System for ultra-wideband (UWB) distance measurement and / or radar

Abstract

System for ultra-wideband (UWB) distance measurement and / or radar, wherein the system comprises a circuit provided on a printed circuit board, the circuit comprising: two receiving antennas, each capable of emitting a radiation pattern with an intended application area; a single transmitting antenna capable of emitting a radiation pattern with an intended area of ​​application; wherein the receiving antennas are positioned on the circuit board such that the radiation patterns of the receiving antennas are emitted in opposite directions relative to each other; wherein the transmitting antenna is positioned between the receiving antennas such that the radiation pattern of the transmitting antenna approximately overlaps with the radiation pattern of the receiving antennas; and furthermore including a ground plane separation provided between the transmitting antenna and the receiving antennas.

Description

field of technology

[0001] The present invention relates to improvements in Passive Entry Passive Start (PEPS) and vehicle occupancy detection. Background of the invention

[0002] Ultra-wideband (UWB) distance measurement applications in an automotive environment are desirable for applications such as Passive Entry Passive Start (PEPS). The primary goal of a UWB distance measurement device is to provide distance estimation between an initiator and a response unit, but it is also desirable for the system to be radar-capable (radio-based detection and distance measurement). One challenge in implementing these applications is achieving an antenna configuration capable of delivering a high-fidelity, undistorted signal across the entire required operating range of the system, i.e., the field of view (FoV).

[0003] It is clear that the discussion of the background of the invention is included to explain the context of the invention. This is not to be understood as an admission that any of the materials mentioned are published, known, or part of the common general knowledge. Description of the invention

[0004] According to a first aspect, the present invention provides a system for ultra-wideband (UWB) distance measurement and / or radar, wherein the system comprises a circuit provided on a printed circuit board, the circuit comprising: two receiving antennas, each capable of emitting a radiation pattern with an intended operating area / field of view (FoV); a single transmitting antenna capable of emitting a radiation pattern with an intended operating area; wherein the receiving antennas are positioned on the printed circuit board such that the radiation patterns of the receiving antennas are emitted in opposite directions relative to each other; and wherein the transmitting antenna is positioned between the receiving antennas such that the radiation pattern of the transmitting antenna approximately overlaps with the radiation pattern of the receiving antennas.

[0005] Advantageously, the use of multiple antennas (i.e., providing antenna diversity) in the proposed configuration reduces limitations such as signal loss at certain points and distortions that cause distance measurement errors in the operational area / field of view (FoV). Advantageously, the arrangement of the present invention improves the communication link between a vehicle and a fob or mobile phone and provides a high-fidelity signal in the FoV, enabling accurate distance measurement (i.e., time-of-flight calculations) and further providing the necessary antenna isolation, allowing the system to function as a radar capable of detecting the presence of passengers in a vehicle.The UWB antenna configuration of the present invention can be seamlessly used with a Bluetooth system (including a Bluetooth Low Energy (BLE) system) that incorporates a Bluetooth antenna oriented in the proposed manner, so that its implementation does not impair the performance of the UWB system.

[0006] It is clear that the antenna configuration can be a standalone antenna design with an interface to an external circuit board, or it can be part of an embedded circuit. The circuit board can take any suitable form, such as a printed circuit board (PCB) or the like, as experts will know.

[0007] The system further includes adequate ground plane separation provided between the transmitting antenna and the receiving antennas, the receiving antennas preferably being positioned on a different horizontal X-axis plane relative to the transmitting antenna. This is necessary to allow for ground metal over the receiving antennas, thereby providing improved isolation between the antennas. Advantageously, the improved isolation offers enhanced radar functionality.

[0008] In one embodiment, the receiving antennas are not positioned in substantially the same horizontal X-axis plane.

[0009] Preferably, the radiation pattern of the receiving antennas is emitted in opposite directions relative to each other and includes a direction far left and a direction far right.

[0010] Preferably, the transmitting antenna is positioned approximately between the receiving antennas.

[0011] Preferably, the receiving and transmitting antennas are broadband antennas. The broadband antennas can be circular, elliptical, or rectangular monopole antennas, or any other type of broadband antenna.

[0012] The system may also include an additional antenna in close proximity to the UWB antennas for use in a Bluetooth system. This additional antenna, or antennas, may be an inverted F-antenna or similar design.

[0013] Preferably, the receiving antennas and the transmitting antennas are provided on receive pins and transmit pins that are provided on an integrated UWB circuit.

[0014] Alternatively, the receiving antennas and the transmitting antennas are provided on transmit / receive pins on an integrated UWB circuit.

[0015] In one embodiment, the receiving and transmitting antennas are provided on an integrated UWB circuit with a single pin, two pins, or four or more pins, connected by a series of RF switches and / or RF antenna dividers / splitters. It is clear that the antenna configuration can be a self-contained antenna design with an interface to an external device.

[0016] According to a second aspect, the present invention provides a system for ultra-wideband (UWB) distance measurement and / or radar, wherein the system comprises a circuit provided on a printed circuit board, the circuit comprising: two transmitting antennas, each capable of emitting a radiation pattern with an intended operating area / field of view (FoV); a single receiving antenna, capable of emitting a radiation pattern with an intended operating area; wherein the transmitting antennas are positioned on the printed circuit board such that the radiation patterns of the transmitting antennas are emitted in opposite directions relative to each other; and wherein the receiving antenna is positioned between the transmitting antennas such that the radiation pattern of the receiving antennas approximately overlaps with the radiation pattern of the transmitting antennas.

[0017] According to a third aspect, the present invention provides a system for ultra-wideband (UWB) distance measurement and / or radar, wherein the system comprises a circuit provided on a printed circuit board, the circuit comprising: two receiving antennas, each capable of emitting a radiation pattern with an intended operating range; a single transmitting antenna, each capable of emitting a radiation pattern with an intended operating range; wherein the receiving antennas and the transmitting antenna are aligned on the printed circuit board such that an isolation value between each of the receiving antennas and the transmitting antenna is less than -15 dB in the one or more required operating frequency bands.

[0018] According to a fourth aspect, the present invention provides a system for ultra-wideband (UWB) distance measurement and / or radar, wherein the system comprises a circuit provided on a printed circuit board, the circuit comprising: two transmitting antennas, each capable of emitting a radiation pattern with an intended operating range; a single receiving antenna, each capable of emitting a radiation pattern with an intended operating range; wherein the transmitting antennas and the receiving antenna are aligned on the printed circuit board such that an isolation value between each of the transmitting antennas and the receiving antenna is less than -15 dB in the one or more required operating frequency bands.

[0019] According to a fifth aspect, the present invention provides a system for ultra-wideband (UWB) distance measurement and / or RADAR essentially as described above with reference to the drawings.

[0020] The system according to claim one or more of the first, second, third, fourth or fifth aspect, wherein two or more receiving antennas and two or more transmitting antennas are provided. Brief description of the drawings Fig. Figure 1 is a schematic diagram illustrating the antenna configuration design on a PCB according to the system of the present invention; Fig. Figure 2 is a schematic diagram illustrating simplified radiation patterns produced by the antennas of Fig. 1 are associated; Fig. 3A-3D are schematic diagrams that illustrate a vehicle, with the aspect in relation to Fig. 1 and Fig. 2. The system described is provided in the vehicle; and Fig. Figure 4 is a diagram of isolation (dB) versus frequency, which shows the operating range / field of view (FoV) of the antennas. Fig. 1 illustrates. Detailed description

[0021] Fig. Figure 1 is a schematic diagram illustrating a PCB design 100 using three UWB antennas 105, 110, 115 for an embedded circuit design using an integrated ultra-wideband (UWB) circuit (UWB IC) with two receive pins and one transmit pin (the IC is not shown in the diagram). A Bluetooth antenna 120 can also be included for a system incorporating Bluetooth, if required. For the purpose of describing the geometries of the PCB design 100, see Figure 1. Fig. Figure 1 shows a coordinate system with a horizontal X-axis and a vertical Y-axis. The Z-axis, which is orthogonal to the X- and Y-axes, is not shown.

[0022] The PCB module 100 is preferably used as a transmitter / receiver unit for a Fig. The vehicle shown in Figure 3 is used. The installation position of PCB module 100 could be as shown in Figure 3. Fig. The PCB module 100 could be oriented as shown in Figure 1, with the X-axis representing the horizontal direction, reflecting the orientation of the surface on which the vehicle is located. Alternatively, the PCB module 100 could be installed rotated by 180° so that the transmitting antenna 115 points downwards towards the X-axis instead of upwards. This results in the transmitting or receiving fields for antennas 105, 110, 115 as shown in Figure 1. Fig. 3 shown.

[0023] After Fig. The transmitting antenna 115 is located at the top of the PCB module 100. The two receiving antennas 110 and 105 are located below the transmitting antenna 115 on the left and right sides of the PCB module 100.

[0024] To meet the design criteria for a UWB and / or radar system, a specific arrangement of the antennas 105, 110, 115 is provided, which uses two receiving antennas 105, 110 and a single transmitting antenna 115 on a PCB design 100.

[0025] It is also clear that the reverse is possible, i.e., there can be two transmitting antennas and a single receiving antenna by using 105, 110 as the two transmitting antennas and 115 as the receiving antenna on a PCB design 100.

[0026] Furthermore, the antenna configuration can be a standalone antenna design with an interface to an external device.

[0027] In Fig. Figure 1 shows that the three required antennas are represented by antennas 105, 110, and 115, which can be circular, elliptical, or rectangular monopole antennas. It is clear that any suitable broadband antenna type can be used. A further antenna 120 is provided, which can, for example, be an inverted F-antenna for a Bluetooth system—that is, this antenna 120 is not part of the UWB system. In one embodiment, the present invention includes the option, in cases where both UWB and Bluetooth systems are required, to provide a suitable position and orientation for a Bluetooth antenna in the unused PCB area in close proximity to the UWB antenna 115, without impairing the UWB performance. For easier reference, antennas 105, 110, 115 and 120 can be positioned with an offset along the Y-axis and X-axis relative to each other.

[0028] Preferably, the two receiving antennas 105, 110 are capable of emitting radiation patterns, the combination of which covers the intended application range. Furthermore, the transmitting antenna 115 is also capable of emitting a radiation pattern with an intended application range. As noted above, it is clear that the reverse configuration can also be provided.

[0029] The receiving antennas 105, 110 are positioned on the circuit board 100 such that their radiation patterns are emitted in opposite directions relative to each other. Furthermore, the transmitting antenna 115 is preferably positioned approximately between the receiving antennas 105, 110 along the X-axis / horizontal plane such that its radiation pattern approximately overlaps with that of the receiving antennas 105, 110. This is described with reference to Fig. 2 further described and shown. Furthermore, in this embodiment, the transmitting antenna 115 is also preferably positioned at a different positional offset in the vertical direction Y.

[0030] It is clear that the respective antennas are positioned such that, for example, the radiation patterns for both the transmitting antennas 115 and the receiving antennas 105, 110 cover a required operating area / field of view (FoV). Furthermore, they are positioned so that isolation occurs between all antennas, such that it is below the requirement for radar performance—for example, less than -15 dB in the one or more required operating frequency bands. It is also preferred that all antennas exhibit a reverse loss above a minimum requirement—for example, > 7 dB in the one or more required operating frequency bands. Finally, the antennas are designed such that the operating frequency covers all UWB frequencies required in the system.

[0031] The system of the present invention fulfills the design criteria for a UWB distance measurement and / or radar system, such that a specific arrangement of antennas utilizing two receiving antennas 105, 110 and one transmitting antenna 115 (or vice versa) is provided on a PCB module 100. As will be clear, the arrangement and positioning of the UWB antennas and the adjacent PCB ground plane must ensure that the above criteria are achieved simultaneously, since all criteria depend on this positioning.

[0032] In one embodiment, two receiving antennas 105, 110 are positioned such that their radiation patterns are emitted in opposite directions—for example, one receiving antenna 110 towards the far left and the other receiving antenna 105 towards the far right. The two receiving antennas 105, 110 are essentially located on or in the same X-axis / horizontal plane, but this is not a requirement, and they can be located in different horizontal planes. It is understood that the receiving antennas 105, 110 are placed on the same circuit board but are oriented to cover opposite hemispheres or the like. The transmitting antenna 115 is positioned between the two receiving antennas 105, 110 and may, for example, be equidistant from both receiving antennas 105, 110, or not.It is clear that the transmitting antenna 115 is preferably provided on a different horizontal plane than the receiving antennas 105, 110 (for example, with reference to . Fig. In Figure 1, antenna 115 is positioned offset from receiving antennas 105 and 110 in the vertical direction Y. This antenna placement advantageously allows the mass metal to be positioned in the Y-axis between and above receiving antennas 105 and 110.

[0033] In an embodiment as described above, the receiving antennas 105, 110 may not be coplanar on the X-axis / in the horizontal plane; for example, one may be raised or vertically offset. The placement of the antennas is further described with reference to Fig. 2 described.

[0034] A metallic ground plane separation area 125, 130, 135 is provided on the PCB module 100 to isolate the antennas 105, 110, 115 from each other. For example, sections of the ground plane separation 125, 130 for isolating the transmitting antenna 115 from the receiving antennas 105, 110 extend across the width of the PCB module 100 (according to the coordinate system in Fig. 1 along the X-direction). Likewise, the section of the mass plane separation 125, 130 in the Y-direction is between the transmitting antenna 115 and the two receiving antennas 105 and 110 (preferably at the same height in accordance with the coordinate system in Fig. 1, the Y-direction) to provide a suitable geometry for sufficient isolation. The ground plane separation 125, 130 can be rectangular in shape. To optimize the isolation between the antennas 105, 110, 115, the end sections of the ground plane separation 125, 130, located on the side edges of the PCB module 100, can preferably be inclined (as is designed in the section in the direction of the receiving antennas 105 and 110, respectively) and / or have increasing straight angles in the Y-direction (as is designed in the section in the direction of the transmitting antenna 115). In addition to straight slopes, rounded or other suitable geometries could also be provided.

[0035] The ground plane separations 125 and 130 merge to form a central ground plane separation area 135. This central area 135 is located between the two receiving antennas 105 and 110. The central area 135 is also located approximately in the center of the PCB module 100 and is positioned further away from the receiving antennas 105 and 110, towards the side faces of the PCB.

[0036] The central surface 135 extends downwards (with a shrinking Y-coordinate) into a separating surface that also surrounds the receiving antennas 105, 110 in the Y-direction and preferably extends to the edge surfaces in the X-direction of the PCB module 100. This lower surface of the separating area extends approximately across the entire width of the PCB module 100 to the bottom of the PCB module 100.

[0037] The PCB module 100 can be constructed in multiple layers or with multiple PCBs. These multiple layers or circuit boards run in the Z-direction (in Fig. (Figure 1 not shown). Therefore, the antennas 105, 110, 115, and 120 can each be positioned on a single layer or, if necessary, multiple layers or circuit boards. For example, one of the receiving antennas 105 or 110 and the transmitting antenna 115 could be arranged on the same layer or PCB, while the other receiving antenna 105 or 110 and / or the other antenna 120 could be arranged on a separate layer or PCB. The additional layers are advantageous for connecting the antennas to their associated electronic circuitry and for the overall functionality and connectivity of the electronic system.

[0038] The ground plane separation 125, 130, 135 can be separated in several layers on the printed circuit boards. The ground plane separation 125, 130, 135 on several layers or printed circuit boards is electrically connected to each other, for example by ground vias, in particular to the ground connection of the PCB module 100.

[0039] Fig. Figure 2 is a schematic diagram 200 illustrating simplified radiation patterns produced by the antennas of Fig. 1 are associated with frequencies of 6.5 GHz (designated 205) and 8 GHz (designated 210), which lie within the desired operating frequency bands. As can be seen from Fig. As can be seen in Figure 2, the placement of the receiving antennas 105 and 110 results in a radiation pattern oriented to the left and right, respectively. The combined received radiation pattern of the two antennas 105 and 110 therefore extends in both directions. This advantageously forms the required operating area / field of view (FoV) of the UWB system. Furthermore, the transmitting antenna 115, as shown in Figure 2, is also positioned in the direction of radiation. Fig. As can be seen in Figure 2, it is positioned approximately in the center. It achieves a radiation pattern in both the left and right directions, i.e., within the required field of view (FoV) of the UWB system.

[0040] The Bluetooth antenna 120 can be used on the in Fig. The antennas should be oriented as shown in Figure 1 without negatively interfering with the UWB radiation patterns for a system requiring both UWB and Bluetooth. To reduce the total PCB area required by the UWB and BLE antennas, BLE can be located in the same PCB area. The metal grounding separation 130 between the transmitting antenna 115 and the receiving antennas 105, 110 (as shown in Figure 1) Fig. 2 shown) advantageously allows a positioning of a BLE antenna 120 in a manner that does not affect the UWB performance (the metal earth separation 125 could also be used).

[0041] In Fig. 2 and Fig. Figure 3 shows simplified radiation patterns of the antenna gain (dBi). These simplified images are for demonstration purposes; that is, the signal continues to radiate beyond the depicted images into the distance at design signal levels as the distance from the antenna increases, as is clear to those skilled in the art. It is also clear that for complete UWB coverage around (for example) a vehicle, multiple modules may be positioned inside the vehicle to meet the required coverage area / field of view (FoV). This is illustrated with reference to Fig. 3 further shown. In addition, both external and internal areas of operation may be required for the vehicle.

[0042] Fig. 3A-3D shows a vehicle 300, inside which are several modules, that is, in relation to Fig. 1 and Fig. The system described in section 2 is provided or is provided in the vehicle. These include a module 305, which is located, for example, in the front left trim panel of the vehicle, a module 310, which is located, for example, in the front right trim panel of the vehicle, a module 315, which is located, for example, in the center console of the vehicle, a module 320, which is located, for example, in the right rear trim panel of the vehicle, and a module 325, which is located, for example, in the left rear trim panel of the vehicle.

[0043] It is clear that the positioning of the modules can be in any suitable shape and with any number of modules, depending on the application. The field of view (FoV) is shown for each module. For example, with regard to module 320, an FoV of 325 is shown, extending to the outer trunk of the vehicle and along one side of the vehicle. By superimposing the radiation patterns of, for example, Fig. 2 on the vehicle 300 are the radiation patterns for the in Fig. Antenna 115 shown in 3C is visible, and the radiation patterns for antennas 105 and 110 (again in relation to Fig. 2) are also evident. In short, by superimposing the radiation patterns, it is evident that it covers the field of view for the vehicle. This is repeated for each of the modules 305, 310, 315, 320, and 325, providing coverage for the entire vehicle 300.

[0044] For each module 305, 310, 315, 320 and 325, the radiation patterns with the vehicle allow for left and right placement of the receiving antennas 105, 110, which causes left- or right-oriented radiation patterns, as shown in Fig. 3B and Fig. Shown in 3D. The combined radiation pattern of the two antennas therefore extends in both the left and right directions. This constitutes the required operating area / field of view (FoV) of the UWB system. Furthermore, the approximately centrally located transmitting antenna 115 achieves a radiation pattern in both the left and right directions, as shown in Fig. 3C shown, i.e., the required FoV of the UWB system.

[0045] It is also clear that, with reference to Fig. 1. Ground plane separations must be provided on PCBs 125 and 130 “above” (in the vertical direction Y) the receiving antennas 105 and 110 and between the transmitting antenna 115 and the receiving antennas 105 and 110. These are crucial to obtain substantial isolation between the antennas. This is shown in diagram 400 of Fig. Figure 4 shows diagrams of the dB of antenna 110 and antenna 105 (S2, 1), as well as of antennas 115 and 105 (S3, 1) and antennas 110 and 115 (S2, 3). The free ends of the ground plane separations 125, 130 can have an angled end section compared to the horizontal orientation of the otherwise horizontally shaped ground plane separation 125 in order to improve the isolation between the antennas.

[0046] In one embodiment, the ground plane separator surrounding the receiving antennas 105 and 110 can be shaped in a U-configuration or any other configuration that allows the ground metal to run along the side and rear faces of each antenna, as shown in 125 and 130. Advantageously, this structure improves the isolation from the centrally located transmitting antenna 115. The central section 135 of the ground plane separator between the antennas 105 and 110 is extended, forming a wider grounded area that further reduces coupling.

[0047] As from Fig. As can be seen in Figure 4, all diagrams are below the -15 dB isolation requirement between the required bandwidth at an operating frequency of approximately 6 to 10 GHz. The ground plane separations 125 and 130 and the alignment of the three UWB antennas 105, 105, and 115 are unique and crucial for achieving this design criterion. This ground plane antenna arrangement is unique in providing the design criteria and is achieved over a substantial bandwidth.

[0048] Experts are aware that additional antennas can be used. They are also aware that the transmitting and receiving antennas are interchangeable. Furthermore, a Bluetooth antenna can be added without affecting UWB performance, as shown in [reference to relevant document]. Fig.Figure 1 shows. It is also clear that the present invention can be used with other integrated circuit transmit and receive pin arrangements. Finally, it is clear that a transmitting antenna with a ground insert can be used to improve the omnidirectional radiation pattern performance.

Claims

[1] System for ultra-wideband (UWB) distance measurement and / or radar, wherein the system comprises a circuit provided on a printed circuit board, the circuit comprising: two receiving antennas, each capable of emitting a radiation pattern with an intended application area; a single transmitting antenna capable of emitting a radiation pattern with an intended area of ​​application; wherein the receiving antennas are positioned on the circuit board such that the radiation patterns of the receiving antennas are emitted in opposite directions relative to each other; wherein the transmitting antenna is positioned between the receiving antennas such that the radiation pattern of the transmitting antenna approximately overlaps with the radiation pattern of the receiving antennas; and furthermore including a ground plane separation provided between the transmitting antenna and the receiving antennas. [2] System according to claim 1, wherein the receiving antennas are preferably positioned on a different horizontal X-axis plane with respect to the transmitting antenna to allow mass metal over the receiving antennas, thereby providing improved isolation between the antennas. [3] System according to claim 1, wherein the receiving antennas are not positioned in substantially the same horizontal X-axis plane. [4] System according to claim 1, wherein the radiation pattern of the receiving antennas, which is emitted in opposite directions relative to each other, includes a direction far left and a direction far right. [5] System according to claim 1, wherein the transmitting antenna is positioned approximately between the receiving antennas. [6] System according to claim 1, wherein the receiving antennas and the transmitting antennas are provided on receive pins and transmit pins provided on an integrated UWB circuit. [7] System according to claim 1, wherein the receiving antennas and the transmitting antennas are provided on transmit / receive pins on an integrated UWB circuit. [8] System according to claim 1, wherein the receiving antennas and the transmitting antennas are provided on an integrated UWB circuit with a single pin, 2 pins or 4 or more pins by a series of RF switches and / or RF antenna dividers / splitters. [9] System according to claim 1, wherein the antenna configuration is a self-contained antenna design with an interface to an external device. [10] System according to claim 1, wherein the receiving antennas and the transmitting antennas are broadband antennas. [11] System according to claim 9, wherein the broadband antennas include circular, elliptical or rectangular monopole antennas or any other type of broadband antenna. [12] System according to claim 1, wherein a further Bluetooth antenna is provided close to the UWB antennas for use in a BLE system. [13] System for ultra-wideband (UWB) distance measurement and / or radar, wherein the system comprises a circuit provided on a printed circuit board, the circuit comprising: two transmitting antennas, each capable of emitting a radiation pattern with an intended area of ​​application; a single receiving antenna capable of emitting a radiation pattern with an intended area of ​​application; wherein the transmitting antennas are positioned on the circuit board such that the radiation patterns of the transmitting antennas are emitted in opposite directions relative to each other; wherein the receiving antenna is positioned between the transmitting antennas such that the radiation pattern of the receiving antennas approximately overlaps with the radiation pattern of the transmitting antennas; and further comprising a ground plane separation provided between the transmitting antennas and the receiving antenna. [14] System for ultra-wideband (UWB) distance measurement and / or radar, wherein the system comprises a circuit provided on a printed circuit board, the printed circuit board comprising: two receiving antennas, each capable of emitting a radiation pattern with an intended application area; a single transmitting antenna, each capable of emitting a radiation pattern with an intended area of ​​application; wherein the receiving antennas and the transmitting antenna are aligned on the circuit board such that an isolation value between each of the receiving antennas and the transmitting antenna is less than -15 dB in the one or more required operating frequency bands. [15] System for ultra-wideband (UWB) distance measurement and / or radar, wherein the system comprises a circuit provided on a printed circuit board, the printed circuit board comprising: two transmitting antennas, each capable of emitting a radiation pattern with an intended area of ​​application; a single receiving antenna, each capable of emitting a radiation pattern with an intended area of ​​application; wherein the transmitting antennas and the receiving antenna are aligned on the circuit board such that an isolation value between each of the transmitting antennas and the receiving antenna is less than -15 dB in the one or more required operating frequency bands.

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