JP5803017B2 - Electronic device and radio wave receiving module - Google Patents

Description

  The present invention relates to an electronic device having a plurality of antennas and a radio wave receiving module incorporated in the electronic device.

  2. Description of the Related Art Electronic devices that perform control to identify an approach relationship between a target and a user by receiving a radio wave transmitted from the target to be detected and notify the user of information regarding the identified approach relationship are known Yes. Examples of the target include an apparatus that measures vehicle speed. The target is often installed in a dangerous place where a traffic accident is likely to occur. Therefore, the electronic device can prompt the user to drive safely in a place where a traffic accident is likely to occur, for example, by notifying the user who drives the vehicle of the approach to the target. Thus, informing the user of the approach relationship between the target and the user contributes to the user's safe driving. For example, if a radio wave is emitted from the target, it is determined that the target is in a close relationship when a radio wave emitted from the target is received. As described above, a radio wave whose position can be specified is received, a user's position (for example, a position where the position of the electronic device is regarded as the user's position) is specified, and the target position stored in advance is specified. And the like are determined to be close to each other when they are within a predetermined range.

  An electronic device is provided with an antenna for receiving such radio waves. When the electronic device is attached to the vehicle, the electronic device is preferably attached to the vehicle so that the reception sensitivity of the antenna is strongest with respect to the direction of radio waves for determining such an approaching relationship. For example, if radio waves are emitted from a target, the user's position can be specified, such as GPS, for the relationship between the direction of radio waves emitted from the target and the direction of the antenna when attached to the vehicle In the case of receiving a radio wave, it is desirable that the relationship between the direction of emission of the radio wave and the direction of the antenna when attached to the vehicle be as opposite as possible.

  On the other hand, the attachment method when an electronic device is attached to a vehicle may differ depending on the user. For example, in the case of an electronic device for an automobile, the electronic device may be attached to a dashboard, a rearview mirror, a windshield, or the like. For example, in the case of an electronic device for a motorcycle, the electronic device may be attached to a gasoline tank, a center portion of a steering wheel, a mirror post, or the like. If the method of attaching the electronic device to the vehicle is different, the angle of attachment of the electronic device to the front of the vehicle is also different. For example, the mounting angle of the electronic device with respect to the front of the vehicle differs depending on whether the electronic device is mounted on a horizontal plane on the dashboard or is mounted on a windshield inclined downward toward the front. Furthermore, the attachment angle also changes depending on the usage mode of the user. For example, when an electronic device is attached to the center of a handle for a motorcycle, the attachment angle of the electronic device is adjusted by the user so that the user can easily see the display provided on the electronic device. For this reason, the attachment angle of the electronic device with respect to the vehicle front also changes according to the user's driving posture.

  As described above, even when the mounting angle of the electronic device is changed, it is necessary to make the reception sensitivity of the antenna always strongest toward the front of the vehicle. For example, by using the technique described in Patent Document 1 and arranging a plurality of antennas so that a wide reception range can be covered by the entire five antenna elements, even when the mounting angle of the electronic device changes, it is always Any one of the antennas can be configured to cover the front of the vehicle. .

JP 2004-336580 A

  Since an electronic device is usually attached to a vehicle by a dedicated mounting component or the like, the method for attaching the electronic device is limited to several patterns. For this reason, the mounting angle of the electronic device with respect to the front of the vehicle is also limited to several patterns. Therefore, the electronic device may be provided with an antenna so that the direction showing the strongest reception sensitivity faces the front of the vehicle in a state where the electronic device is attached to the vehicle at an assumed mounting angle.

  For example, when an electronic device is attached to the center of a steering wheel of a motorcycle, the user may turn the display toward the driver side (rear side of the vehicle) or lean forward so that the display can be easily seen even when tilted backward. It is assumed that the display is directed upward so that the display is easy to see. Therefore, when the mounting angle of the electronic device is adjusted between the state in which the display is directed to the user side (the vehicle rear side) and the state in which the display is directed upward, the electronic device has a strong reception sensitivity in the front of the vehicle. It is sufficient to provide an antenna so as to have it.

  However, in Patent Document 1, a large number of antennas are provided in an electronic device so as to have reception sensitivity in all directions. For this reason, when this technology is used as it is, there is a problem that the cost of the antenna is excessive and the electronic device cannot be provided at a low cost.

  An object of the present invention is to provide an electronic device and a radio wave receiving module that have the highest reception sensitivity of radio waves to be received by an antenna even when the usage mode changes.

  An electronic apparatus according to a first aspect of the present invention includes a first antenna having the strongest reception sensitivity in a first direction and a second antenna having the strongest reception sensitivity in a second direction different from the first direction. In the case where the state of the electronic device can be changed so that the first antenna and the second antenna are directed to the user in different first and second states, respectively. The first direction faces the front of the user when the first state is reached, and the second direction faces the front of the user when the second state is reached.

  According to the first aspect, even when the state of the electronic device changes to the first state and the second state, the direction in which the reception sensitivity of the antenna provided in the electronic device is strongest is always directed forward of the user. be able to. For this reason, the electronic device can detect the target which transmits an electromagnetic wave reliably irrespective of the state with respect to a user.

  In the first aspect, the first antenna and the second antenna may be antennas formed on a plane. As a result, the installation space for the antenna can be saved, and the electronic device can be downsized. In the antenna formed on the plane, the ground can be widely provided on the plane, so that the characteristics of the antenna can be stabilized.

  In the first aspect, it is preferable that a virtual plane including the first antenna intersects the second antenna. Usually, an antenna provided on a plane exhibits strong reception sensitivity in a direction orthogonal to the plane. For this reason, by intersecting the virtual plane including the first antenna with the second antenna, the direction in which the first antenna has the highest reception sensitivity and the direction in which the second antenna has the strongest reception sensitivity are reliably different. Can be made.

  Further, in the first aspect, a box-shaped module that receives radio waves via the first antenna and the second antenna, the first plane, a second plane facing the first plane, and the first plane A wireless module having a third plane provided between the plane end and the second plane end may be provided. The first antenna may be provided on the first plane and parallel to the first plane. The second antenna may be provided on the third plane and in parallel with the third plane. Since the first antenna and the second antenna are directly provided on the surface of the box-shaped wireless module, the first antenna and the second antenna can be fixed in a stable state. In addition, since the first antenna, the second antenna, and the wireless module can be combined in a compact manner, the electronic device can be reduced in size. Furthermore, since the wireless module can be brought close to the first antenna and the second antenna, the length of the signal line between them can be shortened. Therefore, it is possible to reduce transmission loss when an electric signal is transmitted through the signal line. Moreover, impedance matching when the wireless module is connected to the first antenna and the second antenna can be facilitated.

  In the first aspect, a support substrate may be provided that contacts the second plane of the wireless module and supports the wireless module. A portion of the support substrate adjacent to the second antenna may have a space that allows the second antenna to pass in a direction intersecting the support substrate. This allows the second antenna to pass through the space. Even if the second antenna is enlarged, the second antenna does not contact the support substrate. For this reason, the freedom degree of the shape of a 2nd antenna can be raised. Moreover, it can prevent that the characteristic of a 2nd antenna changes because a support substrate contacts a 2nd antenna. Furthermore, the reception sensitivity can be increased by increasing the second antenna.

  In the first aspect, a housing that covers the first antenna, the second antenna, the wireless module, and the support substrate may be provided. Of the second antenna, a portion protruding in the first direction from the virtual plane and a portion protruding to the opposite side of the support substrate from the side on which the wireless module is supported are The length should not touch the body. Thereby, it is possible to prevent the electric characteristics of the second antenna from changing due to the second antenna coming into contact with the housing, and the directivity of the second antenna from changing. Moreover, it can prevent that a 2nd antenna or a housing | casing is damaged because a 2nd antenna contacts a housing | casing repeatedly.

  Further, in the first aspect, by setting the electronic device in the second state, the second direction faces the front of the user, and the first direction faces the user, The radio wave coming from the front of the user may be shielded by the second antenna. As a result, radio waves are not irradiated to at least a portion of the first antenna. Here, when the target is installed above the user, the arrival direction of the radio wave emitted from the target moves upward from the front of the user as the user approaches the target. When the first antenna and the second antenna are installed as described above, the first antenna is disposed behind the second antenna with respect to the arrival direction of the radio wave when the radio wave arrives from the front of the user. Therefore, at least a part of the first antenna is not irradiated with radio waves. For this reason, the intensity of the radio wave received via the first antenna is weakened. On the other hand, in a state where radio waves arrive from above the user, the second antenna does not interfere with radio wave irradiation to the first antenna, so the radio waves are directly irradiated to the first antenna. The intensity of the radio wave received via is increased. Thus, the intensity of the radio wave received via the first antenna changes as the user approaches the target. Therefore, the electronic device can accurately grasp the distance between the target and the user by detecting the change in the intensity of the radio wave received via the first antenna.

  In the first aspect, an end of the second antenna may be in contact with a virtual plane including the first antenna. Accordingly, it is possible to prevent a positional relationship in which one of the first antenna and the second antenna is hidden behind the other antenna with respect to the arrival direction of the radio wave. Therefore, the radio wave emitted from the target can be satisfactorily received by both the first antenna and the second antenna.

  Further, in the first aspect, a box-shaped module that receives radio waves via the first antenna and the second antenna, the first plane, a second plane facing the first plane, and the first plane A wireless module having a third plane provided between a plane end surface and the second plane end surface may be provided. The first antenna may be provided on the first plane and parallel to the first plane. The second antenna may be provided on the third plane and in parallel with the third plane. As a result, the first antenna and the second antenna are directly provided on the surface of the box-shaped wireless module, so that the first antenna and the second antenna can be fixed in a stable state. In addition, since the first antenna, the second antenna, and the wireless module can be combined in a compact manner, the electronic device can be reduced in size. Furthermore, since the wireless module can be brought close to the first antenna and the second antenna, the length of the signal line between them can be shortened. Therefore, it is possible to reduce transmission loss when an electric signal is transmitted through the signal line. Moreover, impedance matching when the wireless module is connected to the first antenna and the second antenna can be facilitated.

  In the first aspect, a support substrate may be provided that contacts the second plane of the wireless module and supports the wireless module. A portion of the support substrate adjacent to the second antenna may have a space that allows the second antenna to pass in a direction intersecting the support substrate. This allows the second antenna to pass through the space. Even if the second antenna is enlarged, the second antenna does not contact the support substrate. For this reason, the freedom degree of the shape of a 2nd antenna can be raised. Moreover, it can prevent that the characteristic of a 2nd antenna changes because a support substrate contacts a 2nd antenna. Furthermore, the reception sensitivity can be increased by increasing the second antenna.

  In the first aspect, a housing that covers the first antenna, the second antenna, the wireless module, and the support substrate may be provided. A portion of the second antenna that protrudes to the side opposite to the side on which the wireless module is supported with respect to the support substrate may have a length that does not contact the housing. Thereby, it is possible to prevent the electric characteristics of the second antenna from changing due to the second antenna coming into contact with the casing, and the directivity of the second antenna from changing. Moreover, it can prevent that a 2nd antenna or a housing | casing is damaged because a 2nd antenna contacts a housing | casing repeatedly.

  Further, in the first aspect, by setting the electronic device in the second state, the second direction faces the front of the user, and the first direction faces the user, Radio waves coming from the front of the user may be applied to the first antenna without being shielded by the second antenna. When the target is installed above the user, the arrival direction of the radio wave emitted from the target moves upward from the front of the user as the user approaches the target. However, when the first antenna and the second antenna are installed as described above, the radio wave is well irradiated to the first antenna and the second antenna in both states where the radio wave arrives from the front and above the user. The phenomenon that the second antenna interferes with the radio wave irradiation to the first antenna does not occur. For this reason, the radio wave emitted from the target can be satisfactorily received by both the first antenna and the second antenna without depending on the approaching relationship between the target and the user.

  In the first aspect, the first antenna and the second antenna may be in contact with each other. As a result, the first antenna and the second antenna can be placed as close as possible. Accordingly, since the space for providing the first antenna and the second antenna can be reduced, the electronic device can be reduced in size.

  In the first aspect, the first direction and the second direction may be orthogonal to each other. Thus, even when the angle when the electronic device is attached is changed by 90 degrees between the first state and the second state, the direction in which the antenna reception sensitivity is strongest can always be directed forward of the user. it can.

  For example, when an electronic device is attached to the center of a steering wheel of a motorcycle, the driver may turn the display toward the driver side (the rear side of the motorcycle) or tilt forward so that the display can be easily seen in a tilted state. It is assumed that the display is directed upward so that the display is easy to see in this state. Therefore, the angle of the electronic device is adjusted between the state where the display is directed toward the driver and the state where the display is directed upward, and the maximum change amount of the angle is about 90 degrees. Therefore, by providing the first antenna and the second antenna so that the first direction and the second direction are orthogonal to each other, the reception sensitivity of the antenna can be improved regardless of the state in which the electronic device is adjusted. It is possible to always keep the strongest direction in front of the user.

  In the first aspect, one of the first antenna and the second antenna may be a horizontally polarized antenna and the other may be a vertically polarized antenna. Of the measuring devices that measure vehicle speed, radio waves output from measuring devices installed near the road surface, such as radar-type fixed orvis or moving orbs, are often vertically polarized or circularly polarized. On the other hand, a radio wave output from a measuring device installed at a position away from the road surface, for example, the new H system, is often horizontally polarized. Therefore, by providing both the vertically polarized antenna and the horizontally polarized antenna, it is possible to satisfactorily receive radio waves transmitted from different types of measuring devices.

  Further, in the first aspect, of the first antenna and the second antenna, the antenna in which the direction of strong reception sensitivity faces the front of the user is a vertically polarized antenna, and the antenna faces the upper side of the user Is a horizontally polarized antenna. By using a vertically polarized antenna as the antenna whose reception sensitivity is directed in front of the user, radio waves output from a measurement device installed near the road surface can be transmitted from a position away from the measurement device. It can be received well. Moreover, when a user approaches a measuring device installed above a road surface by using a horizontally polarized antenna as an antenna whose reception sensitivity is directed upwards, the signal is output from the measuring device. Can be received well.

  In the first aspect, the coupled antenna obtained by coupling the first antenna and the second antenna may have strong directivity over the first direction and the second direction. Thereby, even when the state of the electronic device is continuously changed between the first state and the second state, the coupled antenna always exhibits a strong reception sensitivity toward the front of the user. Therefore, the radio wave emitted from the target can always be received satisfactorily.

  In the first aspect, the electronic device may be attached to the vehicle driven by the user in the first state and the second state. It is good to provide the control means which performs control which alert | reports the information which assists the driving | operation of the said vehicle with respect to the said user based on the electromagnetic wave received via at least one among said 1st antenna and said 2nd antenna. As a result, the electronic device can notify the user of the approaching relationship between the target and the vehicle, which can contribute to safe driving for the user.

  The radio wave receiving module according to the second aspect of the present invention includes a first antenna having the strongest receiving sensitivity in the first direction, a second antenna having the strongest receiving sensitivity in the second direction different from the first direction, A box-shaped module for receiving radio waves via a first antenna and a second antenna, the first plane, a second plane facing the first plane, and the first plane end and the second plane A radio module having a third plane provided between the plane ends and a radio wave receiving module stored in an electronic device, wherein the first antenna is on the first plane, And the second antenna is provided on the third plane and in parallel with the third plane, and the first antenna and the second antenna for the user are provided. The direction of each is different In the case where the state of the electronic device can be changed so as to be in the first state and the second state, when the electronic device is in the first state, the first direction is in front of the user. When the electronic device is in the second state, the second direction faces the front of the user.

  According to the second aspect, even when the state of the electronic device in which the radio wave reception module is stored changes between the first state and the second state, the direction in which the reception sensitivity of the antenna provided in the radio wave reception module is strongest Can always be directed forward of the user. For this reason, the radio wave receiving module can reliably receive radio waves from a target that transmits radio waves, regardless of the mounting method.

  In addition, since the first antenna, the second antenna, and the wireless module can be combined in a compact manner, the radio wave receiving module can be reduced in size. Furthermore, since the wireless module can be brought close to the first antenna and the second antenna, the length of the signal line between them can be shortened. Therefore, it is possible to reduce transmission loss when an electric signal is transmitted through the signal line. Moreover, impedance matching when the wireless module is connected to the first antenna and the second antenna can be facilitated.

  In the second aspect, the first antenna and the second antenna may be antennas formed on a plane. Thereby, the same effect as the first aspect can be obtained.

  In the second aspect, a virtual plane including the first antenna may cross the second antenna. Thereby, the same effect as the first aspect can be obtained.

  Also, in the second aspect, by setting the electronic device in the second state, radio waves coming from the front of the user are shielded by the second antenna in a state where the second direction faces the front of the user. It is good to be done. Thereby, the same effect as the first aspect can be obtained.

  In the second aspect, the end of the second antenna may be in contact with a virtual plane including the first antenna. Thereby, the same effect as the first aspect can be obtained.

  In the second aspect, by setting the electronic device in the second state, radio waves coming from the front of the user are shielded by the second antenna in a state where the second direction faces the front of the user. The first antenna may be reached without being done. Thereby, the same effect as the first aspect can be obtained.

  In the second aspect, an end portion of the second antenna that is close to the second plane of the wireless module is in contact with the second plane of the wireless module to support the wireless module. It may be located on the wireless module side. Thereby, the same effect as the first aspect can be obtained.

  In the second aspect, the first antenna and the second antenna may be in contact with each other. Thereby, the same effect as the first aspect can be obtained.

  In the second aspect, the first direction and the second direction may be orthogonal to each other. Thereby, the same effect as the first aspect can be obtained.

  In the second aspect, one of the first antenna and the second antenna may be a horizontally polarized antenna, and the other may be a vertically polarized antenna. Thereby, the same effect as the first aspect can be obtained.

  In the second aspect, the antenna in which the direction of strong reception sensitivity faces the front of the user among the first antenna and the second antenna is a vertically polarized antenna, and the antenna faces the upper side of the user. Is a horizontally polarized antenna. Thereby, the same effect as the first aspect can be obtained.

  In the second aspect, the coupled antenna obtained by coupling the first antenna and the second antenna may have strong directivity over the first direction and the second direction. Thereby, the same effect as the first aspect can be obtained.

1 is a perspective view showing an outline of an electronic device 1. FIG. It is the perspective view which looked at the electric wave receiving module 10 from the back side and the upper side. It is a left view of the radio wave receiving module 10 in the first state. It is a left view of the receiving module 10 in a 2nd state. It is a left side surface of the radio wave receiving module 10 in the second state in the modified example. It is a left side surface of the radio wave receiving module 30 in the second state in the modified example. It is a photograph which shows the evaluated radio wave receiving module 10 (1). It is a photograph which shows the evaluated radio wave receiving module 10 (2). It is a photograph which shows the radio wave receiving module 10 (3) evaluated. It is a graph which shows the directivity of the electromagnetic wave receiving module 10 (1). It is a graph which shows the directivity of the electromagnetic wave receiving module 10 (2). It is a graph which shows the directivity of the electromagnetic wave receiving module 10 (3).

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. These drawings are used to explain technical features that can be adopted by the present invention. The configuration of the apparatus described is not intended to be limited to that, but merely an illustrative example.

  The electronic device 1 will be described with reference to FIG. The upper side, lower side, left side, right side, near side, and depth side of FIG. 1 are referred to as the upper side, lower side, left side, right side, front side, and back side of the electronic device 1, respectively. The electronic device 1 receives a radio wave from a speed radar for detecting a speed violation, issues a warning, or sends a radio wave from a GPS satellite indicating the position of the speed violation control machine that does not emit a radio wave such as a loop coil type speed violation control machine. Receive and issue a warning. The electronic device 1 is a known radar detector, for example. In the following description, it is assumed that the electronic device 1 is attached to the center of the handle of the motorcycle. However, the present invention is not limited to a usage mode in which the motorcycle is attached to the center of the handle of the motorcycle. For example, the electronic device 1 may be attached to a gasoline tank or a side mirror of a motorcycle. Moreover, you may attach to the dashboard and windshield of a motor vehicle. Further, for example, the electronic device 1 may be used by being directly placed in a user's breast pocket or the like. Hereinafter, the motorcycle is also simply referred to as a vehicle.

  The electronic device 1 includes a housing 2 and a display unit 3. The shape of the housing | casing 2 is a substantially rectangular parallelepiped which makes the left-right direction a longitudinal direction. The display unit 3 is provided on the front side of the housing 2. The electronic device 1 can be switched to an attachment angle with respect to the vehicle as indicated by an arrow 4 in a state of being attached to the center of the handle of the vehicle. As a result, the electronic device 1 has a state in which the back side (depth side in FIG. 1) of the electronic device 1 is directed in front of the vehicle, and a state in which the upper side (upper side in FIG. 1) of the electronic device 1 is directed in front of the vehicle. The mounting angle can be switched freely between. Therefore, the driver is in any state between the state in which the display unit 3 of the electronic device 1 is directed toward the rear of the vehicle (the side on which the driver is seated with respect to the steering wheel) and the state in which the display unit 3 is directed upward of the vehicle. You can switch to For example, the driver can turn the display unit 3 toward the rear of the vehicle so that the display unit 3 is easy to see even when driving in a tilted posture, or the display unit 3 can be easily viewed even when driving in a tilted posture. The display unit 3 is directed upward. Thus, the driver can adjust the image displayed on the display unit 3 so as to be easily seen by switching the mounting angle of the electronic device 1 according to the driving posture.

  As described above, since the electronic device 1 is attached to the handle of the vehicle, the attachment angle of the electronic device 1 with respect to the vehicle may differ depending on the type of vehicle.

  A first antenna 11 and a second antenna 12 (see FIG. 2 and the like) that detect microwaves emitted from the speed measurement device are provided in the housing 2 at positions close to the upper side and the rear side. Further, a microwave receiving module 13 (see FIG. 2 and the like) that receives microwaves via the first antenna 11 and the second antenna 12 is provided. Further, a GPS receiving module, a GPS antenna, a wireless receiving module, a wireless receiving antenna, a control unit, a database, a speaker, and the like (not shown) are provided.

  The control unit includes a CPU, an EEPROM, and a RAM. The functions in the electronic device 1 are realized by the CPU executing a program stored in the EEPROM. The control unit normally displays the standby screen or the radar scope on the display unit 3 by executing processing for realizing the standby screen display function or the radar scope display function. Further, the control unit executes processing for realizing each function such as a GPS alarm function, a radar wave alarm function, and a radio alarm function in accordance with the event that has occurred.

  The GPS alarm function is obtained by calculating the distance between the latitude and longitude of the target object stored in the database and the latitude and longitude of the current position detected by the GPS receiving module during execution of the standby screen display function or the radar scope display function. When the distance becomes the approach warning distance stored in the database, the data of the photograph or schematic diagram stored in the database is read and displayed on the display unit 3, and the voice data stored in the database is read from the speaker. This is a function for performing an approach notification that outputs an approach warning sound.

  These objects include fixed speed measuring devices (including speed measuring devices that emit radar waves (microwaves) like radar and speed measuring devices that do not emit radar waves such as loop coils), speed limit switching Point, control area, inspection area, parking monitoring area, N system, traffic monitoring system, intersection monitoring point, signal ignorance suppression system, police station, accident-prone area, frequent on-vehicle area, sudden / continuous curve (highway), Branch / Joint Point (Expressway), ETC Lane Advance Guidance (Expressway), Service Area (Expressway), Parking Area (Expressway), Parking Area (Expressway), Highway Oasis (Expressway), Smart Interchange (Expressway) Road), PA / SA, gas station (highway), tunnel (highway), highway radio reception Area (highway), prefectural border notice, road station, viewpoint parking, etc. Latitude / longitude information indicating the position of these objects, object type information, and schematic diagram or photo data displayed on the display unit 3 And voice data of the voice output from the speaker are stored in the database in association with each other.

  The radar wave warning function is displayed when the microwave reception module 13 detects a signal corresponding to microwaves in a frequency band emitted from a speed measurement device (speed measurement device that emits radar waves such as a mobile radar). 3 is an alarm function for displaying an alarm screen and outputting an alarm sound from a speaker.

  The wireless alarm function is a function for issuing an alarm so as not to hinder the traveling or the like when the wireless reception module receives a radio signal from an emergency vehicle or the like. In the radio alarm function, enforcement radio, car radio, digital radio, special radio, police radio, police phone, police radio, wrecker radio, heli tele radio, fire helicopter radio, fire fight radio, emergency radio, expressway radio , Scan the frequency of security radio, etc., and when the radio is received at the scanned frequency, a schematic diagram showing that the radio corresponding to that frequency stored in the database for each radio type was received is displayed as an alarm screen The voice data that is displayed on the unit 3 and stored in the database for each wireless type is read out, and an alarm sound indicating the wireless type is output from the speaker.

  Details of the radio wave receiving module 10 will be described with reference to FIGS. The upper side, lower side, depth side, near side, left side, and right side of FIG. 3 correspond to the upper side, lower side, left side, right side, front side, and rear side of the radio wave receiving module 10, respectively. The radio wave receiving module 10 is stored in the housing 2 of the electronic device 1 with the right side in FIG. 3 facing the back side of the electronic device 1. In a state where the radio wave receiving module 10 is stored in the housing 2, the display unit 3 is disposed on the front side (left side in FIG. 3) of the support substrate 18 (described later). The radio wave receiving module 10 includes a first antenna 11, a second antenna 12, and a microwave receiving module 13.

  The first antenna 11 and the second antenna 12 are patch antennas that can satisfactorily receive microwaves in a frequency band emitted from the velocity measuring device. The first antenna 11 and the second antenna 12 have a structure in which a plurality of patch portions are provided on a planar substrate surface. By using a patch antenna, the structure can be simplified and the mechanical strength of the antenna can be increased. Moreover, since the installation space of the 1st antenna 11 and the 2nd antenna 12 can be saved, the electronic device 1 can be reduced in size. In general, since the patch antenna can be provided with a wide ground on the substrate surface, the characteristics of the antenna can be stabilized.

  The microwave receiving module 13 is a wireless module for receiving microwaves via the first antenna 11 and the second antenna 12. The microwave receiving module 13 detects the signal level of the received microwave and outputs it as a received signal strength indication (RSSI). The control unit recognizes the received microwave signal level based on the RSSI voltage level output from the microwave receiving module 13, and predicts the distance between the speed measurement device that transmitted the microwave and the vehicle. can do.

  The shape of the microwave receiving module 13 is a substantially rectangular parallelepiped. As shown in FIG. 3, the microwave receiving module 13 is mounted on a support substrate 18. The microwave receiving module 13 is a flat plate surface forming a substantially rectangular parallelepiped, and includes a first plane 131, a second plane 132, a third plane 133, and a fourth plane 134. The 1st plane 131, the 2nd plane 132, the 3rd plane 133, and the 4th plane 134 are equivalent to the surface of the flat plate of the back side, the front side, the upper side, and the lower side of the microwave receiving module 13, respectively. The first plane 131 and the second plane 132 are opposed to each other. The third plane 133 and the fourth plane 134 are opposed to each other. The third plane 133 and the fourth plane 134 are provided between the first plane 131 and the second plane 132. The first antenna 11 is provided in parallel with the first plane 131 by being in close contact with the first plane 131. The second antenna 12 is provided in parallel with the third plane 133 by being in close contact with the third plane 133. The extending directions of the first antenna 11 and the second antenna 12 are orthogonal to each other.

  Since the first antenna 11 and the second antenna 12 are in direct contact with the surface of the rectangular parallelepiped microwave receiving module 13, the contact area between the first antenna 11 and the second antenna 12 and the microwave receiving module 13 is large. . For this reason, the 1st antenna 11 and the 2nd antenna 12 can be fixed in the stable state. Moreover, since the base etc. which fix the 1st antenna 11 and the 2nd antenna 12 become unnecessary, the 1st antenna 11, the 2nd antenna 12, and the microwave receiving module 13 can be put together compactly. As a result, the electronic device 1 can be reduced in size. Furthermore, since the first antenna 11 and the second antenna 12 and the microwave receiving module 13 can be brought close to each other, the first antenna 11 and the microwave receiving module 13, and the second antenna 12 and the microwave receiving module 13 The length of the signal line between the two can be shortened. Therefore, it is possible to reduce the transmission loss when the electric signal is transmitted through the signal line. Further, impedance matching when the first antenna 11 and the second antenna 12 and the microwave receiving module 13 are connected can be facilitated.

  As shown in FIG. 2, the first antenna 11 includes patch portions 111 and 112 and a strip line 113 on the surface opposite to the side in contact with the first plane 131 (see FIG. 3) of the microwave reception module 13. ing. The patch portions 111 and 112 are square conductor foils. The strip line 113 is a transmission path for connecting the patch units 111 and 112 and the microwave receiving module 13. The first antenna 11 is provided with a plurality of patch portions 111 and 112 to increase reception sensitivity. The first antenna 11 has directivity in the vertical direction with respect to the plane and on the side where the patch portions 111 and 112 are provided, and the reception sensitivity in this direction is increased. The first antenna 11 has the strongest reception sensitivity in the back direction of the electronic device 1 in a state where the radio wave receiving module 10 is stored in the housing 2 of the electronic device 1. Hereinafter, as shown in FIG. 3, the direction showing the strongest reception sensitivity of the first antenna 11 is referred to as a first direction 21.

  As shown in FIG. 2, the second antenna 12 has a patch portion 121 having the same shape as the first antenna 11 on the surface opposite to the side in contact with the third plane 133 (see FIG. 3) of the microwave receiving module 13. , 122 and strip line 123. The second antenna 12 has directivity in the vertical direction with respect to the plane and on the side where the patch portions 121 and 122 are provided, and the reception sensitivity in this direction is increased. The second antenna 12 exhibits the strongest reception sensitivity in the upward direction of the electronic device 1 in a state where the radio wave receiving module 10 is stored in the housing 2 of the electronic device 1. Hereinafter, as shown in FIG. 3, the direction showing the strongest reception sensitivity among the second antennas 12 is referred to as a second direction 22.

  As shown in FIG. 3, the first antenna 11 and the second antenna 12 are in contact with the upper end 114 of the first antenna 11 and the lower surface of the second antenna 12. In this way, the radio wave receiving module 10 brings the first antenna 11 and the second antenna 12 as close as possible. As a result, the space required for providing the first antenna 11 and the second antenna 12 can be reduced, and the electronic device 1 can be downsized.

  In a state where the radio wave receiving module 10 is stored in the housing 2, the first direction 21 corresponds to the back direction of the electronic device 1, and the second direction corresponds to the upward direction of the electronic device 1. For this reason, when the mounting angle of the electronic device 1 is adjusted so that the back side of the electronic device 1 faces the traveling direction 24 of the vehicle, that is, the front of the driver, the first direction 21 faces the traveling direction 24 of the vehicle, The two directions 22 face the upper side of the vehicle. Accordingly, the first antenna 11 can satisfactorily receive microwaves coming from the front of the vehicle. Hereinafter, the state in which the electronic device 1 is attached to the vehicle so that the first direction 21 faces the traveling direction 24 of the vehicle is also referred to as a first state.

  On the other hand, as shown in FIG. 4, when the mounting angle of the electronic device 1 is adjusted so that the upper side of the electronic device 1 faces the traveling direction 24 of the vehicle, that is, the front of the driver, the first direction 21 is Directed downward, the second direction 22 faces the traveling direction 24 of the vehicle. Therefore, the second antenna 12 can satisfactorily receive microwaves coming from the front of the vehicle. Hereinafter, the state where the electronic device 1 is attached to the vehicle so that the second direction 22 faces the traveling direction 24 of the vehicle is also referred to as a second state.

  As described above, at least one of the first antenna 11 and the second antenna 12 even when the attachment angle of the electronic device 1 to the vehicle is changed according to the visibility of the display unit 3 by the driver and the type of the vehicle. Thus, it is possible to satisfactorily receive microwaves coming from the front of the vehicle. Although details will be described later, by providing the first antenna 11 and the second antenna 12, the electronic apparatus 1 exhibits a strong reception sensitivity in the first direction and the second direction. Thereby, the electronic device 1 can always receive a microwave satisfactorily regardless of the mounting angle. Therefore, the electronic device 1 can reliably detect the speed measuring device that transmits the microwave.

  Usually, antennas often have directivity depending on the installation environment. When an antenna having directivity is used for the electronic apparatus 1 as an antenna for receiving microwaves, a direction having the highest reception sensitivity (hereinafter also referred to as “directional axis”) is transmitted from the speed measurement device. It is necessary to turn in the direction of arrival of radio waves. Usually, the directional axis of the antenna is directed to the front of the vehicle. There are mainly the following three methods for directing the antenna pointing axis toward the front of the vehicle.

  As a first method, there is a method in which a plurality of antennas having different directivity axes are prepared, and an antenna that actually receives a microwave among the plurality of antennas is arbitrarily switched. As a method of switching antennas, there is a method of switching appropriately to an antenna having a high reception level among a plurality of antennas. As another method, there is a method of switching an antenna to be used depending on a ground plane. In this method, instead of switching the antenna based on the reception level, the arrival direction of the radio wave is predicted and the antenna is switched in advance before reception.

  As a second method, there is a method of changing a directivity axis by using a reflector. In this method, the directivity can be expanded without changing the installation state of the antenna.

  As a third method, there is a method of rotating an antenna. In this method, a highly directional antenna is used, and the arrival direction of radio waves is specified.

  In the case of the electronic device 1, it is assumed that the microwave comes from the front of the vehicle. Therefore, in many cases, the antenna of the electronic device 1 is installed so as to have a directivity axis in front of the vehicle. Some radar detectors include an antenna having a directional axis behind the vehicle in addition to the front of the vehicle. As described above, the directivity axis of the antenna is limited to the horizontal axis direction. A plurality of radar detectors are known in which the directivity axis of an antenna is adjusted in accordance with the mounting state of the electronic device 1. For example, there are a back antenna type represented by a mirror type, a horn antenna type, and a type found in a separate type and a solar type.

  When the electronic device 1 is attached at an attachment angle different from the assumed attachment state, the detection direction of the speed measuring device may be lowered because the microwave arrival direction and the directivity axis are different. As a solution for this, for example, it may be possible to set a plurality of directional axes by using the second method described above. However, when a reflector is built in the electronic device 1, the housing 2 becomes large and the structure becomes complicated. Moreover, when a reflector is installed outside, it is easy to receive a complicated impression.

  On the other hand, in the electronic device 1, the first antenna 11 and the second antenna 12 are arranged so that the directivity axes of the first antenna 11 and the second antenna 12 are different from each other. This means that a part of the antenna including a plurality of patch antennas is processed so that the directional axis is different from the other parts. In terms of image, the first antenna 11 and the second antenna 12 provided in the electronic apparatus 1 have a configuration in which a four-patch antenna having four patch portions is bent at 90 degrees from the middle. As a result, the directivity of the entire antenna can be widened, so that the directional axis can always be directed to the front of the vehicle even when the electronic device 1 is mounted in an angle.

  When the electronic device 1 is attached to the motorcycle as in the present embodiment, the driver adjusts the attachment angle of the electronic device 1 in order to increase the visibility of the display unit 3 provided in the electronic device 1. There is. This is because the angle of the line of sight toward the display unit 3 varies depending on the driving posture of the driver. In this embodiment, since it is assumed that the electronic device 1 is attached to the center of the handle of the motorcycle, the attachment angle of the electronic device 1 may change depending on the type of the motorcycle. Even in such a case, the directivity of the antenna can be expanded to the front of the vehicle in consideration of the mounting state of the electronic device 1 and the driver's line of sight. This eliminates the need for the electronic device 1 used in the motorcycle to be a separate type in which the display unit 3 and the antenna are separated.

  As shown in FIG. 3, the rear end (right side in FIG. 3) of the second antenna 12 protrudes rearward from the first antenna 11. In other words, when the virtual plane 23 including the first antenna 11 is defined, the second antenna 12 intersects the plane 23. In addition, the front end (left side in FIG. 3) of the second antenna 12 protrudes forward from the support substrate 18 on which the microwave receiving module 13 is mounted. A space 181 for allowing the second antenna 12 to pass forward exists so that the end 125 of the second antenna 12 can protrude forward in the portion of the support substrate 18 that is close to the second antenna 12. Yes. Thereby, even if the second antenna 12 is enlarged in the forward direction, the second antenna 12 does not contact the support substrate 18. Therefore, the freedom degree of the shape which the 2nd antenna 12 can take can be raised. Moreover, it can prevent that the characteristic of the 2nd antenna 12 changes because the support substrate 18 contacts the 2nd antenna 12. FIG. Furthermore, since the second antenna 12 can be enlarged, the reception sensitivity of the second antenna 12 can be further increased.

  In the radio wave receiving module 10, the length of the second antenna 12 in the front-rear direction is set so that the rear end 124 and the front end 125 of the second antenna 12 do not come into contact with the housing 2 that houses the radio wave receiving module 10. Has been adjusted. Specifically, the rear end 124 of the second antenna 12 does not contact the inner surface of the rear wall of the housing 2, and the front end 125 of the second antenna 12 has the housing 2 The length of the second antenna 12 in the front-rear direction is adjusted so as not to contact the inner surface of the front wall. Thereby, it is possible to prevent the electrical characteristics of the second antenna 12 from being changed due to the second antenna 12 coming into contact with the housing 2 and the directivity of the second antenna 12 from being changed. Moreover, it can prevent that the 2nd antenna 12 or the housing | casing 2 is damaged because the 2nd antenna 12 contacts the housing | casing 2 repeatedly. Further, the reception sensitivity of the second antenna 12 is increased by extending the length of the second antenna 12 in the front-rear direction so as not to contact the case 2 and making it substantially the same as the length of the case 2 in the front-rear direction. Can do.

  As described above, in the electronic device 1, the mounting angle of the electronic device 1 with respect to the vehicle changes, and the electronic device 1 changes between the first state (see FIG. 1) and the second state (see FIG. 2). However, the direction with the strongest antenna reception sensitivity can always be directed to the front of the vehicle. For this reason, the electronic device 1 can reliably detect the speed measurement device that transmits the microwaves regardless of the mounting angle with respect to the vehicle.

  Since the first antenna 11 and the second antenna 12 are stored in the housing 2 at different angles, the electronic device 1 has a strong reception sensitivity in a wide range. For this reason, in order to always point an antenna ahead of a vehicle, it is not necessary to attach an antenna outside. This is because even if the mounting angle of the electronic device 1 changes, the antenna built in the electronic device 1 always has strong directivity in front of the vehicle. Therefore, since the number of parts and manufacturing man-hours that constitute the electronic device 1 can be suppressed, the cost can be suppressed and the electronic device 1 can be provided at a low cost.

  The first antenna 11 and the second antenna 12 exhibit strong reception sensitivity in a direction perpendicular to the substrate plane. Therefore, by intersecting the virtual plane 23 including the first antenna 11 and the second antenna 12, the first direction 21, which is a direction in which the first antenna 11 has a strong reception sensitivity, and the reception sensitivity in the second antenna 12. The second direction 22, which is a strong direction, can be reliably made different. Moreover, since the extending directions of the first antenna 11 and the second antenna 12 are orthogonal to each other, even when the mounting angle of the electronic device 1 is changed by 90 degrees between the first state and the second state. The direction in which the reception sensitivity of the antenna is strongest can always be directed to the traveling direction 24 of the vehicle.

  For example, when the electronic device 1 is attached to the center of a steering wheel for a motorcycle, the driver directs the display unit 3 toward the driver side (the rear side of the vehicle) so that the display unit 3 can be easily seen in a tilted posture (see FIG. 3), or the display unit 3 is assumed to be directed upward of the vehicle (see FIG. 4) so that the display unit 3 is easy to see in a forward tilted posture. Therefore, in the electronic device 1, the mounting angle is adjusted between a state in which the display unit 3 is directed toward the driver (rear of the vehicle) (see FIG. 3) and a state in which the display unit 3 is directed upward (see FIG. 4). Therefore, the maximum change amount of the angle is about 90 degrees. Therefore, by providing the first antenna 11 and the second antenna 12 so that the first direction 21 and the second direction 22 are orthogonal to each other, even if the electronic device 1 is adjusted to any state, The direction in which the reception sensitivity of the antenna is strongest can always be directed to the traveling direction 24 of the vehicle.

  In addition, this invention is not limited to the above-mentioned embodiment, A various change is possible. In the above description, the first antenna 11 and the second antenna 12 are patch antennas, but the first antenna 11 and the second antenna 12 may be antennas other than the patch antenna, for example, a dipole antenna. The angle formed by the extending direction of the first antenna 11 and the extending direction of the second antenna 12 is not limited to 90 °. Any angle other than 90 ° may be used as long as the directions intersect each other. The angle formed by the extending direction of the first antenna 11 and the extending direction of the second antenna 12 may be adjusted according to the degree of change when the mounting state of the electronic device 1 changes. For example, when the user uses the electronic device 1 by rotating it by X °, the angle formed by the extending direction of the first antenna 11 and the extending direction of the second antenna 12 may be X °. The position of the lower end 115 of the first antenna 11 may be positioned below the fourth flat surface 134 below the microwave receiving module 13. As a result, the vertical length of the first antenna 11 can be increased, so that the reception sensitivity of the first antenna 11 can be increased.

  The front end 125 of the second antenna 12 may be located behind the support substrate 18, that is, on the side where the microwave receiving module 13 is disposed. As a result, the second antenna 12 does not protrude rearward from the support substrate 18. Thereby, for example, even when the microwave receiving module 13 is attached to the support substrate 18 in which the space portion 181 is not provided, the second antenna 12 can be prevented from contacting the support substrate 18. Therefore, it is possible to prevent the characteristics of the second antenna 12 from changing due to the support substrate 18 coming into contact with the second antenna 12.

  The first antenna 11 and the second antenna 12 are not limited to antennas for receiving microwaves. For example, the first antenna 11 and the second antenna 12 are used as antennas for receiving radio waves from GPS satellites. May be.

  In the above-described embodiment, the first antenna 11 and the second antenna 12 provided in the electronic device 1 are configured separately. On the other hand, the 1st antenna 11 and the 2nd antenna 12 may be comprised by the common 4 patch antenna which has four patch parts. Then, the first antenna 11 and the second antenna 12 may be formed by bending the four-patch antenna at 90 degrees from the center.

  The arrangement of the radio wave receiving module 10 in the housing 2 of the electronic device 1 is not limited to the above example. For example, as shown in FIG. 5, the radio wave receiving module 10 is stored in the housing 2 so that the first direction 21 corresponds to the upper side of the electronic device 1 and the second direction 22 corresponds to the rear side of the electronic device 1. May be. Further, even when the radio wave receiving module 10 is stored in the housing 2 in such a direction, the electronic device 1 is attached to the vehicle so that the back side of the electronic device 1 faces the traveling direction 24 of the vehicle. Good. This state corresponds to the second state because the second direction 22 faces the traveling direction 24 of the vehicle.

  Assume that the speed measuring device 25 is installed above the vehicle in the state shown in FIG. 5. As the vehicle moves in the traveling direction 24 and approaches the speed measuring device 25, the direction of arrival of microwaves emitted from the speed measuring device 25 moves upward from the front of the vehicle (arrow 26). In a state where the microwave comes from the front of the vehicle, the first antenna 11 is arranged behind the second antenna 12 with respect to the direction of arrival of the microwave. Since the upper end 124 of the second antenna 12 shields the microwave, a part of the first antenna 11 is not irradiated with the microwave. For this reason, the intensity of the microwave received via the first antenna 11 becomes weak.

  On the other hand, in the state where the microwave transmitted from the speed measurement device arrives from above the vehicle, the second antenna 12 does not interfere with the microwave irradiation to the first antenna 11. 11 is directly irradiated, and the intensity of the microwave received via the first antenna 11 is increased. Thus, as the vehicle approaches the speed measuring device 25, the intensity of the microwave received via the first antenna 11 gradually increases. Accordingly, the electronic device 1 can accurately grasp the distance between the speed measuring device 25 and the vehicle by detecting a change in the intensity of the radio wave received via the first antenna 11.

  In the state shown in FIG. 5, one of the first antenna 11 and the second antenna 12 may be a horizontally polarized antenna and the other may be a vertically polarized antenna. Among measurement devices that measure vehicle speed, a measurement device installed near a road surface, for example, a microwave output from a radar-type fixed or moving orvis, is often vertically polarized or circularly polarized. . On the other hand, a radio wave output from a measuring device installed at a position away from the road surface, for example, the new H system, is often horizontally polarized. Therefore, by providing both the vertically polarized antenna and the horizontally polarized antenna, it is possible to satisfactorily receive radio waves transmitted from different types of measuring devices. Further, the first antenna 11 may be a horizontally polarized antenna and the second antenna 12 may be a vertically polarized antenna. By using the second antenna 12 as a vertically polarized antenna, the direction of strongest reception sensitivity in the vertically polarized antenna can be directed to the front of the vehicle. For this reason, it is possible to satisfactorily receive radio waves output from a measurement device installed at a position close to the road surface even from a position away from the measurement device. In addition, by using the first antenna 11 as a horizontally polarized antenna, the direction with the highest reception sensitivity in the horizontally polarized antenna can be directed upward of the vehicle. For this reason, when a vehicle approaches the measuring device installed above the road surface, radio waves output from the measuring device can be received well.

  In the above description, the virtual plane 23 including the first antenna 11 and the second antenna 12 intersect each other. The end 124 of the second antenna 12 protrudes from the first antenna 11 on the side opposite to the side where the microwave receiving module 13 is disposed. On the other hand, the second antenna 12 and the virtual plane 23 do not have to cross each other, and the end 124 of the second antenna 12 protrudes on the side opposite to the side where the microwave receiving module 13 is disposed. It does not have to be. Hereinafter, modifications of the present invention will be described.

  With reference to FIG. 6, the detail of the electromagnetic wave receiving module 30 in the modification of this invention is demonstrated. Description of the same parts as those of the radio wave receiving module 10 in the embodiment shown in FIG. 5 is omitted. The radio wave reception module 30 includes a first antenna 31, a second antenna 32, and a microwave reception module 13.

  The radio wave receiving module 30 is different from the radio wave receiving module 10 shown in FIG. 5 in that the upper end 324 of the second antenna 32 does not protrude upward with respect to the first antenna 31. The end 324 is in contact with the virtual plane 23 including the first antenna 31, and the first antenna 31 and the end 324 are located on the same plane 23. Thus, unlike the radio wave receiving module 10 shown in FIG. 5, it is possible to prevent the second antenna 32 from being hidden behind the first antenna 31 in the microwave arrival direction. Therefore, when the electronic device 1 moves in the traveling direction 24 of the vehicle and approaches the speed measuring device 25, the microwaves emitted from the speed measuring device 25 are satisfactorily transmitted by both the first antenna 11 and the second antenna 12. Can be received.

  Further, the length of the second antenna 12 in the extending direction is adjusted so that the lower end 325 of the second antenna 32 does not contact the housing 2 in which the radio wave receiving module 30 is stored. Specifically, the vertical length of the second antenna 12 is adjusted so that the lower end 325 of the second antenna 12 does not contact the inner surface of the lower side wall of the housing 2. Thereby, it is possible to prevent the electrical characteristics of the second antenna 32 from being changed due to the second antenna 32 coming into contact with the housing 2 and the directivity of the second antenna 32 from being changed. Moreover, it can prevent that the 2nd antenna 32 or the housing | casing 2 is damaged because the 2nd antenna 32 contacts the housing | casing 2 repeatedly. Other configurations and effects are the same as those of the radio wave receiving module 10 shown in FIG.

  In the radio wave receiving module 30 shown in FIG. 6, the rear end 314 of the first antenna 31 may protrude rearward from the second antenna 32. Thereby, since the 1st antenna 31 can be enlarged, the receiving sensitivity of the 1st antenna 31 can be raised.

  The electronic device 1 is not limited to being attached to a vehicle, and the user may directly carry it. Even in such a case, the angle of the electronic device 1 with respect to the front of the user differs depending on the mode in which the user carries the electronic device 1. For example, it is assumed that the user holds the electronic device 1 by hand and uses the display unit 3 while viewing the display unit 3 with the display unit 3 facing upward. In this case, the upper side of the electronic device 1 is in a state facing the front of the user. Further, for example, it is assumed that the electronic device 1 is placed in the user's breast pocket and only the sound output from the speaker is heard. In this case, the front side or the back side of the electronic device 1 is in a state facing the front of the user. As described above, the orientation of the electronic device 1 with respect to the front of the user differs depending on how the electronic device 1 is used. However, even in such a case, by providing the first antenna 11 and the second antenna 12 in consideration of the usage mode assumed in the electronic device 1, the electronic device 1 always has strong reception sensitivity with respect to the front of the user. Can be shown. Therefore, even when the electronic device 1 is carried by the user, the electronic device 1 can notify the user of accurate information regarding the position of the target.

  Note that a control unit that is provided in the electronic device 1 and performs control for performing processing for controlling the display unit 3 and the speaker to notify the user of information related to the speed measurement device corresponds to the “control unit” of the present invention.

  Hereinafter, the results of evaluating the directivities of the first antenna 11 and the second antenna 12 in the radio wave receiving module 10 will be described with reference to FIGS.

<Evaluation module>
The following three radio wave receiving modules 10 were created and evaluated for directivity.
(1) The radio wave receiving module 10 in which the first antenna 11 and the second antenna 12 are attached to the microwave receiving module 13.
(2) Radio wave receiving module 10 in which only the first antenna 11 is attached to the microwave receiving module 13
(3) Radio wave receiving module 10 in which only the second antenna 12 is attached to the microwave receiving module 13
The radio wave receiving modules 10 (1), (2), and (3) are shown in FIGS. 7, 8, and 9, respectively.

<Measurement method>
The above-described radio wave receiving modules 10 (1) to (3) were placed on a rotating stage (manufactured by Meiritsu Seiki Co., Ltd.). Radio wave receiving modules 10 (1) to 10 (1), which output a microwave of 10.525 GHz from a microwave output source (Signal Generator (HP83640B, manufactured by HP)) and a horn antenna (manufactured by The Electro Mechanics) and are mounted on a rotating stage. Irradiated (3). In this state, the RSSI output from the radio wave receiving module 10 was detected while rotating the rotary stage by 10 ° for a total of 360 °. The directional characteristics of the reception sensitivity of the first antenna 11 and the second antenna 12 were evaluated by plotting the detection results in a pie chart. The evaluation results when using the radio wave receiving modules 10 (1), (2), and (3) are shown in FIGS. 10, 11, and 12, respectively.

<Evaluation results>
It was found that the radio wave receiving module 10 (2) to which only the first antenna 11 was attached showed the strongest reception sensitivity in the first direction 21 as shown in FIG. In addition, it was found that the radio wave receiving module 10 (3) to which only the second antenna 12 was attached showed the strongest receiving sensitivity in the second direction 22 as shown in FIG.

  On the other hand, in the radio wave receiving module 10 (1) to which the first antenna 11 and the second antenna 12 are attached, it is strongest in the third direction 27 which is a direction inclined by 30 ° from the first direction 21 to the second direction 22 side. It was found that the receiver sensitivity was shown. Further, it was found that the reception sensitivity becomes stronger in a wide angle range from the first direction 21 to the second direction 22. Furthermore, the direction opposite to the second direction 22 and the third direction 27 with respect to the first direction 21 and the direction opposite to the first direction 21 and the third direction 27 with respect to the second direction 22 are also 30 It was found that strong reception sensitivity was exhibited in the range of ˜40 °. As described above, in the radio wave receiving module 10 (3), it was found that when the first antenna 11 and the second antenna 12 are viewed as coupled antennas, the reception sensitivity becomes strong in a very wide angle range. From the above evaluation results, when any direction between the first direction 21 and the second direction 22 of the radio wave module 10 faces the traveling direction of the vehicle, the microwave coming from the front of the vehicle is always good. It became clear that it could be received.

DESCRIPTION OF SYMBOLS 1 Electronic device 2 Case 10, 30 Radio wave receiving module 11, 31 First antenna 12, 32 Second antenna 13 Microwave receiving module 18 Support substrate 21 First direction 22 Second direction 23 Plane

Claims (2)

A first antenna having the strongest receiving sensitivity in the first direction;
A second antenna having the strongest receiving sensitivity in a second direction different from the first direction;
A box-shaped module that receives radio waves via the first antenna and the second antenna, the first plane, a second plane facing the first plane, and the first plane end and the first plane A radio module having a third plane provided between two plane end portions, and stored in an electronic device,
The first antenna is provided on the first plane and parallel to the first plane,
The second antenna is provided on the third plane and parallel to the third plane;
In the case where the state of the electronic device can be changed so that the orientations of the first antenna and the second antenna with respect to the user are different from each other, the electronic device is The first direction faces the front of the user when it is in one state, and the second direction faces the front of the user when the electronic device is in the second state. Radio wave reception module. The radio wave receiving module according to claim 1 , wherein the first antenna and the second antenna are antennas formed on a plane.