VEHICLE RADAR DEVICE AND ASSOCIATED SYSTEM

Abstract

A vehicle radar device (100) comprising: a radar control unit (130); a first antenna assembly (151) communicatively connected to the radar control unit (130), the first antenna assembly (151) comprising a plurality of first transmitting elements (161) and a plurality of first receiving elements (171); a second antenna assembly (152) communicatively connected to the radar control unit (130), the second antenna assembly (152) comprising a plurality of second transmitting elements (162) and a plurality of second receiving elements (172); a first circuit board (181), the first antenna assembly (151) being a plurality of circuit board antennas and being arranged on the first circuit board (181); anda second circuit board (182), wherein the second antenna arrangement (152) is a plurality of circuit board antennas and is arranged on the second circuit board (182);wherein the second transmitting elements (162) are one or more second narrow-angle transmitting elements (160) and one or more second wide-angle transmitting elements (166), the radar control unit (130) serves to switch the second narrow-angle transmitting elements (160) or the second wide-angle transmitting elements (166) into operation, the second receiving elements (172) are one or more second narrow-angle receiving elements (170) and one or more second wide-angle receiving elements (177), and the radar control unit (130) serves to switch the second narrow-angle receiving elements (170) or the second wide-angle receiving elements (177) into operation.;

Description

BACKGROUNDTechnical FieldThe present disclosure relates to a vehicular radar device and a vehicular radar system. More particularly, the present disclosure relates to a vehicular radar device and a vehicular radar system both including two antenna arrays.Description of the Prior ArtIn view of the rapid development of Driver Assistance System (ADAS) technology and autopilot technology, vehicles often need to be equipped with a large number of detector devices or detection devices to achieve the relevant functions, thereby increasing the application requirements of the vehicle radar devices. German patent application DE 10 2013 100 554 A1 discloses a radar device for use in a corner region of a vehicle. It has printed circuit boards which each have planar surfaces. Normal vectors of the planar surfaces of the printed circuit boards point in different directions. German patent DE 10 2014 014 860 B3 discloses a radar sensor arrangement and a motor vehicle. U.S. Pat. No. 5,008,678 A discloses an electronically scanning vehicle radar sensor. U.S. patent application US 2006 / 0 092 086 A1 discloses a feed for a vehicle radar antenna in the form of a pointed groove. However, from the viewpoint of the vehicle manufacturer, the configuration of the large number of detection devices leads to an increase in complexity of the design of electronic systems and the assembly of the entire vehicle. From a consumer perspective, the complexity of the user interface or the connection interface would increase if there were a large number of Aftermarket-type (AM) sensing devices and the various functions of the multiple sensing devices cannot be effectively separated from each other or cause interference problems.In view of the above, there is an urgent need in the present market for an integrated solution of a vehicle detection device or a vehicle radar device, which is distinguished by an effective reduction in the number and complexity of the devices.SUMMARYAccording to an aspect of the present disclosure, a vehicular radar device includes a radar control unit, a first antenna array, a second antenna array, a first circuit board, and a second circuit board. The first antenna array is communicatively connected to the radar controller. The first antenna arrangement comprises a plurality of first transmitting elements and a plurality of first receiving elements. The second antenna array is communicatively connected to the radar controller. The second antenna arrangement comprises a plurality of second transmitting elements and a plurality of second receiving elements. The first antenna array is composed of a plurality of circuit board antennas disposed on the first circuit board. The second antenna array is composed of a plurality of circuit board antennas disposed on the second circuit board. The second transmitting elements consist of one or more second narrow angle transmitting elements and one or more second wide angle transmitting elements, and the radar control unit serves to switch the second narrow angle transmitting elements or the second wide angle transmitting elements into operation. The second receiving elements are one or more second narrow angle receiving elements and one or more second wide angle receiving elements, and the radar control unit is used to switch the second narrow angle receiving elements or the second wide angle receiving elements into operation.In an embodiment, the vehicular radar device further includes a third circuit board. The radar control unit is disposed on the third circuit board, and only one of the first circuit board and the second circuit board is disposed in parallel with the third circuit board.In an embodiment, an operating frequency of the first antenna array and an operating frequency of the second antenna array are both greater than 10 GHz. Each of the first transmitting elements, each of the first receiving elements, each of the second transmitting elements and each of the second receiving elements is a microstrip antenna and has a length of less than 40 mm.According to another aspect of the present disclosure, a vehicular radar system is disposed in a vehicle and includes at least one vehicular radar device. The vehicular radar apparatus includes a radar control unit, a first transceiver unit, and a second transceiver unit. The first transceiver unit is communicatively connected to the radar control unit and includes a first antenna array including a plurality of first transmit elements and a plurality of first receive elements. The second transceiver unit is communicatively connected to the radar control unit and includes a second antenna array including a plurality of second transmit elements and a plurality of second receive elements. The second transmitting elements consist of one or more second narrow angle transmitting elements and one or more second wide angle transmitting elements, and the radar control unit serves to switch the second narrow angle transmitting elements or the second wide angle transmitting elements into operation. The second receiving elements are one or more second narrow angle receiving elements and one or more second wide angle receiving elements, and the radar control unit is used to switch the second narrow angle receiving elements or the second wide angle receiving elements into operation.In an embodiment, the at least one vehicular radar device further comprises a first circuit board and a second circuit board. The first antenna array is composed of a plurality of circuit board antennas disposed on the first circuit board. The second antenna array is composed of a plurality of circuit board antennas disposed on the second circuit board.In an embodiment, the at least one vehicular radar device further comprises a third circuit board. The radar control unit is disposed on the third circuit board, and only one of the first circuit board and the second circuit board is disposed in parallel with the third circuit board.In an embodiment, an operating frequency of the first antenna array and an operating frequency of the second antenna array are both greater than 10 GHz. Each of the first transmitting elements, each of the first receiving elements, each of the second transmitting elements, and each of the second receiving elements is a microstrip antenna extending along a horizontal direction of the vehicle and having a length of less than 40 mm.In one embodiment, a number of the at least one vehicular radar device is two. The two vehicular radar devices are respectively disposed at a left rear corner and a right rear corner of the vehicle. The two first circuit boards of the two vehicular radar devices respectively face a left direction and a right direction of the vehicle, and are arranged symmetrically relative to a longitudinal center line of the vehicle. The two second circuit boards of the two vehicular radar devices are both facing a rear direction of the vehicle and arranged symmetrically to the longitudinal center line of the vehicle.In an embodiment, when an angle of a central blind zone defined by radiation patterns of the second narrow angle receiving elements of the two vehicular radar devices respectively disposed at the left rear corner and the right rear corner is NT2, and an angle of a central blind zone defined by radiation patterns of the second wide angle receiving elements of the two vehicular radar devices respectively disposed at the left rear corner and the right rear corner is WT2, the following conditions are satisfied: 15 degrees ≤ NT2 ≤ 120 degrees; and 60 degrees ≤ WT2 ≤ 175 degrees.In one embodiment, a transmission signal of the two second transceiver units of the two vehicle radar devices is generated using a time division multiplexing method, a frequency division multiplexing method and / or an orthogonal signal method, which are respectively controlled by the two radar control units of the two vehicle radar devices.In one embodiment, one of the two vehicular radar devices is communicatively connected to a vehicle control unit of the vehicle via the other of the two vehicular radar devices.In an embodiment, the radar control unit of each of the two vehicular radar devices includes a circuit circuit configured to switch the first transceiver unit or the second transceiver unit to be in a detection mode. Only the first transceiver unit is in the sensing mode when the vehicle is in a forward driving state and only the second transceiver unit is in the sensing mode when the vehicle is in a rearward driving state.In an embodiment, each unit of the two first transceiver units and the two second transceiver units of the two vehicular radar devices is in a detection mode when the vehicle is in a starting state. The two radar control units of the two vehicular radar devices are configured to determine whether the vehicle satisfies a first emergency condition according to the data of the two first transceiver units of the two vehicular radar devices and whether the vehicle satisfies a second emergency condition according to the data of the two second transceiver units of the two vehicular radar devices. The vehicular radar system further includes an alarm device communicatively connected to the two radar control units. The alarm device is controlled by the two radar control units to generate an alarm signal when the vehicle is in a forward running state and satisfies the first emergency condition. The alarm device is controlled by the two radar control units to generate another alarm signal when the vehicle is in a reverse running state and satisfies the second emergency condition.In an embodiment, when a half-value beam width of a main horizontal lobe of the first reception elements is RA 1, the following condition is satisfied: 75 degrees≤RA 1<180 degrees.In an embodiment, when an angle between a center line of the main horizontal lobe of the first reception elements and a center line of the main horizontal lobe of the second reception elements is R 12, the following condition is satisfied: 15 degrees≤R 12≤75 degrees.According to another aspect of the present disclosure, a vehicular radar system is disposed in a vehicle and includes at least one vehicular radar device disposed at one of four corners of the vehicle. The vehicular radar device includes a radar control unit, a first antenna array, a second antenna array, a first circuit board, and a second circuit board. The first antenna array is communicatively connected to the radar controller. The first antenna arrangement comprises a plurality of first transmitting elements and a plurality of first receiving elements. The second antenna array is communicatively connected to the radar controller. The second antenna arrangement comprises a plurality of first transmitting elements and a plurality of second receiving elements. The first circuit board is vertical to a horizontal direction of the vehicle. The first antenna array is composed of a plurality of circuit board antennas disposed on the first circuit board. The second circuit board is vertical to the horizontal direction of the vehicle. The second antenna array is composed of a plurality of circuit board antennas disposed on the second circuit board. The second transmitting elements consist of one or more second narrow angle transmitting elements and one or more second wide angle transmitting elements, and the radar control unit serves to switch the second narrow angle transmitting elements or the second wide angle transmitting elements into operation. The second receiving elements are one or more second narrow angle receiving elements and one or more second wide angle receiving elements, and the radar control unit is used to switch the second narrow angle receiving elements or the second wide angle receiving elements into operation.In one embodiment, a number of the at least one vehicular radar device is two. The two vehicular radar devices are respectively disposed at a left rear corner and a right rear corner of the four corners of the vehicle. The two first circuit boards of the two vehicular radar devices respectively face a left direction and a right direction of the vehicle, and are arranged symmetrically relative to a longitudinal center line of the vehicle. The two second circuit boards of the two vehicular radar devices are both facing a rear direction of the vehicle and arranged symmetrically to the longitudinal center line of the vehicle.In one embodiment, when an angle of a central blind zone defined by radiation patterns of the second narrow angle receiving elements of the two vehicular radar devices respectively disposed at the left rear corner and the right rear corner is NT2, and an angle of a central blind zone defined by radiation patterns of the second wide angle receiving elements of the two vehicular radar devices respectively disposed at the left rear corner and the right rear corner is WT2, the following conditions are satisfied: 15 degrees ≤ NT2 ≤ 120 degrees; and 60 degrees ≤ WT2 ≤ 175 degrees.In an embodiment, when an angle between the first circuit board and the second circuit board is P 12, the following condition is satisfied: 105 degrees≤P 12≤165 degrees.BRIEF DESCRIPTION OF THE DRAWINGSThe present disclosure can be more fully understood by reading the following detailed description of the embodiment with reference to the accompanying drawings as follows: FIG. 1A is a schematic view of a vehicular radar device according to the first embodiment of the present disclosure. FIG. 1B is another schematic view of the vehicular radar device according to the first embodiment. FIG. 1C is a cross-sectional view taken along line 1C- 1C of FIG. 1B. FIG. 1D is an exploded view of the vehicular radar device according to the first embodiment. FIG. 2 is a schematic view of a vehicular radar device according to the second embodiment of the present disclosure. FIG. 3 is a schematic view of a vehicular radar device according to the third embodiment of the present disclosure. FIG. 4A is a schematic view of a vehicular radar system according to the fourth embodiment of the present disclosure disposed in a vehicle. FIG. 4B is a block diagram of the vehicular radar system according to the fourth embodiment disposed in the vehicle. FIG. 4C is a block diagram of the vehicular radar system according to the fourth embodiment. FIG. 4D is a schematic view of the parameter R 12 according to the fourth embodiment. FIG. 4E is a schematic view of a radiation pattern of first receiving elements according to the fourth embodiment. FIG. 4F is a schematic view of a radiation pattern of second receiving elements according to the fourth embodiment. FIG. 4G is a schematic view of the first transceiver units in a sensing mode according to the fourth embodiment. FIG. 4H is a schematic view of the parameters NT 2 and WT 2 according to the fourth embodiment. FIG. 5A is a block diagram of a vehicular radar system according to the fifth embodiment of the present disclosure disposed in a vehicle. FIG. 5B is a block diagram of the vehicular radar system according to the fifth embodiment.DETAILED DESCRIPTIONThe embodiment will be described with reference to the drawings. For the sake of clarity, some practical details will be described below. It should be noted, however, that the present disclosure should not be limited to the practical details, that is, in some embodiments, the practical details are not required. In addition, for convenience of drawings, some conventional structures and elements are simply illustrated, and repeated elements may be represented by the same names.FIG. 1A is a schematic view of a vehicular radar device 100 according to the first embodiment of the present disclosure. FIG. 1B is another schematic view of the vehicular radar device 100 according to the first embodiment, FIG. 1C is a cross-sectional view taken along line 1C- 1C of FIG. 1B, and FIG. 1D is an exploded view of the vehicular radar device 100 according to the first embodiment. In FIGS. 1A to 1D, the vehicular radar apparatus 100 includes a radar control unit 130, a first antenna array 151, a second antenna array 152, a first circuit board 181, and a second circuit board 182.The first antenna array 151 is communicatively connected to the radar control unit 130. The first antenna arrangement 151 comprises a plurality of first transmitting elements 161 and a plurality of first receiving elements 171. That is, the first transmitting elements 161 are first transmitting antenna elements, and the first receiving elements 171 are first receiving antenna elements. The first antenna array 151 is a plurality of circuit board antennas, and is disposed on the first circuit board 181. The second antenna array 152 is communicatively connected to the radar controller 130. The second antenna arrangement 152 comprises a plurality of second transmitting elements 162 and a plurality of second receiving elements 172. That is, the second transmitting elements 162 are second transmitting antenna elements, and the second receiving elements 172 are second receiving antenna elements. The second antenna array 152 is a plurality of circuit board antennas and is disposed on the second circuit board 182. When an angle between the first circuit board 181 and the second circuit board 182 is P 12, the following condition is satisfied: 60 degrees≤P 12<180 degrees. Accordingly, the first antenna arrangement 151 and the second antenna arrangement 152, which are two non-coplanar antenna arrangements, are advantageous to provide detections with different directions and different antenna radiation patterns according to different application requirements. Moreover, the following condition may be satisfied: 90 degrees ≤ P12 < 180 degrees. In addition, the following condition may be satisfied: 120 degrees ≤ P12 ≤ 150 degrees. In the first embodiment, the angle P 12 between the first circuit board 181 and the second circuit board 182 is 135 degrees.In FIG. 1C, the vehicular radar device 100 may further include a third circuit board 183. The radar control unit 130 is disposed on the third circuit board 183. Only the first circuit board 181 or the second circuit board 182 (specifically, only the second circuit board 182 in the first embodiment) is arranged in parallel with the third circuit board 183. Accordingly, this is advantageous for the vehicular radar apparatus 100 to achieve a compact size. In an embodiment according to the present disclosure, each of a first circuit board, a second circuit board, and a third circuit board may be, but is not limited to, a printed circuit board (PCB), a flexible circuit board, or a ceramic circuit board.An operating frequency of the first antenna array 151 and an operating frequency of the second antenna array 152 may both be greater than 10 GHz. Moreover, the operating frequency of the first antenna array 151 and the operating frequency of the second antenna array 152 may be both greater than 10 GHz and less than 300 GHz. Moreover, the operating frequency of the first antenna array 151 and the operating frequency of the second antenna array 152 may both be 24 GHz + / - 5 GHz, 77 GHz + / - 5 GHz, or 79 GHz + / - 5 GHz. Each of the first transmitting elements 161, each of the first receiving elements 171, each of the second transmitting elements 162 and each of the second receiving elements 172 is a microstrip antenna and has a length of less than 40 mm. The aforementioned microstrip antenna may have a microstrip shape (strip shape or rectangular shape), a patch shape, a comb shape, or a microstrip slot, without being limited thereto. Moreover, each of the first transmitting elements 161, each of the first receiving elements 171, each of the second transmitting elements 162 and each of the second receiving elements 172 is the microstrip antenna and may have a length of less than 30 mm. Moreover, each of the first transmitting elements 161, each of the first receiving elements 171, each of the second transmitting elements 162, and each of the second receiving elements 172 is the microstrip antenna, and may have a length of less than 20 mm and more than 0.2 mm. Therefore, the on-vehicle radar device 100, which is a millimeter wave radar device, is advantageous in reducing the number of the on-vehicle radar devices 100 and maintaining the same applications and functions.The second transmitting elements 162 may be composed of a plurality of second narrow-angle transmitting elements 160 and a plurality of second wide-angle transmitting elements 166, and the radar control unit 130 is for switching the second narrow-angle transmitting elements 160 or the second wide-angle transmitting elements 166 to operation. The second receiving elements 172 may be composed of a plurality of second narrow angle receiving elements 170 and a plurality of second wide angle receiving elements 177, and the radar control unit 130 is for switching the second narrow angle receiving elements 170 or the second wide angle receiving elements 177 to operation. Accordingly, this is advantageous in order to increase the detection range of the second antenna array 152. In addition, a transmission circuit communicatively connected to the second narrow angle transmission elements 160 and a transmission circuit communicatively connected to the second wide angle transmission elements 166 may be separate or the same to operate by switching. A receiving circuit communicatively connected to the second narrow angle receiving elements 170 and a receiving circuit communicatively connected to the second wide angle receiving elements 177 may be separate or the same to operate by switching.Specifically, the operating frequency of the first antenna array 151 and the operating frequency of the second antenna array 152 are both about 77 GHz or 79 GHz. The relative permittivity at the operating frequency of the first circuit board 181, the second circuit board 182, and the third circuit board 183 may be in a range of 2.0 to 4.3. Moreover, the relative permittivity at the operating frequency of the first circuit board 181, the second circuit board 182, and the third circuit board 183 may be in a range of 2.2 to 3.8. Further, a dimension of the first circuit board 181 may be at least 19 mm x 20 mm x 1.4 mm (thickness), and a dimension of the second circuit board 182 may be at least 30 mm x 20 mm x 1.4 mm (thickness). The first circuit board 181 and the second circuit board 182 each include a plurality of through holes 191 and 192 that are properly configured and have electrical conductivity. The first circuit board 181, the second circuit board 182, and the third circuit board 183 may be communicatively connected by flexible flat cables (FFC) having the number of conductors and the space sizes according to requirements. The flexible flat cables may be made of Liquid Crystal Polymers (LCP) thermoplastic organic liquid crystal polymers to function as high frequency and high speed flexible circuit boards with high reliability. The LCP materials with superior electrical properties are advantageous for millimeter waves and the LCP materials with low thermal expansion coefficient can serve as ideal packaging materials for high frequency and high speed products. In addition, the first circuit board 181, the second circuit board 182, and the third circuit board 183 are all disposed in a housing 140 that includes a connector 144.In FIGS. 1A and 1B, each of the first transmitting elements 161 is a rectangular microstrip slot antenna, i.e., a radiation slot formed by a slot of a conductive layer on a surface of the first circuit board 181 and having a dimension of about 3.2 mm (length) x 0.5 mm (width). The first transmitting members 161 are arranged along a width direction. For example, the first transmitting elements 161 may be arranged as a slot array antenna of an array of 1 x 16. A dimension of the slot array antenna constituted by the sixteen first transmitting elements 161 is about 3.2 mm x 17.6 mm. As needed, one of the first transmission elements 161 may be communicatively connected to each other by a series circuit and / or a parallel circuit, and the first transmission elements 161 have at least one feed terminal. Each of the first receiving elements 171 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). The first receiving elements 171 are arranged along a width direction, one of the first receiving elements 171 may be communicatively connected to each other by at least a series circuit and a parallel circuit, and the first receiving elements 171 have at least one feeding terminal. Each of the second narrow angle transmitting elements 160 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). The second narrow-angle transmitting members 160 are arranged along a width direction, one of the second narrow-angle transmitting members 160 may be communicated with another one thereof by a series circuit and / or a parallel circuit, and the second narrow-angle transmitting members 160 have at least one feeding terminal. Each of the second wide-angle transmitting elements 166 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). The second wide-angle transmitting members 166 are arranged along a width direction. As needed, one of the second wide-angle transmitting elements 166 may be communicatively connected to each other by a series connection and / or a parallel connection, and the second wide-angle transmitting elements 166 have at least one feed terminal. Each of the second narrow angle receiving elements 170 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). The second narrow angle receiving elements 170 are arranged along a width direction. As needed, one of the second narrow-angle receiving elements 170 may be communicatively connected to each other by a series circuit and / or a parallel circuit, and the second narrow-angle receiving elements 170 include at least one feed terminal. Each of the second wide-angle receiving elements 177 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). The second wide-angle receiving elements 177 are arranged along a width direction. As needed, one of the second wide-angle receiving elements 177 may be communicatively connected to each other by a series circuit and / or a parallel circuit, and the second wide-angle receiving elements 177 have at least one feeding terminal. Moreover, the series circuits, parallel circuits and feeding terminals mentioned in this paragraph can be configured according to requirements and are therefore not specifically illustrated in the drawings.In an embodiment according to the present disclosure (not shown in the drawings), a dimension of the first circuit board and a dimension of the second circuit board may be larger than the dimensions thereof indicated in the aforementioned first embodiment. For example, the dimension of the first circuit board may be 38 mm x 40 mm x 1.4 mm (thickness), the dimension of the second circuit board may be 60 mm x 40 mm x 1.4 mm (thickness), and a number of the first transmitting elements, first receiving elements, second narrow angle transmitting elements, second wide angle transmitting elements, second narrow angle receiving elements, and second wide angle receiving elements may be larger than the number indicated in the aforementioned first embodiment.FIG. 2 is a schematic view of a vehicular radar device 200 according to the second embodiment of the present disclosure. In FIG. 2, the vehicular radar device 200 includes a radar control unit (not shown in FIG. 2 ), a first antenna array 251, a second antenna array 252, a first circuit board 281, and a second circuit board 282. The first antenna arrangement 251 comprises a plurality of first transmitting elements 261 and a plurality of first receiving elements 271. The first antenna array 251 is composed of a plurality of circuit board antennas disposed on the first circuit board 281. The second antenna array 252 is communicatively connected to the radar controller. The second antenna arrangement 252 comprises a plurality of second transmitting elements 262 and a plurality of second receiving elements 272. The second transmitting elements 262 are a plurality of second narrow-angle transmitting elements 260 and a plurality of second wide-angle transmitting elements 266. The second receiving elements 272 are a plurality of second narrow-angle receiving elements 270 and a plurality of second wide-angle receiving elements 277. The second antenna array 252 is comprised of a plurality of circuit board antennas disposed on the second circuit board 282. An angle P 12 between the first circuit board 281 and the second circuit board 282 is 135 degrees. In addition, the first circuit board 281 and the second circuit board 282 each include a plurality of through holes 291 and 292 that are properly configured and have electrical conductivity. The first circuit board 281, the second circuit board 282, and the third circuit board (not shown in the drawings) are all disposed in a housing 240 including a connector 244.Specifically, with respect to the vehicular radar device 200 of the second embodiment, except that the configurations of the first transmitting elements 261, the first receiving elements 271, the second narrow angle transmitting elements 260, the second wide angle transmitting elements 266, the second narrow angle receiving elements 270, and the second wide angle receiving elements 277 are different from the configurations indicated in the aforementioned first embodiment, the other characteristics of the vehicular radar device 200 may be the same as the corresponding characteristics of the vehicular radar device 100.In the second embodiment, each of the first transmitting elements 261 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). A number of the first transmission elements 261 is sixteen, and the first transmission elements 261 are arranged as an arrangement of 2 x 8. As needed, one of the first transmission elements 261 may be communicatively connected to each other by a series connection and / or a parallel connection, and the first transmission elements 261 have at least one feed terminal. Each of the first receiving elements 271 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). A number of the first reception elements 271 is sixteen, and the first reception elements 271 are arranged as an arrangement of 2 x 8. As needed, one of the first receiving elements 271 may be communicatively connected to each other by a series circuit and / or a parallel circuit, and the first receiving elements 271 include at least one feed terminal. Each of the second narrow angle transmitting elements 260 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). A number of the second narrow angle transmitting elements 260 is sixteen, and the second narrow angle transmitting elements 260 are arranged as an arrangement of 4 x 4. As needed, one of the second narrow-angle transmitting elements 260 may be communicatively connected to each other by a series circuit and / or a parallel circuit, and the second narrow-angle transmitting elements 260 have at least one feed terminal. Each of the second wide-angle transmitting elements 266 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). A number of the second wide-angle transmitting elements 266 are sixteen, and the second wide-angle transmitting elements 266 are arranged as an array of 4 x 4. As needed, one of the second wide-angle transmitting elements 266 may be communicatively connected to each other by a series connection and / or a parallel connection, and the second wide-angle transmitting elements 266 have at least one feed terminal. Each of the second wide-angle receiving elements 270 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). A number of the second narrow angle receiving elements 270 are sixteen, and the second narrow angle receiving elements 270 are arranged as an arrangement of 4 x 4. As needed, one of the second narrow angle receiving elements 270 may be communicatively connected to each other by a series circuit and / or a parallel circuit, and the second narrow angle receiving elements 270 have at least one feeding terminal. Each of the second narrow angle receiving elements 277 is a rectangular microstrip slot antenna and has a dimension of about 3.2 mm (length) x 0.5 mm (width). A number of the second wide-angle receiving elements 277 are sixteen, and the second wide-angle receiving elements 277 are arranged as an array of 4 x 4. As needed, one of the second wide-angle receiving elements 277 may be communicatively connected to each other by a series circuit and / or a parallel circuit, and the second wide-angle receiving elements 277 include at least one feed terminal. Moreover, the series circuits, parallel circuits and feeding terminals mentioned in this paragraph can be configured according to requirements and are therefore not specifically illustrated in the drawings.FIG. 3 is a schematic view of a vehicular radar device 300 according to the third embodiment of the present disclosure. In FIG. 3, the vehicular radar device 300 includes a radar control unit (not shown in the drawings), a first antenna array 351, a second antenna array 352, a first circuit board 381, and a second circuit board 382. The first antenna array 351 is communicatively connected to the radar control unit. The first antenna array 351 includes a plurality of first transmitting elements 361 and a plurality of first receiving elements 371. The first antenna array 351 is composed of a plurality of circuit board antennas disposed on the first circuit board 381. The second antenna array 352 is communicatively connected to the radar controller. The second antenna arrangement 352 comprises a plurality of second transmitting elements 362 and a plurality of second receiving elements 372. The second transmitting elements 362 are a plurality of second narrow-angle transmitting elements 360 and a plurality of second wide-angle transmitting elements 366. The second receiving elements 372 are a plurality of second narrow-angle receiving elements 370 and a plurality of second wide-angle receiving elements 377. The second antenna array 352 is composed of a plurality of circuit board antennas disposed on the second circuit board 382. An angle P 12 between the first circuit board 381 and the second circuit board 382 is 135 degrees. In addition, the first circuit board 381, the second circuit board 382, and the third circuit board (not shown in the drawings) are all disposed in a housing 340 including a connector 344.Specifically, the first transmitting elements 361, the first receiving elements 371, the second narrow angle transmitting elements 360, the second wide angle transmitting elements 366, the second narrow angle receiving elements 370, and the second wide angle receiving elements 377 are a series fed patch array (SFPA), and a configuration and at least one feeding port thereof may be configured according to requirements, and are not shown in detail in the drawings. Further, with respect to the vehicular radar device 300 of the third embodiment, except that the antenna type of the first antenna array 351, the antenna type of the second antenna array 352, the dimensions of the first circuit board 381, and the dimensions of the second circuit board 382 are different from those indicated in the aforementioned first embodiment, the other characteristics of the vehicular radar device 300 may be the same as the corresponding characteristics of the vehicular radar device 100.FIG. 4A is a schematic view of a vehicular radar system 4000 disposed in a vehicle 40 according to the fourth embodiment of the present disclosure. FIG. 4B is a block diagram of the on-vehicle radar system 4000 according to the fourth embodiment disposed in the vehicle 40. FIG. 4C is a block diagram of the on-vehicle radar system 4000 according to the fourth embodiment. In FIGS. 1A and 4A to 4C, the on-vehicle radar system 4000 is disposed in the vehicle 40, and includes the on-vehicle radar device 100 listed in the aforementioned first embodiment. The vehicular radar apparatus 100 includes the radar control unit 130, a first transceiver unit 141, and a second transceiver unit 142. The first transceiver unit 141 is communicatively connected to the radar control unit 130 and includes the first antenna array 151, and thereby the first antenna array 151 is also communicatively connected to the radar control unit 130. The second transceiver unit 142 is communicatively connected to the radar control unit 130 and includes the second antenna array 152, and thereby the second antenna array 152 is also communicatively connected to the radar control unit 130. In addition, it is noted that another on-vehicle radar device according to the present disclosure may be included in the on-vehicle radar system 4000.FIG. 4D is a schematic view of a parameter R 12 according to the fourth embodiment. FIG. 4E is a schematic view of a radiation pattern in a horizontal plane (oriented like a horizontal direction of the vehicle 40) of the first receiving elements 171 according to the fourth embodiment. FIG. 4F is a schematic view of a radiation pattern in a horizontal plane of the second reception elements 172 (specifically, the second wide-angle reception elements 177 thereof) according to the fourth embodiment. In particular, a schematic view of a parameter T 12 is similar to FIG. 4D. In FIGS. 4D to 4F, the first antenna array 151 may include the first transmitting elements 161 and the first receiving elements 171. The second antenna arrangement 152 may include the second transmitting elements 162 and the second receiving elements 172. When an angle between a center line of a main horizontal lobe (i.e., a main lobe in the horizontal plane) of the first transmitting elements 161 and a center line of a main horizontal lobe of the second transmitting elements 162 is T 12, and an angle between a center line C 1 of a main horizontal lobe MLR 1 of the first receiving elements 171 and a center line C 2 of a main horizontal lobe MLR 2 of the second receiving elements 172 is R 12, the following conditions may be satisfied: 0 degree<T 12≤90 degrees; and 0 degree<R 12≤90 degrees. Accordingly, the vehicular radar system 4000 is advantageous in simultaneously providing detections in different directions and maintaining the individual detection accuracy by the first antenna array 151 and the second antenna array 152. Moreover, the following condition may be satisfied: 15 degrees ≤ R12 ≤ 75 degrees. In addition, the following condition may be satisfied: 30 degrees≤R 12≤60 degrees. In the first embodiment, the parameter T 12 is 45 degrees and the parameter R 12 is 45 degrees.Further, in FIGS. 1C and 4A, the vehicular radar device 100 may be disposed at one of four corners (i.e., a left front corner 48L, a right front corner 48R, a left rear corner 49L, and a right rear corner 49R shown in FIG. 4A ) of the vehicle 40. Specifically, the vehicular radar device 100 is disposed at the left rear corner 49L as shown in FIG. 4A. The vehicular radar device 100 may further include the first circuit board 181 and the second circuit board 182. The first circuit board 181 is disposed vertically to the horizontal direction of the vehicle 40. The first antenna array 151 is the circuit board antennas and is disposed on the first circuit board 181. The second circuit board 182 is disposed vertically to the horizontal direction of the vehicle 40. The second antenna array 152 is the circuit board antennas and is disposed on the second circuit board 182. When the angle between the first circuit board 181 and the second circuit board 182 is P 12, the following condition may be satisfied: 60 degrees≤P 12<180 degrees. Accordingly, the first antenna array 151 and the second antenna array 152 are advantageous in providing detections in accordance with various application requirements, reducing the cost of the on-vehicle radar system 4000, and simplifying the detection optimization procedure, respectively. Moreover, the following condition may be satisfied: 90 degrees ≤ P12 < 180 degrees. In addition, the following condition may be satisfied: 105 degrees≤P 12≤165 degrees. In addition, the following condition may be satisfied: 120 degrees ≤ P12 ≤ 150 degrees.In FIG. 4E, the following condition may be satisfied when a half power beam width (HPBW) of the main horizontal lobe MLR 1 of the first reception elements 171 is RA 1 defined by half-value marks m 1 and m 2: 75 degrees≤RA 1<180 degrees. In the fourth embodiment, a value of the parameter RA 1 is 84 degrees. Therefore, a broader detection range can be provided by the first antenna array 151.In FIG. 4F, a half-value beam width of the main horizontal lobe MLR 2 of the second wide-angle reception elements 177 of the second reception elements 172 is RAW 2 defined by the half-value marks m 1 and m 2. In the fourth embodiment, a value of the parameter RAW 2 is 118 degrees.The vehicular radar device 100 may further include the third circuit board 183. The radar control unit 130 is disposed on the third circuit board 183. Only the first circuit board 181 or the second circuit board 182 (specifically, only the second circuit board 182 in the fourth embodiment) is arranged in parallel with the third circuit board 183. Accordingly, this is advantageous for the vehicular radar system 4000 to achieve a compact size. In an embodiment according to the present disclosure (not shown in the drawings), it may be only the first circuit board of the first circuit board and the second circuit board parallel to the third circuit board.Specifically, a transmission circuit of the first transceiver unit 141 may include other elements (not shown in the drawings) such as a local oscillator, a phase locked loop (PLL), a power amplifier, and the like, in addition to the first transmission elements 161, which may be disposed on the first circuit board 181 or the third circuit board 183. The local oscillator supporting a wider bandwidth is advantageous for increasing the range resolution, since the range resolution of the vehicular radar system 4000 is determined by the signal bandwidth generated by the transmitting circuit. Moreover, the phase locked loop is advantageous for the phase control of the local oscillator in order to minimize the phase noise of the local oscillator. Besides including the first receiving elements 171, a receiving circuit of the first transceiver unit 141 may further include other elements (not shown in the drawings), such as a low noise amplifier, an image suppressing and interference suppressing circuit portion, etc., which may be disposed on the first circuit board 181 or the third circuit board 183. The configurations of a transmission circuit and a reception circuit of the second transceiver unit 142 may be different from, but similar to, those of the first transceiver unit 141, and the elements of the second transceiver unit 142 may be disposed on the second circuit board 182 or the third circuit board 183. Alternatively, both a transmitting circuit and a receiving circuit (except for the first antenna array 151 and the second antenna array 152) may be switched to be used by the first transceiver unit 141 or the second transceiver unit 142.In addition, the first transceiver unit 141 and the second transceiver unit 142 are configured to generate frequency modulated continuous wave (FMCW) triangular waveform signals. After the first transceiver unit 141 and the second transceiver unit 142 receive a plurality of echo signals, the radar control unit 130 performs a Fast Fourier Transform (FFT) step to obtain a beat frequency and Doppler shift data of a target object (or a target vehicle), and then estimates distance, speed, and angle information of the target object with respect to the on-vehicle radar device 100 according to the data. An algorithm configured in the radar controller 130 includes the steps of FFT, beamforming, and constant false alarm rate (CFAR), wherein the FFT step is configured to provide the range and velocity information, the beamforming step is configured to estimate the angle and position information, and the CFAR step is configured to detect the target object while noise and other noise are present.In FIGS. 1B and 4A, the operating frequency of the first antenna array 151 and the operating frequency of the second antenna array 152 may both be greater than 10 GHz. Each of the first transmitting elements 161, each of the first receiving elements 171, each of the second transmitting elements 162, and each of the second receiving elements 172 is the microstrip antenna that extends along the horizontal direction of the vehicle 40 and has a length of less than 40 mm. Accordingly, this is advantageous in reducing the number of the on-vehicle radar device 100 equipped in the on-vehicle radar system 4000 and maintaining the same applications and functions.In an embodiment according to the present disclosure, the first transmitting elements, the first receiving elements, the second transmitting elements, and the second receiving elements may be printed circuit board antennas, which may be specifically microstrip antennas, for example slot antennas, patch antennas, microstrip shape antennas, or comb antennas, extending along a horizontal direction or a vertical direction of a vehicle. Alternatively, the first transmitting elements, the first receiving elements, the second transmitting elements and the second receiving elements cannot be printed circuit board antennas, e.g. parabolic antennas. Moreover, the types of the first transmitting elements, the first receiving elements, the second transmitting elements, and the second receiving elements are not limited thereto, and the following conditions are satisfied: 0 degrees<T 12≤90 degrees; and 0 degrees<R 12≤90 degrees.In FIG. 4A, the vehicular radar system 4000 includes two vehicular radar devices, i.e., the vehicular radar devices 100 and 100 a, which are respectively disposed at the left rear corner 49L and the right rear corner 49R of the vehicle 40 and are located inside the bumper trim. The first circuit board 181 included in the vehicular radar device 100 and a first circuit board 181 aincluded in the vehicular radar device 100 aface a left direction and a right direction of the vehicle 40, respectively, and are arranged symmetrically relative to a longitudinal center line y of the vehicle 40. That is, the first transceiver units 141 and 141 aincluded in the vehicular radar devices 100 and 100 a, respectively, are configured to detect a left environment and a right environment of the vehicle 40, respectively, and moreover, both detect a rear environment of the vehicle 40. The second circuit board 182 included in the vehicular radar device 100 and a second circuit board 182 aincluded in the vehicular radar device 100 aare both facing a rear direction of the vehicle 40 and are arranged symmetrically to the longitudinal center line y of the vehicle 40. That is, the second transceiver units 142 and 142 aincluded in the vehicular radar devices 100 and 100 a, respectively, are both configured to detect the rear environment of the vehicle 40. Accordingly, the vehicular radar system 4000 may provide the detection information of the left direction, the right direction, and the rear direction of the vehicle 40 to achieve the functions of blind spot detection (BSD), lane change assistance (LCA), and backward detection of the vehicle 40 via a single device set (i.e., the vehicular radar devices 100 and 100 a).Specifically, the vehicular radar device 100 adisposed at the right rear corner 49R of the vehicle 40 includes the radar control unit 130 a, the first transceiver unit 141 a, the second transceiver unit 142 a, the first circuit board 181 a, the second circuit board 182 a, and the third circuit board 183 a. The first transceiver unit 141 ais communicatively connected to the radar control unit 130 aand comprises a first antenna arrangement 151 a. The second transceiver unit 142 ais communicatively connected to the radar control unit 130 aand comprises a second antenna arrangement 152 a. The first circuit board 181 is disposed vertically to the horizontal direction of the vehicle 40. The first antenna array 151 ais a plurality of circuit board antennas, and is disposed on the first circuit board 181 a. The second circuit board 182 ais disposed vertically to the horizontal direction of the vehicle 40. The second antenna array 152 ais a plurality of circuit board antennas, and is disposed on the second circuit board 182 a. The radar control unit 130 ais disposed on the third circuit board 183 a. Only the second circuit board 182 aof the first circuit board 181 aand the second circuit board 182 aare arranged in parallel with the third circuit board 183 a. In addition, the first circuit board 181 a, the second circuit board 182 a, and the third circuit board 183 aare all disposed in a housing 140 aincluding the connector 144 a. In short, the vehicular radar apparatus 100 amay have the same equipment as the vehicular radar apparatus 100 indicated in the aforementioned first and fourth embodiments. The vehicular radar devices 100 and 100 amay be different devices, and the physical structures of the vehicular radar devices 100 and 100 a, respectively, are symmetric relative to the longitudinal centerline y of the vehicle 40. Alternatively, the vehicular radar devices 100 and 100 amay be the same devices, and the physical structures of the vehicular radar devices 100 and 100 aare symmetrical relative to the longitudinal center line y of the vehicle 40.In FIG. 4B, the vehicular radar device 100 amay be communicatively connected to a vehicle control unit 43 of the vehicle 40 via the vehicular radar device 100. Accordingly, the control and interface design of the on-vehicle radar system 4000, which is simplified, are advantageous to be integrated into the on-vehicle control unit 43 and installed into the vehicle 40. With respect to the vehicular radar system 4000 in the fourth embodiment, the vehicular radar device 100 functions as a master radar, the vehicular radar device 100 afunctions as a slave radar, and the vehicular radar device 100 ais communicatively connected to the vehicle control unit 43 of the vehicle 40 via the vehicular radar device 100. The vehicular radar device 100 and the vehicular control unit 43 may be communicatively connected via the controller area network (CAN), and the vehicular radar devices 100 and 100 amay be communicatively connected by CAN. In addition, the on-vehicle radar system 4000 may further include an alarm device 4400 connected to the on-vehicle radar device 100 in a wired or wireless communication manner. The alarm device 4400 is configured to generate alarm signals to reminder a driver to the vehicle 40 when the vehicle 40 meets emergency conditions. The alarm device 4400 may be a speaker, a buzzer, a display, or a light display to resemble the driver by a sound or a light signal, without being limited thereto.In FIGS. 4B and 4C, the radar control units 130 and 130 arespectively include circuit circuits 133 and 133 aconfigured to switch the first transceiver units 141, 141 aor the second transceiver units 142, 142 ato a detection mode. Only the first transceiver units 141, 141 aare in the sensing mode when the vehicle 40 is in a forward driving state (e.g., when the D-gear of a gear selection unit 45 is selected), so that the sensing information of the left direction, the right direction, and the rear direction of the vehicle 40 may be provided to perform the BSD and LCA functions of the vehicle 40. Only the second transceiver units 142, 142 aare in the sensing mode when the vehicle 40 is in a rearward travel state (e.g., when the R gear of the gear selection unit 45 is selected), so that the sensing information of the rearward direction of the vehicle 40 may be provided to perform the rearward travel sensing function of the vehicle 40. Therefore, it is advantageous for the vehicle 40 to switch the first transceiver units 141, 141 aor the second transceiver units 142, 142 ato the sensing mode according to the forward running state or the rearward running state.FIG. 4G is a schematic view of the first transceiver units 141 and 141 ain the sensing mode according to the fourth embodiment. In FIGS. 4A and 4G, the first transceiver units 141 and 141 ahave both angles of arrival (AOA) over 30 degrees and detection distances between 50 m and 70 m. When the vehicular radar devices 100 and 100 aare applied to the BSD function of the vehicle 40 based on a relative position and a relative speed of a moving object (or target vehicle) with respect to the vehicle 40, it would be determined whether the moving object is within a blind zone of the vehicle 40, and the driver would be promptly reminiscent of the risks associated with changing lanes and other movements. When the vehicular radar devices 100 and 100 aare applied to the LCA function of the vehicle 40, the vehicular radar devices 100 and 100 aare configured to calculate the moving information of the moving objects in the left, right, and rear directions and obtain the current state (e.g., the forward running state or the rearward running state) of the vehicle 40, and then the alarm device 4400 would reminder the driver to assist in the determination of the lane change timing to prevent a traffic accident caused by the lane change.Specifically, when the vehicular radar devices 100 and 100 aare applied to the BSD and LCA functions of the vehicle 40, the operating frequency thereof is about 77 GHz or 79 GHz, and a voltage range thereof is 9 V to 16 V. The BSD mode may be triggered or activated to activate the first transceiver units 141 and 141 awhen the vehicle 40 is in the forward running state, or the BSD mode may be activated while the vehicle 40 is in the forward running state and a vehicle speed calculated by a vehicle speed calculation unit 46 is greater than 10 km / h. When the vehicular radar devices 100 and 100 aare applied to the LCA function of the vehicle 40, the LCA mode may be activated while the BSD mode is activated and the vehicle speed is greater than 20 km / h. The BSD mode may be terminated after termination of the LCA mode while the vehicle 40 is in the reverse mode or the vehicle speed is less than 10 km / h. Therefore, when detecting multiple target vehicles (e.g., target vehicles 81 and 82), the vehicle radar system 4000 is advantageous for analyzing the range and speed information related to the vehicle 40 to obtain time-to-collision (TTC) information between each target vehicle and the vehicle 40. A target vehicle among the target vehicles that reach a TTC threshold (i.e., one of the first emergency conditions) closest to the vehicle 40 acts as an alarm target, whereupon the alarm device 4400 generates the alarm signal to reminder the driver thereof.When the vehicular radar devices 100 and 100 aare applied to the LCA function of the vehicle 40, an alarm threshold (another one of the first emergency conditions that causes the alarm device 4400 to generate the alarm signal) of a rear side of the vehicle 40 approaching the target vehicle is TTC≤5 seconds, and a distance range is 35 m to 10 m between the target vehicle and the rear side of the vehicle 40, or a distance range is 0.5 m to 5 m between the target vehicle and a left side or a right side of the vehicle 40, where the target vehicle approaches the vehicle 40 with TTC>2 seconds, or a distance greater than 20 m between the target vehicle and the rear of the vehicle 40, or a distance greater than 3 m between the target vehicle and the left side or the right side of the vehicle 40. The LCA mode being terminated follows the BSD mode being terminated.FIG. 4H is a schematic view of the parameters NT 2 and WT 2 according to the fourth embodiment. In FIGS. 1A, 4A, and 4H, the second transmission elements 162 of the vehicular radar device 100 may be the second narrow-angle transmission elements 160 and the second wide-angle transmission elements 166, and the radar control unit 130 is to switch the second narrow-angle transmission elements 160 or the second wide-angle transmission elements 166 to operation. The second reception elements 172 of the vehicular radar device 100 may be the second narrow angle reception elements 170 and the second wide angle reception elements 177 and 172, and the radar control unit 130 is for switching the second narrow angle reception elements 170 or the second wide angle reception elements 177 to operation. The second transmission elements of the vehicular radar apparatus 100 may be a plurality of second narrow angle transmission elements and a plurality of second wide angle transmission elements (not shown in the drawings), and the radar control unit 130 ais to switch the second narrow angle transmission elements or the second wide angle transmission elements into operation. The second reception elements of the vehicular radar apparatus 100 amay be a plurality of second narrow angle reception elements and a plurality of second wide angle reception elements (not shown in the drawings), and the radar control unit 130 ais to switch the second narrow angle reception elements or the second wide angle reception elements to operation.When the second transceiver units 142 and 142 aare in the detection mode, an angle of a central blind zone (whose reference numeral is omitted) defined by the radiation pattern of the second narrow angle receiving element 170 disposed at the left rear corner 49L and the radiation pattern of the second narrow angle receiving element disposed at the right rear corner 49R is NT 2, that is, the central blind zone is formed between incident angles of horizontal planes of the aforementioned second narrow angle receiving elements. The parameter NT2 corresponds to FIG. 4H and has a value of about 80 degrees. An angle of a central blind zone (whose reference numeral is omitted) defined by the radiation pattern of the second wide-angle receiving element 177 disposed at the left rear corner 49L and the radiation pattern of the second wide-angle receiving element disposed at the right rear corner 49R is WT 2, that is, the central blind zone is formed between incident angles of horizontal planes of the aforementioned second wide-angle receiving elements. The parameter WT2 corresponds to FIG. 4H and has a value of about 140 degrees. Thus, the vehicular radar system 4000 of the fourth embodiment can satisfy the following conditions: 15 degrees ≤ NT2 ≤ 120 degrees; and 60 degrees ≤ WT2 ≤ 175 degrees. Therefore, the radar control units 130 and 130 ashould switch from the second narrow-angle transceiver elements (center and short range antennas) to the second wide-angle transceiver elements (short range antennas) when an obstacle approaches the rear of the vehicle 40 to accurately detect the obstacle behind the vehicle 40. Further, the signals generated by the second antenna arrays 152 and 152a form a cross-connect network. The central blind zone is formed from the intersection network. As the angles of the central blind zones are larger, the detection ranges are larger.Moreover, the conventional ultrasonic radar usually has a smaller detection angle, and thereby a plurality of conventional ultrasonic radars (generally, four radars are required) must be equipped to cover the rear of the vehicle. The vehicular radar devices 100 and 100 aaccording to the present disclosure are millimeter wave radars; it is obviously advantageous to solve the detection problems resulting from the blind zone and adjust the detection angles via the design of the second antenna arrays 152 and 152 a(or the second circuit boards 182 and 182 a). Thus, the vehicular radar devices 100 and 100 aarranged at the left rear corner 49L and the right rear corner 49R, respectively, can cover the rear detection of the vehicle 40 to prevent the bumper from being damaged and to save time and labors in installation.A transmission signal of the second transceiver units 142 and 142 amay be generated using a time division multiplexing method, a frequency division multiplexing method, and an orthogonal signal method controlled by the radar control units 130 and 130 a. Therefore, the second transceiver units 142 and 142 acan be effectively prevented from detecting interference caused by a rear overlap zone of the vehicle 40.When the vehicular radar devices 100 and 100 aare applied to the backup detection function of the vehicle 40, its operating frequency is about 77 GHz or 79 GHz, and its voltage range is 9 V to 16 V. The backup detection mode may be triggered or activated to activate the second transceiver units 142 and 142 awhen the vehicle 40 is in the backup state, or the backup detection mode may be activated while the vehicle 40 is in the backup state and the vehicle speed calculated by the vehicle speed calculation unit 46 is less than 8 km / h. When the second emergency condition related to the distance, the vehicle speed, or the TTC is satisfied, the alarm device 4400 generates an alarm signal. The radar control units 130 and 130 aswitch from the second narrow-angle transceiver elements (center and short range antennas, large detection distance, and large alarm distance) to the second wide-angle transceiver elements (short range antennas, short detection distance, and short alarm distance) when an obstacle approaches the rear of the vehicle 40, to accurately detect the obstacle behind the vehicle 40.FIG. 5A is a block diagram of a vehicular radar system 5000 according to the fifth embodiment of the present disclosure disposed in a vehicle 50. FIG. 5B is a block diagram of the vehicular radar system 5000 according to the fifth embodiment. In FIGS. 2, 5A, and 5B, the vehicular radar system 5000 is disposed in the vehicle 50, and includes two vehicular radar devices, i.e., the vehicular radar devices 200 aand 200 indicated in the aforementioned second embodiment, which are respectively disposed at a left rear corner and a right rear corner of the vehicle 50. The vehicular radar device 200 amay have the same features as those of the vehicular radar device 200 indicated in the aforementioned second embodiment.The vehicular radar apparatus 200 includes the radar control unit 230, a first transceiver unit 241, and a second transceiver unit 242. The first transceiver unit 241 is communicatively connected to the radar control unit 230 and includes the first antenna array 251 and the second transceiver unit 242 is communicatively connected to the radar control unit 230 and includes the second antenna array 252. The vehicular radar apparatus 200 aincludes a radar control unit 230 a, a first transceiver unit 241 a, and a second transceiver unit 242 a. The first transceiver unit 241 ais communicatively connected to the radar control unit 230 aand includes a first antenna array (not shown in the drawings), and the second transceiver unit 242 ais communicatively connected to the radar control unit 230 aand includes a second antenna array (not shown in the drawings).Specifically, each unit of the first transceiver units 241, 241 aand the second transceiver units 242, 242 ais in a sensing mode when the vehicle 50 is in the starting state. The radar control units 230, 230 aare configured to determine whether the vehicle 50 satisfies a first emergency condition (e.g., the first emergency condition indicated in the fourth embodiment) in accordance with data from the first transceiver units 241, 241 a. The radar control units 230, 230 aare further configured to determine whether the vehicle 50 satisfies a second emergency condition (e.g., the second emergency condition indicated in the fourth embodiment) in accordance with data from the second transceiver units 242, 242 a. The vehicular radar system 5000 further includes an alarm device 5400 communicatively connected to the radar control units 230, 230 a(specifically, the alarm device 5400 is communicatively connected to the radar control unit 230 avia the radar control unit 230). The alarm device 5400 is controlled by the radar control units 230, 230 ato generate an alarm signal when the vehicle 50 is in a forward running state and satisfies the first emergency condition according to data of a vehicle control unit 53, a gear selection unit 55, and a vehicle speed calculation unit 56, and the alarm device 5400 is controlled by the radar control units 230, 230 ato generate another alarm signal when the vehicle 50 is in a rearward running state and satisfies the second emergency condition. Therefore, all of the first transceiver units 241, 241 aand the second transceiver units 242, 242 atransmit and receive signals, i.e., continue to operate when the vehicle 50 is in the starting state, rather than being activated based on the gear selection. Moreover, an alarm signal associated with the BSD, LCA functions or an alarm signal associated with the reversing detection function may be selected to be generated by the alarm device 5400 according to the gear selection, so that a circuit for switching between transceiver units or between antenna channels (selecting a first antenna array or a second antenna array) may be omitted.With respect to the vehicular radar system 5000 of the fifth embodiment, the other characteristics of the vehicular radar system 5000 may be the same as the corresponding characteristics of the vehicular radar system 4000, except that the characteristics mentioned in the last paragraph are different from the characteristics mentioned in the aforementioned fourth embodiment.

Claims

A vehicular radar apparatus (100) comprising: a radar control unit (130); a first antenna array (151) communicatively connected to the radar control unit (130), the first antenna array (151) comprising a plurality of first transmitting elements (161) and a plurality of first receiving elements (171); a second antenna array (152) communicatively connected to the radar control unit (130), the second antenna array (152) comprising a plurality of second transmitting elements (162) and a plurality of second receiving elements (172); a first printed circuit board (181), the first antenna array (151) being a plurality of printed circuit board antennas and being disposed on the first printed circuit board (181); and a second printed circuit board (182), the second antenna array (152) being a plurality of printed circuit board antennas and being disposed on the second printed circuit board (182); wherein the second transmitting elements (162) are one or more second narrow angle transmitting elements (160) and one or more second wide angle transmitting elements (166), the radar control unit (130) is for switching the second narrow angle transmitting elements (160) or the second wide angle transmitting elements (166) into operation, the second receiving elements (172) are one or more second narrow angle receiving elements (170) and one or more second wide angle receiving elements (177), and the radar control unit (130) is for switching the second narrow angle receiving elements (170) or the second wide angle receiving elements (177) into operation.The vehicular radar apparatus (100) according to claim 1, further comprising: a third circuit board (183), wherein the radar control unit (130) is disposed on the third circuit board (183), and only one of the first circuit board (181) and the second circuit board (182) is disposed in parallel with the third circuit board (183).The vehicular radar apparatus (100) according to claim 1, wherein an operation frequency of the first antenna array (151) and an operation frequency of the second antenna array (152) are both greater than 10 GHz, and each of the first transmitting elements (161), each of the first receiving elements (171), each of the second transmitting elements (162), and each of the second receiving elements is a microstrip antenna (172) and has a length of less than 40 mm.A vehicular radar system (4000) disposed in a vehicle (40) and comprising at least one vehicular radar device (100), the at least one vehicular radar device (100) comprising: a radar control unit (130); a first transceiver unit (141) communicatively connected to the radar control unit (130) and comprising a first antenna array (151), the first antenna array (151) comprising a plurality of first transmitting elements (161) and a plurality of first receiving elements (171); and a second transceiver unit (142) communicatively connected to the radar control unit (130) and comprising a second antenna array (152), the second antenna array (152) comprising a plurality of second transmitting elements (162) and a plurality of second receiving elements (172); wherein the second transmitting elements (162) are one or more second narrow angle transmitting elements (160) and one or more second wide angle transmitting elements (166), the radar control unit (130) is for switching the second narrow angle transmitting elements (160) or the second wide angle transmitting elements (166) into operation, the second receiving elements (172) are one or more second narrow angle receiving elements (170) and one or more second wide angle receiving elements (177), and the radar control unit (130) is for switching the second narrow angle receiving elements (170) or the second wide angle receiving elements (177) into operation.The vehicular radar system (4000) of claim 4, wherein the at least one vehicular radar device (100) further comprises: a first printed circuit board (181), wherein the first antenna array (151) is a plurality of printed circuit board antennas and is disposed on the first printed circuit board (181); and a second printed circuit board (182), wherein the second antenna array (152) is a plurality of printed circuit board antennas and is disposed on the second printed circuit board (182).The vehicular radar system (4000) according to claim 5, wherein the at least one vehicular radar device (100) further comprises: a third circuit board (183), wherein the radar control unit (130) is disposed on the third circuit board (183), and only one of the first circuit board (181) and the second circuit board (182) is disposed in parallel with the third circuit board (183).The vehicular radar system (4000) according to claim 5, wherein an operation frequency of the first antenna array (151) and an operation frequency of the second antenna array (152) are both greater than 10 GHz, and each of the first transmitting elements (161), each of the first receiving elements (171), each of the second transmitting elements (162), and each of the second receiving elements (172) is a microstrip antenna that extends along a horizontal direction of the vehicle (40) and has a length of less than 40 mm.The vehicular radar system (4000) according to claim 5, wherein a number of the at least one vehicular radar device (100, 100a) is two, the two vehicular radar devices (100, 100a) are respectively disposed at a left rear corner (49L) and a right rear corner (49R) of the vehicle (40), the two first circuit boards (181, 181a) of the two vehicular radar devices (100, 100a) face a left direction and a right direction of the vehicle (40), respectively, and are symmetrically disposed with respect to a longitudinal center line (y) of the vehicle (40), and the two second circuit boards (182, 182a) of the two vehicular radar devices (100, 100a) are both facing a rear direction of the vehicle (40) and are symmetrically disposed with respect to the longitudinal center line (y) of the vehicle (40).The vehicular radar system (4000) according to claim 8, wherein an angle of a central blind zone defined by radiation patterns of the second narrow angle receiving elements (170) of the two vehicular radar devices (100, 100a) respectively disposed at the left rear corner (49L) and the right rear corner (49R) is NT2, an angle of a central blind zone defined by radiation patterns of the second wide angle receiving elements (177) of the two vehicular radar devices (100, 100a) respectively disposed at the left rear corner (49L) and the right rear corner (49R) is WT2, and the following conditions are satisfied: 15 degrees ≤ NT 2 ≤ 120 degrees; and 60 degrees ≤ WT 2 ≤ 175 degrees. The vehicular radar system (4000) according to claim 8, wherein a transmission signal of the two second transceiver units (142, 142a) and the two vehicular radar devices (100, 100a), respectively, is generated by a time division multiplexing method, a frequency division multiplexing method, and / or an orthogonal signal method controlled by the two radar control units (130, 130a) of the two vehicular radar devices (100, 100a), respectively.The vehicular radar system (4000) according to claim 8, wherein one of the two vehicular radar devices (100, 100a) is communicatively connected to a vehicle control unit (43) of the vehicle (40) via the other of the two vehicular radar devices (100, 100a).The vehicular radar system (4000) according to claim 8, wherein the radar control unit (130) of each of the two vehicular radar devices (100, 100a) comprises: a circuit circuit (133) configured to switch the first transceiver unit (141) or the second transceiver unit (142) to a detection mode, wherein only the first transceiver unit (141) is in the detection mode when the vehicle (40) is in a forward running state, and only the second transceiver unit (142) is in the detection mode when the vehicle (40) is in a rearward running state.The vehicular radar system (4000) according to claim 8, wherein each of the two first transceiver units (141, 141a) and the two second transceiver units (142, 142a) of the two vehicular radar devices (100, 100a) is in a detection mode when the vehicle (40) is in a starting state, the two radar control units (130, 130a) of the two vehicular radar devices (100, 100a) are configured to determine whether the vehicle (40) satisfies a first emergency condition according to data from the two first transceiver units (141, 141a) of the two vehicular radar devices (100, 100a) and whether the vehicle (40) satisfies a second emergency condition according to data from the two second transceiver units (142, 142a) of the two vehicular radar devices (100, 100a); wherein the vehicular radar system (4000) further comprises an alarm device (4400) communicatively connected to the two radar control units (130, 130a), the alarm device (4400) is controlled by the two radar control units (130, 130a) to generate an alarm signal when the vehicle (40) is in a forward driving state and satisfies the first emergency condition, and the alarm device (4400) is controlled by the two radar control units (130, 130a) to generate another alarm signal when the vehicle (40) is in a rearward driving state and satisfies the second emergency condition.The vehicular radar system (4000) according to claim 4, wherein a half-value beam width of a main horizontal lobe (MLR1) of the first reception elements (171) is RA1, and the following condition is satisfied: 75 degrees ≤ RA 1 < 180 degrees. The vehicular radar system (4000) according to claim 4, wherein an angle between a center line (C1) of the main horizontal lobe (MLR1) of the first reception elements (171) and a center line (C2) of a main horizontal lobe (MLR2) of the second reception elements (172) is R12, and the following condition is satisfied: 15 degrees ≤ R 12 ≤ 75 degrees. A vehicular radar system (4000) disposed in a vehicle (40) and comprising at least one vehicular radar device (100), the at least one vehicular radar device (100) being disposed at one of the four corners (48L, 48R, 49L, 49R) of the vehicle (40) and comprising: a radar control unit (130); a first antenna array (151) communicatively connected to the radar control unit (130), the first antenna array (151) comprising a plurality of first transmitting elements (161) and a plurality of first receiving elements (171); a second antenna array (152) communicatively connected to the radar control unit (130), the second antenna array (152) comprising a plurality of second transmitting elements (162) and a plurality of second receiving elements (172); a first printed circuit board (181) vertical to a horizontal direction of the vehicle (40), the first antenna array (151) being a plurality of printed circuit board antennas and being disposed on the first printed circuit board (181); and a second printed circuit board (182) vertical to the horizontal direction of the vehicle (40), the second antenna array (152) being a plurality of printed circuit board antennas and being disposed on the second printed circuit board (182); wherein the second transmitting elements (162) are one or more second narrow angle transmitting elements (160) and one or more second wide angle transmitting elements (166), the radar control unit (130) is for switching the second narrow angle transmitting elements (160) or the second wide angle transmitting elements (166) into operation, the second receiving elements (172) are one or more second narrow angle receiving elements (170) and one or more second wide angle receiving elements (177), and the radar control unit (130) is for switching the second narrow angle receiving elements (170) or the second wide angle receiving elements (177) into operation.The vehicular radar system (4000) according to claim 16, wherein a number of the at least one vehicular radar device (100, 100a) is two, the two vehicular radar devices (100, 100a) are respectively disposed at a left rear corner (49L) and a right rear corner (49R) of the four corners (48L, 48R, 49L, 49R) of the vehicle (40), the two first circuit boards (181, 181a) of the two vehicular radar devices (100, 100a) face a left direction and a right direction of the vehicle (40), respectively, and are disposed symmetrically to a longitudinal center line (y) of the vehicle (40), and the two second circuit boards (182, 182a) of the two vehicular radar devices (100, 100, 100a) both face a rear direction of the vehicle (40) and are arranged symmetrically with respect to the longitudinal centre line (y) of the vehicle (40).The vehicular radar system (4000) according to claim 17, wherein an angle of a central blind zone defined by radiation patterns of the second narrow angle receiving elements (170) of the two vehicular radar devices (100, 100a) respectively disposed at the left rear corner (49L) and the right rear corner (49R) is NT2, an angle of a central blind zone defined by radiation patterns of the second wide angle receiving elements (177) of the two vehicular radar devices (100, 100a) respectively disposed at the left rear corner (49L) and the right rear corner (49R) is WT2, and the following conditions are satisfied: 15 degrees ≤ NT 2 ≤ 120 degrees; and 60 degrees ≤ WT 2 ≤ 175 degrees. The vehicular radar system (4000) according to claim 16, wherein an angle between the first circuit board (181) and the second circuit board (182) is P12 and the following condition is satisfied: 105 degrees ≤ P 12 ≤ 165 degrees.

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