CN217880387U - Radio frequency circuit, roadside device and ETC system - Google Patents

Abstract

The utility model discloses a radio frequency circuit, roadside equipment and ETC system, radio frequency circuit include the main control unit, N group transmission link, close way coupling unit, transmitting antenna, M group receiving link, receive distribution unit and receiving antenna; the transmitting links are all connected with the main control unit, the output ends of the transmitting links are all connected with the input end of the combined coupling unit, the combined coupling unit is connected with the transmitting antenna, and the combined coupling unit is used for transmitting signals to be combined and output to the transmitting antenna; the receiving chains are all connected with the main control unit, the input ends of the receiving chains are all connected with the output ends of the receiving distribution units, the receiving distribution units are connected with the receiving antennas, and the receiving distribution units are used for respectively inputting the input signals received by the receiving antennas into the receiving chains. The radio frequency circuit of this scheme is through setting up multiunit transmitting link and receiving link simultaneously to adopt frequency division full duplex's receiving and dispatching mode, can support trackside equipment and mobile unit to carry out the high-speed bidirectional transmission of data, and then satisfy the big file transmission of ETC system.

Description

Radio frequency circuit, roadside device and ETC system

Technical Field

The utility model relates to the intelligent transportation field, more specifically say and indicate a radio frequency circuit, trackside equipment and ETC system.

Background

According to the Electronic Toll Collection (ETC) on roads in China, after a high-speed test is carried out at a capital airport in 1996, the national ETC networking is carried out in 2015, the national highway toll station-saving project is cancelled in 2019, the ETC is carried out for 25 years so far, especially under the vigorous promotion of national policies in 2019, the unprecedented development opportunity of the ETC is obtained, 12 and 31 days in 2019, the national ETC users are accumulated to 2.04 hundred million, and 2.46 sets of ETC gantries and corresponding infrastructures such as power supply and communication are built together. As a new infrastructure in the transportation industry, a good foundation is laid for developing comprehensive road network management, safe operation, intelligent maintenance, information service and the like for intelligent roads.

ETC system (RSU, OBU) of traditional mode is based on GB20851 standard, can support functions such as route discernment and access & exit consumption to adopt ASK modulation, the data bulk that can transmit in the short time is limited, has low transmission rate's shortcoming, can't satisfy the requirement of intellectuality to data transmission.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art.

SUMMERY OF THE UTILITY MODEL

In order to solve the defects of the prior art, the utility model aims to provide a radio frequency circuit, roadside equipment and ETC system.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

in a first aspect, the present invention provides a radio frequency circuit, which includes a main control unit, N groups of transmitting links, a combining coupling unit, a transmitting antenna, M groups of receiving links, a receiving distribution unit and a receiving antenna, wherein N and M are natural numbers greater than 1;

the input ends of the transmitting links are all connected with the main control unit, the output ends of the transmitting links are all connected with the input ends of the combined coupling unit, the output end of the combined coupling unit is connected with the transmitting antenna, and the combined coupling unit is used for combining and outputting N transmitting signals from N groups of the transmitting links to the transmitting antenna for transmitting;

the output ends of the receiving links are connected with the main control unit, the input ends of the receiving links are connected with the output ends of the receiving distribution units, the input ends of the receiving distribution units are connected with the receiving antennas, and the receiving distribution units are used for dividing input signals received by the receiving antennas into M paths and inputting the M paths of input signals into the receiving links respectively.

The output end of the power detection unit is connected with the main control unit, the detection end is connected with the combining coupling unit, and the power detection unit is used for detecting the power of the transmitted signal.

Furthermore, the combining coupling unit includes a power combiner, a high pass filter, and a directional coupler, the output ends of the N groups of the transmitting links are simultaneously connected to the input end of the power combiner, the output end of the power combiner is connected to the input end of the high pass filter, the output end of the high pass filter is connected to the directional coupler, and the output end of the directional coupler is connected to the transmitting antenna.

Furthermore, the receiving and distributing unit comprises a power distributor, a low-pass filter and a VGA module, the input end of the VGA module is connected with the receiving antenna, the output end of the VGA module is connected with the input end of the low-pass filter, the output end of the low-pass filter is connected with the input end of the power distributor, and the output end of the power distributor is simultaneously connected with the input ends of the M groups of receiving links.

Further, the sum of the bandwidths of the M groups of receiving links is less than or equal to the available bandwidth; the sum of the bandwidths of the N groups of the transmission links is less than or equal to the available bandwidth.

Furthermore, the transmitting link includes a transmitting control module, a first radio frequency module, a numerical control attenuation module and a power amplifier, an input end of the transmitting control module is connected to the main control unit, an output end of the transmitting control module is connected to an input end of the first radio frequency module, an output end of the first radio frequency module is connected to an input end of the numerical control attenuation module, an output end of the numerical control attenuation module is connected to the power amplifier, the power amplifier is connected to the power combiner, and the main control unit is connected to the numerical control attenuation module.

Furthermore, the receiving link comprises a receiving control module, a second radio frequency module and a low noise amplifier, the output end of the receiving control module is connected with the main control unit, the input end of the receiving control module is connected with the output end of the second radio frequency module, the input end of the second radio frequency module is connected with the low noise amplifier, and the low noise amplifier is connected with the power distributor.

Furthermore, the radio frequency circuit simultaneously adopts an ASK modulation mode and an FSK modulation mode for modulation.

In a second aspect, the present invention further provides a roadside apparatus, including the radio frequency circuit as described in any one of the above.

The third aspect, the utility model also provides an ETC system, including the mobile unit, and as above the trackside equipment, the trackside equipment is through built-in radio frequency circuit with the mobile unit carries out data transmission.

Compared with the prior art, the utility model beneficial effect be: the utility model provides a pair of radio frequency circuit, roadside equipment and ETC system, radio frequency circuit is through setting up N group transmission link and M montage receiving link simultaneously to adopt frequency division full duplex's receiving and dispatching mode, can support among the ETC system roadside equipment and vehicle-mounted equipment to carry out the high-speed bidirectional transmission of data, and then satisfy the scene that transmits big files such as pronunciation, picture, and video between high-speed portal and the vehicle and use, in order to be applicable to more and more intelligent ECT system.

The invention is further described with reference to the accompanying drawings and specific embodiments.

Drawings

In order to more clearly illustrate the technical solution of the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic block diagram of a specific embodiment of a radio frequency circuit according to an embodiment of the present invention;

fig. 2 is a schematic block diagram illustrating a structure of an embodiment of a radio frequency circuit according to the present invention;

fig. 3 is a circuit connection diagram of a transmission link of a radio frequency circuit according to an embodiment of the present invention;

fig. 4 is a circuit connection diagram of the combining coupling unit and the power detection unit of the rf circuit according to an embodiment of the present invention;

fig. 5 is a circuit diagram of a receiving link of a radio frequency circuit according to an embodiment of the present invention;

fig. 6 is a circuit diagram of a receiving and distributing unit of a radio frequency circuit according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention will be described in further detail with reference to the accompanying drawings and the following detailed description.

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and to simplify the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically limited otherwise.

In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "secured" are to be construed broadly and can, for example, be connected or detachably connected or integrated; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In the present disclosure, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may comprise direct contact between the first and second features, or may comprise contact between the first and second features not directly. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the terminology used in the description presented above should not be understood as necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by one skilled in the art.

The first embodiment:

referring to fig. 1-6, the present invention provides a radio frequency circuit, which includes a main control unit 10, n groups of transmitting links 20, a combining coupling unit 30, a transmitting antenna 40, M groups of receiving links 60, a receiving distribution unit 70 and receiving antennas 80, where n and M are natural numbers greater than 1.

As shown in fig. 1, the input ends of the transmitting links 20 are all connected to the main control unit 10, the output ends of the transmitting links are all connected to the input end of the combining coupling unit 30, the output end of the combining coupling unit 30 is connected to the transmitting antenna 40, and the combining coupling unit 30 is configured to combine N transmitting signals from N groups of transmitting links 20 and output the combined transmitting signals to the transmitting antenna 40 for transmission.

As shown in fig. 1, the output ends of the receiving links 60 are all connected to the main control unit 10, the input ends of the receiving links 60 are all connected to the output ends of the receiving and distributing unit 70, the input ends of the receiving and distributing unit 70 are connected to the receiving antennas 80, and the receiving and distributing unit 70 is configured to divide the input signals received by the receiving antennas 80 into M paths and input the M paths into different receiving links 60, according to the scheme, M groups of receiving links 60 can receive data/signals simultaneously, and the receiving efficiency of the data/signals in the same time can be improved by M times.

Specifically, the radio frequency circuit of the present solution can improve the data/signal transmission efficiency by multiple times by simultaneously setting N sets of transmitting links 20 and M sets of receiving links 60 and adopting a frequency division full duplex transceiving mode, thereby realizing more efficient data/signal transmission and reception.

In the present embodiment, the sum of the bandwidths of the M groups of receiving links 60 is less than or equal to the available bandwidth of the ETC system, and the sum of the bandwidths of the N groups of transmitting links 20 is less than or equal to the available bandwidth, so as to ensure that the bandwidth capability of the ETC system can be exerted to the maximum extent, and ensure that data/signal transmission is performed stably. As shown in fig. 2, in this embodiment, N and M are both 3, and it should be clear that specific values of N and M can be adjusted according to the bandwidth size and the device requirement, which is not limited herein.

As shown in fig. 2, the combining coupling unit 30 includes a power combiner 31, a high pass filter 32 and a directional coupler 33, where the power combiner 31 is configured to combine multiple radio frequency signals from different transmission links 20 into one path, and send the path to the radio frequency device transmitted by the transmission antenna 40, and meanwhile avoid mutual influence between signals at various ports; the high-pass filter 32, also called a low-cut filter or a low-cut filter, allows a frequency higher than a certain cut frequency to pass through, and greatly attenuates a lower frequency, and is used for removing unnecessary low-frequency components in the radio-frequency signal or removing low-frequency interference; the directional coupler 33 is a general microwave/millimeter wave component, and can be used for isolation, separation, and mixing of signals, such as power monitoring, source output power stabilization, signal source isolation, frequency sweep test of transmission and reflection, and the like. Specifically, in this embodiment, the output ends of the N groups of transmission links 20 are simultaneously connected to the input end of the power combiner 31, the output end of the power combiner 31 is connected to the input end of the high-pass filter 32, the output end of the high-pass filter 32 is connected to the directional coupler 33, and the output end of the directional coupler 33 is connected to the transmission antenna 40. In a specific embodiment, a specific circuit connection diagram of the combining coupling unit 30 and the power detection unit 50 is shown in fig. 4.

Referring to fig. 2, in this embodiment, the transmission link 20 includes a transmission control module 21, a first radio frequency module 22, a numerical control attenuation module 23, and a power amplifier 24, an input end of the transmission control module 21 is connected to the main control unit 10, an output end of the transmission control module 21 is connected to an input end of the first radio frequency module 22, an output end of the first radio frequency module 22 is connected to an input end of the numerical control attenuation module 23, an output end of the numerical control attenuation module 23 is connected to the power amplifier 24, the power amplifier 24 is connected to the power combiner 31, and the main control unit 10 is connected to the numerical control attenuation module 23. When the device works, the emission control module 21 configures the corresponding first radio frequency module 22 to output corresponding data of downlink frequency point channel, the data is subjected to numerical control attenuation by the numerical control attenuation module 23, the data is input into the power amplifier 24 to be amplified and output to the power combiner 31 to be combined and then input into the high-pass filter 32, and the inhibition of the uplink frequency band of the high-pass filter 32 can reach 30dB; the signal output from the high pass filter 32 is input to the transmitting antenna 40 through the directional coupler 33, and the signal is radiated through the transmitting antenna 40. In one embodiment, the specific circuit connection diagram of the transmit chain 20 is shown in fig. 3.

As shown in fig. 2, the receiving and distributing unit 70 includes a power divider 71, a low-pass filter 72 and a VGA module 73, wherein the power divider 71 (power divider) is a device that divides one path of input signal energy into two or more paths of input signal energy and outputs equal or unequal energy, and may also combine multiple paths of input signal energy into one path of input signal energy and output the same; the low-pass filter 72 is an electronic filter device that allows signals below the cutoff frequency to pass, but does not allow signals above the cutoff frequency to pass. Specifically, in this embodiment, the input terminal of the VGA module 73 is connected to the receiving antenna 80, the output terminal of the VGA module 73 is connected to the input terminal of the low-pass filter 72, the output terminal of the low-pass filter 72 is connected to the input terminal of the power divider 71, and the output terminals of the power divider 71 are simultaneously connected to the input terminals of the M groups of receiving links 60. In one embodiment, the specific circuit connection diagram of the receiving and distributing unit 70 is shown in fig. 6.

Referring to fig. 2, in the present embodiment, the receiving link 60 includes a receiving control module 61, a second radio frequency module 62 and a low noise amplifier 63, an output end of the receiving control module 61 is connected to the main control unit 10, an input end of the receiving control module 61 is connected to an output end of the second radio frequency module 62, an input end of the second radio frequency module 62 is connected to the low noise amplifier 63, and the low noise amplifier 63 is connected to the power divider 71. During operation, the receiving antenna 80 receives the air signal and inputs the air signal into the VGA module 73, the VGA module 73 can adjust the gain according to the power of the input signal, and inputs the adjusted signal into the low-pass filter 72, and the inhibition of the downlink frequency band of the low-pass filter 72 can reach 30dB; the signals output from the low-pass filter 72 are input to the M groups of receiving chains 60 through the power divider 71; the signals input by each group of receiving links 60 are amplified by the low noise amplifier 63 and input to the second radio frequency module 62, the second radio frequency module 62 is configured to be in a receiving mode by the receiving control module 61, and the receiving control module 61 can upload the received correct data to the main control unit 10. In one embodiment, the specific circuit connection diagram of the receiving chain 60 is shown in fig. 5.

In this embodiment, the radio frequency circuit of this embodiment further includes a power detection unit 50, an output end of the power detection unit 50 is connected to the main control unit 10, a detection end is connected to the combining coupling unit 30, and the power detection unit 50 is configured to detect the power of the transmission signal. Specifically, the power detection unit 50 is connected to the directional coupler 33, and is configured to detect the power of the radio frequency signal passing through the directional coupler 33.

Furthermore, the radio frequency circuit simultaneously adopts an ASK modulation mode and an FSK modulation mode for modulation so as to simultaneously support an ETC1.0 mode and an ETC2.0 mode, adopt the ASK modulation when entering the ETC1.0 mode and adopt the FSK modulation when entering the ETC2.0 mode. A conventional ETC system only adopts ASK modulation, has the defects of limited data volume capable of being transmitted in a short time and low transmission rate, and cannot meet the requirement of intellectualization on data transmission. The radio frequency circuit of the scheme adopts ASK modulation and FSK modulation at the same time, and actively adjusts and sets the attenuation of the numerical control attenuation module 23 through the main control unit 10; for example, when the ETC1.0 mode is used, the numerical control attenuation value is increased to avoid the power amplifier 24 from operating in a saturation region; when the ETC2.0 mode is used, the numerical control attenuation value is reduced, the power amplifier 24 works in a saturation region, and the efficiency of the power amplifier 24 can be increased. FSK (Frequency-shift keying) is a modulation mode used earlier in information transmission, and has the main advantages of being easy to realize and good in anti-noise and anti-attenuation performances. The method is widely applied to medium and low speed data transmission.

In addition, the radio frequency circuit of this scheme can realize ETC1.0 mode and ETC2.0 mode's hardware compatibility when using ETC system. In a specific embodiment, the frequency point allocation schemes of ETC1.0 and ETC2.0 are as follows:

the downstream channels of ETC1.0 are: 5830MHz and 5840MHz, the uplink corresponding channels are: 5790MHz and 5800MHz; the available frequency bands of ETC are: 5790mhz to 5840mhz, three groups of transmitting links 20 and three groups of receiving links 60 are provided, and 3 channels can be distributed respectively, because the ETC2.0 adopts 4FSK adjustment, the modulation rate is 4Mbps, the frequency deviation is 900kHz, the occupied bandwidth is about 6.7MHz, and the channel interval is set to 7MHz; because full duplex operation is required, the transmit and receive channels differ by at least 20MHz, taking into account the effects of intermodulation.

ETC2.0 uplink channels are respectively set as: 5790MHz, 5797MHz, and 5804MHz; the downlink channels are respectively set as: 5826MHz, 5833MHz and 5840MHz.

The main control unit 10 sets channels of each group of the transmitting link 20 and the receiving link 60, and each group of the transmitting link 20 and the receiving link 60 can configure channel frequency points of ETC1.0 and ETC 2.0.

When the system works, the main control unit 10 can communicate with the transmission control module 21 and the reception control module 61 respectively, and the main control unit 10 is used for allocating each channel frequency point and informing each transmission control module 21 and each reception control module 61 respectively; the transmission control module 21 configures the corresponding first rf module 22, and the reception control module 61 configures the corresponding second rf module 62, so that the rf circuit operates to the corresponding channel.

The radio frequency circuit of the scheme can support the vehicle-mounted equipment and the roadside equipment in the ETC system to realize high-speed bidirectional data transmission mutually by simultaneously arranging N groups of transmitting links 20 and M groups of receiving links 60 and adopting a frequency division full duplex receiving and transmitting mode, so that the requirement of scene application of large files such as voice, pictures and videos transmitted between a high-speed upper portal frame and a vehicle is met, and the radio frequency circuit is suitable for increasingly intelligent ECT systems.

Example two:

in a specific embodiment, the present invention further provides a roadside apparatus including the radio frequency circuit as described in the first embodiment. The road side equipment with the built-in radio frequency circuit can be installed on the road side, and can realize high-speed data/signal transmission with a vehicle-mounted unit in a vehicle based on the radio frequency circuit when the vehicle runs on the road, so that the data transmission of large files such as voice, pictures, videos and the like is realized, and the radio frequency circuit is suitable for more and more intelligent ECT system scenes.

Example three:

in a concrete embodiment, the utility model discloses still provide an ETC system, including the mobile unit, and as above embodiment two the roadside equipment, the roadside equipment carries out data transmission through built-in radio frequency circuit and mobile unit, compares in traditional ETC system, and this scheme realizes the data transmission of big files such as pronunciation, picture, and video to be applicable to in the more and more intelligent ECT system application scene.

The utility model provides a pair of ETC system, including the mobile unit and the trackside equipment that have all used above-mentioned radio frequency circuit, radio frequency circuit receives link 60 through setting up N group transmission link 20 and M montage simultaneously to adopt frequency division full duplex's receiving and dispatching mode, can support among the ETC system roadside equipment and a plurality of mobile unit to carry out the high-speed bidirectional transmission of data, and then satisfy the scene application of big files such as transmission pronunciation, picture, and video between portal and the vehicle in high speed, in order to be applicable to more and more intelligent ECT system.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope of the present invention, and these modifications or replacements should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (10)

1. A radio frequency circuit is characterized by comprising a main control unit, N groups of transmitting links, a combined coupling unit, a transmitting antenna, M groups of receiving links, a receiving distribution unit and a receiving antenna, wherein both N and M are natural numbers larger than 1;

the input ends of the transmitting links are all connected with the main control unit, the output ends of the transmitting links are all connected with the input ends of the combined coupling unit, the output end of the combined coupling unit is connected with the transmitting antenna, and the combined coupling unit is used for combining and outputting N transmitting signals from N groups of the transmitting links to the transmitting antenna for transmitting;

the output ends of the receiving links are connected with the main control unit, the input ends of the receiving links are connected with the output ends of the receiving distribution units, the input ends of the receiving distribution units are connected with the receiving antennas, and the receiving distribution units are used for dividing input signals received by the receiving antennas into M paths and inputting the M paths of input signals into the receiving links respectively.

2. The RF circuit of claim 1, further comprising a power detection unit, wherein an output terminal of the power detection unit is connected to the main control unit, a detection terminal is connected to the combining coupling unit, and the power detection unit is configured to detect a transmission signal power.

3. The RF circuit of claim 1, wherein the combining coupling unit comprises a power combiner, a high pass filter and a directional coupler, outputs of N sets of the transmitting chains are simultaneously connected to an input of the power combiner, an output of the power combiner is connected to an input of the high pass filter, an output of the high pass filter is connected to the directional coupler, and an output of the directional coupler is connected to the transmitting antenna.

4. The radio frequency circuit according to claim 1, wherein the receiving and distributing unit includes a power divider, a low pass filter, and a VGA module, an input terminal of the VGA module is connected to the receiving antenna, an output terminal of the VGA module is connected to an input terminal of the low pass filter, an output terminal of the low pass filter is connected to an input terminal of the power divider, and an output terminal of the power divider is simultaneously connected to input terminals of M groups of the receiving chains.

5. The RF circuit of claim 1, wherein the sum of the bandwidths of the M groups of the receive chains is less than or equal to an available bandwidth; the sum of the bandwidths of the N groups of the transmission links is less than or equal to the available bandwidth.

6. The radio frequency circuit according to claim 3, wherein the transmission link comprises a transmission control module, a first radio frequency module, a digital controlled attenuation module and a power amplifier, an input end of the transmission control module is connected to the main control unit, an output end of the transmission control module is connected to an input end of the first radio frequency module, an output end of the first radio frequency module is connected to an input end of the digital controlled attenuation module, an output end of the digital controlled attenuation module is connected to the power amplifier, the power amplifier is connected to the power combiner, and the main control unit is connected to the digital controlled attenuation module.

7. The RF circuit according to claim 4, wherein the receiving chain comprises a receiving control module, a second RF module and a low noise amplifier, an output terminal of the receiving control module is connected to the main control unit, an input terminal of the receiving control module is connected to an output terminal of the second RF module, an input terminal of the second RF module is connected to the low noise amplifier, and the low noise amplifier is connected to the power divider.

8. The radio frequency circuit according to claim 1, wherein the radio frequency circuit simultaneously employs an ASK modulation scheme and an FSK modulation scheme for modulation.

9. A roadside apparatus characterized by comprising the radio frequency circuit according to any one of claims 1 to 8.

10. An ETC system, characterized by comprising an on-board device and the roadside device according to claim 9, the roadside device performing data transmission with the on-board device through the built-in radio frequency circuit.

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