Variable frequency device, terminal device and vehicle

Abstract

The application relates to the technical field of satellite communication, and provides a frequency conversion device, a terminal device and a vehicle. The transmitting link frequency conversion module of the frequency conversion device comprises a first frequency conversion unit and a second frequency conversion unit. The input end of the first frequency conversion unit is connected with a high-orbit satellite intermediate frequency sending end of a satellite online terminal. The input end of the second frequency conversion unit is respectively connected with the output end of the first frequency conversion unit and a low-orbit satellite intermediate frequency sending end of the satellite online terminal. The output end of the second frequency conversion unit is connected with a communication satellite through a transmitting antenna. The input end of the receiving link frequency conversion module of the frequency conversion device is connected with the communication satellite through a receiving antenna. The output end of the receiving link frequency conversion module is respectively connected with a high-orbit satellite intermediate frequency receiving end and a low-orbit satellite intermediate frequency receiving end of the satellite online terminal. The application can support the frequency conversion requirement of high-orbit and low-orbit satellites and the satellite online terminal in communication, and realizes the compatibility of the frequency conversion of the high-orbit and low-orbit satellites and the satellite online terminal in communication.

Description

Technical Field

[0001] This application relates to the technical field of satellite communications, and in particular to a frequency converter, terminal equipment, and vehicle. Background Technology

[0002] In the field of satellite communications, satellite internet terminals rely on specific frequency bands of electromagnetic waves to interact with high-orbit and low-orbit satellites. Communication satellites transmit / receive radio frequency (RF) signals, while satellite internet terminals transmit / receive intermediate frequency (IF) signals. Therefore, frequency converters are needed to achieve RF-IF and IF-RF conversion.

[0003] In related technologies, the intermediate frequency signals sent by satellite internet terminals to high-orbit and low-orbit satellites have a large frequency range. For example, high-orbit satellites require intermediate frequency signals of 950MHz~2400MHz, while low-orbit satellites require intermediate frequency signals of 4GHz±62MHz, with a frequency range of nearly 1.6GHz.

[0004] However, due to the limitations of the built-in component parameters of the frequency converter, the frequency converters in related technologies are difficult to support the frequency conversion between intermediate frequency signals and radio frequency signals of high and low orbit satellites at the same time, and there is a lack of frequency converters that can be compatible with communication between high and low orbit satellites and satellite Internet terminals. Utility Model Content

[0005] In view of this, this application aims to propose a frequency conversion device to support the frequency conversion conversion requirements of high- and low-Earth orbit satellites and satellite Internet terminals during communication, thereby achieving compatibility between high- and low-Earth orbit satellites and satellite Internet terminals.

[0006] To achieve the above objectives, the technical solution of this application is implemented as follows: A frequency conversion device is suitable for converting intermediate frequency signals and radio frequency signals of high-orbit and low-orbit satellites, including a transmit link frequency conversion module and a receive link frequency conversion module. The transmit link frequency conversion module includes a first-level frequency conversion unit adapted to convert a preset high-orbit uplink intermediate frequency band signal into a preset low-orbit uplink intermediate frequency band signal, and a second-level frequency conversion unit adapted to convert the preset low-orbit uplink intermediate frequency band signal into a preset uplink radio frequency band signal. The input terminal of the first-level frequency conversion unit is connected to the high-orbit satellite intermediate frequency transmission terminal of the satellite internet terminal. The input terminal of the second-level frequency conversion unit is connected to the output terminal of the first-level frequency conversion unit and the low-orbit satellite intermediate frequency transmission terminal of the satellite internet terminal. The output terminal of the second-level frequency conversion unit is connected to the communication satellite communicating with the satellite internet terminal through the transmitting antenna. The input terminal of the receiving link frequency conversion module is connected to the communication satellite via a receiving antenna, and the output terminal of the receiving link frequency conversion module is connected to the high-orbit satellite intermediate frequency receiving terminal and the low-orbit satellite intermediate frequency receiving terminal of the satellite internet terminal, respectively.

[0007] Furthermore, the primary frequency conversion unit includes a primary frequency conversion circuit, which includes a first mixer and a first phase-locked loop; The first mixer includes a local oscillator terminal, a mixer output terminal, and a mixer input terminal. The local oscillator terminal is connected to the first phase-locked loop, the mixer input terminal is connected to the high-orbit satellite intermediate frequency transmitter of the satellite internet terminal, and the mixer output terminal is connected to one input terminal of the secondary frequency conversion unit.

[0008] Furthermore, the primary frequency converter unit also includes a resistive coupling circuit: The resistive coupling circuit is located on the connection path between the mixing input terminal of the first mixer and the high-orbit satellite intermediate frequency transmitter of the satellite internet terminal.

[0009] Furthermore, the secondary frequency conversion unit includes switching elements and a secondary frequency conversion circuit; The switching element includes a common terminal, a first switching terminal, and a second switching terminal. The first switching terminal is connected to the output terminal of the first-stage frequency conversion unit, and the second switching terminal is used to connect to the low-orbit satellite intermediate frequency transmitter of the satellite Internet terminal. The common terminal is connected to the input terminal of the secondary frequency converter circuit, and the output terminal of the secondary frequency converter circuit is connected to the communication satellite through a transmitting antenna.

[0010] Furthermore, the secondary frequency conversion unit also includes a first signal amplifier and a first filter; The input terminal of the first signal amplifier is connected to the output terminal of the second-stage frequency converter circuit, the output terminal of the first signal amplifier is connected to the input terminal of the first filter, and the output terminal of the first filter is connected to the communication satellite through the transmitting antenna.

[0011] Furthermore, the secondary frequency conversion unit also includes a signal strength attenuator: The signal strength attenuator is installed in the connection path between the common terminal of the switching element and the input terminal of the secondary frequency converter circuit.

[0012] Furthermore, the receiving link frequency conversion module includes a downlink frequency conversion circuit and a power distribution circuit adapted to divide one input signal into two output signals. The input terminal of the downlink frequency converter circuit is connected to the communication satellite via the receiving antenna, and the output terminal of the downlink frequency converter circuit is connected to the input terminal of the power distribution circuit. The output terminals of the power distribution circuit include a first power distribution output terminal and a second power distribution output terminal. The first power distribution output terminal is connected to the high-orbit satellite intermediate frequency receiver of the satellite internet terminal, and the second power distribution output terminal is connected to the low-orbit satellite intermediate frequency receiver of the satellite internet terminal.

[0013] Furthermore, the receiving link frequency conversion module also includes a second signal amplifier and a second filter; The input terminal of the second signal amplifier is connected to the communication satellite via the receiving antenna, the output terminal of the second signal amplifier is connected to the input terminal of the second filter, and the output terminal of the second filter is connected to the input terminal of the downlink frequency conversion circuit.

[0014] Furthermore, the receiving link frequency conversion module also includes a first power compensation circuit and a second power compensation circuit; The input terminal of the first power compensation circuit is connected to the output terminal of the first power divider, and the output terminal of the first power compensation circuit is connected to the high-orbit satellite intermediate frequency receiver of the satellite Internet terminal. The input terminal of the second power compensation circuit is connected to the output terminal of the second power divider, and the output terminal of the second power compensation circuit is connected to the low-orbit satellite intermediate frequency receiver of the satellite Internet terminal.

[0015] Furthermore, the first power compensation circuit includes a third signal amplifier and an impedance matching circuit: The input terminal of the third signal amplifier is connected to the output terminal of the first power divider, the output terminal of the third signal amplifier is connected to the input terminal of the impedance matching circuit, and the output terminal of the impedance matching circuit is connected to the high-orbit satellite intermediate frequency receiver of the satellite internet terminal.

[0016] Compared with related technologies, this application has at least the following advantages: The frequency conversion device described in this application, when a satellite internet terminal transmits intermediate frequency (IF) signals to a communication satellite, can utilize the first-stage frequency conversion unit of the transmit link frequency conversion module to upscale the IF signal corresponding to the high-orbit satellite to the frequency band corresponding to the low-orbit satellite. Then, it can share the second-stage frequency conversion unit with the IF signal corresponding to the low-orbit satellite to complete the IF-RF conversion. This two-stage frequency conversion method can simultaneously cover the frequency conversion requirements of IF-RF signals from both high- and low-orbit satellites. Furthermore, when a communication satellite transmits RF signals to a satellite internet terminal, the receive link frequency conversion module can convert the RF signal into the IF signal corresponding to both high- and low-orbit satellites. Thus, the transmit and receive link frequency conversion modules can satisfy the frequency conversion requirements between IF and RF signals from high- and low-orbit satellites.

[0017] Another objective of this application is to provide a terminal device, which includes a satellite internet terminal and the aforementioned frequency conversion device; One end of the frequency converter is connected to the satellite internet terminal, and the other end of the frequency converter is connected to a communication satellite that communicates with the satellite internet terminal via a satellite antenna.

[0018] Another object of this application is to provide a vehicle that includes the aforementioned terminal equipment.

[0019] The terminal equipment and vehicle described in this application can realize radio frequency-to-intermediate frequency and intermediate frequency-to-radio frequency conversion between the satellite internet terminal and high-orbit and low-orbit satellites through a frequency conversion device, thereby achieving compatibility between high-orbit and low-orbit satellites and the satellite internet terminal for communication. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the configuration of the frequency converter described in the embodiments of this application.

[0021] Explanation of reference numerals in the attached figures: 1. Transmitting link frequency conversion module; 2. Receiving link frequency conversion module; 11. First-stage frequency converter unit; 111. First-stage frequency converter circuit; 1111. First phase-locked loop; 1112. First mixer; 112. Resistive coupling circuit; 12. Second-stage frequency converter unit; 121. Switching element; 122. Second-stage frequency converter circuit; 123. First signal amplifier; 124. First filter; 125. Signal strength attenuator; 21. Downlink frequency converter circuit; 22. Power distribution circuit; 23. Second signal amplifier; 24. Second filter; 25. First power compensation circuit; 26. Second power compensation circuit; 251. Third signal amplifier; 252. Impedance matching circuit. Detailed Implementation

[0022] To make the technical solution and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0024] Furthermore, it should be noted that in the description of this application, if terms such as "upper," "lower," "inner," or "outer" appear, indicating orientation or positional relationship, these are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. In addition, if terms such as "first" or "second" appear, they are also used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] Furthermore, in the description of this application, unless otherwise expressly defined, the terms "installation," "connection," "joining," and "connector" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application in light of the specific circumstances.

[0026] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0027] The present application will now be described in detail through exemplary embodiments. However, it should be understood that, without further description, elements, structures, and features in one embodiment may be advantageously incorporated into other embodiments.

[0028] An embodiment of the first aspect of this application provides a frequency conversion device that, through a primary frequency conversion unit 11 and a secondary frequency conversion unit 12 in the transmit link frequency conversion module 1, first upsamples the intermediate frequency (IF) signal corresponding to a high-orbit satellite to the frequency band of the IF signal corresponding to a low-orbit satellite. Then, it can share the secondary frequency conversion unit 12 with the IF signal corresponding to the low-orbit satellite to complete the IF-RF conversion. Furthermore, the receive link frequency conversion module 2 can meet the RF-IF signal conversion requirements of both high-orbit and low-orbit satellites. This single frequency conversion device can meet the communication frequency conversion requirements of high-orbit satellites, low-orbit satellites, and satellite internet terminals, thereby reducing equipment procurement costs.

[0029] In related technologies, services such as navigation and communication rely on satellites for communication. Satellite internet terminals transmit information with communication satellites using electromagnetic wave signals in corresponding frequency bands, such as the Ku band (K-under band, a sub-band of the K band). In the field of satellite communication, the Ku band is one of the dedicated radio frequency bands for satellite communication.

[0030] Communication satellites transmit and receive radio frequency signals, such as those in the Ku band. Satellite internet terminals process intermediate frequency signals.

[0031] After receiving radio frequency (RF) signals from a communication satellite, a satellite internet terminal cannot directly process them. Instead, it needs to down-convert the RF signal to an intermediate frequency (IF) signal before demodulating it to identify and process the transmitted information. Similarly, when transmitting information, the satellite internet terminal uses an IF signal to carry the information, then up-converts the IF signal back to an RF signal before transmitting it to the communication satellite via its antenna.

[0032] In order to achieve the conversion between radio frequency (RF) and intermediate frequency (IF) signals, a frequency converter is usually required between the satellite internet terminal and the communication satellite. This frequency converter is used to convert the RF signals transmitted by the communication satellite into IF signals in the IF band, and to convert the IF signals of the satellite internet terminal into RF signals.

[0033] Communication satellites are generally classified into low-Earth orbit (LEO) satellites and high-Earth orbit (HEO) satellites according to their orbital altitude. Furthermore, LEO satellites and HEO satellites require different frequency bands for signals when communicating with satellite internet terminals.

[0034] For example, the signal frequency band requirements for high-orbit and low-orbit satellites using the Ku band are shown in Table 1 below: Table 1

[0035] Among them, the signal transmission link refers to the communication link corresponding to the satellite Internet terminal sending signals to the communication satellite, and the signal reception link refers to the communication link corresponding to the satellite Internet terminal receiving signals sent by the communication satellite.

[0036] In the signal receiving link corresponding to the high-orbit satellite, when the high-orbit satellite transmits radio frequency signals, it sends radio frequency signals in the preset downlink radio frequency band (10.7GHz~12.75GHz in Table 1). When the satellite Internet terminal receives the radio frequency signal, it needs to use a frequency converter to down-convert the radio frequency signal to obtain the intermediate frequency signal in the preset high-orbit downlink intermediate frequency band (950MHz~2150MHz band).

[0037] In the signal transmission link corresponding to the high-orbit satellite, when the satellite Internet terminal transmits intermediate frequency signals to the high-orbit satellite, it sends intermediate frequency signals in the preset high-orbit uplink intermediate frequency band (950MHz~2400MHz band). The frequency conversion device needs to convert the intermediate frequency signal in the 950MHz~2400MHz band (preset high-orbit uplink intermediate frequency band) into a radio frequency signal in the preset uplink radio frequency band (13.75GHz~14.5GHz band) before it can be received by the receiving antenna of the high-orbit satellite.

[0038] In the signal receiving link corresponding to low-Earth orbit satellites, when low-Earth orbit satellites transmit radio frequency signals, they send radio frequency signals in a preset downlink radio frequency band (10.7GHz~12.75GHz band). When the satellite Internet terminal receives this radio frequency signal, it needs to use a frequency converter to down-convert the radio frequency signal to obtain an intermediate frequency signal in a preset low-Earth orbit downlink intermediate frequency band (2GHz±125MHz band).

[0039] In the signal transmission link corresponding to low-Earth orbit satellites, when a satellite internet terminal transmits an intermediate frequency signal to a low-Earth orbit satellite, it sends an intermediate frequency signal in the preset low-Earth orbit uplink intermediate frequency band (4GHz±62MHz band). The frequency converter needs to convert the intermediate frequency signal in the 4GHz±62MHz band into an radio frequency signal in the preset uplink radio frequency band (13.75GHz~14.5GHz band) so that it can be received by the receiving antenna of the low-Earth orbit satellite.

[0040] It is evident that for the signal receiving link, the radio frequency bands corresponding to high-orbit satellites and low-orbit satellites are the same (both are preset downlink radio frequency bands of 10.7GHz to 12.75GHz), and the preset low-orbit downlink intermediate frequency band is similar to the preset high-orbit downlink intermediate frequency band with a small span. Therefore, for the signal receiving link, high-orbit satellites and low-orbit satellites can often share the same frequency conversion device.

[0041] However, the intermediate frequency band of the signal transmission link corresponding to high-orbit satellites, which is also the preset high-orbit uplink intermediate frequency band (950MHz~2400MHz), has a large span (the frequency band interval is nearly 1.6GHz) compared to the intermediate frequency band of the signal transmission link corresponding to low-orbit satellites, which is also the preset low-orbit uplink intermediate frequency band (4GHz±62MHz).

[0042] Most frequency conversion devices in related technologies employ mixers and phase-locked loops (PLLs) to achieve frequency conversion. The PLL provides the local oscillator signal, while the mixer mixes the local oscillator signal and the signal to be frequency-converted to obtain the converted signal. Due to the limitations of mixers, it is difficult to simultaneously meet the intermediate frequency (IF) to radio frequency (RF) signal conversion requirements of signal transmission links for both high-Earth orbit (HEO) and low-Earth orbit (LEO) satellites, making it difficult to share frequency conversion devices between HEO and LEO satellites.

[0043] For example, if the conversion needs of high-Earth orbit (HEO) satellites are prioritized, a mixer with a small frequency span should be selected. This type of mixer can avoid crosstalk and maintain signal stability, but its frequency processing capabilities are limited and cannot cover the frequency conversion requirements of low-Earth orbit (LEO) satellites. If the conversion needs of LEO satellites are prioritized, a mixer with a large frequency span should be used to meet the wide frequency range conversion requirements. However, a large frequency span mixer will significantly degrade the signal-to-noise ratio of HEO satellite communication, failing to meet the requirements for stable HEO communication. Therefore, due to the limitations of the physical characteristics and performance of circuit components, it is difficult for the intermediate frequency (IF) to radio frequency (RF) conversion of HEO and LEO satellites to share the same frequency conversion device.

[0044] This means that a frequency converter is required when the satellite internet terminal communicates with low-Earth orbit satellites, and when the satellite internet terminal switches to communicating with high-Earth orbit satellites instead of low-Earth orbit satellites, a separate frequency converter for high-Earth orbit satellites needs to be purchased, resulting in increased costs.

[0045] In view of this, in order to overcome the shortcomings of related technologies, the frequency converter in this embodiment combines... Figure 1 In terms of overall design, this frequency converter is suitable for converting intermediate frequency (IF) and radio frequency (RF) signals for high-orbit and low-orbit satellites. For details, refer to... Figure 1 The frequency converter includes a transmit link frequency converter module 1 and a receive link frequency converter module 2.

[0046] The transmit link frequency conversion module 1 includes a first-stage frequency conversion unit 11 adapted to convert a preset high-orbit uplink intermediate frequency band signal into a preset low-orbit uplink intermediate frequency band signal, and a second-stage frequency conversion unit 12 adapted to convert a preset low-orbit uplink intermediate frequency band signal into a preset uplink radio frequency band signal.

[0047] The input terminal of the first-stage frequency converter unit 11 is connected to the high-orbit satellite intermediate frequency (IF) transmitter of the satellite internet terminal. This IF transmitter is the port through which the satellite internet terminal sends the corresponding IF signal when it needs to communicate with a high-orbit satellite. In other words, when the satellite internet terminal sends an IF signal to a high-orbit satellite, the IF signal is output from the IF transmitter to the input terminal of the first-stage frequency converter unit 11.

[0048] The input terminal of the secondary frequency conversion unit 12 is connected to the output terminal of the primary frequency conversion unit 11 and the low-Earth orbit (LEO) satellite intermediate frequency (IF) transmitter of the satellite internet terminal. The LEO satellite IF transmitter of the satellite internet terminal is the port used by the satellite internet terminal to send the corresponding IF signal when it needs to communicate with a LEO satellite. That is, when the satellite internet terminal sends an IF signal to a LEO satellite, the IF signal is output from the LEO satellite IF transmitter to the secondary frequency conversion unit 12.

[0049] The output of the secondary frequency converter unit 12 is connected to a communication satellite for communication with the satellite internet terminal. Specifically, the satellite internet terminal is connected to the communication satellite via a satellite antenna, which includes a receiving antenna and a transmitting antenna. The output of the secondary frequency converter unit 12 is connected to the transmitting antenna, and through the transmitting antenna, it is connected to the communication satellite.

[0050] For example, when communicating with a low-Earth orbit (LEO) satellite, the output of the secondary frequency converter 12 is connected to the LEO satellite via a transmitting antenna. When communicating with a high-Earth orbit (HEO) satellite, the output of the secondary frequency converter 12 is connected to the HEO satellite via the transmitting antenna.

[0051] Based on the above overall introduction of the transmission link frequency conversion module 1, specifically, when the satellite internet terminal communicates with a low-orbit satellite, the low-orbit satellite intermediate frequency transmitter of the satellite internet terminal is connected to the input terminal of the secondary frequency conversion unit 12, while the connection between the high-orbit satellite intermediate frequency transmitter of the satellite internet terminal and the input terminal of the primary frequency conversion unit 11 is disconnected (that is, there is no signal input to the input terminal of the primary frequency conversion unit 11), and the output terminal of the secondary frequency conversion unit 12 (through the transmitting antenna) is connected to the low-orbit satellite.

[0052] It is worth noting that for satellite internet terminals, the intermediate frequency (IF) transmitter for low-Earth orbit (LEO) satellites and the IF transmitter for high-Earth orbit (HEO) satellites may share the same port, for example, both being IF signal transmitters. In this case, if the frequency converter is used for frequency conversion between the satellite internet terminal and LEO satellites, the IF signal transmitter acts as the LEO satellite IF transmitter and is connected to the input of the secondary frequency converter unit 12 of the frequency converter, but not to the input of the primary frequency converter unit 11 of the satellite internet terminal. Similarly, when the frequency converter is used for frequency conversion between the satellite internet terminal and LEO satellites, the IF signal transmitter acts as the HEO satellite IF transmitter and is connected to the input of the primary frequency converter unit 11 of the satellite internet terminal, but not to the input of the secondary frequency converter unit 12 of the frequency converter.

[0053] When the satellite internet terminal sends an intermediate frequency (IF) signal to a low-Earth orbit (LEO) satellite for communication, the satellite internet terminal transmits an IF signal in the preset LEO uplink IF band (i.e., 4GHz±62MHz) to the input terminal of the secondary frequency converter 12 via the LEO satellite's IF transmitter. The primary frequency converter 11 has no signal input and no signal output to the secondary frequency converter 12.

[0054] The secondary frequency conversion unit 12 receives an intermediate frequency signal in the preset low-Earth orbit uplink intermediate frequency band (4GHz±62MHz), that is, it receives a preset low-Earth orbit uplink intermediate frequency band signal. It converts the frequency of the intermediate frequency signal in the preset low-Earth orbit uplink intermediate frequency band (4GHz±62MHz) into a radio frequency signal in the preset uplink radio frequency band (13.75GHz~14.5GHz), that is, it obtains a preset uplink radio frequency band signal, and outputs it to the low-Earth orbit satellite through the transmitting antenna, thus completing the intermediate frequency-to-radio frequency band conversion of the signal transmission link corresponding to the low-Earth orbit satellite.

[0055] When the satellite internet terminal communicates with a high-orbit satellite, the intermediate frequency (IF) transmitter of the high-orbit satellite is connected to the input of the first-stage frequency converter unit 11, while the IF transmitter of the low-orbit satellite is disconnected from the input of the second-stage frequency converter unit 12. The output of the second-stage frequency converter unit 12 is connected to the high-orbit satellite. The signal transmission process is as follows: The satellite internet terminal transmits an intermediate frequency (IF) signal in the preset high-orbit uplink IF band (950MHz~2400MHz) to the first-stage frequency converter unit 11 via the high-orbit satellite IF transmitter. The first-stage frequency converter unit 11 then receives the signal from the preset high-orbit uplink IF band at its input, upscales it to the preset low-orbit uplink IF band, and outputs the preset low-orbit uplink IF band signal to the second-stage frequency converter unit 12.

[0056] The secondary frequency conversion unit 12 receives the preset low-orbit uplink intermediate frequency band signal output by the primary frequency conversion unit 11, up-frequencys it to the preset uplink radio frequency band (13.75GHz~14.5GHz), obtains the preset uplink radio frequency band signal and outputs it to the high-orbit satellite through the transmitting antenna, thus completing the conversion of the intermediate frequency to radio frequency band of the corresponding transmission link of the high-orbit satellite.

[0057] Furthermore, the receiving link frequency conversion module 2 is suitable for completing the frequency conversion of the signal receiving link of the satellite Internet terminal, that is, completing the frequency conversion process of converting the radio frequency signal transmitted by the low-orbit satellite into the intermediate frequency signal of the corresponding intermediate frequency band, or converting the radio frequency signal transmitted by the high-orbit satellite into the intermediate frequency signal of the corresponding intermediate frequency band.

[0058] The input of the receiving link frequency conversion module 2 is connected to the communication satellite through the receiving antenna, and the output of the receiving link frequency conversion module 2 is connected to the high-orbit satellite intermediate frequency receiver of the satellite Internet terminal and the low-orbit satellite intermediate frequency receiver of the satellite Internet terminal, respectively.

[0059] Specifically, the satellite internet terminal is equipped with a signal modem, which includes a high-orbit satellite signal modem and a low-orbit satellite signal modem.

[0060] For intermediate frequency (IF) signals received by satellite internet terminals from high-orbit satellites, they must first be demodulated by the high-orbit satellite signal modem before processing. Similarly, IF signals sent from low-orbit satellites must first be demodulated by the low-orbit satellite signal modem.

[0061] Therefore, the output of the receiving link frequency conversion module 2 is connected to the high-orbit satellite signal modem of the satellite Internet terminal through the high-orbit satellite intermediate frequency receiver, and to the low-orbit satellite signal modem of the satellite Internet terminal through the low-orbit satellite intermediate frequency receiver.

[0062] More specifically, the output of the receiving link frequency conversion module 2 may include a low-orbit intermediate frequency signal output (which is connected to a low-orbit satellite signal modem via a low-orbit satellite intermediate frequency receiver) and a high-orbit intermediate frequency signal output (which is connected to a high-orbit satellite signal modem via a high-orbit satellite intermediate frequency receiver).

[0063] It is worth noting that for satellite internet terminals where the intermediate frequency (IF) receiver for low-Earth orbit (LEO) satellites and the intermediate frequency (IF) receiver for high-Earth orbit (HEO) satellites share the same port (IF signal receiver), if the frequency converter is used for frequency conversion between the satellite internet terminal and the LEO satellite, then the IF signal receiver is connected to the output of the receiving link frequency converter module 2 (more specifically, to the LEO IF signal output of the receiving link frequency converter module 2) to connect to the LEO satellite signal modem, but not to the HEO IF signal output of the receiving link frequency converter module 2, so that the HEO satellite signal modem does not receive the corresponding IF signal.

[0064] Similarly, if the frequency converter is used for frequency conversion between the satellite internet terminal and the high-orbit satellite, the intermediate frequency signal receiver is used as the high-orbit satellite intermediate frequency receiver and is connected to the output of the receiving link frequency converter module 2 (more specifically, to the high-orbit intermediate frequency signal output of the receiving link frequency converter module 2) to connect to the high-orbit satellite signal modem, but not to the low-orbit intermediate frequency signal output of the receiving link frequency converter module 2.

[0065] Based on the above overall introduction of the receiving link frequency conversion module 2, specifically, when the communication satellite is a low-Earth orbit (LEO) satellite, the LEO satellite transmits a radio frequency signal at a preset downlink radio frequency band and transmits it to the receiving link frequency conversion module 2 via a receiving antenna. The receiving link frequency conversion module 2 reduces the frequency of the radio frequency signal from the preset downlink radio frequency band to a preset LEO downlink intermediate frequency band (i.e., 2GHz±125MHz) and outputs it to the satellite internet terminal. The LEO satellite signal modem of the satellite internet terminal receives the frequency-converted intermediate frequency signal transmitted by the LEO satellite and performs demodulation processing, thereby completing the radio frequency-intermediate frequency conversion of the signal receiving link corresponding to the LEO satellite.

[0066] When the communication satellite is a high-orbit satellite, the high-orbit satellite transmits radio frequency signals at a preset downlink radio frequency band and transmits them to the receiving link frequency conversion module 2 via the receiving antenna. The receiving link frequency conversion module 2 reduces the frequency of the radio frequency signal from the preset downlink radio frequency band to a preset high-orbit downlink intermediate frequency band (i.e., 950MHz to 2150MHz) and outputs it to the satellite Internet terminal. The high-orbit satellite signal modem of the satellite Internet terminal receives the intermediate frequency signal transmitted by the high-orbit satellite after frequency conversion and performs demodulation processing, thereby completing the radio frequency to intermediate frequency frequency conversion of the signal receiving link corresponding to the high-orbit satellite.

[0067] In the signal receiving link, the frequency conversion from radio frequency to intermediate frequency (from 10.7GHz to 12.75GHz to 950MHz to 2150MHz) for high-orbit satellites and the frequency conversion from radio frequency to intermediate frequency (from 10.7GHz to 12.75GHz to 2GHz±125MHz) for low-orbit satellites have similar conversion amplitudes, so they can share a single frequency conversion module.

[0068] In this embodiment, when a satellite internet terminal transmits signals to a communication satellite, the frequency conversion device can, through the architecture of the first-stage frequency conversion unit 11 and the second-stage frequency conversion unit 12 of the transmit link frequency conversion module 1, first upscale the intermediate frequency (IF) signal corresponding to the high-orbit satellite to the frequency band corresponding to the low-orbit satellite. Then, it can share the second-stage frequency conversion unit 12 with the low-orbit satellite's IF signal to complete the IF-RF conversion. This two-stage frequency conversion method can simultaneously cover the IF-RF signal conversion requirements of both high- and low-orbit satellites. Furthermore, when the communication satellite transmits signals to the satellite internet terminal, the receive link frequency conversion module 2 can fulfill the RF-IF signal conversion requirements of both high- and low-orbit satellites, thus enabling the frequency conversion device to support frequency conversion between IF and RF signals from both high- and low-orbit satellites.

[0069] Furthermore, using the frequency converter in this embodiment eliminates the need to purchase separate frequency converters for high-Earth orbit and low-Earth orbit satellites. A single device can meet the communication frequency conversion requirements of high-Earth orbit satellites, low-Earth orbit satellites, and satellite internet terminals, thus reducing equipment procurement costs. In the event of a communication satellite switchover, only the connection between the satellite internet terminal, the communication satellite, and the frequency converter needs to be modified, thereby saving on equipment investment costs.

[0070] Continue to combine Figure 1 As shown, in some exemplary embodiments, the first-stage frequency conversion unit 11 in the transmit link frequency conversion module 1 includes a first-stage frequency conversion circuit 111. The first-stage frequency conversion circuit 111 includes a first mixer 1112 and a first phase-locked loop 1111. The first mixer 1112 includes a local oscillator terminal, a mixer output terminal, and a mixer input terminal.

[0071] A mixer is a device that mixes an input signal with a local oscillator signal to adjust the frequency of the input signal. A mixer typically includes an RF terminal (also known as the LO terminal), an intermediate frequency terminal (also known as the IF terminal), and a radio frequency terminal (also known as the RF terminal). The mixing output terminal of the first mixer 1112 is the RF terminal of the mixer, and the mixing input terminal of the first mixer 1112 is the intermediate frequency terminal of the mixer.

[0072] Specifically, the local oscillator terminal of the first mixer 1112 is connected to the first phase-locked loop 1111, and can receive the local oscillator signal provided by the first phase-locked loop 1111. The mixer input terminal (i.e., the IF terminal) is connected to the high-orbit satellite intermediate frequency transmitter of the satellite internet terminal, and can receive the intermediate frequency signal sent by the satellite internet terminal when communicating with the high-orbit satellite. The mixer output terminal (i.e., the RF terminal) is connected to one input terminal of the second-stage frequency conversion unit 12.

[0073] The first phase-locked loop 1111 is capable of providing a local oscillator signal. In this embodiment, the frequency of the local oscillator signal provided by the first phase-locked loop 1111 may be, for example, 5.7 GHz.

[0074] When the satellite internet terminal communicates with a high-orbit satellite, the high-orbit satellite intermediate frequency transmitter of the satellite internet terminal is connected to the intermediate frequency terminal of the first mixer 1112, and inputs the intermediate frequency signal of the preset high-orbit uplink intermediate frequency band (0.95G~2.4GHz) to the intermediate frequency terminal of the first mixer 1112, which is the preset high-orbit uplink intermediate frequency band signal.

[0075] The first mixer 1112 mixes the preset high-rail uplink intermediate frequency band signal with the local oscillator signal provided by the first phase-locked loop 1111 to obtain a signal with a frequency in the preset low-rail uplink intermediate frequency band, and then outputs it from the mixer output terminal (i.e., the radio frequency terminal) to the secondary frequency conversion unit 12.

[0076] In other embodiments, the first mixer 1112 and the first phase-locked loop 1111 can also be used to convert the signal of the preset high-orbit uplink intermediate frequency band into a frequency band similar to the preset low-orbit uplink intermediate frequency band. For example, the signal of the preset high-orbit uplink intermediate frequency band of 0.95 GHz to 2.4 GHz can be mixed with the local oscillator signal of 5.7 GHz to obtain the signal of the 3.3 GHz to 4.75 GHz frequency band. The 3.3 GHz to 4.75 GHz frequency band is similar to the preset low-orbit uplink intermediate frequency band and can share the same frequency conversion circuit with the signal of the preset low-orbit uplink intermediate frequency band corresponding to the low-orbit satellite, that is, share the second-level frequency conversion unit 12 to realize the intermediate frequency to radio frequency conversion.

[0077] Therefore, through the first mixer 1112 and the first phase-locked loop 1111, when the satellite internet terminal sends an intermediate frequency signal to a high-orbit satellite, its frequency band can be converted from the preset high-orbit uplink intermediate frequency band to the intermediate frequency band of the signal transmission link corresponding to the low-orbit satellite (that is, the preset low-orbit uplink intermediate frequency band) or a frequency band close to the preset low-orbit uplink intermediate frequency band, so that it can share the secondary frequency conversion unit 12 with the low-orbit satellite to achieve frequency conversion.

[0078] Continue to combine Figure 1 As shown, the IF terminal of the first mixer 1112 receives a relatively high frequency high-orbit uplink intermediate frequency band signal (950MHz~2150MHz) sent by the satellite internet terminal. During the transmission of this signal to the first mixer 1112, if there is a large impedance difference between the satellite internet terminal and the first mixer 1112, signal reflection will occur, resulting in a weakening of the signal strength input to the first mixer 1112 or waveform distortion.

[0079] Therefore, in some exemplary embodiments, the first-stage frequency converter 11 may further include a resistive coupling circuit 112. The resistive coupling circuit 112 is disposed on the connection path between the intermediate frequency (IF) terminal of the first mixer 1112 and the high-orbit satellite IF transmitter of the satellite internet terminal. That is, the high-orbit satellite IF transmitter of the satellite internet terminal is connected to one end of the resistive coupling circuit 112, and the other end of the resistive coupling circuit 112 is connected to the mixing input terminal (i.e., the IF terminal) of the first mixer 1112.

[0080] When the satellite internet terminal sends a preset high-orbit uplink intermediate frequency band signal to a high-orbit satellite, the signal first undergoes impedance matching via a resistive coupling circuit 112. After impedance matching, the preset high-orbit uplink intermediate frequency band signal is transmitted to the intermediate frequency (IF) end of the first mixer 1112 for mixing. Therefore, by adding a resistive coupling circuit 112 between the first mixer 1112 and the high-orbit satellite IF transmitter of the satellite internet terminal, the impedance matching between the satellite internet terminal and the first mixer 1112 can be adjusted, reducing the probability of signal distortion caused by signal reflection due to impedance mismatch and improving the stability of the IF signal input to the first mixer 1112.

[0081] In some embodiments, the resistive coupling circuit 112 may specifically include a first resistor and a second resistor. One end of the first resistor is connected to the intermediate frequency (IF) terminal of the first mixer 1112, and the other end is connected to the high-orbit satellite IF transmitter of the satellite internet terminal. The first resistor is connected in series between the first mixer 1112 and the satellite internet terminal to suppress reflections. One end of the second resistor is connected to the IF terminal of the first mixer 1112, and the other end is grounded. Impedance matching is achieved through parallel resistors, which helps to improve the stability of signal transmission.

[0082] Continue to combine Figure 1 As shown, in some exemplary embodiments, the secondary frequency conversion unit 12 of the transmit link frequency conversion module 1 includes a switching element 121 and a secondary frequency conversion circuit 122.

[0083] The two-stage frequency converter circuit 122 may specifically include a second mixer and a second phase-locked loop (PLL). The second PLL provides a local oscillator signal of a corresponding frequency to the second mixer. The second PLL can provide multiple fixed-frequency local oscillator signals, allowing the user to select the desired frequency.

[0084] More specifically, the second phase-locked loop may include multiple oscillators and switching switches. Each oscillator is used to output a local oscillator signal at a corresponding fixed frequency. If a local oscillator signal at a preset frequency is required, the user can switch the local oscillator signal through the switching switch and provide the local oscillator signal at the preset frequency to the second mixer.

[0085] The switching element 121 includes a common terminal, a first switching terminal, and a second switching terminal. Specifically, the switching element 121 can be a single-pole double-throw switch. The first switching terminal is connected to the output terminal of the first-stage frequency conversion unit 11. The second switching terminal is used to connect to the low-orbit satellite intermediate frequency transmitter of the satellite internet terminal. The common terminal is connected to the input terminal of the second-stage frequency conversion circuit 122, and the output terminal of the second-stage frequency conversion circuit 122 is connected to the communication satellite through a transmitting antenna.

[0086] Specifically, when the frequency converter is used for frequency conversion in satellite internet terminal and high-orbit satellite communication, the switching element 121 is connected between the common terminal and the second switching terminal. The second phase-locked loop can be configured by the user to provide a local oscillator signal corresponding to the frequency of the high-orbit satellite, for example, it can be configured to provide a local oscillator signal of 12.8 GHz or 13.05 GHz. The first switching terminal receives the signal of the preset low-orbit uplink intermediate frequency band output by the first-stage frequency converter unit 11, and transmits it to the second-stage frequency converter circuit 122 via the first switching terminal and the common terminal. In the second-stage frequency converter circuit 122, the preset low-orbit uplink intermediate frequency band signal is mixed with the local oscillator signal provided by the second phase-locked loop to obtain a radio frequency signal of the preset uplink radio frequency band, i.e., the preset uplink radio frequency band signal, which is then output to the high-orbit satellite through the transmitting antenna.

[0087] When the frequency converter is used for frequency conversion between satellite internet terminal and low-Earth orbit satellite communication, the low-Earth orbit satellite intermediate frequency transmitter of the satellite internet terminal is connected to the second switch terminal, the common terminal of the switch element 121 is in a connected state with the second switch terminal, and the second phase-locked loop can be configured by the user to provide the local oscillator signal of the corresponding frequency point of the low-Earth orbit satellite, such as 14.0625GHz, 14.1875GHz, 14.3125GHz or 14.4375GHz.

[0088] The second switch receives the intermediate frequency signal of the preset low-orbit uplink intermediate frequency band sent by the satellite Internet terminal and transmits it to the secondary frequency conversion circuit 122. In the secondary frequency conversion circuit 122, the intermediate frequency signal is mixed with the preset uplink low-frequency local oscillator signal to convert its frequency into the preset uplink radio frequency band, thereby obtaining the radio frequency signal of the preset uplink radio frequency band, that is, obtaining the preset uplink radio frequency band signal, and outputting it to the low-orbit satellite through the transmitting antenna.

[0089] Therefore, according to the communication requirements (high orbit / low orbit) of the satellite Internet terminal, the signal transmission path can be switched by the switching element 121 to realize the frequency conversion of the two intermediate frequency signals. It is not necessary to design corresponding frequency conversion circuits for the two intermediate frequency signals separately. Instead, the frequency conversion of the intermediate frequency signals of the two frequency bands can be shared by using the two-stage frequency conversion circuit 122, which helps to reduce circuit complexity and hardware cost.

[0090] Continue to combine Figure 1 As shown, in some exemplary embodiments, to improve the quality and transmission capability of the uplink radio frequency signal, the secondary frequency converter 12 further includes a first signal amplifier 123 and a first filter 124. The first signal amplifier 123 and the first filter 124 are disposed in the connection path between the output of the secondary frequency converter circuit 122 and the communication satellite.

[0091] Specifically, the input terminal of the first signal amplifier 123 is connected to the output terminal of the second-stage frequency converter circuit 122, the output terminal of the first signal amplifier 123 is connected to the input terminal of the first filter 124, and the output terminal of the first filter 124 is connected to the communication satellite through the transmitting antenna.

[0092] The frequency conversion of the secondary frequency conversion circuit 122 will cause a certain attenuation of the signal strength. The first signal amplifier 123 is used to compensate for the signal attenuation during the frequency conversion process. It can increase the signal strength by gain amplification, so as to reduce the probability that the communication satellite cannot receive the signal stably due to the weak signal strength of the preset uplink radio frequency band output by the secondary frequency conversion circuit 122.

[0093] After the signal in the preset uplink radio frequency band passes through the first signal amplifier 123 to enhance the signal strength, it then passes through the first filter 124. The first filter 124 can filter out interference signals such as harmonics or noise in the preset uplink radio frequency band signal (e.g., signals from other frequency bands generated during the mixing process). The first filter 124 only allows the target radio frequency signal of 13.75GHz~14.5GHz (that is, the preset uplink radio frequency band) to pass through, so as to filter out noise and improve the stability of satellite communication.

[0094] For example, after the secondary frequency converter circuit 122 outputs a radio frequency signal in the 13.75GHz~14.5GHz frequency band (that is, the preset uplink radio frequency band), it is amplified by the first signal amplifier 123 to increase the signal strength. The amplified radio frequency signal is input to the first filter 124. The first filter 124 only allows signals in the 13.75GHz~14.5GHz range to pass through. The local oscillator leakage signal generated by mixing and other noise interference signals can be effectively filtered out. The filtered radio frequency signal is transmitted to the communication satellite through the transmitting antenna, so that the communication satellite can stably receive and process the radio frequency signal.

[0095] Continue to combine Figure 1 As shown, in some exemplary embodiments, the secondary frequency converter unit 12 may further include a signal strength attenuator 125, which is disposed in the connection path between the common terminal of the switching element 121 and the input terminal of the secondary frequency converter circuit 122. That is, by placing the signal strength attenuator 125 between the switching element 121 and the secondary frequency converter circuit 122, the strength of the intermediate frequency signal input to the secondary frequency converter circuit 122 can be balanced to prevent the secondary frequency converter circuit 122 from overloading and burning out components due to excessively high signal strength.

[0096] Continue to combine Figure 1 As shown, in some exemplary embodiments, the receive link frequency conversion module 2 includes a downlink frequency conversion circuit 21 and a power distribution circuit 22.

[0097] Specifically, the input terminal of the downlink frequency converter circuit 21 is connected to the communication satellite through the aforementioned receiving antenna, and the output terminal of the downlink frequency converter circuit 21 is connected to the input terminal of the power distribution circuit 22.

[0098] The downlink frequency converter circuit 21 is used to down-convert the Ku-band radio frequency signal transmitted by the satellite to an intermediate frequency signal. Specifically, it may include a third phase-locked loop and a third mixer. The radio frequency terminal of the third mixer serves as the input terminal of the downlink frequency converter circuit 21 and is connected to the communication satellite. The local oscillator terminal of the third mixer is connected to the third phase-locked loop. The intermediate frequency terminal of the third mixer serves as the output terminal of the downlink frequency converter circuit 21, outputting the frequency-converted signal.

[0099] The third phase-locked loop is used to provide a local oscillator signal of a corresponding frequency, wherein the frequency of the local oscillator signal provided by the third phase-locked loop can be configured by the user as needed.

[0100] When the satellite internet terminal communicates with a low-Earth orbit (LEO) satellite, the input of the downlink frequency conversion circuit 21 is connected to the LEO satellite via a receiving antenna, and receives the radio frequency signal transmitted by the LEO satellite in the preset downlink radio frequency band (10.7GHz to 12.75GHz) via the receiving antenna. At this time, the local oscillator signal provided by the third phase-locked loop can be set by the user according to the frequency of the radio frequency signal transmitted by the LEO satellite. For example, when communicating with an LEO satellite, the frequency of the down-converted local oscillator signal can be set to 10.825GHz, or 11.075GHz, 11.325GHz, 11.575GHz, 11.825GHz, 12.075GHz, 12.325GHz, 12.575GHz, etc. In this way, the third mixer can mix the local oscillator signal with the preset downlink radio frequency band (10.7GHz~12.75GHz) radio frequency signal to obtain the preset low rail downlink intermediate frequency band (2GHz±125MHz) intermediate frequency signal, and output it to the power distribution circuit 22.

[0101] When the satellite internet terminal communicates with a high-orbit satellite, the input of the downlink frequency conversion circuit 21 is connected to the high-orbit satellite via a receiving antenna, and receives the radio frequency signal (RF signal) transmitted by the high-orbit satellite in a preset downlink RF band (10.7GHz~12.75GHz) via the receiving antenna. At this time, the local oscillator signal provided by the third phase-locked loop can be set by the user according to the frequency of the RF signal transmitted by the high-orbit satellite. For example, when communicating with a high-orbit satellite, the frequency of the downconverted local oscillator signal can be set to 9.75GHz or 10.6GHz. In this way, the third mixer can mix the local oscillator signal with the RF signal in the preset downlink RF band (10.7GHz~12.75GHz) to obtain the intermediate frequency signal in the preset high-orbit downlink intermediate frequency band (950MHz~2150MHz), and output it to the power distribution circuit 22.

[0102] The power distribution circuit 22 is adapted to divide one input signal into two output signals. The output terminals of the power distribution circuit 22 include a first power-dividing output terminal and a second power-dividing output terminal. The first power-dividing output terminal is connected to the high-orbit satellite intermediate frequency (IF) receiver of the satellite internet terminal, and through the IF receiver, it is connected to the aforementioned high-orbit satellite signal modem. The second power-dividing output terminal is connected to the low-orbit satellite intermediate frequency (IF) receiver of the satellite internet terminal, and through the IF receiver, it is connected to the aforementioned low-orbit satellite signal modem.

[0103] Specifically, the power distribution circuit 22 can be a Y-type resistor power divider, which uses a symmetrical resistor network to divide one input signal into two output signals.

[0104] For example, the power distribution circuit 22 can be a Y-shaped resistor network. This resistor network consists of three resistors forming a "Y"-shaped topology, specifically including a first power divider resistor, a second power divider resistor, and a third power divider resistor. One end of the first power divider resistor serves as the input terminal of the power distribution circuit 22. The other end of the first power divider resistor is connected to one end of the second power divider resistor and one end of the third power divider resistor. The other end of the second power divider resistor serves as the first power divider output terminal, and the other end of the third power divider resistor serves as the second power divider output terminal. In this way, the power distribution circuit 22 can split one input signal into two output signals, and the strength of the two output signals is determined by the resistance values ​​of the first, second, and third power divider resistors.

[0105] Specifically, when the satellite internet terminal communicates with a high-orbit satellite, the user can connect the high-orbit satellite intermediate frequency receiver of the satellite internet terminal to the first power divider output terminal. The low-orbit satellite intermediate frequency receiver of the satellite internet terminal does not establish a connection with the second power divider output terminal, that is, the second power divider output terminal and the low-orbit satellite intermediate frequency receiver of the satellite internet terminal are in a disconnected state.

[0106] In this way, the downlink frequency conversion circuit 21 outputs the intermediate frequency signal of the preset high-orbit downlink intermediate frequency band (950MHz~2150MHz) to the power distribution circuit 22. The power distribution circuit 22 can divide the original single preset high-orbit downlink intermediate frequency band intermediate frequency signal into two paths according to the equal power distribution method. The frequencies of both signals are within the preset high-orbit downlink intermediate frequency band. One of the divided signals is output to the first power divider output terminal, and the other signal is output to the second power divider output terminal. Since the high-orbit satellite intermediate frequency receiver of the satellite Internet terminal is connected to the first power divider output terminal at this time, it can receive the signal of the preset high-orbit downlink intermediate frequency band transmitted by the high-orbit satellite and after frequency conversion from the high-orbit satellite intermediate frequency receiver, and then demodulate and process it by the high-orbit satellite signal modem.

[0107] Similarly, when a satellite internet terminal communicates with a low-Earth orbit satellite, the user does not need to establish a connection between the high-Earth orbit satellite intermediate frequency receiver of the satellite internet terminal and the first power divider output terminal; that is, the first power divider output terminal and the high-Earth orbit satellite intermediate frequency receiver of the satellite internet terminal are disconnected. Furthermore, the user connects the low-Earth orbit satellite intermediate frequency receiver of the satellite internet terminal to the second power divider output terminal.

[0108] In this way, the downlink frequency conversion circuit 21 outputs the intermediate frequency signal of the preset low-Earth orbit downlink intermediate frequency band (2GHz±125MHz) to the power distribution circuit 22. The power distribution circuit 22 divides the original single preset low-Earth orbit downlink intermediate frequency band intermediate frequency signal into two paths according to the equal power distribution method. One of the paths is output to the first power divider output terminal, and the other is output to the second power divider output terminal and then to the low-Earth orbit satellite intermediate frequency receiver of the satellite internet terminal. The satellite internet terminal receives the preset low-Earth orbit downlink intermediate frequency band signal transmitted from the low-Earth orbit satellite after frequency conversion, and then performs demodulation and processing by the low-Earth orbit satellite signal modem.

[0109] Therefore, for this signal receiving link, the receiving link module can be compatible with the frequency conversion of radio frequency signals transmitted by high-orbit and low-orbit satellites, and the intermediate frequency signal can be split and output through the power distribution circuit 22, so that the satellite Internet terminal can receive the corresponding intermediate frequency signal. Thus, the downlink frequency conversion circuit 21 can be compatible with the frequency conversion requirements of high-orbit and low-orbit signal receiving links, and can be shared.

[0110] Continue to combine Figure 1 As shown, in some exemplary embodiments, the receive link frequency converter module 2 further includes a second signal amplifier 23 and a second filter 24.

[0111] The second signal amplifier 23 and the second filter 24 can be installed in the connection path between the downlink frequency converter circuit 21 and the communication satellite, that is, adding the second signal amplifier 23 and the second filter 24 before the input terminal of the downlink frequency converter circuit 21. Specifically, the input terminal of the second signal amplifier 23 is connected to the communication satellite through a receiving antenna, the output terminal of the second signal amplifier 23 is connected to the input terminal of the second filter 24, and the output terminal of the second filter 24 is connected to the input terminal of the downlink frequency converter circuit 21.

[0112] Because the radio frequency signal transmitted from the communication satellite to the ground is weak due to atmospheric attenuation and long transmission distance, the radio frequency signal transmitted by the communication satellite will first pass through the second signal amplifier 23 to pre-amplify the radio frequency signal so that the signal strength input to the downlink frequency conversion circuit 21 can meet the requirements of the downlink frequency conversion circuit 21, thereby reducing the probability that the signal strength is too weak to achieve effective frequency conversion.

[0113] Meanwhile, the amplified radio frequency signal can also pass through the second filter 24 to filter out interference signals in the ground environment (such as filtering signals that do not belong to the preset downlink radio frequency band). After amplification and filtering, the amplified and filtered radio frequency signal is output to the downlink frequency conversion circuit 21 for frequency conversion, thereby improving the quality of the intermediate frequency signal obtained after frequency conversion.

[0114] Continue to combine Figure 1 As shown, in some exemplary embodiments, the receiving link frequency conversion module 2 may further include a first power compensation circuit 25 disposed between the first power divider output terminal and the high-orbit satellite intermediate frequency receiver of the satellite internet terminal, and a second power compensation circuit 26 disposed between the second power divider output terminal and the low-orbit satellite intermediate frequency receiver of the satellite internet terminal.

[0115] Specifically, the input terminal of the first power compensation circuit 25 is connected to the output terminal of the first power divider, and the output terminal of the first power compensation circuit 25 is connected to the high-orbit satellite intermediate frequency (IF) receiver of the satellite internet terminal, and through the high-orbit satellite IF receiver, it is connected to the high-orbit satellite signal modem of the satellite internet terminal. The input terminal of the second power compensation circuit 26 is connected to the output terminal of the second power divider, and the output terminal of the second power compensation circuit 26 is connected to the low-orbit satellite IF receiver of the satellite internet terminal, and through the low-orbit satellite IF receiver, it is connected to the low-orbit satellite signal modem of the satellite internet terminal.

[0116] The intermediate frequency signal obtained after frequency conversion by downlink frequency conversion circuit 21 is divided by the power distribution circuit 22. The two intermediate frequency signals obtained may have a certain strength difference. Furthermore, the requirements of satellite Internet terminal for the signal strength of intermediate frequency signals corresponding to high orbit and low orbit may be different (e.g., the strength of the downlink intermediate frequency signal sent to the satellite Internet terminal by the high orbit satellite is slightly lower than the strength of the downlink intermediate frequency signal sent to the satellite Internet terminal by the low orbit satellite).

[0117] In this embodiment, a power compensation circuit is independently provided after the first power divider output terminal and the second power divider output terminal, that is, a corresponding first power compensation circuit 25 and a second power compensation circuit 26 are respectively provided to compensate for the strength requirements of the corresponding intermediate frequency signals before outputting. This helps to ensure that the signal strength of the intermediate frequency signal input to the satellite internet terminal meets the requirements of the satellite internet terminal, reducing the probability of the signal not being received due to the signal strength not meeting the requirements.

[0118] Continue to combine Figure 1 As shown, in some exemplary embodiments, the first power compensation circuit 25 includes a third signal amplifier 251 and an impedance matching circuit 252.

[0119] Specifically, the input terminal of the third signal amplifier 251 is connected to the output terminal of the first power divider, the output terminal of the third signal amplifier 251 is connected to the input terminal of the impedance matching circuit 252, the output terminal of the impedance matching circuit 252 is connected to the high-orbit satellite intermediate frequency receiver of the satellite internet terminal, and is connected to the high-orbit satellite signal modem through the high-orbit satellite intermediate frequency receiver.

[0120] The third signal amplifier 251 is used to increase the strength of the signal output from the first power output terminal so that the signal strength can meet the requirements of the satellite internet terminal after the satellite internet terminal receives the signal, so that the high-orbit satellite signal modem of the satellite internet terminal can successfully demodulate the signal.

[0121] Furthermore, there is often a difference between the output impedance of the third signal amplifier 251 and the input impedance of the intermediate frequency receiver of the high-orbit satellite in the satellite internet terminal, which may lead to signal reflection loss. Therefore, an impedance matching circuit 252 is also provided at the output of the third signal amplifier 251. This impedance matching circuit 252 can specifically adopt an LCπ network topology, and achieve impedance matching through the capacitive reactance and inductive reactance of the inductor and capacitor to reduce signal reflection loss and the probability of signal distortion caused by impedance mismatch, thereby improving the stability of signal transmission.

[0122] Correspondingly, the second power compensation circuit 26 includes a fourth signal amplifier and another impedance matching circuit. The connection relationship between the fourth signal amplifier and the other impedance matching circuit can be referenced to the connection relationship between the third signal amplifier 251 and the aforementioned impedance matching circuit 252. Figure 1 The connection relationships shown are not elaborated here.

[0123] In some embodiments, the receiving link frequency conversion module 2 may further include a fifth signal amplifier. The fifth signal amplifier is disposed between the power distribution circuit 22 and the downlink frequency conversion circuit 21. This fifth signal amplifier can increase the strength of the signal input to the power distribution circuit 22, preventing the signal strength after the signal is divided into two paths by the power distribution circuit 22 from being too low, thereby increasing the signal strength in advance and improving signal transmission stability.

[0124] It is worth noting that, regarding the frequency converter of this embodiment, based on the above exemplary implementations, in specific implementation, as a preferred embodiment, it is still based on... Figure 1 As shown, it may include, for example: When the frequency converter is used for frequency conversion between a satellite internet terminal and a high-orbit satellite, the user needs to connect the intermediate frequency signal transmitting end of the satellite internet terminal (more specifically, the high-orbit satellite intermediate frequency transmitting end of the satellite internet terminal) to the input end of the first-level frequency conversion unit 11 in the transmitting link frequency conversion module 1 of the frequency converter, connect the output end of the second-level frequency conversion unit 12 to the high-orbit satellite through the transmitting antenna, connect the input end of the receiving link frequency conversion module 2 to the high-orbit satellite, connect the intermediate frequency signal receiving end of the satellite internet terminal (more specifically, the high-orbit satellite intermediate frequency receiving end of the satellite internet terminal) to the first power divider output end of the receiving link frequency conversion module 2, and set the switching element 121 to a state where the common end and the first switching end are closed.

[0125] At this time, the port in the secondary frequency converter unit 12 used to connect to the low-orbit satellite intermediate frequency transmitter of the satellite internet terminal (that is, the second switch terminal of the switching element 121) is in a disconnected state, that is, it is not connected to the satellite internet terminal and there is no signal input.

[0126] In addition, at this time, the output end of the receiving link frequency conversion module 2 (more specifically, the second power divider output end) is not connected to the low-orbit satellite intermediate frequency receiver of the satellite internet terminal, and there is no signal output.

[0127] The signal transmission process between the satellite internet terminal and the communication satellite is divided into an uplink signal transmission process (the satellite internet terminal sends signals to the communication satellite) and a downlink signal transmission process (the communication satellite sends signals to the satellite internet terminal).

[0128] Specifically, the uplink signal transmission process from the satellite internet terminal to the high-orbit satellite is as follows: the intermediate frequency (IF) transmitter of the high-orbit satellite of the satellite internet terminal outputs an IF signal of 0.95 GHz to 2.4 GHz, which is transmitted through the resistive coupling circuit 112 to the IF terminal of the first mixer 1112 of the first-stage frequency conversion unit 11. After mixing with the 5.7 GHz local oscillator signal provided by the first phase-locked loop 1111, an IF signal of 3.3 GHz to 4.75 GHz is generated, which is then output from the RF terminal of the first mixer 1112 to the first switching terminal of the switching element 121 of the second-stage frequency conversion unit 12.

[0129] Since the switching element 121 is in the closed state between the common terminal and the first switching terminal, the converted intermediate frequency signal is input to the signal strength attenuator 125 through the common terminal, and then enters the intermediate frequency terminal of the second mixer of the secondary frequency conversion circuit 122. It is mixed with the local oscillator signal (12.8GHz, 13.05GHz) provided by the second phase-locked loop to generate a Ku-band radio frequency signal of 13.75GHz~14.5GHz. After filtering and amplification, it is transmitted to the high-orbit satellite to complete the uplink signal transmission from the satellite Internet terminal to the high-orbit satellite.

[0130] Meanwhile, the downlink signal transmission process from the high-orbit satellite to the satellite internet terminal is as follows: The 10.7GHz~12.75GHz radio frequency signal transmitted by the high-orbit satellite is received by the antenna of the receiving link frequency conversion module 2, filtered and amplified, and then input to the radio frequency terminal of the third mixer of the downlink frequency conversion circuit 21. It is then mixed with the local oscillator signal (9.75GHz, 10.6GHz) provided by the third phase-locked loop to obtain an intermediate frequency signal of 0.95GHz~2.15GHz. This intermediate frequency signal is evenly split into two paths by the power distribution circuit 22. The first path, after passing through the first power compensation circuit 25, is transmitted to the high-orbit satellite intermediate frequency receiver of the satellite internet terminal, and then to the high-orbit satellite signal modem of the satellite internet terminal for demodulation. The second path, after passing through the second power compensation circuit 26, is not transmitted to the low-orbit satellite intermediate frequency receiver of the satellite internet terminal because it is not connected to it, thus completing the downlink signal transmission from the high-orbit satellite to the satellite internet terminal.

[0131] When the frequency converter is modified for use in satellite internet terminal communication with low-Earth orbit satellites, the user needs to directly connect the intermediate frequency signal transmitting end of the satellite internet terminal (more specifically, the low-Earth orbit satellite intermediate frequency transmitting end of the satellite internet terminal) to the second switch terminal of the switching element 121 of the secondary frequency conversion unit 12 in the transmitting link frequency conversion module 1 of the frequency converter, and connect the output end of the secondary frequency conversion unit 12 to the low-Earth orbit satellite communication. Connect the input end of the receiving link frequency conversion module 2 to the low-Earth orbit satellite communication, and at the same time connect the intermediate frequency signal receiving end of the satellite internet terminal (more specifically, the low-Earth orbit satellite intermediate frequency receiving end of the satellite internet terminal) to the second power divider output end of the receiving link frequency conversion module 2. At this time, the switching element 121 is set to a state where the common terminal and the second switch terminal are closed.

[0132] At this time, the input terminal of the first-level frequency conversion unit 11 in the transmit link frequency conversion module 1 is in a disconnected state because it does not need to process the high-orbit intermediate frequency signal. It is not connected to the high-orbit satellite intermediate frequency transmitter of the satellite internet terminal and there is no signal input. The first power divider output terminal of the receive link frequency conversion module 2 is also not connected to the high-orbit satellite intermediate frequency receiver of the satellite internet terminal and there is no signal output.

[0133] At this time, the uplink signal transmission process from the satellite internet terminal to the low-Earth orbit satellite is as follows: The satellite internet terminal outputs an intermediate frequency (IF) signal of 4GHz±62.5MHz through the IF transmitter of the low-Earth orbit (LEO) satellite. This IF signal is directly transmitted to the second switch terminal of the switching element 121 of the secondary frequency conversion unit 12. Since the common terminal and the second switch terminal of the switching element 121 are closed, the IF signal enters the signal strength attenuator 125 through the common terminal and is then input to the IF terminal of the second mixer of the secondary frequency conversion circuit 122. It is mixed with the local oscillator signal (e.g., frequencies of 14.0625GHz, 14.1875GHz, 14.3125GHz, and 14.4375GHz) provided by the second phase-locked loop inside the second mixer to generate a Ku-band radio frequency signal of 13.75GHz~14.5GHz. After filtering and amplification, the signal is transmitted to the LEO satellite through the output terminal of the secondary frequency conversion unit 12, thus completing the uplink communication from the ground to the LEO satellite.

[0134] The downlink signal transmission process from the satellite internet terminal to the low-Earth orbit satellite is as follows: The 10.7GHz~12.75GHz Ku-band radio frequency signal transmitted by the low-Earth orbit satellite is received by the antenna of the receiving link frequency conversion module 2. After amplification and filtering, the radio frequency signal enters the radio frequency terminal of the third mixer of the downlink frequency conversion circuit 21, and is mixed with the local oscillator signal (such as 10.825GHz, 11.075GHz, 11.325GHz, 11.575GHz, 11.825GHz, 12.075GHz, 12.325GHz, 12.575GHz) provided by the third phase-locked loop to generate an intermediate frequency signal of 2GHz±125MHz. This intermediate frequency signal is input to the power distribution circuit 22, and is evenly split into two paths by the internal resistor network. The second path enters the second power compensation circuit 26, and is then transmitted to the low-Earth orbit satellite intermediate frequency receiver of the satellite internet terminal. After that, it is transmitted to the low-Earth orbit satellite signal modem of the satellite internet terminal for demodulation processing, realizing downlink communication from the low-Earth orbit satellite to the satellite internet terminal. It is worth noting that the first signal output from the power distribution circuit 22, after passing through the first power compensation circuit 25, will not be transmitted to the high-orbit satellite intermediate frequency receiver of the satellite internet terminal because the first power distribution output is not connected to the satellite internet terminal.

[0135] In the above preferred embodiments, the specific settings and arrangements of the primary frequency converter 11, the secondary frequency converter 12, the power distribution network, etc. can still be referred to the descriptions in the above exemplary embodiments. Furthermore, in this preferred embodiment, the beneficial effects brought about by the design of the primary frequency converter 11, the secondary frequency converter 12, the power distribution network, etc. can also be referred to the descriptions in the above exemplary embodiments.

[0136] The frequency conversion device in this embodiment, using the design described above, can upscale the intermediate frequency (IF) signal from a satellite internet terminal to a communication satellite. This can be achieved through the architecture of the primary frequency conversion unit 11 and the secondary frequency conversion unit 12 in the transmit link frequency conversion module 1. For high-orbit satellites, the IF signal can be upscaled to the frequency band of the IF signal corresponding to low-orbit satellites. Then, it can share the secondary frequency conversion unit 12 with the IF signal corresponding to the low-orbit satellite to complete the IF-RF conversion. This two-stage frequency conversion method can simultaneously cover the IF-RF signal conversion requirements of both high- and low-orbit satellites. Furthermore, when the communication satellite transmits signals to the satellite internet terminal, the RF-IF signal conversion requirements of high- and low-orbit satellites can be met through the receive link frequency conversion module 2. This allows the frequency conversion device to support frequency conversion between IF and RF signals from high- and low-orbit satellites.

[0137] Furthermore, it's worth noting that using the frequency converter in this embodiment eliminates the need to purchase separate frequency converters for high-Earth orbit and low-Earth orbit satellites. A single device can meet the communication frequency conversion requirements of high-Earth orbit satellites, low-Earth orbit satellites, and satellite internet terminals, thus reducing equipment procurement costs. In the event of a communication satellite switchover, only the connections between the satellite internet terminal, the communication satellite, and the frequency converter need to be modified, further saving on equipment investment costs.

[0138] Meanwhile, through the first mixer 1112 and the first phase-locked loop 1111 included in the first-level frequency conversion unit 11, the local oscillator signal provided by the first phase-locked loop 1111 can be mixed with the intermediate frequency signal sent by the satellite internet terminal to the high-orbit satellite by the first mixer 1112 to obtain the intermediate frequency signal of the preset low-orbit uplink intermediate frequency band. In this way, the second-level frequency conversion unit 12 can be shared with the low-orbit satellite to realize the frequency conversion from the preset low-orbit uplink intermediate frequency band to the preset uplink radio frequency band.

[0139] In addition, in this embodiment, a resistive coupling circuit 112 is set on the connection path between the intermediate frequency end of the first mixer 1112 and the high-orbit satellite intermediate frequency transmission end of the satellite internet terminal to adjust the impedance matching state between the satellite internet terminal and the first mixer 1112, reduce the probability of signal distortion caused by signal reflection due to impedance mismatch, and improve the stability of the intermediate frequency signal input to the first mixer 1112.

[0140] In this embodiment, the secondary frequency conversion unit 12 can realize the conversion between the preset low-orbit uplink intermediate frequency band and the preset uplink radio frequency band through the secondary frequency conversion circuit 122. Furthermore, the switching element 121 can switch between the secondary frequency conversion of the intermediate frequency signal corresponding to the high-orbit satellite and the frequency conversion of the intermediate frequency signal corresponding to the low-orbit satellite, and both are realized through the secondary frequency conversion unit 12. It is not necessary to set up two separate frequency conversion circuits for the secondary frequency conversion of the high-orbit satellite and the frequency conversion of the low-orbit satellite, which helps to reduce circuit complexity and hardware cost.

[0141] Secondly, in this embodiment, the first filter 124 and the first signal amplifier 123 can enhance the signal strength and filter out interference signals such as noise, so that the radio frequency signal output to the communication satellite can be stably received and demodulated by the communication satellite. The signal strength attenuator 125 set before the input of the secondary frequency converter circuit 122 can prevent the secondary frequency converter circuit 122 from being overloaded and burning out its components due to excessively high signal strength.

[0142] In this embodiment, the receiving link module can be compatible with the frequency conversion of radio frequency signals to intermediate frequency signals transmitted by high-orbit and low-orbit satellites, and the intermediate frequency signal is split and output through the power distribution circuit 22, so that the satellite Internet terminal can receive the corresponding intermediate frequency signal. Thus, the receiving link module can be compatible with the frequency conversion requirements of radio frequency to intermediate frequency for high-orbit and low-orbit satellites.

[0143] Furthermore, in this embodiment, the radio frequency signal transmitted by the communication satellite can be amplified and filtered by the second signal amplifier 23 and the second filter 24 before being input to the downlink frequency conversion circuit 21, so as to prevent the situation where the signal strength is too low and the frequency conversion cannot be achieved. In addition, filtering out interference signals can also improve the quality of the intermediate frequency signal obtained by the downlink frequency conversion circuit 21.

[0144] In this embodiment, a first power compensation circuit 25 and a second power compensation circuit 26 are respectively set after the first power distribution output terminal and the second power distribution output terminal of the power distribution circuit 22. The output intermediate frequency signal strength can be compensated according to the strength requirements of the corresponding high-orbit or low-orbit satellite before output, thereby reducing the probability that the intermediate frequency signal is difficult to be received by the satellite Internet terminal due to the signal strength not meeting the requirements.

[0145] In addition, in this embodiment, a third signal amplifier 251 and an impedance matching circuit 252 are provided in the first power compensation circuit 25. This can not only compensate for the strength of the intermediate frequency signal, but also achieve impedance matching between the satellite internet terminal and the frequency converter through the impedance matching circuit 252, thereby reducing the probability of signal distortion caused by impedance mismatch to the satellite internet terminal.

[0146] An embodiment of the second aspect of this application provides a terminal device, which includes a satellite internet terminal and the frequency converter described in the first aspect embodiment. One end of the frequency converter is connected to the satellite internet terminal (specifically, a signal modem connected to the satellite internet terminal), and the other end of the frequency converter is connected to a communication satellite communicating with the satellite internet terminal via a satellite antenna.

[0147] The satellite antenna may specifically include a transmitting antenna and a receiving antenna. The transmitting antenna is used to send radio frequency signals to the communication satellite, and the receiving antenna is used to receive the radio frequency signals sent by the communication satellite.

[0148] Specifically, the terminal device includes, but is not limited to: mobile terminals such as mobile phones, laptops, digital radio receivers, PDAs (personal digital assistants), PADs (tablet computers), PMPs (portable multimedia players), and in-vehicle terminals (such as in-vehicle navigation terminals), as well as fixed terminals such as digital TVs and desktop computers.

[0149] Specifically, the satellite internet terminal can be a core functional module in the terminal device, used to receive the intermediate frequency signal output by the frequency converter and demodulate it using the corresponding signal modem, or output the intermediate frequency signal and transmit it to the frequency converter, which then performs frequency conversion processing and transmits it to the communication satellite via the transmitting antenna.

[0150] The terminal device connects to a communication satellite via a transmitting antenna and a receiving antenna. The radio frequency (RF) signal received by the satellite via the receiving antenna is converted into an intermediate frequency (IF) signal by a frequency converter within the terminal device and then output to the modem of the satellite internet terminal for demodulation. When the terminal device transmits a signal to the communication satellite, the satellite internet terminal sends an IF signal, which is then converted into an RF signal of the corresponding frequency by the frequency converter and transmitted to the communication satellite via the transmitting antenna.

[0151] Furthermore, in the terminal device of this embodiment, when transmitting intermediate frequency (IF) signals to communication satellites, the satellite internet terminal also transmits IF signals. Through the two-stage frequency conversion architecture of the transmit link frequency conversion module 1 of the frequency conversion device, the IF-RF signal conversion requirements of both high-Earth orbit and low-Earth orbit satellites are simultaneously covered. Moreover, when receiving RF signals transmitted by communication satellites, the frequency conversion device can fulfill the RF-IF signal conversion requirements of high-Earth orbit and low-Earth orbit satellites. This enables the terminal device to support frequency conversion between IF and RF signals from high-Earth orbit and low-Earth orbit satellites.

[0152] An embodiment of the third aspect of this application provides a vehicle, which may specifically include the terminal equipment described in the embodiments of the second aspect above.

[0153] Specifically, the terminal device can be an in-vehicle terminal device, configured in a vehicle.

[0154] This vehicle, through its onboard terminal equipment, can simultaneously transmit intermediate frequency (IF) signals to communication satellites via its satellite internet terminal, and achieve simultaneous coverage of IF-RF signal conversion requirements for both high-Earth orbit (HEO) and low-Earth orbit (LEO) satellites through a two-stage frequency conversion architecture in the transmit link frequency conversion module 1 of the frequency conversion device. Furthermore, when receiving RF signals transmitted from communication satellites, the frequency conversion device can also fulfill the RF-IF signal conversion requirements for HEO and LE satellites. This allows the vehicle, through its terminal equipment, to support frequency conversion between IF and RF signals from HEO and LE satellites.

[0155] The above are merely some embodiments of this application and are not intended to limit this application. The technical features or structures in the foregoing different embodiments can be arbitrarily combined to form other specific technical solutions as needed. For those skilled in the art, this application can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the protection scope of the claims of this application.

Claims

1. A frequency conversion device suitable for converting intermediate frequency signals and radio frequency signals of high-orbit and low-orbit satellites, characterized in that: It includes a transmit link frequency conversion module (1) and a receive link frequency conversion module (2); The transmit link frequency conversion module (1) includes a first-level frequency conversion unit (11) adapted to convert a preset high-orbit uplink intermediate frequency band signal into a preset low-orbit uplink intermediate frequency band signal, and a second-level frequency conversion unit (12) adapted to convert the preset low-orbit uplink intermediate frequency band signal into a preset uplink radio frequency band signal. The input terminal of the first-level frequency conversion unit (11) is connected to the high-orbit satellite intermediate frequency transmission terminal of the satellite internet terminal. The input terminal of the second-level frequency conversion unit (12) is connected to the output terminal of the first-level frequency conversion unit (11) and the low-orbit satellite intermediate frequency transmission terminal of the satellite internet terminal. The output terminal of the second-level frequency conversion unit (12) is connected to the communication satellite communicating with the satellite internet terminal through the transmitting antenna. The input end of the receiving link frequency conversion module (2) is connected to the communication satellite via the receiving antenna, and the output end of the receiving link frequency conversion module (2) is connected to the high-orbit satellite intermediate frequency receiving end of the satellite Internet terminal and the low-orbit satellite intermediate frequency receiving end of the satellite Internet terminal.

2. The frequency converter according to claim 1, characterized in that: The first-stage frequency conversion unit (11) includes a first-stage frequency conversion circuit (111), which includes a first mixer (1112) and a first phase-locked loop (1111). The first mixer (1112) includes a local oscillator terminal, a mixer output terminal and a mixer input terminal. The local oscillator terminal is connected to the first phase-locked loop (1111), the mixer input terminal is connected to the high-orbit satellite intermediate frequency transmitter of the satellite internet terminal, and the mixer output terminal is connected to one input terminal of the secondary frequency conversion unit (12).

3. The frequency converter according to claim 2, characterized in that: The primary frequency converter unit (11) also includes a resistive coupling circuit (112): The resistive coupling circuit (112) is set on the connection path between the mixing input terminal of the first mixer (1112) and the high-orbit satellite intermediate frequency transmitter of the satellite Internet terminal.

4. The frequency converter according to claim 1, characterized in that: The secondary frequency conversion unit (12) includes a switching element (121) and a secondary frequency conversion circuit (122); The switching element (121) includes a common terminal, a first switching terminal and a second switching terminal. The first switching terminal is connected to the output terminal of the first-level frequency conversion unit (11), and the second switching terminal is used to connect to the low-orbit satellite intermediate frequency transmission terminal of the satellite Internet terminal. The common terminal is connected to the input terminal of the secondary frequency converter circuit (122), and the output terminal of the secondary frequency converter circuit (122) is connected to the communication satellite through the transmitting antenna.

5. The frequency converter according to claim 4, characterized in that: The secondary frequency conversion unit (12) also includes a first signal amplifier (123) and a first filter (124); The input terminal of the first signal amplifier (123) is connected to the output terminal of the second-stage frequency converter circuit (122), the output terminal of the first signal amplifier (123) is connected to the input terminal of the first filter (124), and the output terminal of the first filter (124) is connected to the communication satellite through the transmitting antenna.

6. The frequency converter according to claim 4, characterized in that: The secondary frequency conversion unit (12) also includes a signal strength attenuator (125): The signal strength attenuator (125) is disposed on the connection path between the common terminal of the switching element (121) and the input terminal of the secondary frequency converter circuit (122).

7. The frequency converter according to claim 1, characterized in that: The receiving link frequency conversion module (2) includes a downlink frequency conversion circuit (21) and a power distribution circuit (22) adapted to divide one input signal into two output signals; The input terminal of the downlink frequency converter circuit (21) is connected to the communication satellite through the receiving antenna, and the output terminal of the downlink frequency converter circuit (21) is connected to the input terminal of the power distribution circuit (22). The output terminals of the power distribution circuit (22) include a first power distribution output terminal and a second power distribution output terminal. The first power distribution output terminal is connected to the high-orbit satellite intermediate frequency receiver of the satellite internet terminal, and the second power distribution output terminal is connected to the low-orbit satellite intermediate frequency receiver of the satellite internet terminal.

8. The frequency converter according to claim 7, characterized in that: The receiving link frequency conversion module (2) also includes a second signal amplifier (23) and a second filter (24); The input terminal of the second signal amplifier (23) is connected to the communication satellite through the receiving antenna, the output terminal of the second signal amplifier (23) is connected to the input terminal of the second filter (24), and the output terminal of the second filter (24) is connected to the input terminal of the downlink frequency converter circuit (21).

9. The frequency converter according to claim 7, characterized in that: The receiving link frequency conversion module (2) further includes a first power compensation circuit (25) and a second power compensation circuit (26); The input terminal of the first power compensation circuit (25) is connected to the first power divider output terminal, and the output terminal of the first power compensation circuit (25) is connected to the high-orbit satellite intermediate frequency receiver of the satellite Internet terminal. The input terminal of the second power compensation circuit (26) is connected to the output terminal of the second power divider, and the output terminal of the second power compensation circuit (26) is connected to the low-orbit satellite intermediate frequency receiver of the satellite Internet terminal.

10. The frequency converter according to claim 9, characterized in that: The first power compensation circuit (25) includes a third signal amplifier (251) and an impedance matching circuit (252): The input terminal of the third signal amplifier (251) is connected to the output terminal of the first power divider, the output terminal of the third signal amplifier (251) is connected to the input terminal of the impedance matching circuit (252), and the output terminal of the impedance matching circuit (252) is connected to the high-orbit satellite intermediate frequency receiver of the satellite internet terminal.

11. A terminal device, characterized in that, The terminal device includes a satellite internet terminal and a frequency conversion device as described in any one of claims 1-10 above; One end of the frequency converter is connected to the satellite internet terminal, and the other end of the frequency converter is connected to a communication satellite that communicates with the satellite internet terminal via a satellite antenna.

12. A vehicle, characterized in that, The vehicle includes the terminal device as described in claim 11.

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