OBU device
By adding an LNA module and power amplifier circuit to the OBU device, the signal attenuation problem caused by the silver-plated metal film was solved, improving communication performance and transaction success rate, while reducing device power consumption and repair rate.
Patent Information
- Application Number
- CN202422993673.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-12-04
AI Technical Summary
When the OBU device is installed on a windshield with a silver-plated metallic film, the communication effect is affected by signal attenuation, resulting in poor communication performance.
Design an OBU device comprising a main control module, an antenna module, a wake-up branch, a transmit branch, and a receive branch. Add an LNA module to the wake-up branch, a power amplifier circuit to the transmit branch, and a low-noise amplifier circuit to the receive branch to compensate for RF signal attenuation.
By amplifying and compensating the radio frequency signal, the communication performance of the OBU device in signal attenuation scenarios is improved, transaction distance and success rate are increased, device power consumption is reduced, device life is extended, and repair and return rates are reduced.
Smart Images
Figure CN223528063U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to intelligent transportation technical field especially relates to a kind of OBU equipment. BACKGROUND
[0002] With the development of new energy vehicles, most vehicles on the market use metal film with silver plating for the front windshield when they are shipped. This kind of metal film can cause attenuation and shielding effect on wireless communication signals, so it has a certain impact on the communication of electronic devices.
[0003] OBU equipment, as an electronic device installed on the front windshield, will be affected by this kind of metal film if the customer does not install the OBU equipment in the specified microwave window on the customer vehicle model with metal film installed, resulting in a decline in the communication effect of the OBU equipment. INVENTION CONTENTS
[0004] The technical problem to be solved by the utility model is that the OBU equipment has poor communication effect in the use scenario that causes large signal attenuation. Therefore, an improved OBU equipment is provided.
[0005] The technical solution adopted by the utility model to solve its technical problem is: a kind of OBU equipment is constructed, including main control module, and antenna module connected with the main control module, the main control module communicates with external equipment through the antenna module, and the main control module includes dormant state and active state; the OBU equipment further includes: wake-up branch, transmitting branch and receiving branch connected between the main control module and the antenna module; the wake-up branch is used to transmit the wake-up signal entering from the antenna module to the main control module to wake up the main control module, and an LNA module is arranged on the wake-up branch; the transmitting branch is used to transmit the transmitting signal generated by the main control module to the antenna module, and a power amplification circuit is arranged on the transmitting branch to amplify and compensate the transmitting signal; the receiving branch is used to transmit the feedback signal entering from the antenna module to the main control module, and a low-noise amplification circuit is arranged on the receiving branch; the OBU equipment further includes a first switch module for switching the path of radio frequency signal flow, and the first switch module is connected with the wake-up branch, the transmitting branch and the receiving branch to make the radio frequency signal transmit on the wake-up branch in the dormant state, and make the radio frequency signal transmit on the transceiving branch containing the transmitting branch and the receiving branch in the active state.
[0006] In some embodiments, two ends of the transmitting branch are respectively connected with two ends of the receiving branch; the OBU device further comprises a second switch module for switching the transmission of signals on one path between the transmitting branch and the receiving branch, and the second switch module is connected with the main control module.
[0007] In some embodiments, the first switch module comprises a first switch unit, a PIN tube D1, a PIN tube D2 and an isolation unit; a control end of the first switch unit is connected with a first control pin of the main control module, an input end of the first switch unit is connected with a power input, an output end of the first switch unit is connected with a positive pole of the PIN tube D1, the positive pole of the PIN tube D1 is connected with a converging end of the transmitting and receiving branch connected with the antenna module, a negative pole of the PIN tube D1 is connected with the antenna module, one end of the isolation unit is connected between the negative pole of the PIN tube D1 and the antenna module, and the other end of the isolation unit is connected with the wake-up branch; a positive pole of the PIN tube D2 is connected with one end of the isolation unit connected with the wake-up branch, and a negative pole of the PIN tube D2 is grounded.
[0008] In some embodiments, the isolation unit comprises a quarter-wavelength microstrip line.
[0009] In some embodiments, the second switch module comprises a single-pole double-throw switch chip.
[0010] The switch chip comprises a main path end, a first sub-path end and a second sub-path end; the main path end is connected with a transceiving pin of the main control module, the first sub-path end is connected with the transmitting branch, and the second sub-path end is connected with the receiving branch; the switch chip further comprises a first control end and a second control end for controlling the signal flow direction of the end pins, the first control end is connected with a second control pin of the main control module, and the second control end is connected with a third control pin of the main control module.
[0011] In some embodiments, an external detection module for demodulating a wake-up signal from a radio frequency signal is arranged on the wake-up branch; the external detection module comprises a detection diode D3, a resistive unit and a second filter unit; a positive pole of the detection diode D3 is connected between a signal input end of the external detection module and a signal output end of the external detection module, a negative pole of the detection diode D3 is grounded, and a power supply end of the external detection module is connected to the positive pole of the detection diode D3 through the resistive unit; the second filter unit is connected between at least one pair of combinations of the signal input end of the external detection module and the detection diode D3, the signal output end of the external detection module and the detection diode D3, and the power supply end of the external detection module and the resistive unit.
[0012] In some embodiments, the LNA module comprises an amplifier, a voltage dividing unit and a first filter unit; a signal input end of the LNA module is connected to an input end of the amplifier, a signal output end of the LNA module is connected to an output end of the amplifier, a power supply end of the LNA module is connected to the voltage dividing unit, and the voltage dividing unit is provided with two output paths, one of which is connected to the input end of the amplifier and the other of which is connected to the output end of the amplifier; the first filter unit is connected between at least one pair of combinations among the signal input end of the LNA module and the input end of the amplifier, the signal output end of the LNA module and the output end of the amplifier, the input end of the amplifier and the voltage dividing unit, and the output end of the amplifier and the voltage dividing unit.
[0013] In some embodiments, the OBU device comprises a radio frequency front-end chip connected between the second switch module and the first switch module, and the radio frequency front-end chip is integrated with the power amplification circuit and a low-noise amplification circuit; the radio frequency front-end chip comprises a transceiving end, a transmitting end and a receiving end, the transmitting end and the receiving end of the radio frequency front-end chip are commonly connected to a transceiving pin of the main control module through the second switch module, and the transceiving end of the radio frequency front-end chip is connected to the first switch module; the radio frequency front-end chip further comprises a first signal input end and a second signal input end for controlling the signal flow direction of the end pins, the first signal input end is connected to a second control pin of the main control module, and the second signal input end of the radio frequency front-end chip is connected to a third control pin of the main control module.
[0014] In some embodiments, the OBU device further comprises a bypass switch circuit connected to the low-noise amplification circuit, so as to switch the transmission path of the radio frequency signal between the low-noise amplification circuit and the bypass switch circuit; the bypass switch circuit comprises a second switch unit, an input end of the second switch unit is connected to an input end of the low-noise amplification circuit, an output end of the second switch unit is connected to an output end of the low-noise amplification circuit, and a control end of the second switch unit is connected to the main control module.
[0015] In some embodiments, the OBU device further comprises a band-pass filter module connected between the antenna module and the first switch module.
[0016] The OBU device has the following beneficial effects: the OBU device increases the LNA module on the wake-up branch, increases the power amplification circuit on the transmitting branch and increases the low-noise amplification circuit on the receiving circuit, amplifies and compensates the part of the radio frequency signal that is attenuated, and thus solves the problem of poor communication effect of the OBU device in a use scenario that causes large signal attenuation. BRIEF DESCRIPTION OF DRAWINGS
[0017] The utility model will be further described below in combination with the drawings and examples, in the drawings:
[0018] Figure 1 It is the logic block diagram of the internal constitution of OBU equipment in some embodiments of the utility model;
[0019] Figure 2 It is the logic block diagram of the internal constitution of OBU equipment in some other embodiments of the utility model;
[0020] Figure 3 It is the circuit schematic diagram of LNA module in some embodiments of the utility model;
[0021] Figure 4 It is the circuit schematic diagram of external detection module in some embodiments of the utility model;
[0022] Figure 5 It is the circuit schematic diagram of the third switch unit control LNA module and / or external detection module power supply in some embodiments of the utility model;
[0023] Figure 6 It is the circuit schematic diagram of the first switch module in some embodiments of the utility model;
[0024] Figure 7 It is the circuit schematic diagram of the radio frequency front-end chip of integrated power amplification circuit and low noise amplifier circuit in some embodiments of the utility model;
[0025] Figure 8 It is the circuit schematic diagram of the second switch module in some embodiments of the utility model;
[0026] Figure 9 It is the circuit schematic diagram of band-pass filter module in some embodiments of the utility model;
[0027] Figure 10 It is Figure 2 The working logic block diagram of OBU equipment shown in the figure.
[0028] Reference signs:
[0029] The main control module 1; the antenna module 2; the wake-up branch 3; the LNA module 31; the amplifier 311; the voltage division unit 312; the first filter unit 313; the external detection module 32; the resistive unit 321; the second filter unit 322; the third switch unit 33; the transmitting branch 4; the power amplifier circuit 41; the receiving branch 5; the low-noise amplifier circuit 51; the bypass switch circuit 52; the second switch unit 521; the radio frequency front-end chip 6; the first switch module 7; the first switch unit 71; the isolation unit 72; the second switch module 8; the switch chip 81; the band-pass filter module 9; the band-pass filter 91; the third filter unit 92. DETAILED DESCRIPTION
[0030] In order to have a clearer understanding of the technical features, objectives and effects of the present application, the specific embodiments of the present application will be described in detail with reference to the drawings. In the following description, it should be understood that the directions or positional relationships indicated by "front", "back", "upper", "lower", "left", "right", "vertical", "horizontal", "vertical", "horizontal", "top", "bottom", "inner", "outer", "head", "tail" and the like are based on the directions or positional relationships shown in the drawings, constructed and operated in a particular direction, and are only for the convenience of describing the present technical solution, and cannot be understood as indicating that the devices or elements indicated must have a particular direction, therefore, it cannot be understood as a limitation on the present application.
[0031] It should also be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing", "setting" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements or the interaction relationship between two elements. When an element is referred to as "on" or "below" another element, the element can be "directly" or "indirectly" located on the other element, or there can be one or more intervening elements. The terms "first", "second", "third" and the like are only for the convenience of describing the present technical solution, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features, therefore, the features with "first", "second", "third" and the like can be explicitly or implicitly included one or more of the features. For ordinary skilled persons in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0032] In the following description, for the purpose of explanation and not limitation, specific details are set forth, such as particular system configurations, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to those skilled in the art that the present application can be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
[0033] In view of the poor communication effect of the OBU device in the use scene that causes large signal attenuation, the present application constructs an OBU device, which can be referred to Figure 1 The OBU device mainly comprises a main control module 1 and an antenna module 2 connected with the main control module 1, and the main control module 1 communicates with external devices through the antenna module 2. As an improvement, as shown in Figure 1 The OBU device further comprises a wake-up branch 3, a transmitting branch 4 and a receiving branch 5 connected between the main control module 1 and the antenna module 2, and a first switch module 7 for switching the transmission of the radio frequency signal on one of the transceiving branch containing the transmitting branch 4 and the receiving branch 5 and the wake-up branch 3.
[0034] Among them, the wake-up branch 3 is used for transmitting the wake-up signal entering from the antenna module 2 to the main control module 1, and an LNA module 31 is arranged on the wake-up branch 3 to access the radio frequency signal containing the wake-up signal, and the LNA module 31 can amplify the radio frequency signal and reduce the introduction of noise; the transmitting branch 4 is used for transmitting the transmitting signal generated by the main control module 1 to the antenna module 2, and a power amplifier circuit 41 is arranged on the transmitting branch 4 to amplify and compensate the transmitting signal; the receiving branch 5 is used for transmitting the feedback signal entering from the antenna module 2 to the main control module 1, and a low noise amplifier circuit 51 is arranged on the receiving branch 5 to amplify the feedback signal and reduce the introduction of noise.
[0035] The first switch module 7 is connected with the main control module 1 to control the transmission path controlled by the main control module 1.
[0036] The main control module 1 can be configured to include a sleep state and an active state, in the sleep state, the main control module 1 controls the first switch module 7 to keep the wake-up branch 3 open, and the radio frequency signal with the wake-up signal can be transmitted on the wake-up branch 3, then, when the main control module 1 receives the wake-up signal, the main control module 1 switches from the sleep state to the active state, and controls the first switch module 7 to switch the transmission path of the radio frequency signal, so that the radio frequency signal is transmitted on the transceiving branch including the transmitting branch 4 and the receiving branch 5. The active state of the main control module 1 further includes a transmitting state and a receiving state, in the active state, the main control module 1 can transmit the transmitting signal generated by the main control module 1 to the antenna module 2 through the transmitting branch 4, and transmit the feedback signal from the antenna module 2 to the main control module 1 through the receiving branch 5.
[0037] It can be understood that the use scenario that causes large signal attenuation can be that the OBU device is installed on a material that causes large signal attenuation, such as a front windshield with a silver-plated metal film, or that there is an object that shields / shields signals around the vehicle, and the like, which are not limited herein.
[0038] The OBU device in the utility model, by increasing the LNA module 31 on the wake-up branch 3, increasing the power amplification circuit 41 on the transmitting branch 4 and increasing the low-noise amplification circuit 51 on the receiving branch 5, amplifies and compensates the part of the radio frequency signal that is attenuated, thereby solving the problem that the communication effect of the OBU device is poor in the use scenario that causes large signal attenuation. At the same time, as a low-power device, the OBU device, the multiple added amplification circuits cause the device power consumption to become large, especially the power amplification circuit 41, which in turn shortens the service life of the device; therefore, by designing the wake-up branch 3, the working time of the transceiving branch is minimized under the condition of ensuring normal transmitting and receiving work, so as to reduce the influence of the multiple added amplification circuits, so as to realize the processing of low power consumption.
[0039] In some embodiments, since the two ends of the transmitting branch 4 are connected to the two ends of the receiving branch 5 respectively, that is, the respective corresponding one end of the transmitting branch 4 and the receiving branch 5 can be commonly connected to a transceiving pin of the main control module 1, and the respective corresponding other end of the two can be commonly connected to the antenna module 2; based on this, the OBU device can further include a second switch module 8 for switching the transmission of the radio frequency signal on one of the transmitting branch 4 and the receiving branch 5. Figure 2 The second switch module 8 is connected with the main control module 1 and is controlled by the main control module 1. The main control module 1 can control the second switch module 8 to switch the transmitting branch 4 and the receiving branch 5 to send the transmitting signal and receive the feedback signal.
[0040] Of course, the transmitting branch 4 and the receiving branch 5 can also be two completely independent paths, the transmitting signal and the feedback signal can be respectively received and transmitted through two different pins of the main control module 1, and the switching between the wake-up branch 3, the transmitting branch 4 and the receiving branch 5 is controlled by the first switch module 7, at this time, the second switch module 8 can not be set.
[0041] With reference to the accompanying drawings Figure 2 , first, looking at the circuit modules on the wake-up branch 3, in some embodiments, an external detection module 32 can also be provided on the wake-up branch 3. The external detection module 32 is connected with the LNA module 31 to demodulate the amplified radio frequency signal to obtain a wake-up signal; and the external detection module 32 is connected with the signal input end of the main control module 1 to transmit the wake-up signal to the main control module 1. The main control module 1 can switch from the dormant state to the active state after obtaining the wake-up signal.
[0042] Secondly, optionally, the wake-up branch 3 can be configured to be periodically started to achieve the purpose of further reducing power consumption. For example, the working power supply of the circuit modules on the wake-up branch 3 can be periodically turned on and off to achieve the purpose of periodic starting of the wake-up branch 3.
[0043] Further, please refer to the accompanying drawings Figure 3 , the LNA module 31 can include an amplifier 311, a voltage dividing unit 312 and a plurality of first filter units 313. Among them, the signal input end of the LNA module 31 is connected with the input end of the amplifier 311, and the signal output end of the LNA is connected with the output end of the amplifier 311. The power supply end of the LNA module 31 is connected with the voltage dividing unit 312, and the voltage dividing unit 312 is provided with two output paths, one of which is connected with the input end of the amplifier 311, and the other of which is connected with the output end of the amplifier 311. In this embodiment, please refer to Figure 3 , the signal input end of the LNA module 31 can refer to the WKIN end, the signal output end of the LNA can refer to the WKOUT end, and the power supply end of the LNA module 31 can refer to the VDD_LNA end; the input end of the amplifier 311 is the B pin of the amplifier 311, and the output end of the amplifier 311 is the C pin of the amplifier 311.
[0044] As shown in Figure 3 , the plurality of first filter units 313 can be connected between the signal input end of the LNA module 31 and the input end of the amplifier 311, between the signal output end of the LNA module 31 and the output end of the amplifier 311, between the voltage dividing unit 312 and the input end of the amplifier 311, and between the voltage dividing unit 312 and the output end of the amplifier 311.
[0045] Understandably, amplifier 311 is used to amplify radio frequency signals. Multiple first filter units 313 are used to filter out unwanted noise, including noise from the radio frequency signal and power supply, to minimize noise introduction and avoid affecting subsequent signal demodulation. Therefore, this LNA module 31 has amplification capabilities and low noise characteristics. Furthermore, the amplifier 311 of this LNA module 31 can be a low-noise amplifying transistor. Since the power consumption of this amplifying transistor can be autonomously adjusted through configuration parameters, the LNA module 31 also has low power consumption characteristics. Secondly, any first filter unit 313 can include at least one capacitor and at least one inductor, which can be connected in series or in parallel.
[0046] For example, such as Figure 3 As shown, the first filter unit 313 between the signal input terminal of the LNA module 31 and the input terminal of the amplifier 311 includes capacitors C60 and C61 and inductor L15. Capacitors C60 and C61 are connected in series between the signal input terminal of the LNA module 31 and the input terminal of the amplifier 311, and inductor L15 is connected in parallel between capacitors C60 and C61 and is grounded. The first filter unit 313 between the voltage divider unit 312 and the output terminal of the amplifier 311 includes capacitor C54 and inductor L11. Inductor L11 is connected in series between the voltage divider unit 312 and the output terminal of the amplifier 311, and capacitor C54 is connected in parallel between inductor L11 and the voltage divider unit 312 and is grounded.
[0047] It can be added here that, in such Figure 3 In the LNA module 31 shown, several first filter units 313 are enumerated and selected by bounding boxes. However, this does not mean that the LNA module 31 only includes the first filter units 313 marked with reference numerals in the figure. There should also be several other first filter units 313 that are not selected by bounding boxes. The same operation is applied to filter units in other circuit diagrams below, and this will be explained uniformly here.
[0048] Continue reading for more information. Figure 4 The external detector module 32 may include a signal input terminal and a signal output terminal. The signal input terminal of the external detector module 32 is used to connect to the LNA module 31, and the signal output terminal of the external detector module 32 is connected to the pin of the main control module 1 for receiving the wake-up signal.
[0049] like Figure 4As shown, the external detection module 32 may further include a detection diode D3, a resistive unit 321, and multiple second filter units 322. The positive terminal of the detection diode D3 is connected between the signal input terminal and the signal output terminal of the external detection module 32, and the negative terminal of the detection diode D3 is grounded. The power supply terminal of the external detection module 32 is connected to the positive terminal of the detection diode D3 via the resistive unit 321. In this embodiment, refer to... Figure 4 The signal input terminal of the external detector module 32 can be referenced to the WKOUT terminal, the signal output terminal of the external detector module 32 can be referenced to the WAKE_14K terminal, and the power supply terminal of the external detector module 32 can be referenced to the VDD_LNA terminal.
[0050] Multiple second filter units 322 can be connected between the signal input terminal of the external detector module 32 and the detector diode D3, between the signal output terminal of the external detector module 32 and the detector diode D3, and between the power supply terminal of the external detector module 32 and the resistive unit 321.
[0051] Understandably, the detector diode D3 is used to extract the wake-up signal from the radio frequency signal. Multiple second filter units 322 are used to filter out unwanted noise. The resistive unit 321 is used to adjust the conduction current of the detector diode, so adjusting the resistance value of the resistive unit 321 can reduce the power consumption of the external detector module 32. Therefore, by appropriately increasing the resistance value of the resistive unit 321, this external detector module 32 can achieve low power consumption.
[0052] Secondly, any second filter unit 322 may include at least one capacitor and at least one inductor, which may be connected in series between the two ends or in parallel.
[0053] For example, such as Figure 4 As shown, the second filter unit 322 between the signal output terminal of the external detector module 32 and the detector diode D3 includes capacitors C56, C57, C62 and inductor L12. Capacitors C56 and C57 are between the signal output terminal of the external detector module 32 and the detector diode D3. Inductor L12 is connected in series between capacitors C56 and C57. Capacitor C62 is connected in parallel between capacitors C56 and inductor L12 and is grounded.
[0054] See again Figure 5 A third switch unit 33 can also be set on the wake-up branch 3. The third switch unit 33 is set between the power supply and the power supply terminal of the external detector module 32 and / or the power supply terminal of the LNA module 31 to control the connection and disconnection between the power supply and the power supply terminal of the external detector module 32 and / or the power supply terminal of the LNA module 31, so as to cut off the power supply to the wake-up branch 3 after the main control module 1 is woken up, so as to reduce power consumption.
[0055] like Figure 5 As shown, the control terminal of the third switch unit 33 is connected to the fourth control pin of the main control module 1, the input terminal of the third switch unit 33 is connected to the power supply, and the output terminal of the third switch unit 33 is connected to the power supply terminal of the external detector module 32 and / or the power supply terminal of the LNA module 31. Understandably, after the main control module 1 is woken up, the main control module 1 can output a control signal to the control terminal of the third switch unit 33, thereby disconnecting the circuit between the power supply and the power supply terminals of the external detector module 32 and / or the LNA module 31. In this embodiment, as... Figure 5 As shown, the power supply can be referenced to the BAT terminal; the power supply terminal of the external detector module 32 is shared with the power supply terminal of the LNA module 31, and can be referenced to the VDD_LNA terminal; the fourth control pin of the main control module 1 can be referenced to the CE_RF terminal.
[0056] Please refer to the following: Figure 6 , Figure 6 The configuration of the first switch module 7 in some embodiments is shown. The first switch module 7 may include a first switch unit 71, PIN diode D1, PIN diode D2, and an isolation unit 72. The control terminal of the first switch unit 71 is connected to the first control pin of the main control module 1, the input terminal of the first switch unit 71 is connected to the power input, and the output terminal of the first switch unit 71 is connected to the positive terminal of PIN diode D1. PIN diode D1 is connected between the junction of the transceiver branch and the antenna module 2, wherein the positive terminal of PIN diode D1 is connected to the junction of the transceiver branch and the antenna module 2, and the negative terminal of PIN diode D1 is connected to the antenna module 2. One end of the isolation unit 72 is connected between the negative terminal of PIN diode D1 and the antenna module 2, and the other end of the isolation unit 72 is connected to the wake-up branch 3. PIN diode D2 is connected between the isolation unit 72 and the wake-up branch 3, wherein the positive terminal of PIN diode D2 is connected to one end of the isolation unit 72 connected to the wake-up branch 3, and the negative terminal of PIN diode D2 is grounded. In this embodiment, reference can be made to... Figure 6 The junction of the transceiver branch and the antenna module 2 can be referenced to the TRX1 terminal. The end of the antenna module 2 used for signal transmission can be referenced to the ANT terminal. The power input connected to the input terminal of the first switch unit 71 can be referenced to the BAT terminal. The first control pin of the main control module 1 can be referenced to the TRX_EN terminal.
[0057] It can be understood that the first switch unit 71 controls the circuit between the power supply end of the first switch module 7 and the PIN tube D1 according to the control signal of the main control module 1, and the flow direction of the control signal in combination with the isolation unit 72. The isolation unit 72 is used to isolate the transmission of the transmission signal of the transmission branch 4 to the wake-up branch 3. Because the two ends of the transmission branch 4 are respectively connected to the two ends of the receiving branch 5, the converging end of the transceiver branch can be understood as the common connection end of the transmission branch 4 and the receiving branch 5, and the converging end of the transceiver branch connected to the antenna module 2 is the common connection end of the transmission branch 4 and the receiving branch 5 for connecting the antenna module 2.
[0058] For example, as shown in Figure 6 , the first switch unit 71 can be a p-channel JFET tube. When the main control module 1 is in sleep state, its first control pin can output high level, so that the first switch unit 71 is turned off, and the PIN tube D1 and the PIN tube D2 are turned off. At this time, the signal from the antenna module 2 is transmitted to the wake-up branch 3 through the isolation unit 72. When the main control module 1 is woken up, its first control pin can output low level, so that the first switch unit 71 is turned on, and the PIN tube D1 and the PIN tube D2 are turned on. The transmission signal is successfully transmitted to the antenna module 2. In this process, the isolation unit 72 blocks the transmission of the transmission signal to the wake-up branch 3. Subsequently, after the antenna module 2 receives the feedback signal, because the PIN tube D1 is turned on, the feedback signal can pass through the PIN tube D1 and be transmitted to the TRX1 end. It can be understood that because the wake-up branch 3 needs to be in a long-time open state to ensure that the wake-up signal can be received at any time, the first switch module 7 is designed with the PIN tube D1, which can ensure that the first switch module 7 has no power loss during the long-time opening of the wake-up branch 3.
[0059] In addition, the isolation unit 72 can also be a quarter-wavelength microstrip line.
[0060] Please see the circuit module on the transceiver branch. In some embodiments, please refer to Figure 7 , the OBU device can include a radio frequency front-end chip 6 connected between the second switch module 8 and the first switch module 7, and the radio frequency front-end chip 6 is integrated with a power amplification circuit 41 and a low-noise amplification circuit 51.
[0061] The radio frequency front-end chip 6 includes a transceiver end, a transmission end and a receiving end. The transmission end and the receiving end of the radio frequency front-end chip 6 are commonly connected to the transceiver pin of the main control module 1 through the second switch module 8, and the transceiver end of the radio frequency front-end chip 6 can be understood as the converging end of the transceiver branch connected to the antenna module 2, which is connected to the first switch module 7. In this embodiment, as shown in Figure 7 , the transceiver end of the radio frequency front-end chip 6 is its ANT pin, the transmission end of the radio frequency front-end chip 6 is its TX pin, and the receiving end of the radio frequency front-end chip 6 is its RX pin.
[0062] Meanwhile, the RF front-end chip 6 further comprises a first signal input end and a second signal input end. The first signal input end of the RF front-end chip 6 is connected to the second control pin of the main control module 1, and the second signal input end of the RF front-end chip 6 is connected to the third control pin of the main control module 1. It can be understood that the main control module 1 controls the flow direction of the RF signal of the RF front-end chip 6 by controlling the high and low levels of the first signal input end and the second signal input end of the RF front-end chip 6. In the embodiment, as shown in Figure 7 , the first signal input end of the RF front-end chip 6 is the PA_EN pin thereof, the second signal input end of the RF front-end chip 6 is the RX_EN pin thereof, the second control pin of the main control module 1 can refer to the ZPA_EN end, and the third control pin of the main control module 1 can refer to the ZRX_EN end.
[0063] For example, when the level of the first signal input end of the RF front-end chip 6 is high and the level of the second signal input end of the RF front-end chip 6 is low, the signal can be transmitted from the transmitting end to the transceiving end of the RF front-end chip 6, and in the transmission process, the signal flows through the power amplification circuit 41. Conversely, when the level of the first signal input end of the RF front-end chip 6 is low and the level of the second signal input end of the RF front-end chip 6 is high, the signal can be transmitted from the transceiving end to the receiving end of the RF front-end chip 6, and in the transmission process, the signal flows through the low-noise amplification circuit 51.
[0064] In addition, optionally, as shown in Figure 2 , the OBU device can further comprise a bypass switch circuit 52 connected to the low-noise amplification circuit 51, for controlling the RF signal to flow through the low-noise amplification circuit 51 or the bypass switch circuit 52.
[0065] As shown in Figure 2 , the bypass switch circuit 52 can comprise a second switch unit 521, the second switch unit 521 comprising an input end, an output end and a control end, wherein the input end of the second switch unit 521 is connected to the input end of the low-noise amplification circuit 51, the output end of the second switch unit 521 is connected to the output end of the low-noise amplification circuit 51, and the control end of the second switch unit 521 can be connected to the control pin of the main control module 1.
[0066] In some embodiments, the bypass switch circuit 52 can be integrated in the RF front-end chip 6, as shown in Figure 7 , the control end of the second switch unit 521 can refer to the LNA_EN pin of the RF front-end chip 6 and be connected to the second control pin of the main control module 1.
[0067] Continuing to refer to Figure 8 , Figure 8The second switch module 8 is shown in some embodiments. The second switch module 8 can include a single-pole double-throw switch chip 81. The switch chip 81 includes a main path end, a first branch path end and a second branch path end. The main path end is connected to the transceiver pin of the main control module 1, the first branch path end is connected to the transmitting end of the RF front-end chip 6, and the second branch path end is connected to the receiving end of the RF front-end chip 6. In this embodiment, as shown in Figure 8 , the main path end of the switch chip 81 is its RF pin, the first branch path end of the switch chip 81 is its RF1 pin, and the second branch path end of the switch chip 81 is its RF2 pin. The transceiver pin of the main control module 1 can refer to the RTX end.
[0068] At the same time, the switch chip 81 also includes a first control end and a second control end. The first control end of the switch chip 81 is connected to the second control pin of the main control module 1, and the second control end of the switch chip 81 is connected to the third control pin of the main control module 1. It can be understood that the main control module 1 controls the signal flow direction of the switch chip 81 by controlling the high and low levels of the first control end and the second control end of the switch chip 81. In this embodiment, as shown in Figure 8 , the first control end of the switch chip 81 is its VC1 pin, and the second control end of the switch chip 81 is its VC2 pin.
[0069] In some embodiments, when the level of the first signal input end of the switch chip 81 is high and the level of the second signal input end of the switch chip 81 is low, the signal can be transmitted from the main path end of the switch chip 81 to the first branch path end. Conversely, when the level of the first signal input end of the switch chip 81 is low and the level of the second signal input end of the switch chip 81 is high, the signal can be transmitted from the second branch path end of the switch chip 81 to the main path end.
[0070] Also, as can be seen from Figure 2 , the OBU device can also include a band-pass filter module 9 for suppressing out-of-band signals to avoid introducing interference signals and causing false wake-up problems. At the same time, the band-pass filter module 9 also has the function of suppressing the transmitting signal harmonics amplified by the power amplification circuit 41 and the transmitting signal harmonic components generated by the nonlinearity of the power amplification circuit 41. The band-pass filter module 9 can be connected between the antenna module 2 and the first switch module 7.
[0071] In some embodiments, as can be seen from Figure 9The band-pass filter module 9 can include a band-pass filter 91 and a plurality of third filter units 92. The first signal end of the band-pass filter 91 is connected to the antenna module 2, and the second signal end of the band-pass filter 91 is connected to the positive electrode of the PIN tube D1 of the first switch module 7. The plurality of third filter units 92 are respectively connected between the first signal end of the band-pass filter 91 and the antenna module 2 and between the second signal end of the band-pass filter 91 and the first switch module 7.
[0072] Any third filter unit 92 can include at least one capacitor and / or at least one inductor, which can be connected in series between two ends or connected in parallel to ground.
[0073] In summary, the wake-up branch 3, the transmitting branch 4 and the receiving branch 5 in the OBU device are in a time-sharing working mode. In the case of no signal interaction, the main control module 1 is in a dormant state, and the wake-up branch is opened. The branch opening can be understood as that the circuit modules thereon are in a working state. When the antenna module 2 receives a wake-up signal and transmits the wake-up signal to the main control module 1 through the wake-up branch 3, the main control module 1 is woken up, at this time, the wake-up branch is closed, the transmitting and receiving branch is opened, the main control module 1 generates a transmitting signal, and transmits the transmitting signal to the antenna module 2 through the transmitting branch 4 to send outward; subsequently, after the antenna module 2 receives a feedback signal, the feedback signal is transmitted to the main control module 1 through the receiving branch 5 for processing; after the processing is completed, the main control module 1 can be switched to the dormant state, and the wake-up branch is re-opened. The specific working logic of the OBU device can be referred to Figure 10 , which will not be repeated here.
[0074] The improved OBU device can greatly improve the use effect of the OBU device on the metal film glass with high signal attenuation, improve the transaction distance and the success rate of transaction, and improve the user experience. At the same time, through low-power processing, the influence of the circuit modules on the transmitting and receiving branch on the service life of the OBU device is minimized, thereby reducing the repair and return rate of the OBU device, and also reducing the human, financial and other costs caused thereby, increasing the competitiveness of the device in the market, and having a good promoting effect on the development of the new energy automobile market.
[0075] It can be understood that the above embodiments only express the preferred embodiments of the utility model, and the description is more specific and detailed, but it cannot be understood as a limitation on the patent scope of the utility model; it should be pointed out that for ordinary skilled persons in the art, the above technical features can be freely combined without departing from the concept of the utility model, and some deformations and improvements can be made, which all belong to the protection scope of the utility model; therefore, any equivalent transformation and modification within the scope of the claims of the utility model shall belong to the scope of the claims of the utility model.
Claims
1. An OBU device, comprising a main control module (1) and an antenna module (2) connected with the main control module (1), the main control module (1) communicates with external devices through the antenna module (2), characterized in that the main control module (1) comprises a sleep state and an active state; the OBU device further comprises: a wake-up branch (3), a transmitting branch (4) and a receiving branch (5) connected between the main control module (1) and the antenna module (2); the wake-up branch (3) is used for transmitting a wake-up signal from the antenna module (2) to the main control module (1) to wake up the main control module (1), and an LNA module (31) is arranged on the wake-up branch (3); the transmitting branch (4) is used for transmitting a transmitting signal generated by the main control module (1) to the antenna module (2), and a power amplifier circuit (41) is arranged on the transmitting branch (4); the receiving branch (5) is used for transmitting a feedback signal from the antenna module (2) to the main control module (1), and a low-noise amplifier circuit (51) is arranged on the receiving branch (5); the OBU device further comprises a first switch module (7) used for switching a path of a radio frequency signal, the first switch module (7) is connected with the wake-up branch (3), the transmitting branch (4) and the receiving branch (5) to make the radio frequency signal transmitted on the wake-up branch (3) in the sleep state and make the radio frequency signal transmitted on a transceiving branch comprising the transmitting branch (4) and the receiving branch (5) in the active state. Both ends of the transmitting branch (4) are connected with both ends of the receiving branch (5) in common; The OBU device further comprises a second switch module (8) used for switching a signal to be transmitted on one of the transmitting branch (4) and the receiving branch (5), and the second switch module (8) is connected with the main control module (1). The first switch module (7) comprises a first switch unit (71), a PIN tube D1, a PIN tube D2 and an isolation unit (72); A control end of the first switch unit (71) is connected with a first control pin of the main control module (1), an input end of the first switch unit (71) is connected with a power input, an output end of the first switch unit (71) is connected with a positive electrode of the PIN tube D1, the positive electrode of the PIN tube D1 is connected with a converging end of the transceiving branch connected with the antenna module (2), a negative electrode of the PIN tube D1 is connected with the antenna module (2), one end of the isolation unit (72) is connected between the negative electrode of the PIN tube D1 and the antenna module (2), and the other end of the isolation unit (72) is connected with the wake-up branch (3); a positive electrode of the PIN tube D2 is connected with one end of the isolation unit (72) connected with the wake-up branch (3), and a negative electrode of the PIN tube D2 is grounded. The isolation unit (72) comprises a quarter-wavelength microstrip line. The second switch module (8) comprises a single-pole double-throw switch chip (81). 2. The OBU device of claim 1, wherein, 3. The OBU device of claim 2, wherein, 4. The OBU device of claim 3, wherein, 5. The OBU device of claim 2, wherein, The switch chip (81) comprises a main path end, a first sub-path end and a second sub-path end; the main path end is connected with a transceiving pin of the main control module (1), the first sub-path end is connected with the transmitting branch (4), and the second sub-path end is connected with the receiving branch (5); The switch chip (81) further comprises a first control end and a second control end for controlling the signal flow direction of the end pin, the first control end is connected with a second control pin of the main control module (1), and the second control end is connected with a third control pin of the main control module (1).
6. The OBU device of any one of claims 1-5, wherein, An external detection module (32) for demodulating a radio frequency signal into a wake-up signal is arranged on the wake-up branch (3). The external detection module (32) comprises a detection diode D3, a resistive unit (321) and a second filter unit (322); the positive electrode of the detection diode D3 is connected between the signal input end of the external detection module (32) and the signal output end of the external detection module (32), the negative electrode of the detection diode D3 is grounded, and the power supply end of the external detection module (32) is connected to the positive electrode of the detection diode D3 through the resistive unit (321); and the second filter unit (322) is connected between at least one pair of combinations of the signal input end and the detection diode D3 of the external detection module (32), the signal output end and the detection diode D3 of the external detection module (32), and the power supply end and the resistive unit (321) of the external detection module (32).
7. The OBU device of claim 6, wherein, The LNA module (31) comprises an amplifier (311), a voltage dividing unit (312) and a first filter unit (313); the signal input end of the LNA module (31) is connected with the input end of the amplifier (311), the signal output end of the LNA module (31) is connected with the output end of the amplifier (311), the power supply end of the LNA module (31) is connected with the voltage dividing unit (312), and the voltage dividing unit (312) is provided with two output paths, one of which is connected with the input end of the amplifier (311) and the other of which is connected with the output end of the amplifier (311); and the first filter unit (313) is connected between at least one pair of combinations of the signal input end and the input end of the amplifier (311) of the LNA module (31), the signal output end and the output end of the amplifier (311) of the LNA module (31), the input end and the voltage dividing unit (312) of the amplifier (311), and the output end and the voltage dividing unit (312) of the amplifier (311).
8. The OBU device of any one of claims 2-5, wherein, The OBU device comprises a radio frequency front-end chip (6) connected between the second switch module (8) and the first switch module (7), and the radio frequency front-end chip (6) is integrated with the power amplification circuit (41) and the low-noise amplification circuit (51); The radio frequency front-end chip (6) includes a transceiver end, a transmitting end and a receiving end, the transmitting end and the receiving end of the radio frequency front-end chip (6) are commonly connected to a transceiver pin of the main control module (1) through the second switch module (8), and the transceiver end of the radio frequency front-end chip (6) is connected with the first switch module (7); The radio frequency front-end chip (6) further includes a first signal input end and a second signal input end for controlling the signal flow direction of the end pin, the first signal input end is connected to a second control pin of the main control module (1), and the second signal input end of the radio frequency front-end chip (6) is connected to a third control pin of the main control module (1).
9. The OBU device of claim 1, wherein, The OBU device further includes a bypass switch circuit (52) connected with the low-noise amplification circuit (51) to switch the transmission of the radio frequency signal on one path between the low-noise amplification circuit (51) and the bypass switch circuit (52). The bypass switch circuit (52) includes a second switch unit (521), an input end of the second switch unit (521) is connected with an input end of the low-noise amplification circuit (51), an output end of the second switch unit (521) is connected with an output end of the low-noise amplification circuit (51), and a control end of the second switch unit (521) is connected with the main control module (1).
10. The OBU device of claim 1, wherein, The OBU device further includes a band-pass filter module (9) connected between the antenna module (2) and the first switch module (7).