CN114924206A - Antenna detection circuit, vehicle terminal and vehicle - Google Patents

Abstract

The present application relates to the field of vehicle electronic information, in particular to an antenna detection circuit, a vehicle-mounted terminal and an engineering vehicle. This antenna detection circuit includes a system power supply, a voltage divider module, a detection module and a judgment module. The voltage output from the system power supply is divided by the voltage divider module. The voltage relationship is different, so that the judgment module can judge the on-off or short-circuit of the antenna and the type of the antenna according to the voltage of the third terminal of the detection module. Not only the circuit is simple, the cost is low, but also the detection functions are diverse. In addition to short-circuiting and ensuring the safety of the vehicle, the type of the antenna can also be determined, which is convenient for the management and application of the antenna.

Description

Antenna detection circuit, vehicle terminal and vehicle

technical field

The present application relates to the field of vehicle electronic information, in particular to an antenna detection circuit, a vehicle-mounted terminal and a vehicle.

Background technique

At present, the vehicle-mounted terminal of the vehicle is often equipped with an antenna. The antenna enables the vehicle's GPS navigation, positioning and other functions to be used normally. At the same time, the vehicle-mounted terminal should also have an antenna detection function. However, the existing antenna detection circuit has high hardware cost and complex software logic. In addition, the detection function is single, and it is impossible to accurately determine the antenna type while detecting the antenna state. Therefore, a better detection circuit should be sought.

SUMMARY OF THE INVENTION

In view of this, the present application provides an antenna detection circuit, a vehicle-mounted terminal and a vehicle, which solve or improve the high hardware cost, complicated software logic and single detection function of the antenna detection circuit in the prior art, and it is impossible to detect the state of the antenna at the same time. The technical problem of accurately judging the antenna type.

According to a first aspect of the present application, the present application provides an antenna detection circuit, the antenna detection circuit includes: a system power supply; a voltage dividing module, a first end of the voltage dividing module and an output end of the system power supply connection; a detection module, the first end of the detection module is connected with the second end of the voltage divider module, and the second end of the detection module is connected with the antenna; and a judgment module, the input end of the judgment module is connected with the The third end of the detection module is connected; wherein, the judgment module judges the state of the antenna and the type of the antenna according to the voltage of the third end of the detection module; wherein, the state of the antenna includes a short-circuit state, open circuit and normal state.

In a possible implementation manner, the antenna includes a communication antenna, and the communication antenna includes a first radio frequency connector and a second radio frequency connector; wherein the detection module includes: a first inductance, the first inductance The first end of the first resistor is connected to the first radio frequency connector, the second end of the first inductor is connected to the voltage divider module; and a first resistor, the first end of the first resistor is connected to the first The second end of the inductor is connected to the second end of the first resistor, and the second end of the first resistor is connected to the judgment module; wherein, the voltage dividing module includes: a second resistor, the first end of the second resistor is connected to the power supply The output end is connected, the second end of the second resistor is connected to the second end of the first inductor; the third resistor, the first end of the third resistor is grounded, and the second end of the third resistor is connected to The second radio frequency connector is connected.

In a possible implementation manner, the antenna detection circuit further includes: an anti-damage module, a first end of the anti-damage module is connected to a first end of the second resistor, and a second end of the The terminal is connected to the output terminal of the system power supply.

In a possible implementation manner, the antenna includes a GNSS antenna; wherein the detection module includes: a first triode, the third end of the first triode is connected to the judgment module, and the The first end of the first triode is connected to the GNSS antenna; the fourth resistor, the first end of the fourth resistor is connected to the voltage divider module, and the second end of the fourth resistor is connected to the A first end of a triode is connected; and a fifth resistor, the first end of the fifth resistor is connected to the voltage dividing module, the second end of the fifth resistor is connected to the judgment module, the The voltage dividing module is used to divide the power supply voltage output by the output end of the system power supply, so that the first triode works in the saturation region or the amplification region.

In a possible implementation manner, the voltage dividing module includes: a second triode, and both the third end and the second end of the second triode are the same as the second end of the first triode connection; a sixth resistor, the first end of the sixth resistor is grounded, and the second end of the sixth resistor is connected to the third end of the second triode; and a seventh resistor, the seventh resistor The first end of the resistor is connected to the output end of the system power supply, and the second end of the seventh resistor is connected to the first end of the second triode.

In a possible implementation manner, the antenna detection circuit further includes: a short-circuit protection module, a first end of the short-circuit protection module is connected to the output end of the system power supply, and a second end of the short-circuit protection module is connected to the output end of the system power supply. The first end of the voltage divider module is connected, and the third end of the short circuit protection module is connected to the antenna.

In a possible implementation manner, the short-circuit protection module includes: an output acquisition module, one end of the output acquisition module is connected to the antenna; a third triode, the second end of the third triode connected with the second end of the output acquisition module, and the first end of the third triode is grounded; a voltage dividing resistor, the first end of the voltage dividing resistor is connected to the third end of the third triode connection, the second end of the voltage dividing resistor is connected to the output end of the system power supply; and a fourth triode, the first end of the fourth triode is connected to the third end of the voltage dividing resistor , the third end of the fourth triode is connected to the first end of the voltage divider module; wherein, the output acquisition module is used to divide the voltage of the antenna, so that the third triode The transistor is in a saturation region or a cut-off region; the voltage dividing resistor is used to divide the voltage of the system power supply, so that the fourth transistor is turned on or off.

In a possible implementation manner, the output collection module includes: an eighth resistor, a first end of the eighth resistor is connected to the antenna; and a ninth resistor connected in series with the eighth resistor, the The first end of the ninth resistor is connected to the second end of the eighth resistor, and the second end of the ninth resistor is connected to the second end of the third transistor.

In a possible implementation manner, the voltage dividing resistor includes: a tenth resistor; and an eleventh resistor connected in series with the tenth resistor; wherein a first end of the tenth resistor is connected to the tenth resistor. The second end of a resistor is connected to the second end of the tenth resistor, the second end of the tenth resistor is connected to the output end of the system power supply, and the first end of the eleventh resistor is connected to the third end of the third transistor .

According to a second aspect of the present application, the present application provides an in-vehicle terminal. The in-vehicle terminal includes: an antenna; and the antenna detection circuit described in any one of the above.

According to a third aspect of the present application, the present application provides a vehicle, and the vehicle includes: any of the above vehicle-mounted terminals.

The antenna detection circuit provided by this application includes a system power supply, a voltage divider module, a detection module and a judgment module. The voltage output by the system power supply is divided by the voltage divider module, and the output voltage of the detection module is different from the antenna state, Different types of voltage divider relationships are different, so that the judgment module can judge the on-off, short-circuit and antenna type of the antenna according to the voltage of the third terminal of the detection module. In addition to the on-off of the antenna to ensure the safety of the vehicle, the type of the antenna can also be determined, which is convenient for the management and application of the antenna.

Description of drawings

FIG. 1 is a schematic structural diagram of an antenna detection circuit according to an embodiment of the present application.

FIG. 2 is a circuit diagram of a communication antenna detection circuit in an antenna detection circuit according to an embodiment of the present application.

FIG. 3 is a circuit diagram of a GNSS antenna detection circuit in an antenna detection circuit provided by an embodiment of the present application.

FIG. 4 is a circuit diagram of an antenna short-circuit protection circuit in an antenna detection circuit according to an embodiment of the present application.

FIG. 5 is a schematic structural diagram of a vehicle-mounted terminal according to an embodiment of the present application.

Detailed ways

In the description of the present application, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically defined. All directional indications (such as up, down, left, right, front, back, top, bottom...) in the embodiments of the present application are only used to explain the difference between the various components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly. Furthermore, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes unlisted steps or units, or optionally also includes For other steps or units inherent to these processes, methods, products or devices.

Additionally, reference herein to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor a separate or alternative embodiment that is mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

FIG. 1 is a circuit diagram of an antenna detection circuit provided by an embodiment of the present application. As shown in FIG. 1 , this antenna detection circuit specifically includes a system power supply VCC, a voltage dividing module 100 , a detection module 200 and a judgment module 300 . The first end of the voltage dividing module 100 is connected to the output end of the system power supply VCC, and the voltage dividing module 100 divides the voltage output by the output end of the system power supply VCC; The two ends are connected, the second end of the detection module 200 is connected to the antenna 10, and the voltage drop of the detection module 200 is related to the on-off, short-circuit and the type of the antenna 10; The terminal is connected, and the judgment module 300 judges the state of the antenna 10 and the type of the antenna 10 according to the voltage of the third terminal of the detection module 200, wherein the state of the antenna 10 includes a normal state, a short-circuit state and an open-circuit state. Depending on the type of antenna provided by the supplier, the supplier of the antenna can be deduced correspondingly. The antenna detection circuit has low cost, simple circuit and high reliability, and can detect the type of the antenna 10 in addition to detecting the on-off and short-circuit of the antenna 10 , which is convenient for the daily management of the antenna 10 .

The antenna detection circuit provided by the present application includes a system power supply VCC, a voltage divider module 100 , a detection module 200 and a judgment module 300 . The output voltage is different in different states and different types of voltage division relationship of the antenna 10, so that the judgment module 300 can judge the state of the antenna 10 and the type of the antenna 10 according to the voltage of the third terminal of the detection module 200, not only the circuit is simple, the cost is low, At the same time, there are various detection functions. In addition to basically judging whether the antenna 10 is on/off or short-circuited to ensure vehicle safety, the type of the antenna 10 can also be judged, which is convenient for the management and application of the antenna 10 .

It should be understood that, in order to ensure the safe operation of the circuit, the above-mentioned system power VCC is preferably VCC-3V3 type, and the voltage should not be greater than 5V under normal circumstances.

In a possible implementation manner, FIG. 2 shows a circuit diagram of a 4G antenna detection circuit in an antenna detection circuit provided by an embodiment of the present application. As shown in Figure 2, the antenna used by the antenna detection circuit can be a communication antenna, specifically a 2G antenna, a 4G antenna, and a 5G antenna. H1 and the second radio frequency connector H2, the first radio frequency connector H1 is connected to the detection module 200 of the antenna detection circuit, and the second radio frequency connector H2 is connected to the voltage divider module 100 of the antenna detection circuit, so that the antenna detection circuit can be connected to the 4G The access, open circuit and short circuit of the antenna are detected. Based on the above-mentioned 4G antenna, the detection module 200 of the antenna detection circuit further includes a first inductor L1 and a first resistor R1. The first end of the first inductor L1 is connected to the first radio frequency connector H1, and the second end of the first inductor L1 is connected to the output end of the system power supply VCC. The inductor L1 reduces the influence of external interference signals on the RF signal quality of the 4G antenna RF line; the second end of the first resistor R1 is the second end of the detection module 200, and the first end of the first resistor R1 and the first end of the first inductor L1 The second end is connected. The voltage dividing module 100 of the antenna detection circuit includes a second resistor R2 and a third resistor R3. The first end of the second resistor R2 is connected to the output end of the system power supply VCC, the second end of the second resistor R2 is connected to the second end of the first inductor L1; the first end of the third resistor R3 is grounded, and the second end It is connected to the second radio frequency connector H2. Optionally, the second end of the third resistor R3 can also be connected to a DC blocking first capacitor C1. The third resistor R3 and the second resistor R2 can divide the voltage in the detection circuit. effect. The first capacitor C1 may be 470 picofarads, and the determination module 300 of the antenna detection circuit may be an analog-to-digital converter ADC provided by the communication module. In addition, the first end of the second resistor R2 is connected in series with the first transistor D1, and the second end of the second resistor R2 is connected with the second capacitor C2 and the third capacitor C3 in parallel. At the same time, the second capacitor C2 and the third capacitor C3 Both are set to ground, the second capacitor C2 may be 100 nanofarads, and the third capacitor C3 may be 33 picofarads.

When the antenna detection circuit is not connected to the 4G antenna, that is, the first RF connector H1 is suspended, the DC circuit of the first inductor L1 is disconnected, and the voltage of the system power supply VCC directly enters the input terminal of the judgment module 300. At this time, the judgment module 300 displays the detection The voltage of the third terminal of the module 200 is about 3.2V-3.3V; when the antenna detection circuit is connected to the 4G antenna, the first RF connector H1 is connected to the second RF connector H2, and the voltage across the first resistor R1 is the detection module The voltage of the third terminal of 200 is the voltage divided by the third resistor R3, so the voltage value is also related to the size of the third resistor R3 and the output voltage of the system power supply VCC, usually around 1.5V-2.1V, that is When the voltage at the third end of the detection module 200 is within the above range, the determination module 300 can determine that the current 4G antenna is in a connected state; when the 4G antenna is short-circuited, it is equivalent to a short-circuit of the first inductor L1 to ground, and the first resistor The voltage of R1 entering the ADC interface of the analog-to-digital converter is about 0V-0.1V, that is, when the voltage of the third terminal of the detection module 200 is within the above range, it can be determined that the current 4G antenna is in a short-circuit state. This circuit determines whether the current 4G antenna is connected and whether it is short-circuited by detecting the difference in voltage across the first resistor R1 in the module 200 .

At the same time, when the 4G antenna is connected, due to the different sizes of the third resistor R3 configured by different types of 4G antennas, for example, the resistance value of the third resistor R3 of supplier A is 10K ohms, and the analog-to-digital conversion is entered through the first resistor R1. The voltage of the ADC interface of the converter is about 1.5V-1.6V, and the resistance of the third resistor R3 of supplier B is 20K ohms, the voltage entering the ADC interface of the analog-to-digital converter through the first resistor R1 is about 2.0V-2.1 V. In the same way, when the resistance value of the third resistor R3 is known, the voltage at the third end of the detection module 200 can be calculated when the 4G antenna path is obtained, so as to determine the type or supplier of the current 4G antenna, which is convenient for different types of antennas. Different management is more convenient.

Specifically, as shown in FIG. 2, the second end of the first inductor L1 is also connected to the first end of the fourth capacitor C4, and the second end of the fourth capacitor C4 is connected to a twelfth resistor R12. The twelfth resistor R12 can be a 0 ohm resistor, and the 4G antenna detection circuit also includes a backup capacitor C5 and a backup capacitor C6. The second end of the second resistor R2 is also connected to the first end of the seventh capacitor C7, the second end of the seventh capacitor C7 is grounded, and the seventh capacitor C7 may be 100 nanofarads.

Optionally, as shown in FIG. 2 , the antenna detection circuit may further include an anti-damage module 400 , the first end of the anti-damage module 400 is connected to the second end of the first inductor L1 , and the second end of the anti-damage module 400 is connected to the second end of the first inductor L1 . Connected to the output terminal of the system power supply VCC, the use of the anti-damage module 400 can reduce the possibility of reverse voltage damage to the circuit.

Specifically, as shown in FIG. 2 , the damage prevention module 400 may specifically include a first transistor D1 , which uses the characteristics of the transistor to prevent reverse protection of the detection circuit, thereby reducing the probability of an accident occurring in a misconnected circuit.

In a possible implementation manner, FIG. 3 shows a circuit diagram of a GNSS antenna detection circuit in an antenna detection circuit provided by an embodiment of the present application. As shown in FIG. 3 , the antenna applied by the antenna detection circuit can also be a GNSS antenna. When the antenna detection circuit is applied to the detection of the GNSS antenna, the detection module 200 of the circuit may include a first transistor Q1, a fourth resistor R4 and a fifth resistor R5. The model of the above-mentioned first transistor Q1 can be SST3906, the third end of which is the third end of the detection module 200, the first end of which is connected to the GNSS antenna, and the second end of which is connected to the voltage divider module 100, and is connected to the GNSS antenna. An eighth capacitor C8 with one end grounded and a second inductor L2 are also connected to the first end of the first triode Q1; the fourth resistor R4 is connected to the first end of the first triode Q1; the fifth resistor R5 Connected to the third end of the first transistor Q1. At the same time, the voltage dividing module 100 is used to divide the power supply voltage output from the output end of the system power supply VCC, so that the first transistor Q1 works in the saturation region or the amplification region.

When the GNSS antenna is disconnected, the voltage divider module 100 divides the power supply voltage, so that the first transistor Q1 works in the saturation region; when the GNSS antenna is normally connected, the voltage divider module 100 divides the power supply voltage, so that the first transistor Q1 works in the saturation region. A triode Q1 works in the amplifying area; and when the GNSS antenna is short-circuited, the current does not pass through the first triode Q1. It can be seen from the above content that the different connection states of the GNSS antenna and the detection module 200 cause the voltages at both ends of the first transistor Q1 to be different, so the judgment module 300 can judge the current GNSS connection state according to the different voltages at the third end of the detection module 200, Thus, the detection function of the antenna is realized. The determination module 300 may include a thirteenth resistor R13 and an analog-to-digital converter ADC, the first end of the thirteenth resistor R13 is connected to the third end of the first transistor Q1, and the second end of the thirteenth resistor R13 Connect with the analog-to-digital converter ADC. In addition, since different suppliers use different active low-noise amplifier devices, and different active low-noise amplifier devices make the current drawn by the antenna detection circuit different, when the GNSS antenna is normally connected, it can also be determined according to the detection module 200. The type of the currently used GNSS antenna is determined by the voltage value of the third terminal in the interval, which facilitates differentiated management and application of different types of antennas.

Specifically, as shown in FIG. 3 , when the antenna detection circuit is applied to the detection of GNSS antennas, the voltage dividing module 100 of the circuit may further include a second transistor Q2 , a sixth resistor R6 and a seventh resistor R7 . Among them, the optional model of the second transistor Q2 is SST3906, and its third end and its second end are both connected to the second end of the first transistor Q1; the first end of the sixth resistor R6 is grounded, and the sixth resistor The second end of R6 is connected to the third end of the second transistor Q2; the first end of the seventh resistor R7 is connected to the output end of the system power supply VCC, and the first end of the seventh resistor R7 is also connected in parallel with a ninth capacitor C9, the second end of the seventh resistor R7 is connected to the first end of the second transistor Q2.

When the GNSS antenna is not connected, the GNSS antenna port is suspended, and the voltage at the second end of the second transistor Q2 is the voltage drop between the seventh resistor R7 and the diode of the second transistor Q2 (refer to the data to see that the voltage of the transistor with the model SST3906 is The voltage drop between the base and the emitter is 0.64VDC) and the voltage divided by the sixth resistor R6, it can be calculated that the voltage at the second end of the second transistor Q2 is 2.633V, the first transistor Q1 The voltage of the first terminal of the first transistor Q1 is 3.3VDC, and the voltage of the first terminal of the first transistor Q1 to the second terminal is 0.667VDC (that is, the voltage of the first terminal of the first transistor Q1 is 3.3V minus the second transistor. The voltage at the second end of the transistor Q2 is 2.633V), which is greater than the turn-on voltage of the first transistor Q1 by 0.64V. At this time, the first transistor Q1 can be turned on and works in the saturation region. The voltage drop between the first end of the transistor Q1 and the third end is 0V, and the voltage of the third end of the first transistor Q1 is about 3.3V, that is, the voltage of the third end of the detection module 200 is 3.3V. It can be seen from this that when the judgment module 300 obtains that the voltage of the third terminal of the detection module 200 is about 3.3V, such as 3.2V-3.3V, it can be judged that the current GNSS antenna is disconnected.

When the GNSS antenna is short-circuited, the voltage of the GNSS antenna port is 0V, and the voltage of the third terminal of the detection module 200 is also about 0V at this time, that is, when the judgment module 300 obtains that the voltage of the third terminal of the detection module 200 is about 0V, such as 0V When -0.06V, it can be judged that the current GNSS antenna is short-circuited.

When the GNSS antenna is normally connected, the current drawn by the antenna detection circuit from the GNSS antenna circuit is also different due to the different active low noise amplifier devices used by different suppliers and the current of the circuit where the GNSS antenna is located. For example, when the GNSS antenna provided by supplier A is used, the voltage of the GNSS antenna is 3.193V, and the voltage of the first terminal of the first transistor Q1 to the second terminal is 0.56VDC (that is, the voltage of the GNSS antenna is 3.193V minus 3.193V). The voltage at the second end of the second transistor Q2 is 2.633V), which is less than the turn-on voltage of the first transistor Q1. At this time, the first transistor Q1 works in the amplification area. According to the manual, the first transistor Q1 The impedance of the first end of the transistor Q1 to its third end is 7.8K ohms, and the voltage of the second end of the first transistor Q1 is about 1.2V at this time. It can be seen from this that when the judging module 300 obtains that the voltage of the third terminal of the detection module 200 is about 1.2V, it can be judged that the current GNSS antenna is in a normal connection state, and the GNSS antenna type used in this circuit is the GNSS provided by supplier A. antenna.

For another example, when the GNSS antenna provided by supplier B is used, the voltage of the GNSS antenna is 3.177V, and the voltage of the first terminal of the first transistor Q1 to the second terminal is 0.56VDC (that is, the voltage of the GNSS antenna is 3.177V minus 3.177V). The voltage to the second end of the second transistor Q2 is 2.633V), which is less than the turn-on voltage of the first transistor Q1. The first transistor Q1 works in the amplification area. According to the manual, the voltage of the first transistor Q1 is The impedance of the first end to the third end is 10K ohm, and the voltage of the second end of the first transistor Q1 is about 1.02V at this time. It can be seen from this that when the judging module 300 obtains that the voltage of the third terminal of the detection module 200 is about 1.02V, it can be judged that the current GNSS antenna is in a normal connection state, and the GNSS antenna type used in this circuit is the GNSS provided by supplier B. antenna.

Similarly to the above judgment process, different types of GNSS antennas can obtain corresponding preset voltage values by pre-calculating the voltage, so as to determine whether the GNSS antenna is connected and short-circuited according to the different voltages of the third end of the detection module 200, and the antenna type. , not only the judgment result is intuitive and accurate, but also the component cost is low.

Optionally, FIG. 4 shows a circuit diagram of a short circuit protection circuit in an antenna detection circuit provided by an embodiment of the present application. As shown in FIGS. 3 and 4 , the antenna detection circuit may further include a short-circuit protection module 500 for circuit protection, wherein the short-circuit protection module is applicable to circuits including communication antennas and GNSS antennas, and the GNSS antennas are hereinafter referred to as example to illustrate. The second end of the short-circuit protection module 500 is connected to the second end of the voltage divider module 100 , and the third end of the short-circuit protection module 500 is connected to the GNSS antenna. The short-circuit protection module 500 is used for circuit protection when the GNSS antenna is short-circuited, so as to protect the power supply and improve the safety of the circuit.

In a possible implementation manner, as shown in FIG. 4 , the short-circuit protection module 500 further includes an output acquisition module 510 , a third transistor Q3 , a voltage dividing resistor 520 and a fourth transistor Q4 . One end of the output acquisition module 510 is connected to the GNSS antenna, and the output acquisition module 510 is used to divide the voltage of the GNSS antenna so that the third transistor Q3 is in the saturation region or the cut-off region. The eighth resistor R8 and the ninth resistor R9, wherein the first end of the eighth resistor R8 is connected to the GNSS antenna, the second end of the eighth resistor R8 is connected to the first end of the ninth resistor R9, and the The second end is connected to the second end of the third triode Q3; the model of the third triode Q3 can be selected as SST3904, its second end is connected to the second end of the output acquisition module 510, and its first end is grounded The first end of the voltage dividing resistor 520 is connected with the third end of the third transistor Q3, the second end of the voltage dividing resistor 520 is connected with the output end of the system power supply VCC, and the voltage dividing resistor 520 is used for the system power supply VCC. The voltage is divided, so that the fourth transistor Q4 is turned on or off. The voltage dividing resistor 520 may specifically include a tenth resistor R10 and an eleventh resistor R11 connected in series with each other, wherein the first end of the tenth resistor R10 is connected to the first end of the tenth resistor R10. The second end of the eleventh resistor R11 is connected, and the first end of the eleventh resistor R11 is the first end of the voltage dividing resistor 520 , that is, the first end of the eleventh resistor R11 and the third end of the third transistor Q3 The second end of the tenth resistor R10 is the second end of the voltage dividing resistor 520, that is, the second end of the tenth resistor R10 is connected to the output end of the system power supply VCC; the first end of the fourth transistor Q4 It is connected to the second end of the tenth resistor R10, and the third end of the fourth transistor Q4 is connected to the first end of the seventh resistor R7. The output end of the system power supply VCC is connected to the first end of the fourteenth resistor R14 of 0 ohms, the second end of the fourteenth resistor R14 of 0 ohms is connected to the second end of the fourth transistor Q4, the system power supply VCC The power supply voltage is output to the third terminal through the second terminal of the fourth transistor Q4, and finally output to the first terminal of the voltage divider module 100, that is, the detection power supply VCC_GNSS of the GNSS in FIG. 4, and the system power supply VCC in FIG. 3. end.

When the GNSS antenna is normally connected, after the power supply voltage output by the antenna power supply VCC_RF passes through the output acquisition module 510, the third transistor Q3 works in the saturation region, and the third end of the third transistor Q3 is opposite to the first end of the third transistor Q3. The impedance is 0 ohm. At this time, the eleventh resistor R11 is equivalent to grounding, and the voltage of the tenth resistor R10 is the voltage divided by the tenth resistor R10 and the eleventh resistor R11. Since the eleventh resistor R11 is equivalent to Grounded, so the voltage of the tenth resistor R10 is 3.3V, and the voltage of the fourth transistor Q4 is -3.3V at this time, that is, the PMOS transistor VGS (pin 2 to pin 1) is -3.3V, and its second terminal to its third end is in a conducting state.

When the GNSS antenna is short-circuited, the voltage of the GNSS antenna is 0V, the eighth resistor R8 and the eleventh resistor R11 make the third transistor Q3 work in the cut-off region, and the third terminal of the third transistor Q3 is paired with The impedance of its first end is 5M ohms. At this time, the impedance of the eleventh resistor R11 to ground is 5M ohms. The voltage of the tenth resistor R10 is opposite to the eleventh resistor R11 and the third end of the third transistor Q3. The voltage divided by the impedance of the first end is approximately equal to 0V, that is, the PMOS transistor VGS (pin 2 to pin 1) is 0V, and the second end to the third end of the fourth transistor Q4 is in the off state. , which plays a role in protecting the power supply. Until the short-circuit state of the GNSS antenna ends, the second transistor Q3 will resume conduction, which reduces the probability of power supply damage when the GNSS antenna is short-circuited.

It should be understood that the fourth transistor Q4 provided in the above-mentioned embodiment is preferably a PMOS transistor, and its cost is relatively low, but it can also be replaced with an NMOS transistor if necessary. The specific element types of the fourth transistor Q4 are further limited. The eighth resistor R8 and the ninth resistor R9 provided in the above embodiment may be resistors with the same resistance value or resistors with different resistance values, and the specific resistance values should be determined according to specific application scenarios.

Specifically, as shown in FIG. 4 , a fifteenth resistor R15 is connected in parallel with the second end of the tenth resistor R10 , the first end of the fifteenth resistor R15 is connected in parallel with the tenth resistor R10 , and the second end of the fifteenth resistor R15 is connected in parallel Connect with the ninth resistor R9.

An embodiment of the present application further provides a vehicle-mounted terminal, and FIG. 5 is a schematic structural diagram of a vehicle-mounted terminal provided by an embodiment of the present application. As shown in FIG. 5 , such a vehicle-mounted terminal specifically includes an antenna and the antenna detection circuit provided in any of the above embodiments.

Specifically, as shown in FIG. 5 , the antenna 10 included in the vehicle-mounted terminal may be one or both of a GNSS antenna or a communication antenna.

The on-board terminal provided by the present application includes the above-mentioned antenna detection circuit. The antenna detection circuit includes a system power supply VCC, a voltage divider module 100, a detection module 200 and a judgment module 300, so that the on-board terminal can pass the voltage divider module 100 to the system. The voltage output by the power supply VCC is divided, and at the same time, the output voltage of the detection module 200 is different from the different states and types of the voltage division relationship of the antenna 10, so that the judgment module 300 can judge the voltage of the antenna 10 according to the voltage of the third terminal of the detection module 200. The on-off and the type of the antenna 10 not only have a simple circuit and low cost, but also have various detection functions. In addition to basically judging the on-off of the antenna to ensure the safety of the vehicle, it can also determine the type of the antenna 10, which is convenient for the management and operation of the antenna 10. application.

In a possible implementation manner, as shown in FIG. 5 , the vehicle-mounted terminal may further include a communication module 600, and the communication module 600 may further include an analog-to-digital converter ADC, wherein the determination module 300 in the antenna detection circuit is the The analog-to-digital converter ADC uses the analog-to-digital converter ADC built in the communication module 600 to detect and output the voltage of the third terminal of the detection module 200, so that the detection result is more intuitive and reliable.

In addition, an embodiment of the present application further provides a vehicle, and the vehicle includes the vehicle-mounted terminal in the above embodiment.

The vehicle provided by the present application includes the above-mentioned vehicle-mounted terminal, and since the vehicle-mounted terminal includes the above-mentioned antenna detection circuit, the antenna detection circuit includes the system power supply VCC, the voltage divider module 100, the detection module 200 and the judgment module 300, so that the The in-vehicle terminal can divide the voltage output by the system power supply VCC through the voltage dividing module 100, and at the same time use the output voltage of the detection module 200 to have different voltage division relationships in different states and different types of the antenna, so that the judgment module 300 can be based on the detection module 200. The voltage at the third end of the UPS determines the on-off of the antenna and the type of the antenna, which not only has a simple circuit and low cost, but also has various detection functions. It is convenient for the management and application of the antenna.

The above descriptions are only preferred embodiments created by the present application, and are not intended to limit the creation of the present application. Any modifications, equivalent replacements, etc., made within the spirit and principles of the creation of the present application shall be included in the present application. within the scope of protection created.

Claims (11)

1. An antenna detection circuit, comprising:

a system power supply;

the voltage division module (100), wherein a first end of the voltage division module (100) is connected with an output end of the system power supply;

a first end of the detection module (200) is connected with a second end of the voltage division module (100), and a second end of the detection module (200) is connected with an antenna; and

the input end of the judgment module (300) is connected with the third end of the detection module (200);

the judging module (300) judges the state of the antenna and the type of the antenna according to the voltage of the third end of the detecting module (200);

wherein the states of the antenna include a short circuit state, an open circuit state, and a normal state.

2. The antenna detection circuit of claim 1, wherein the antenna comprises a communication antenna comprising a first radio frequency connector and a second radio frequency connector;

wherein the detection module (200) comprises:

a first inductor, wherein a first end of the first inductor is connected with the first radio frequency connector, and a second end of the first inductor is connected with the voltage division module (100); and

a first end of the first resistor is connected with a second end of the first inductor, and a second end of the first resistor is connected with the judging module (300);

wherein the voltage division module (100) comprises:

a first end of the second resistor is connected with an output end of the system power supply, and a second end of the second resistor is connected with a second end of the first inductor;

and the first end of the third resistor is grounded, and the second end of the third resistor is connected with the second radio frequency connector.

3. The antenna detection circuit of claim 2, further comprising:

loss prevention module (400), the first end of loss prevention module (400) with the first end of second resistance is connected, the second end of loss prevention module (400) with the output of system's power is connected.

4. The antenna detection circuit of claim 1, wherein the antenna comprises a GNSS antenna;

wherein the detection module (200) comprises:

the third end of the first triode is connected with the judging module (300), and the first end of the first triode is connected with the GNSS antenna;

a first end of the fourth resistor is connected with the voltage division module (100), and a second end of the fourth resistor is connected with a first end of the first triode; and

a first end of the fifth resistor is connected with the voltage division module (100), and a second end of the fifth resistor is connected with the judgment module (300);

the voltage division module (100) is used for dividing the power supply voltage output by the output end of the system power supply so that the first triode works in a saturation region or an amplification region.

5. The antenna detection circuit according to claim 4, characterized in that the voltage division module (100) comprises:

the third end and the second end of the second triode are both connected with the second end of the first triode;

a first end of the sixth resistor is grounded, and a second end of the sixth resistor is connected with a third end of the second triode; and

and a first end of the seventh resistor is connected with the output end of the system power supply, and a second end of the seventh resistor is connected with the first end of the second triode.

6. The antenna detection circuit of claim 1, further comprising:

the first end of the short-circuit protection module (500) is connected with the output end of the system power supply, the second end of the short-circuit protection module (500) is connected with the first end of the voltage division module (100), and the third end of the short-circuit protection module (500) is connected with the antenna.

7. The antenna detection circuit according to claim 6, characterized in that the short-circuit protection module (500) comprises:

an output acquisition module (510), wherein one end of the output acquisition module (510) is connected with the antenna;

a second end of the third triode is connected with the second end of the output acquisition module (510), and a first end of the third triode is grounded;

a divider resistor (520), wherein a first end of the divider resistor (520) is connected with a third end of the third triode, and a second end of the divider resistor (520) is connected with an output end of the system power supply; and

a first end of the fourth triode is connected with a third end of the voltage division resistor (520), and a third end of the fourth triode is connected with a first end of the voltage division module (100);

the output acquisition module (510) is configured to divide the voltage of the antenna so that the third triode is in a saturation region or a cut-off region; the voltage dividing resistor (520) is used for dividing the voltage of the system power supply, so that the fourth triode is switched on or switched off.

8. The antenna detection module (200) of claim 7, wherein the output acquisition module (510) comprises:

the first end of the eighth resistor is connected with the antenna; and

and the first end of the ninth resistor is connected with the second end of the eighth resistor, and the second end of the ninth resistor is connected with the second end of the third triode.

9. The antenna detection module (200) of claim 7, wherein the voltage divider resistor (520) comprises:

a tenth resistor; and

an eleventh resistor in series with the tenth resistor;

the first end of the tenth resistor is connected with the second end of the eleventh resistor, the second end of the tenth resistor is connected with the output end of the system power supply, and the first end of the eleventh resistor is connected with the third end of the third triode.

10. A vehicle-mounted terminal characterized by comprising:

an antenna; and

the antenna detection circuit of any one of claims 1-9.

11. A vehicle characterized by comprising the in-vehicle terminal of claim 10.

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