control unit controls the operation of the first antenna and the second antenna. The control unit performs control to switch between a first mode in which one of the first antenna and the second antenna is operated and a second mode in which both the first antenna and the second antenna are operated. 。 In the second mode, the first antenna and the second antenna have directivity in a third direction different from the first direction and the second direction. [Effects of the Invention]

[0008] According to one embodiment, it is possible to provide an electronic device that improves convenience in object detection technology such as millimeter wave radar. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating a configuration of an electronic device according to an embodiment. [Figure 2] FIG. 1 is a diagram illustrating a configuration of an electronic device according to an embodiment. [Figure 3] 1A and 1B are diagrams illustrating the directivity of an electronic device according to an embodiment. [Figure 4] 1A and 1B are diagrams illustrating the directivity of an electronic device according to an embodiment. [Figure 5] 1A and 1B are diagrams illustrating the directivity of an electronic device according to an embodiment. [Figure 6] FIG. 10 is a diagram illustrating a simulation of an operation of an electronic device according to an embodiment. [Figure 7] FIG. 10 is a diagram illustrating a simulation result of an operation of an electronic device according to an embodiment. [Figure 8] FIG. 10 is a diagram illustrating a configuration of an electronic device according to a comparative example of an embodiment. [Figure 9] FIG. 10 is a diagram illustrating a configuration of an electronic device according to a comparative example of an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] In the present disclosure, an "electronic device" may refer to a device powered by electricity. An electronic device according to an embodiment may include a transmitting antenna and a receiving antenna. The electronic device according to an embodiment transmits electromagnetic waves as transmission waves from the transmitting antenna. For example, if a predetermined object is present around the electronic device according to an embodiment, at least a portion of the transmission waves transmitted from the electronic device is reflected by the object and becomes a reflected wave. The electronic device can then detect the object by receiving such a reflected wave with the receiving antenna of the electronic device. For example, the electronic device according to an embodiment can measure the distance to the predetermined object. The electronic device according to an embodiment can also measure the relative speed with respect to the predetermined object. Furthermore, the electronic device according to an embodiment can also measure the direction (arrival angle) in which the reflected wave from the predetermined object arrives at the electronic device.

[0011] An electronic device according to an embodiment can be installed in a roadside device that monitors the operation status of a vehicle (mobile body) such as an automobile, and can detect a predetermined object such as a mobile body that exists around the roadside device. Also, an electronic device according to an embodiment can be installed in any device such as a traffic light, and can detect a predetermined object such as a mobile body that exists around the device.

[0012] An electronic device according to an embodiment may typically be a radar (Radio Detecting and Ranging) sensor that transmits and receives radio waves. However, an electronic device according to an embodiment is not limited to a radar sensor. Such sensors may include, for example, a patch antenna. Since RADAR-like technologies are already known, detailed descriptions may be appropriately simplified or omitted. An electronic device according to an embodiment may employ, for example, an LED or a laser as a light source. An electronic device according to an embodiment may employ, for example, a photodiode as a light receiving element. An electronic device according to an embodiment may use, for example, a lens to control directivity.

[0013] Before describing an electronic device according to an embodiment, an electronic device according to a comparative example of the embodiment will be described below.

[0014] 8 and 9 are diagrams showing the configuration of an electronic device according to a comparative example of an embodiment. Fig. 8 is a diagram showing the electronic device according to the comparative example of an embodiment as viewed from a predetermined direction. Fig. 9 is a diagram showing the electronic device according to the comparative example of an embodiment as viewed from a direction opposite to the predetermined direction in Fig. 8.

[0015] 8 and 9, the X-axis direction may be the horizontal direction or the left-right direction. In FIGS. 8 and 9, the Y-axis direction may be the vertical direction or the up-down direction. In particular, in FIGS. 8 and 9, the positive Y-axis direction may be the upward direction, and the negative Y-axis direction may be the downward direction. In FIGS. 8 and 9, the Z-axis direction may be the front-to-back direction. In particular, in FIGS. 8 and 9, the positive Z-axis direction may be the forward direction or the front direction, and the negative Z-axis direction may be the backward direction.

[0016] As shown in FIGS. 8 and 9, an electronic device 100 according to a comparative example of an embodiment may include a substrate 10′. The substrate 10′ may be a circuit board used in a normal electric circuit or electronic circuit. The surface of the substrate 10′ shown in FIG. 8 (i.e., the surface of the substrate 10′ facing the positive Z-axis direction) will also be referred to as the front surface or surface for convenience. Furthermore, the surface of the substrate 10′ shown in FIG. 9 (i.e., the surface of the substrate 10′ facing the negative Z-axis direction) will also be referred to as the back surface or backside for convenience. FIGS. 8 and 9 show functional parts of a transmission system of the electronic device 100, and functional parts of a reception system of the electronic device 100 are not shown.

[0017] As shown in FIG. 8, the electronic device 100 includes a first antenna 11′ and a second antenna 12′ on the surface of a substrate 10′. The first antenna 11′ and the second antenna 12′ may be planar antennas (patch antennas) commonly used in millimeter-wave radar. The first antenna 11′ includes a radiating element group 21A′ and a radiating element group 21B′. The second antenna 12′ includes a radiating element group 22A′ and a radiating element group 22B′. A feed point 41A′ of the radiating element group 21A′ supplies power to the radiating element group 21A′. A feed point 41B′ of the radiating element group 21B′ supplies power to the radiating element group 21B′. A feed point 42A′ of the radiating element group 22A′ supplies power to the radiating element group 22A′. A feed point 42B′ of the radiating element group 22B′ supplies power to the radiating element group 22B′. Feed points 41A', 41B', 42A', and 42B' respectively supply power from the back surface of substrate 10' shown in FIG. 9 to the front surface of substrate 10' shown in FIG.

[0018] The radiating element group 21A' includes a plurality of radiating elements 31a' to 31d' arranged in the vertical direction, and a plurality of radiating elements 31e' to 31h' arranged in the vertical direction. Each of these radiating elements may be made of a metal material such as copper.

[0019] As shown in Fig. 8, the radiating elements 31a' to 31d' may be electrically connected by being wired in series. The respective wires (wires connecting adjacent radiating elements) that connect the radiating elements 31a' to 31d' in series may be the same length. The respective wires (wires connecting adjacent radiating elements) that connect the radiating elements 31a' to 31d' in series may be the same length as the wavelength λ of the transmission wave transmitted from the radiating element group 21A', for example. By making the length of the wires connecting adjacent radiating elements the same as the wavelength λ of the transmission wave, the phases of the transmission waves transmitted from the radiating elements 31a' to 31d' can be aligned.

[0020] Similarly, the radiating elements 31e' to 31h' may be electrically connected in series by being wired in series. The respective wires (wires connecting adjacent radiating elements) that connect the radiating elements 31e' to 31h' in series may be the same length. The respective wires (wires connecting adjacent radiating elements) that connect the radiating elements 31e' to 31h' in series may be the same length as the wavelength λ of the transmission wave transmitted from the radiating element group 21A', for example. By making the length of the wires connecting adjacent radiating elements the same as the wavelength λ of the transmission wave, the phases of the transmission waves transmitted from the radiating elements 31e' to 31h' can be aligned.

[0021] The feed point 41A' may be electrically connected to the radiating element 31a' by being wired. The wiring connecting the feed point 41A' and the radiating element 31a' may have a length equal to the wavelength λ of the transmission wave transmitted from the radiating element group 21A', for example. Similarly, the feed point 41A' may be electrically connected to the radiating element 31e' by being wired. The wiring connecting the feed point 41A' and the radiating element 31e' may have a length equal to the wavelength λ of the transmission wave transmitted from the radiating element group 21A', for example. With this configuration, it is possible to align the phases of the transmission waves transmitted from the radiating element group 21A', i.e., the transmission waves transmitted from the radiating element group 21A', i.e., the radiating elements 31a' to 31d' and the radiating elements 31e' to 31h'. The radiating element group 21B', the radiating element group 22A', and the radiating element group 22B' may also have a configuration similar to that of the radiating element group 21A'.

[0022] 9, electronic device 100 includes control unit 50′ on the back surface of substrate 10′. Electronic device 100 also includes feed point 61A′, feed point 61B′, feed point 62A′, and feed point 62B′ on the back surface of substrate 10′.

[0023] The control unit 50' can control the overall operation of the electronic device 100, including the control of each functional unit constituting the electronic device 100. The control unit 50' may include at least one processor, such as a central processing unit (CPU) or a digital signal processor (DSP), to provide control and processing capabilities for executing various functions. The control unit 50' may be implemented as a single processor, several processors, or individual processors. The processor may be implemented as a single integrated circuit. An integrated circuit is also called an IC (integrated circuit). The processor may be implemented as multiple integrated circuits and discrete circuits connected to each other in a communicative manner. The processor may be implemented based on various other known technologies. In one embodiment, the control unit 50' may be configured as, for example, a CPU and a program executed by the CPU. The control unit 50' may also be configured as an arbitrary SoC (system-on-a-chip) or the like. The control unit 50' may include an arbitrary memory, as appropriate. In one embodiment, the optional memory may store various parameters for defining the transmission waves transmitted from the first antenna 11' and / or the second antenna 12'.

[0024] Feed point 61A' shown in FIG. 9 is electrically connected to feed point 41A' shown in FIG. 8. Feed point 61B' shown in FIG. 9 is electrically connected to feed point 41B' shown in FIG. 8. Feed point 62A' shown in FIG. 9 is electrically connected to feed point 42A' shown in FIG. 8. Feed point 62B' shown in FIG. 9 is electrically connected to feed point 42B' shown in FIG. 8. Feed point 61A', feed point 61B', feed point 62A', and feed point 62B' may be connected to feed point 41A', feed point 41B', feed point 42A', and feed point 42B', respectively, via through holes drilled in substrate 10', for example.

[0025] As shown in Fig. 9, feed point 61A' and feed point 61B' may be electrically connected by being wired. Also, feed point 62A' and feed point 62B' may be electrically connected by being wired. The midpoint of the wiring connecting feed point 61A' and feed point 61B' may be electrically connected to an RF (Radio Frequency) port 51' of the control unit 50' by a wiring 91'. The midpoint of the wiring connecting feed point 62A' and feed point 62B' may be electrically connected to an RF (Radio Frequency) port 52' of the control unit 50' by a wiring 92'.

[0026] The length of wiring 91' may be the same as the length of wiring 92'. With this configuration, if transmission waves of the same phase are output simultaneously from RF port 51' and RF port 52' of control unit 50', the phases of the transmission waves supplied to feed point 61A', feed point 61B', feed point 62A', and feed point 62B' can be aligned. Power wired at equal lengths from RF port 51' and RF port 52' is supplied to feed point 41A', feed point 41B', feed point 42A', and feed point 42B' on the surface of the substrate.

[0027] The first antenna 11' and the second antenna 12' of the electronic device 100 may transmit radio waves in a frequency band such as millimeter waves (30 GHz or higher) or quasi-millimeter waves (for example, around 20 GHz to 30 GHz). For example, the first antenna 11' and the second antenna 12' of the electronic device 100 may transmit radio waves having a frequency bandwidth of 4 GHz, such as 77 GHz to 81 GHz. In the electronic device 100, a transmission signal for transmitting such transmission waves may be generated by, for example, the control unit 50'.

[0028] When measuring distances and the like using millimeter-wave radar, frequency-modulated continuous-wave radar (hereinafter referred to as FMCW radar) is often used. FMCW radar generates a transmission signal by sweeping the frequency of the radio waves to be transmitted. Therefore, in a millimeter-wave FMCW radar that uses radio waves in the 79 GHz frequency band, for example, the frequency of the radio waves used has a frequency bandwidth of 4 GHz, such as 77 GHz to 81 GHz. Radar using the 79 GHz frequency band is characterized by a wider usable frequency bandwidth than other millimeter-wave / quasi-millimeter-wave radars, such as those using the 24 GHz, 60 GHz, and 76 GHz frequency bands.

[0029] With the above-described configuration, the first antenna 11' and the second antenna 12' of the electronic device 100 can transmit electromagnetic waves for detecting an object.

[0030] Here, we consider a case where a transmission wave is transmitted from only one of the first antenna 11' and the second antenna 12'. For example, we will explain a case where the control unit 50' controls to transmit the transmission wave from only the first antenna 11'. As described above, the feed paths from each of the radiating elements 31a' to 31d' and the radiating elements 31e' to 31h' to the feed point 41A' are integer multiples of the wavelength λ of the transmission wave. Therefore, as described above, the transmission waves transmitted from the radiating elements 31a' to 31d' and the radiating elements 31e' to 31h' are in phase. Therefore, the first antenna 11' as a whole has directivity in the positive direction of the Z axis shown in FIG. 1, i.e., in the forward direction, and forms a beam of the transmission wave.

[0031] Also, for example, a case will be described in which the control unit 50' controls the second antenna 12' to transmit a transmission wave only. In this case, as with the first antenna 11', the feed path from each radiating element 31 to the feed point 41A' or the feed point 42B' is an integer multiple of the wavelength λ of the transmission wave. Therefore, the phases of the transmission waves transmitted from each radiating element are aligned. Therefore, the second antenna 12' as a whole has directivity in the positive direction of the Z axis shown in FIG. 1, i.e., in the forward direction, and forms a beam of the transmission wave.

[0032] Next, consider the case where transmission waves are transmitted from both the first antenna 11' and the second antenna 12'. As described above, the transmission signals output from the RF port 51' and the RF port 52' are supplied to the feed points 41A' and 41B' and the feed points 42A' and 42B', respectively, via wiring of equal length. Therefore, the first antenna 11' and the second antenna 12' are connected in phase. Therefore, the transmission waves transmitted from the first antenna 11' and the transmission waves transmitted from the second antenna 12' are combined in phase. Furthermore, the first antenna 11' has directivity in the positive direction of the Z axis, i.e., the frontward direction, and the second antenna 12' also has directivity in the positive direction of the Z axis, i.e., the frontward direction. Therefore, the combination (composite wave) of the transmission waves transmitted from both the first antenna 11' and the second antenna 12' has directivity in the positive direction of the Z axis, i.e., the frontward direction, and forms a beam of the composite wave in the positive direction of the Z axis, i.e., the frontward direction.

[0033] As described above, the composite wave transmitted from the first antenna 11' and the second antenna 12' has its main lobe directed in the positive direction of the Z axis, i.e., in the front direction (0° in both the X-axis and Y-axis directions) relative to the surface of the substrate 10'. Furthermore, the composite wave transmitted from the first antenna 11' and the second antenna 12' has a greater gain than a transmission wave transmitted from only one of the first antenna 11' and the second antenna 12'. Therefore, the composite wave transmitted from the first antenna 11' and the second antenna 12' can perform object detection with higher accuracy than a transmission wave transmitted from only one of the first antenna 11' and the second antenna 12'. Meanwhile, the directivity of the transmission wave transmitted from the first antenna 11' and / or the second antenna 12' in the front direction (0° in both the X-axis and Y-axis directions) becomes sharper (narrower) as the number of radiating elements increases, as will be described later. Therefore, the directivity of the transmission waves transmitted from the radiating elements 31a' to 31d' and radiating elements 31e' to 31h' is relatively sharp (narrow).

[0034] To detect objects at relatively long distances using technologies such as millimeter-wave radar, a high-gain antenna is required. In such cases, multiple antenna elements are arranged according to the required gain, and by combining them in phase, the directivity can be directed in the desired direction. In this case, the higher the gain of the antenna, the more elements are required, and the narrower the directivity becomes.

[0035] The electronic device 100 described above is useful in certain use cases. However, there are also expected use cases in which functions that are difficult to achieve with the electronic device 100 are desired. For example, as in the above-mentioned radar device installed at or near a roadside unit or traffic light to detect automobiles traveling on a road, functions that can be switched appropriately depending on several use cases may be desired. For example, a use case is also expected in which a device installed at a relatively high position, such as a roadside unit or traffic light or near a roadside unit or traffic light, detects automobiles and pedestrians traveling on a road. In such use cases, a function to detect automobiles and pedestrians traveling relatively close below the device may be desired. Furthermore, in the above-mentioned use cases, it may be desired to detect automobiles and pedestrians located relatively far from the device.

[0036] Even if an attempt is made to meet such demands, the electronic device 100 cannot change the direction of directivity. Therefore, the electronic device 100 cannot switch its directivity from a horizontal direction relatively far away from the electronic device 100 to a downward direction relatively close to the electronic device 100. It is possible for the control unit 50′ to change the directivity of the transmission waves by controlling the phase of the transmission waves transmitted from each radiating element (beamforming). However, even with such beamforming, the directivity of the transmission waves transmitted from a relatively large number of radiating elements, such as radiating elements 31a′ to radiating elements 31h′, will be relatively sharp (narrow). It is also possible that the desired detection accuracy cannot be achieved even with the transmission waves beamformed by radiating elements 31a′ to radiating elements 31h′ due to the presence of null points, etc. As described above, a millimeter-wave radar installed at a relatively high location, such as a roadside unit or a traffic light, requires high antenna gain in the downward direction to detect objects at close range. However, since the directivity of the antennas combined in phase becomes relatively narrow, it is possible that the gain may be insufficient to detect an object.

[0037] Therefore, an electronic device according to an embodiment can switch the beam direction of a transmitted wave or a received wave, as well as the width or narrowness of the directivity, thereby improving convenience in specific usage situations. Such an electronic device will be described in further detail below.

[0038] 1 and 2 are diagrams showing the configuration of an electronic device according to a comparative example of an embodiment. Fig. 1 is a diagram showing the electronic device according to the comparative example of an embodiment as viewed from a predetermined direction. Fig. 2 is a diagram showing the electronic device according to the comparative example of an embodiment as viewed from a direction opposite to the predetermined direction in Fig. 1.

[0039] 1 and 2, the X-axis direction may be the horizontal direction or the left-right direction. In FIGS. 1 and 2, the Y-axis direction may be the vertical direction or the up-down direction. In particular, in FIGS. 1 and 2, the positive Y-axis direction may be the upward direction, and the negative Y-axis direction may be the downward direction. In FIGS. 1 and 2, the Z-axis direction may be the front-to-back direction. In particular, in FIGS. 1 and 2, the positive Z-axis direction may be the forward direction or the front direction, and the negative Z-axis direction may be the backward direction.

[0040] As shown in FIGS. 1 and 2, an electronic device 1 according to a comparative example of an embodiment may include a substrate 10. The substrate 10 may be a circuit board used in a normal electric circuit or electronic circuit. The surface of the substrate 10 shown in FIG. 1 (i.e., the surface of the substrate 10 in the positive direction of the Z axis) will also be referred to as the front surface or surface for convenience. Furthermore, the surface of the substrate 10 shown in FIG. 2 (i.e., the surface of the substrate 10 in the negative direction of the Z axis) will also be referred to as the back surface or backside for convenience. FIGS. 1 and 2 show the functional parts of the transmission system of the electronic device 1, and the functional parts of the reception system of the electronic device 1 are not shown.

[0041] As shown in Fig. 1, electronic device 1 includes a first antenna 11 and a second antenna 12 on the surface of substrate 10. First antenna 11 and second antenna 12 may be planar antennas (patch antennas) commonly used in millimeter-wave radar. As shown in Fig. 1, first antenna 11 may be configured as a patch antenna on the upper half of electronic device 1, and second antenna 12 may be configured as a patch antenna on the lower half of electronic device 1. First antenna 11 includes radiating element group 21A, radiating element group 21B, radiating element group 21C, and radiating element group 21D. Second antenna 12 includes radiating element group 22A, radiating element group 22B, radiating element group 22C, and radiating element group 22D.

[0042] A feed point 41A of the radiating element group 21A supplies power to the radiating element group 21A. A feed point 41B of the radiating element group 21B supplies power to the radiating element group 21B. A feed point 41C of the radiating element group 21C supplies power to the radiating element group 21C. A feed point 41D of the radiating element group 21D supplies power to the radiating element group 21D. A feed point 42A of the radiating element group 22A supplies power to the radiating element group 22A. A feed point 42B of the radiating element group 22B supplies power to the radiating element group 22B. A feed point 42C of the radiating element group 22C supplies power to the radiating element group 22C. A feed point 42D of the radiating element group 22D supplies power to the radiating element group 22D.

[0043] Feed point 41A, feed point 41B, feed point 41C, and feed point 41D, and feed point 42A, feed point 42B, feed point 42C, and feed point 42D each supply power from the back surface of substrate 10 shown in FIG. 2 to the front surface of substrate 10 shown in FIG. 1.

[0044] The radiating element group 21A includes a plurality of radiating elements 31a to 31d arranged in the vertical direction. The radiating element group 22A includes a plurality of radiating elements 32a to 32d arranged in the vertical direction. Each of these radiating elements may be made of a metal material such as copper.

[0045] As shown in FIG. 1, the radiating elements 31a to 31d may be electrically connected by being wired in series. The respective wires (wires connecting adjacent radiating elements) connecting the radiating elements 31a to 31d in series may be the same length. The respective wires (wires connecting adjacent radiating elements) connecting the radiating elements 31a to 31d in series may have a length that is different from, for example, an integer multiple of the wavelength λ of the transmission wave transmitted from the radiating element group 21A. For example, the respective wires (wires connecting adjacent radiating elements) connecting the radiating elements 31a to 31d in series may have a length such as (3 / 4)λ, where λ is the wavelength of the transmission wave transmitted from the radiating element group 21A. By making the length of the wires connecting adjacent radiating elements a length that is different from an integer multiple of the wavelength λ of the transmission wave, the phases of the transmission waves transmitted from the radiating elements 31a to 31d can be shifted. In this way, the first antenna 11 may have a plurality of radiating elements connected at equal intervals by wiring. Also, the first antenna 11 may have a plurality of radiating elements connected at intervals that are different from an integral multiple of the wavelength λ of the transmitted wave or the received wave.

[0046] Similarly, the radiating elements 32a to 32d may be electrically connected in series by being wired in series. The respective wirings (wirings connecting adjacent radiating elements) connecting the radiating elements 32a to 32d in series may be the same length. The respective wirings (wirings connecting adjacent radiating elements) connecting the radiating elements 32a to 32d in series may have a length different from, for example, an integer multiple of the wavelength λ of the transmission wave transmitted from the radiating element group 22A. For example, the respective wirings (wirings connecting adjacent radiating elements) connecting the radiating elements 32a to 32d in series may have a length such as (3 / 4)λ, where λ is the wavelength of the transmission wave transmitted from the radiating element group 22A. By making the length of the wirings connecting adjacent radiating elements a length different from an integer multiple of the wavelength λ of the transmission wave, the phases of the transmission waves transmitted from the radiating elements 32a to 32d can be shifted. In this way, the second antenna 12 may have a plurality of radiating elements connected at equal intervals by wiring. Also, the second antenna 12 may have a plurality of radiating elements connected at intervals that are different from an integral multiple of the wavelength of the transmitted wave or the received wave.

[0047] In this way, the first antenna 11 includes a configuration in which a plurality of radiating elements (e.g., 31a to 31d) are connected in series in a straight line. Also, the second antenna 12 includes a configuration in which a plurality of radiating elements are connected in series in a straight line in parallel to the first antenna 11. In one embodiment, the spacing between the radiating elements of the first antenna 11 and the spacing between the radiating elements of the second antenna 12 may be different from each other.

[0048] The feed point 41A may be electrically connected to the radiating element 31a. With this configuration, the phases of the transmission waves transmitted from the radiating element group 21A, i.e., the transmission waves transmitted from the radiating elements 31a to 31d, can be shifted by the same amount. The radiating element group 21B, the radiating element group 21C, and the radiating element group 21D may also have the same configuration as the radiating element group 21A. That is, the feed point 41B may be electrically connected to the radiating elements that constitute the radiating element group 21B. The feed point 41C may be electrically connected to the radiating elements that constitute the radiating element group 21C. The feed point 41D may be electrically connected to the radiating elements that constitute the radiating element group 21D.

[0049] The feed point 42A may be electrically connected to the radiating element 32a. With this configuration, the phases of the transmission waves transmitted from the radiating element group 22A, i.e., the transmission waves transmitted from the radiating elements 32a to 32d, can be shifted by the same amount. The radiating element groups 22B, 22C, and 22D may also be configured similarly to the radiating element group 22A. That is, the feed point 42B may be electrically connected to the radiating elements that constitute the radiating element group 22B. The feed point 42C may be electrically connected to the radiating elements that constitute the radiating element group 22C. The feed point 42D may be electrically connected to the radiating elements that constitute the radiating element group 22D.

[0050] 2, the electronic device 1 includes a control unit 50 on the rear surface of the substrate 10. The electronic device 1 also includes, on the rear surface of the substrate 10, a feed point 61A, a feed point 61B, a feed point 61C, a feed point 61D, a feed point 62A, a feed point 62B, a feed point 62C, and a feed point 62D.

[0051] The control unit 50 can control the overall operation of the electronic device 1, including the control of each functional unit constituting the electronic device 1. In one embodiment, the control unit 50 may control the operation of the first antenna 11 and the second antenna 12. The control unit 50 may include at least one processor, such as a central processing unit (CPU) or a digital signal processor (DSP), to provide control and processing capabilities for executing various functions. The control unit 50 may be implemented as a single processor, several processors, or individual processors. The processor may be implemented as a single integrated circuit. An integrated circuit is also called an integrated circuit (IC). The processor may be implemented as multiple integrated circuits and discrete circuits connected to each other in a communicative manner. The processor may be implemented based on various other known technologies. In one embodiment, the control unit 50 may be configured as, for example, a CPU and a program executed by the CPU. The control unit 50 may also be configured as an arbitrary system-on-a-chip (SoC). The control unit 50 may include an arbitrary memory as appropriate. In one embodiment, the optional memory may store various parameters for defining the transmission waves transmitted from the first antenna 11 and / or the second antenna 12.

[0052] 1. Feed point 61A shown in FIG. 2 is electrically connected to feed point 41A shown in FIG. 1. Feed point 61B shown in FIG. 2 is electrically connected to feed point 41B shown in FIG. 1. Feed point 61C shown in FIG. 2 is electrically connected to feed point 41C shown in FIG. 1. Feed point 61D shown in FIG. 2 is electrically connected to feed point 41D shown in FIG. 1. Furthermore, feed point 62A shown in FIG. 2 is electrically connected to feed point 42A shown in FIG. 1. Feed point 62B shown in FIG. 2 is electrically connected to feed point 42B shown in FIG. 1. Feed point 62C shown in FIG. 2 is electrically connected to feed point 42C shown in FIG. 1. Feed point 62D shown in FIG. 2 is electrically connected to feed point 42D shown in FIG. 1. Feed point 61A, feed point 61B, feed point 61C, and feed point 61D may be connected to feed point 41A, feed point 41B, feed point 41C, and feed point 41D, respectively, via through holes drilled in substrate 10. Also, feed point 62A, feed point 62B, feed point 62C, and feed point 62D may be connected to feed point 42A, feed point 42B, feed point 42C, and feed point 42D, respectively, via through holes drilled in substrate 10, respectively.

[0053] As shown in FIG. 2 , feed point 61A and feed point 61B may be electrically connected by being wired. Feed point 61C and feed point 61D may be electrically connected by being wired. Feed point 62A and feed point 62B may be electrically connected by being wired. Feed point 62C and feed point 62D may be electrically connected by being wired. The midpoint of the wiring connecting feed point 61A and feed point 61B may be electrically connected to the midpoint of the wiring connecting feed point 61C and feed point 61D by wiring 71. The midpoint of the wiring connecting feed point 62A and feed point 62B may be electrically connected to the midpoint of the wiring connecting feed point 62C and feed point 62D by wiring 72. The midpoint of wiring 71 may be electrically connected to an RF (Radio Frequency) port 51 of control unit 50 by wiring 81. The midpoint of the wiring 72 may be electrically connected to an RF (Radio Frequency) port 52 of the control unit 50 by a wiring 82 .

[0054] The length of wiring 71 may be the same as the length of wiring 72. Furthermore, the length of wiring 81 may be the same as the length of wiring 82. With this configuration, if transmission waves of the same phase are output simultaneously from RF port 51 and RF port 52 of control unit 50, the phases of the transmission waves supplied to feed points 61A to 61D and feed points 62A to 62D can be aligned. Power wired at equal lengths from RF port 51 and RF port 52 is supplied to feed points 41A to 41D and feed points 42A to 42D on the surface of the substrate.

[0055] The first antenna 11 and the second antenna 12 of the electronic device 1 may transmit radio waves in a frequency band such as millimeter waves or quasi-millimeter waves. For example, the first antenna 11 and the second antenna 12 of the electronic device 1 may transmit radio waves having a frequency bandwidth of 4 GHz, such as 77 GHz to 81 GHz. In the electronic device 1, a transmission signal for transmitting such transmission waves may be generated by, for example, the control unit 50.

[0056] With the above-described configuration, the first antenna 11 and the second antenna 12 of the electronic device 1 can transmit electromagnetic waves for detecting an object.

[0057] The electronic device 1 shown in Fig. 1 has the same number of radiating elements as the electronic device 100 shown in Fig. 8. On the other hand, in the electronic device 1 shown in Fig. 1, the radiating elements connected to the RF port 51 and the RF port 52 of the control unit 50 are different from those in the electronic device 100 shown in Fig. 8. In the electronic device 1 shown in Fig. 1, the 16 radiating elements in the upper half form the first antenna 11, and the 16 radiating elements in the lower half form the second antenna 12.

[0058] Here, a case where a transmission wave is transmitted from only one of the first antenna 11 and the second antenna 12 will be considered. For example, a case where the control unit 50 controls to transmit a transmission wave from only the first antenna 11 will be described. As described above, in the first antenna 11, the radiating elements constituting the radiating element group 21A, etc., may have a length of (3 / 4)λ, where λ is the wavelength of the transmission wave. In this way, by making the length of the wiring connecting adjacent radiating elements a length that is different from an integer multiple of the wavelength λ of the transmission wave, the phases of the transmission waves transmitted from the radiating elements 31a to 31d, etc. can be shifted. Therefore, the first antenna 11 as a whole has directivity in, for example, the direction d1 shown in FIG. 3, and can form a beam of the transmission wave. In this way, the first antenna 11 has directivity in the first direction d1. Furthermore, the first antenna 11 may have directivity in the first direction d1 by connecting multiple radiating elements at intervals that are different from an integer multiple of the wavelength λ of the transmission wave or the reception wave. For example, as shown in FIG. 3, the first antenna 11 may have directivity including a component in the vertically upward direction as the first direction d1.

[0059] Next, for example, a case will be described in which the control unit 50 controls the second antenna 12 to transmit a transmission wave only. As described above, in the second antenna 12, the radiating elements constituting the radiating element group 22A, etc., may have a length such as (3 / 4)λ, where λ is the wavelength of the transmission wave. In this way, by making the length of the wiring connecting adjacent radiating elements a length that is different from an integer multiple of the wavelength λ of the transmission wave, the phases of the transmission waves transmitted from the radiating elements 32a to 32d, etc. can be shifted. Therefore, the second antenna 12 as a whole has directivity in, for example, the direction d2 shown in FIG. 4, and can form a beam of the transmission wave. In this way, the second antenna 12 has directivity in the second direction d2, which includes a component in a direction different from the first direction d1. Furthermore, the second antenna 12 may have directivity in the second direction d2 by connecting multiple radiating elements at intervals that are different from an integer multiple of the wavelength of the transmission wave or the reception wave. For example, as shown in FIG. 4, the second antenna 12 may have directivity that includes a component in the vertically downward direction as the second direction d2.

[0060] Next, consider the case where a transmission wave is transmitted from both the first antenna 11 and the second antenna 12. When the transmission wave transmitted from the first antenna 11 and the transmission wave transmitted from the second antenna 12 are combined in phase, the directivity of the combined wave will be in a direction that combines the directional vectors of the directivities of the respective antennas. Therefore, as shown in Fig. 5, the combined transmission waves transmitted from both the first antenna 11 and the second antenna 12 (composite wave) have directivity in the positive direction of the Z axis, i.e., the front direction, and form a beam of the combined wave in the positive direction of the Z axis, i.e., the front direction.

[0061] In this way, the composite wave transmitted from the first antenna 11 and the second antenna 12 has its main lobe directed in the positive direction of the Z axis, i.e., in the front direction (0° in both the X-axis direction and the Y-axis direction) with respect to the surface of the substrate 10. Furthermore, the composite wave transmitted from the first antenna 11 and the second antenna 12 has a greater gain than a transmission wave transmitted from only one of the first antenna 11 and the second antenna 12. Therefore, the composite wave transmitted from the first antenna 11 and the second antenna 12 can perform object detection with higher accuracy than a transmission wave transmitted from only one of the first antenna 11 and the second antenna 12. Furthermore, the composite wave transmitted from the first antenna 11 and the second antenna 12 can detect objects that are farther away than a transmission wave transmitted from only one of the first antenna 11 and the second antenna 12.

[0062] Furthermore, in the electronic device 1, when transmitting a transmission wave from one of the first antenna 11 and the second antenna 12, the number of radiating elements arranged in the vertical direction of the radiating element group 21A is four, as shown in Fig. 1. On the other hand, in the electronic device 100, when transmitting a transmission wave from one of the first antenna 11' and the second antenna 12', the number of radiating elements arranged in the vertical direction of the radiating element group 21A' is eight, as shown in Fig. 8. Therefore, in the electronic device 1, when transmitting a transmission wave from one of the first antenna 11 and the second antenna 12, the directivity of the transmission wave can be made relatively wider than in the electronic device 100.

[0063] In the electronic device 1 according to an embodiment, the control unit 50 may have multiple operating modes. Furthermore, in the electronic device 1 according to an embodiment, the control unit 50 may control the electronic device 1 to be switchable between the multiple operating modes. For example, the control unit 50 controls the electronic device 1 to be switchable between a first mode and a second mode. Here, the first mode may be a mode in which one of the first antenna 11 and the second antenna 12 is operated. For example, the control unit 50 may operate only the second antenna 12 in the first mode. Furthermore, the second mode may be a mode in which both the first antenna 11 and the second antenna 12 are operated. In the second mode in which both the first antenna 11 and the second antenna 12 are operated, the control unit 50 of the electronic device 1 according to an embodiment may set the directionality of the combined radio waves from the first antenna 11 and the second antenna 12 to a third direction d3 different from the first direction d1 and the second direction d2. In this case, the third direction d3 may be a direction perpendicular to the antenna substrate surface.

[0064] By operating in the above-described manner, the electronic device 1 can transmit a transmission wave having a relatively wide directivity in the downward direction (diagonally downward direction) as shown in Fig. 4 by operating in the first mode, for example. Also, by operating in the above-described manner, the electronic device 1 can transmit a transmission wave having a relatively narrow directivity in the front direction (forward direction) and a relatively high gain as shown in Fig. 5 by operating in the second mode, for example.

[0065] The electronic device 1 according to one embodiment can be used, for example, as a device installed in or near a roadside device or a traffic light to detect automobiles and pedestrians traveling on a road. That is, the electronic device 1 realizes a function to detect automobiles and the like located relatively close below the device. The electronic device 1 also realizes a function to detect automobiles and the like located relatively far away from the device in a direction close to the horizontal direction of the device.

[0066] In this way, the electronic device 1 according to one embodiment can change the direction of directivity. Furthermore, the electronic device 1 according to one embodiment can switch its operation so as to change the width of the directivity as well as the direction of the beam of the transmitted wave or the received wave. Therefore, the electronic device 1 according to one embodiment can improve convenience in a particular mode of use by being able to switch the width of the directivity as well as the direction of the beam of the transmitted wave or the received wave.

[0067] The effect of changing the number of radiating elements arranged vertically in the radiating element group will be further described below.

[0068] Fig. 6 is a diagram showing an example of a configuration in which radiating elements in a radiating element group are arranged vertically. Fig. 7 is a diagram showing the results of simulating the operation of the antenna when the number of radiating elements arranged vertically in the configuration shown in Fig. 6 is changed.

[0069] In this simulation, as shown in Fig. 6, eight radiating elements (radiating elements 31a to 31d and radiating elements 32a to 32d) were arranged in the vertical direction and connected in series. In this simulation, the radiating elements shown in Fig. 6 were matched to 79 GHz. In this simulation, a feed point was provided for each radiating element, and the amplitude and phase of the transmitted wave could be changed individually.

[0070] In the simulation results shown in Fig. 7, the vertical axis represents the antenna gain, and the horizontal axis represents the vertical angle. The vertical direction shown on the horizontal axis in Fig. 7 may be the downward vertical direction shown in Fig. 6.

[0071] In Figure 7, the curve shown by the dashed dotted line is the result of simulating the gain for each vertical angle when the eight radiating elements shown in Figure 6 are combined in phase. As shown in Figure 7, the curve shown by the dashed dotted line shows that in addition to the main lobe, side lobes are regularly arranged. In the simulation results shown in Figure 6, null points were observed near vertical angles of 10° and 20°. In other words, this type of operation is presumed to be unsuitable for achieving the directivity shown in Figure 4, for example.

[0072] In FIG. 7, the dashed curves represent the results of simulating the gain for each vertical angle when only the bottom four radiating elements are fed and the phase difference is shifted by 20°. This assumes the operation mode shown in FIG. 4 as the first mode operation of the electronic device 1 according to one embodiment. As shown in FIG. 7, the dashed curves represent directivity directed downward (the positive direction of the horizontal axis). Furthermore, compared to the result when the eight radiating elements are in phase (the curve shown by the dashed-dotted line), the dashed curves in FIG. 7 achieve smoother directivity without null points near vertical angles of 10° and 20°. In other words, this operation mode is suitable for achieving the directivity shown in FIG. 4, for example.

[0073] In Fig. 7, the solid curves represent the results of simulating the gain for each vertical angle when the phase is shifted and power is supplied to all eight radiating elements. This assumes the operation mode shown in Fig. 5 as the second mode operation of the electronic device 1 according to one embodiment. As shown in Fig. 7, the solid curves have tilted directivity both upward and downward, so the gain peak is slightly lower than the result when the eight radiating elements are in phase (the curve shown by the dashed dotted line). However, in Fig. 7, the main lobe is directed forward (the vertical angle is zero). In other words, this operation mode is suitable for achieving the directivity shown in Fig. 5, for example.

[0074] As described above, in the electronic device 1 according to one embodiment, when detecting an object at a relatively long distance, at least two or more antennas may be combined to increase the gain in the forward direction. On the other hand, in the electronic device 1 according to one embodiment, when detecting an object at a relatively short distance, at least one antenna among the multiple antennas with a downward directivity may be used to increase the gain in the downward direction. In this case, instead of combining multiple antennas, only one antenna may be used, i.e., an antenna with a small number of radiating elements may be used. By performing such an operation, the electronic device 1 according to one embodiment can widen the directivity in the vertical direction.

[0075] In the operation example shown in FIG. 5, the direction of directivity d3 of the transmission wave transmitted by the electronic device 1 operating in the second mode may be adjusted by the direction of directivity d1 of operation by the first antenna 11 and the direction of directivity d2 of operation by the second antenna 12. In FIG. 5, the direction of directivity d3 in the second mode is shown as pointing in the positive direction of the Z axis and parallel to the Z axis, as an example. However, the direction of directivity d3 in the second mode may have a depression angle of, for example, about 1 to 2 degrees from the positive direction of the Z axis. In this case, the direction of directivity d1 in the first mode may have an elevation angle of, for example, about 10 degrees from the positive direction of the Z axis. In this case, the direction of directivity d2 in the first mode may have a depression angle of, for example, about 11 to 12 degrees from the positive direction of the Z axis.

[0076] While the present disclosure has been described based on various drawings and examples, it should be noted that those skilled in the art would easily be able to make various modifications and alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are within the scope of the present disclosure. For example, the functions contained in each functional unit can be rearranged so as not to cause logical inconsistencies. Multiple functional units may be combined into one or divided. The above-described embodiments of the present disclosure are not limited to faithful implementation of each of the described embodiments, but may be implemented by combining features or omitting some features as appropriate. In other words, those skilled in the art can make various modifications and alterations based on the present disclosure. Therefore, these modifications and alterations are within the scope of the present disclosure. For example, in each embodiment, each functional unit, means, step, etc. can be added to other embodiments so as not to cause logical inconsistencies, or can be replaced with each functional unit, means, step, etc. of other embodiments. Furthermore, in each embodiment, multiple functional units, means, steps, etc. can be combined into one or divided into two or more. Furthermore, each of the above-described embodiments of the present disclosure is not limited to being implemented faithfully according to each of the described embodiments, but can also be implemented by combining each feature or omitting some of them as appropriate.

[0077] In the above-described embodiment, the electronic device 1 includes a transmitting antenna and transmits a transmission wave. Meanwhile, in another embodiment, the electronic device 1 may include a receiving antenna and receive a reflected wave of the transmission wave reflected by a predetermined object. In this case, the control unit 50 may switch between the first mode and the second mode, for example. That is, in the first mode, the control unit 50 may operate one of the first antenna 11 and the second antenna 12 to receive a reflected wave. For example, in the first mode, the control unit 50 may operate only the second antenna 12 to receive a reflected wave. Furthermore, in the second mode, the control unit 50 may operate both the first antenna 11 and the second antenna 12 to receive a reflected wave. In the above-described embodiment, the number of antenna patches has been described as eight elements in the vertical direction and four rows in the horizontal direction. However, in the present disclosure, the number of antenna patches may be changed as appropriate.

[0078] Furthermore, the above-described embodiments are not limited to implementation as the electronic device 1. For example, the above-described embodiments may be implemented as a control method for a device such as the electronic device 1. Furthermore, for example, the above-described embodiments may be implemented as a control program for a device such as the electronic device 1. Furthermore, the above-described embodiments may be implemented as a recording medium on which a program executed in a device such as the electronic device 1 is recorded, i.e., a computer-readable recording medium. [Explanation of symbols]

[0079] 1 Electronic equipment 10 Substrate 11 First Antenna 12 Second Antenna 21,22 Series-connected radiating elements 31,32 Radiating element 41,42 Power supply point 50 control section 51,52 Outbound Ports 61,62 Power supply point 71, 72, 81, 82 Wiring

Claims

1. a first antenna having directivity in a first direction; a second antenna having directivity in a second direction including a component in a direction different from the first direction; a control unit that controls operations of the first antenna and the second antenna; An electronic device comprising: the control unit switchably controls a first mode in which one of the first antenna and the second antenna is operated, and a second mode in which both the first antenna and the second antenna are operated; In the second mode, the first antenna and the second antenna have directivity in a third direction different from the first direction and the second direction.

2. 2. The electronic device according to claim 1, wherein the first antenna has a plurality of first radiating elements, and the plurality of first radiating elements connected in series in a straight line are connected at intervals that are different from an integer multiple of the wavelength of the transmitted wave or the received wave, thereby giving the first antenna directivity in the first direction.

3. 3. The electronic device according to claim 2, wherein the second antenna has a plurality of second radiating elements, and the plurality of second radiating elements connected in series in a straight line are connected at intervals that are different from an integer multiple of the wavelength of the transmitted wave or the received wave, thereby giving the second antenna directivity in the second direction.

4. The electronic device according to claim 3 , wherein at least one of the first radiating element of the first antenna and the second radiating element of the second antenna are connected at equal intervals by wiring.

5. The electronic device according to claim 3 , wherein a spacing between the first radiating elements of the first antenna and a spacing between the second radiating elements of the second antenna are different from each other.

6. The electronic device according to claim 1 , wherein the first antenna has directivity including a component in a vertically upward direction as the first direction.

7. The electronic device according to claim 1 , wherein the second antenna has directivity including a component in a vertically downward direction as the second direction.

8. The electronic device according to claim 1 , wherein the control unit operates only the second antenna in the first mode.

Images