An airborne channel front-end module and its antenna

Abstract

The utility model discloses an airborne channel front end module and its antenna, including a plurality of peripheral radio frequency unit and center radio frequency unit, and peripheral radio frequency unit includes RNSS's B3B1 radio frequency receiving circuit, and center radio frequency unit contains RNSS's B3B1 radio frequency receiving circuit, RDSS's short message B2bS receiving circuit and RDSS's short message L radio frequency transmitting circuit, two RNSS's B3B1 radio frequency receiving circuit is used for receiving satellite's B3 and B1 frequency band signal, and the output B3B1 radio frequency signal, short message B2bS receiving circuit is used for receiving satellite's B2b and S frequency band signal, and the output B2bS radio frequency signal, short message L radio frequency transmitting circuit is used for transmitting L frequency band signal, and the output L radio frequency signal. The utility model relates to communication technical field, and the more frequency band of support, adopts the form of comprehensive cable, and the RNSS receiving channel is increased, and the anti -interference ability is strong, and the channel interval isolation degree is high and the structural design satisfies multiple technical indexes.

Description

Technical Field

[0001] This utility model relates to the field of communication technology, and more specifically, to an airborne channel front-end module and its antenna. Background Technology

[0002] Existing BeiDou RDSS (Radio Determination Service) and RNSS (Radio Navigation Service) transceiver antennas are commonly used for receiving and transmitting various signals. These devices are capable of receiving signals from the BDS S band (the short message communication band of the BeiDou Navigation Satellite System), the BDS B1 band (one of the open service bands of the BeiDou Navigation Satellite System), and the GPS L1 band (the main civilian band of the Global Positioning System), while also being able to transmit BDS L band signals (the short message communication transmission band of the BeiDou Navigation Satellite System).

[0003] However, these devices still have many problems. First, the existing devices have limited receiving frequency bands. In RNSS (Navigation Receiver) mode, they only support signal reception in the BDS B1 band and GPS L1 band, and are not compatible with other frequency bands of the BeiDou system (such as B2, B3, etc.) or other global satellite navigation systems (such as GLONASS, Galileo, etc.). In RDSS (Short Message Service) mode, they only support signal reception in the S band. Second, the number of RNSS receiving channels is insufficient, and the anti-interference capability is weak. The limited number of receiving channels in RNSS mode makes it difficult to process signals from multiple satellites simultaneously, especially in complex electromagnetic environments or when satellite signals are severely blocked, resulting in a significant decrease in receiving performance. In addition, the anti-interference capability of the devices is relatively weak, and the suppression effect on interference such as multipath effect and co-channel interference is poor, which can easily lead to a decrease in positioning accuracy or even signal loss. Furthermore, the power splitter and combiner unit has a complex design and poor channel isolation performance. Inside the transceiver device, the power splitter and combiner unit is a crucial component for signal distribution and combining. However, the power splitter and combiner units in existing devices are complex in design, have high hardware costs and power consumption, and poor isolation performance between channels, resulting in signal crosstalk and leakage, which affects the purity and stability of received and transmitted signals and reduces the overall system performance.

[0004] To address the aforementioned issues, there is an urgent need to design a BeiDou RDSS and RNSS transceiver antenna device that supports more frequency bands, has more RNSS receiving channels, and features a superior power splitter / combiner unit design. Utility Model Content

[0005] The present invention aims to overcome at least one of the defects of the prior art and provide an airborne channel front-end module to solve the problems of limited receiving frequency bands, insufficient number of RNSS receiving channels, poor anti-interference capability, and complex design of power splitter and combiner units.

[0006] This invention employs an airborne channel front-end module, comprising multiple peripheral radio frequency (RF) units and a central RF unit. The peripheral RF units include B3 / B1 RF receiving circuits for the RNSS (Radio Reception Array Array). The central RF unit includes B3 / B1 RF receiving circuits for the RNSS, a B2b / S short message receiving circuit for the RDSS (Radio Reception Array Array), and a L-band short message transmitting circuit for the RDSS. The two B3 / B1 RF receiving circuits receive B3 and B1 band signals from the satellite and output B3 / B1 RF signals. The B2b / S short message receiving circuit receives B2b and S band signals from the satellite and outputs B2b / S RF signals. The L-band short message transmitting circuit transmits L-band signals and outputs L-band RF signals. The airborne channel front-end module completes the reception of B3 / B1 navigation anti-jamming array signals, the reception of S / B2b short message signals, and the transmission of L-band signals, transmitting RNSS and RDSS signals.

[0007] To receive cleaner B3 / B1 band signals, the RNSS's B3 / B1 RF receiver circuit includes a B1 first-stage filter, a B1 limiter, a B1 first-stage low-noise amplifier, a B1 first-stage π-attenuation network, a B1 second-stage filter, a B1 phase adjustment circuit, a B3 first-stage filter, a B3 limiter, a B3 first-stage low-noise amplifier, a B3 first-stage π-attenuation network, a B3 second-stage filter, a B3 second-stage π-attenuation network, a B3 phase adjustment circuit, a B3 third-stage filter, a duplexer, a second-stage low-noise amplifier, a combining π-attenuation network, and an RF interface. The B1 first-stage filter is connected to the B1 limiter, the B1 limiter is connected to the B1 first-stage low-noise amplifier, the B1 first-stage low-noise amplifier is connected to the B1 first-stage π-attenuation network, and the B1 first-stage π-attenuation network is connected to the B1 second-stage filter. The B1 second-stage filter is connected to the B1 phase adjustment circuit, and the B1 phase adjustment circuit is connected to the duplexer. The B3 first-stage filter is connected to the B3 limiter, the B3 limiter is connected to the B3 first-stage low-noise amplifier, the B3 first-stage low-noise amplifier is connected to the B3 first-stage π-attenuation network, the B3 first-stage π-attenuation network is connected to the B3 second-stage filter, the B3 second-stage filter is connected to the B3 second-stage π-attenuation network, the π-attenuation network is connected to the B3 phase adjustment circuit, the B3 phase adjustment circuit is connected to the B3 third-stage filter, the B3 third-stage filter is connected to the duplexer, the duplexer is connected to the second-stage low-noise amplifier, the second-stage low-noise amplifier is connected to the combining π-attenuation network, and the combining π-attenuation network is connected to the RF interface. The B3 / B1 RF receiver circuit can be understood as a filter to remove out-of-band interference, a limiter to clamp the input power and protect the subsequent circuit, a low-noise amplifier to amplify the signal, a π-fading network to adjust the link gain, a phase adjustment circuit to control phase consistency, and a duplexer to combine two signals into one.

[0008] Since the B1 operating frequency band is 1575.42±16.368 MHz, and its upper sideband is close to the Lf1 transmission frequency band of 1614.26±4.08 MHz, the first-stage filter of B1 should be selected with low insertion loss, high Q value, and high out-of-band rejection. Both the first-stage and second-stage filters of B1 are thin-film cavity acoustic resonator (FBAR) filters. Furthermore, since a high-suppression FBAR filter is selected for the first stage, the B1 link only needs to add another FBAR filter in the second stage to meet the out-of-band rejection requirements.

[0009] The first-stage filter of B3 is selected based on its low insertion loss and high input power. The first-stage filter of B3 is a dielectric filter. The second and third-stage filters of B3 are both thin-film resonant (FBAR) filters. To meet out-of-band rejection requirements, the subsequent two filter stages are selected as high-suppression FBAR filters.

[0010] The selection of low-noise amplifiers B3 and B1 is the same. In order to meet the requirements of moderate gain, low noise figure, high P1dB and power consumption within the limit, the first-stage low-noise amplifiers B1 and B3 are selected with low noise figure and high gain characteristics, and the second-stage low-noise amplifier is selected with moderate gain and high P1dB characteristics.

[0011] The central radio frequency unit, in addition to including the RNSS B3 / B1 radio frequency receiving circuit and the RDSS short message B2b / S radio frequency receiving circuit to perform out-of-band filtering, power protection, and low-noise amplification of weak satellite navigation signals, also includes the RDSS short message L radio frequency transmitting circuit to perform transmit enable signal conversion, radio frequency signal power amplification, and out-of-band harmonic suppression. The RDSS short message B2b / S receiving circuit and the RDSS short message L radio frequency transmitting circuit include a comparator, an L first-stage π-attenuation network, an L first-stage filter, an L radio frequency amplifier, an L second-stage π-attenuation network, an L power amplifier, an L cavity filter, a B2b first-stage filter, and a B2b limiter. The system includes an amplifier, a B2b first-stage low-noise amplifier, a B2b first-stage π-attenuation network, a B2b second-stage filter, a B2b second-stage π-attenuation network, a B2b third-stage filter, an S first-stage filter, an S limiter, an S first-stage low-noise amplifier, an S second-stage filter, an S first-stage π-attenuation network, an S third-stage filter, a B2b / S receiver combiner, a second-stage low-noise amplifier, an RDSS transceiver combiner, a combining π-attenuation network, and an RF interface. The L cavity filter is connected to the L power amplifier, the L power amplifier is connected to the comparator, the L power amplifier is connected to the L second-stage π-attenuation network, and the L second-stage π-attenuation network is connected to the L RF amplifier. The L RF amplifier is connected to the L first-stage filter, and the L first-stage filter is connected to the L first-stage π-attenuation network; the B2b first-stage filter is connected to the B2b limiter, the B2b limiter is connected to the B2b first-stage low-noise amplifier, the B2b first-stage low-noise amplifier is connected to the first-stage π-attenuation network, the first-stage π-attenuation network is connected to the B2b second-stage filter, the B2b second-stage filter is connected to the B2b second-stage π-attenuation network, and the B2b second-stage π-attenuation network is connected to the B2b third-stage filter; the S first-stage filter is connected to the S limiter, and the S limiter... The circuit is connected to the S-stage first-level low-noise amplifier, which is connected to the S-stage second-level filter. The S-stage second-level filter is connected to the S-stage first-level π-attenuation network, which is connected to the S-stage third-level filter. The S-stage third-level filter and the B2b-stage third-level filter are both connected to the B2b / S receiver combiner. The B2b / S receiver combiner is connected to the second-level low-noise amplifier. The second-level low-noise amplifier and the L-stage first-level π-attenuation network are both connected to the RDSS transceiver combiner. The RDSS transceiver combiner is connected to the combining π-attenuation network, which is connected to the RF interface. The B3 / B1 RF receiver circuit in the central RF unit is designed the same as that in the peripheral RF unit, and can be referred to the design description above.The basic structure of the RDSS B2b / S RF receiver circuit is similar to that of the RNSS B3 / B1. The circuit design involves first filtering out out-of-band interference, then a limiter to prevent high-power injection, followed by a low-noise amplifier to amplify the signal, an added π-attenuation network to adjust link gain, and second and third stage filters for out-of-band suppression. After being combined by the B2b / S receiver combiner, the signal is amplified again by a second-stage high-gain low-noise amplifier before finally entering the RDSS transceiver combiner, sharing a single RF interface with the transmit link. In the RDSS L RF transmitter circuit, after the signal enters from the one-line RF interface, it is first split by the RDSS transceiver combiner, filtered by the first-stage L RF filter to select the L RF signal, then amplified by an RF amplifier to compensate for link loss. A π-attenuation network is also used to adjust the gain, ensuring the signal level input to the power amplifier is within the required range. The power amplifier uses a two-stage cascaded power amplifier scheme to meet the requirements of gain and output power, while also considering linearity and power consumption.

[0012] Because anti-interference satellite navigation antennas have high requirements for phase consistency, each link needs to add a phase adjustment circuit to control the phase. Phase advance is achieved by changing the circuit structure. The circuit structure of the B1 phase adjustment circuit and the B3 phase adjustment circuit is a series connection of capacitors and a parallel connection of inductors, which is used to achieve phase advance.

[0013] Phase delay is achieved by changing the circuit structure. The circuit structures of the B1 phase adjustment circuit and the B3 phase adjustment circuit are inductors connected in series and capacitors connected in parallel, which is used to achieve phase delay.

[0014] An airborne channel front-end module and its antenna are disclosed. The airborne channel front-end module includes the aforementioned airborne channel front-end module, and further includes an RF connector, an array antenna, a composite cable, and an anti-interference processing unit. The array antenna includes seven B1 / B3 RF receiving antennas and one short message transceiver antenna. Six of the B1 / B3 RF receiving antennas are connected to six peripheral RF units of the airborne channel front-end module via the RF connector, and the remaining B1 / B3 RF receiving antennas are connected to the B3 / B1 RF receiving circuit of the central RF unit of the airborne channel front-end module via the RF connector. The short message transceiver antenna is connected to the short message B2b / S receiving circuit and the short message L RF transmitting circuit of the central RF unit via the RF connector. The airborne channel front-end module is connected to the anti-interference processing unit via the composite cable. The airborne channel front-end module and the array antenna form a satellite navigation antenna, which completes the reception of B3 / B1 navigation anti-jamming array signals, the reception of S / B2b short message signals, and the transmission of L signals. The signal interaction of the channel front-end module is connected to the anti-jamming processing unit through a composite cable to transmit RNSS and RDSS signals.

[0015] To increase the number of RNSS receiving channels and enhance the device's anti-interference capability, the integrated cable has an 8-core structure. Seven cores are used for RNSS radio frequency signals and provide 5V power to the circuit; one core is used for RDSS radio frequency signals and provides either 12V or 28V power to the circuit. When 12V is provided, no radio frequency signal is transmitted; when 28V is provided, a radio frequency signal is transmitted. The RDSS radio frequency signal includes B2b and S signals for reception and L signals for transmission. The B2b and S signals are amplified and filtered, and then combined with the L signal transmitted by the anti-interference processing unit. The L signal is then amplified and filtered by the power amplifier unit before being finally output to the antenna array.

[0016] Compared with the prior art, the beneficial effects of this utility model are mainly reflected in the following aspects:

[0017] 1. Supports more frequency bands:

[0018] The airborne channel front-end module receives RNSS and RDSS frequency band signals. RNSS includes BDS B3, BDS B1 and GPS L1 frequency bands, while RDSS supports the regional short message S band and the global short message B2b band.

[0019] 2. Strong anti-interference ability

[0020] The RNSS has multiple receiving channels, with 7 channels per frequency band. It can perform anti-interference processing on the seven-element B3 signal and the seven-element B1 signal, and can effectively filter out broadband suppression interference, narrowband interference and frequency sweeping interference from up to six directions.

[0021] 3. The circuit structure design meets multiple technical specifications.

[0022] To achieve higher gain, a low-noise amplifier combination with higher gain is selected; to achieve linearity, an output stage amplifier with a high P1dB is selected; to achieve phase consistency, a phase adjustment circuit is added; to achieve out-of-band rejection, a multi-stage FBAR filter is added; and to achieve output VSWR, a π-attenuation network is added at the output.

[0023] 4. High channel isolation

[0024] The One-Line Connect uses a composite cable design, with each channel corresponding to each core in the cable, resulting in a simpler design and better isolation between channels. Attached Figure Description

[0025] Figure 1 This is a structural diagram of the present invention.

[0026] Figure 2 This is a structural diagram of the B1 / B3 radio frequency circuit of this utility model.

[0027] Figure 3This is a structural diagram of the B2b / S receiving circuit and the L radio frequency transmitting circuit of this utility model.

[0028] Figure 4 This is a structural diagram of the phase adjustment circuit of this utility model. Detailed Implementation

[0029] The accompanying drawings are for illustrative purposes only and should not be construed as limiting the scope of this invention. To better illustrate the following embodiments, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0030] Example

[0031] like Figure 1 As shown, an airborne channel front-end module 200 of this embodiment is connected to an array antenna 100 via an RF connector and to an anti-interference processing unit 300 via a composite cable. The array antenna 100 includes seven B1 / B3 RF receiving antennas 110 and short message transceiver antennas 120. The airborne channel front-end module 200 and the array antenna 100 form a satellite navigation antenna, which completes the reception of B3 / B1 navigation anti-interference array signals, the reception of B2b / S short message signals, and the transmission of L signals. The signal interaction of the channel front-end module 200 is connected to the anti-interference processing unit 300 via an 8-core composite cable. Seven cores are used for RNSS signals and one core is used for RDSS one-line communication signals. The power supply of the channel front-end module is realized by connecting to the anti-interference processor via a composite cable. It provides 5V power supply for all B3 and B1 RF receiving circuits and 28V / 12V power supply for short message receiving and transmitting circuits. The detailed circuit design takes into account many technical specifications. The receiver circuit includes operating frequency band, gain, noise figure, input / output VSWR, P1dB, channel isolation, phase consistency, out-of-band rejection, burn-out resistance, and power consumption. The transmitter circuit includes operating frequency band, input power, output power, input / output VSWR, harmonic noise level, out-of-band noise spectrum level, and power consumption.

[0032] The airborne channel front-end module 200 includes six peripheral radio frequency units 210 and a central radio frequency unit 220. The six B1 / B3 radio frequency receiving antennas 110 in the array antenna 100 are connected to the six peripheral radio frequency units 210 of the airborne channel front-end module 200 respectively through radio frequency cables. The remaining B1 / B3 radio frequency receiving antennas and short message transceiver antennas 120 are connected to the central radio frequency unit 220 through radio frequency cables. The peripheral radio frequency unit 210 includes the B3 / B1 radio frequency receiving circuit of the RNSS, and the central radio frequency unit 220 includes the B3 / B1 radio frequency receiving circuit of the RNSS, the short message B2b / S receiving circuit of the RDSS, and the short message L radio frequency transmitting circuit of the RDSS. The B3 / B1 radio frequency receiving circuit 400 receives the B3 and B1 band signals of the satellite and outputs the B3 / B1 radio frequency signal. The short message B2b / S receiving circuit 500 receives the B2b and S band signals of the satellite and outputs the B2b / S radio frequency signal. The short message L radio frequency transmitting circuit 600 transmits the L band signal and outputs the L radio frequency signal.

[0033] In this embodiment, as Figure 2 As shown, the RNSS B3 / B1 RF receiving circuit 400 of the peripheral RF unit 210 includes a B1 RF receiving circuit and a B3 RF receiving circuit. Specifically, the B1 RF receiving circuit involves the following steps: the B1 signal is filtered by a first-stage B1 filter 410 to remove out-of-band interference; a B1 limiter 411 clamps the input power to protect the subsequent circuitry; a first-stage B1 low-noise amplifier 412 amplifies the B1 band signal; a first-stage B1 π-attenuation network 413 adjusts the link gain; a second-stage B1 filter 414 filters out interference; and a B1 phase adjustment circuit 415 controls phase consistency. The processed B1 signal is then input to a duplexer 430. Since the operating frequency of B1 is 1575.42±16.368 MHz, its upper sideband is close to L. The f1 transmit frequency band is 1614.26±4.08MHz, so the first-stage filter of B1 is an FBAR (film cavity acoustic resonance) filter with low insertion loss, high Q value and high out-of-band rejection. Since the first stage is a high-suppression FBAR filter, the B1 link only needs to add another FBAR filter in the second stage to meet the out-of-band rejection requirements.

[0034] The B3 RF receiving circuit specifically consists of the following steps: the B3 signal is filtered by the first-stage filter 420 to remove out-of-band interference; the B3 limiter 421 clamps the input power to protect the subsequent circuitry; the first-stage low-noise amplifier 422 amplifies the B3 band signal; the first-stage π-attenuation network 423 adjusts the link gain; the second-stage filter 424 filters out interference; the second-stage π-attenuation network 425 adjusts the link gain; the B3 phase adjustment circuit 426 controls phase consistency; and the third-stage filter 427 filters out interference. The processed B3 signal is then input to a duplexer 430, which combines the B1 and B3 signals into a single signal. This signal is then amplified by the second-stage low-noise amplifier 431, and the combining π-attenuation network 432 adjusts the link gain before finally transmitting the signal to the RF interface 433. For the B3's specifications, the first-stage filter is a dielectric filter with low insertion loss and high input power. To meet out-of-band rejection requirements, the subsequent two stages also use high-suppression FBAR filters. For both the B3 and B1 channels, the low-noise amplifier selection is the same. The first stage should use a model with a low noise figure and high gain, while the second stage should use a model with moderate gain and a higher P1dB. This combination satisfies the requirements of moderate gain, low noise figure, high P1dB, and within-limit power consumption.

[0035] In this embodiment, as Figure 3The B3 / B1 RF receiving circuit of the central RF unit 220 shown is designed identically to the B3 / B1 RF receiving circuit of the peripheral RF unit 210, and can be referred to the design description above. The RDSS short message B2b / S receiving circuit and short message L RF transmitting circuit perform out-of-band filtering, energy protection, and low-noise amplification of weak satellite navigation signals, while also performing transmit enable signal conversion, RF signal power amplification, and out-of-band harmonic suppression. The RDSS short message B2b / S receiving circuit and short message L RF transmitting circuit include an L-band transmitting circuit, a B2b band receiving circuit, and an S-band receiving circuit. Specifically, the L-band transmitting circuit splits a signal from the RDSS transceiver combiner 540, adjusts the link gain through the L first-stage π-attenuation network 610, filters out the L RF signal through the L first-stage filter 611, amplifies the signal through the L RF amplifier 612 to compensate for link loss, and then adjusts the link gain through the L second-stage π-attenuation network 613 before inputting it into the L power amplifier 614. At the same time, a 28V / 12V level is input to the comparator 620, which outputs a TTL level to the L power amplifier 614 to amplify the signal. Finally, the signal passes through the L cavity filter 615 to filter out transmission harmonics and out-of-band spurious emissions. The power amplifier adopts a two-stage cascaded power amplifier scheme to meet the requirements of gain and output power, while also taking into account linearity and power consumption. The power amplifier is enabled by a DC signal loaded by a single-pass circuit. After processing by the comparator, the 12V voltage will output a TTL low level, at which time the power amplifier is in the off state. The 28V voltage will output a TTL high level, that is, transmit the enable signal, at which time the power amplifier is in the on state.

[0036] The B2b band receiving circuit is as follows: the RDSS B2b band signal input is filtered by the first-stage B2b filter 510 to remove out-of-band interference; the B2b limiter 511 prevents high-power injection; the first-stage B2b low-noise amplifier 512 amplifies the signal; the first-stage B2b π-attenuation network 513 adjusts the link gain; the second-stage B2b filter 514 increases out-of-band rejection; the second-stage B2b π-attenuation network 515 adjusts the link gain; the third-stage B2b filter 516 increases out-of-band rejection; and finally, the signal enters the B2b / S receiver combiner 530.

[0037] The S-band receiving circuit is as follows: the RDSS S-band signal is input to the first-stage S filter 520 to filter out out-of-band interference, the S limiter 521 to prevent high-power injection, the first-stage S low-noise amplifier 522 to amplify the signal, the second-stage S filter 523 to increase out-of-band rejection, the first-stage S π-attenuation network 524 to adjust the link gain, and the third-stage S filter 425 to increase out-of-band rejection. Finally, it enters the RDSS transceiver combiner 530. The S-band signal and the B2b band signal are combined into one after entering the B2b / S receiving combiner 530. The signal is then amplified by the second-stage low-noise amplifier 531 and finally enters the RDSS transceiver combiner 540. The link gain is then adjusted by the combining π-attenuation network 541. It shares a radio frequency interface 542 with the transmitting link.

[0038] In this embodiment, as Figure 4 As shown, the B1 phase adjustment circuit 415 and the B3 phase adjustment circuit 426 are based on a π-shaped circuit with a parallel inductor, a series capacitor, and a parallel inductor, with four adjustment branches added to the other end of the inductor pair. When the phase of a certain link lags behind the reference link, it is necessary to advance the phase, which can be achieved by changing the values ​​of the series capacitor and the parallel inductor, such as... Figure 4 The smaller the capacitance and inductance values, the larger the phase change. Conversely, when the phase of a certain link is ahead of the reference link, the phase needs to be delayed. This can be achieved in two ways: one is to extend the RF trace by debugging the stubs to achieve the purpose of phase delay; the other is to change the circuit structure, using the method of placing the inductor in series and the capacitor in parallel to achieve phase delay. The smaller the inductance and capacitance values, the larger the phase change will be.

[0039] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the technical solution of this utility model, and are not intended to limit the specific implementation of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the claims of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An airborne channel front-end module, characterized in that, The airborne channel front-end module includes multiple peripheral radio frequency (RF) units and a central RF unit. The peripheral RF units include B3 / B1 RF receiving circuits for the RNSS. The central RF unit includes B3 / B1 RF receiving circuits for the RNSS, a short message B2b / S receiving circuit for the RDSS, and a short message L RF transmitting circuit for the RDSS. The two B3 / B1 RF receiving circuits are used to receive B3 and B1 band signals from the satellite and output B3 / B1 RF signals. The short message B2b / S receiving circuit is used to receive B2b and S band signals from the satellite and output B2b / S RF signals. The short message L RF transmitting circuit is used to transmit L band signals and output L RF signals.

2. The airborne channel front-end module according to claim 1, characterized in that, The B3 / B1 RF receiving circuit of the RNSS includes a B1 first-stage filter, a B1 limiter, a B1 first-stage low-noise amplifier, a B1 first-stage π-attenuation network, a B1 second-stage filter, a B1 phase adjustment circuit, a B3 first-stage filter, a B3 limiter, a B3 first-stage low-noise amplifier, a B3 first-stage π-attenuation network, a B3 second-stage filter, a B3 second-stage π-attenuation network, a B3 phase adjustment circuit, a B3 third-stage filter, a duplexer, a second-stage low-noise amplifier, a combining π-attenuation network, and an RF interface. The B1 first-stage filter is connected to the B1 limiter, the B1 limiter is connected to the B1 first-stage low-noise amplifier, the B1 first-stage low-noise amplifier is connected to the B1 first-stage π-attenuation network, and the B1 first-stage π-attenuation network is connected to the B1 second-stage filter. The filter is connected to the B1 phase adjustment circuit, which is connected to the duplexer. The first-stage B3 filter is connected to the B3 limiter, which is connected to the first-stage B3 low-noise amplifier. The first-stage B3 low-noise amplifier is connected to the first-stage B3 π-attenuation network. The first-stage B3 π-attenuation network is connected to the second-stage B3 filter, which is connected to the second-stage B3 π-attenuation network. The π-attenuation network is connected to the B3 phase adjustment circuit, which is connected to the third-stage B3 filter. The third-stage B3 filter is connected to the duplexer, which is connected to the second-stage low-noise amplifier. The second-stage low-noise amplifier is connected to the combining π-attenuation network, which is connected to the RF interface.

3. The airborne channel front-end module according to claim 2, characterized in that, Both the B1 first-stage filter and the B1 second-stage filter are thin-film cavity acoustic resonator (FBAR) filters.

4. An airborne channel front-end module according to claim 3, characterized in that, The first-stage filter of B3 is a dielectric filter, and the second-stage filter and the third-stage filter of B3 are both thin-film resonant (FBAR) filters.

5. An airborne channel front-end module according to claim 4, characterized in that, The B1 first-stage low-noise amplifier and the B3 first-stage low-noise amplifier are selected from models with low noise figure and high gain characteristics, and the second-stage low-noise amplifier is selected from models with moderate gain and high P1dB characteristics.

6. An airborne channel front-end module according to claim 2, characterized in that, The short message B2b / S receiving circuit and the short message L radio frequency transmitting circuit of the RDSS include a comparator, an L first-stage π-attenuation network, an L first-stage filter, an L radio frequency amplifier, an L second-stage π-attenuation network, an L power amplifier, an L cavity filter, a B2b first-stage filter, a B2b limiter, a B2b first-stage low-noise amplifier, a B2b first-stage π-attenuation network, a B2b second-stage filter, a B2b second-stage π-attenuation network, a B2b third-stage filter, an S first-stage filter, an S limiter, an S first-stage low-noise amplifier, an S second-stage filter, and an S first... The system includes a first-stage π-attenuation network, a third-stage S filter, a B2b / S receiver combiner, a second-stage low-noise amplifier, an RDSS transceiver combiner, a combining π-attenuation network, and an RF interface. The L cavity filter is connected to the L power amplifier, the L power amplifier is connected to the comparator, the L power amplifier is connected to the second-stage L π-attenuation network, the second-stage L π-attenuation network is connected to the L RF amplifier, the L RF amplifier is connected to the first-stage L filter, and the first-stage L filter is connected to the first-stage L π-attenuation network. The B2b first-stage filter is connected to the B... The B2b limiter is connected to the B2b first-stage low-noise amplifier, which is connected to the first-stage π-attenuation network. The first-stage π-attenuation network is connected to the B2b second-stage filter, which is connected to the B2b second-stage π-attenuation network, and the B2b second-stage π-attenuation network is connected to the B2b third-stage filter. The S first-stage filter is connected to the S limiter, which is connected to the S first-stage low-noise amplifier. The S first-stage low-noise amplifier is connected to the... The second-stage S filter is connected to the first-stage S π-attenuation network, which is connected to the third-stage S filter. Both the third-stage S filter and the third-stage B2b filter are connected to the B2b / S receiver combiner. The B2b / S receiver combiner is connected to the second-stage low-noise amplifier. Both the second-stage low-noise amplifier and the first-stage L π-attenuation network are connected to the RDSS transceiver combiner. The RDSS transceiver combiner is connected to the combined π-attenuation network, which is connected to the RF interface.

7. An airborne channel front-end module according to claim 6, characterized in that, The circuit structures of the B1 phase adjustment circuit and the B3 phase adjustment circuit are capacitors connected in series and inductors connected in parallel, which are used to achieve phase advance.

8. An airborne channel front-end module according to claim 6, characterized in that, The circuit structures of the B1 phase adjustment circuit and the B3 phase adjustment circuit are inductors connected in series and capacitors connected in parallel, which are used to achieve phase delay.

9. An antenna, characterized in that, The airborne channel front-end module, comprising any one of claims 1 to 8, further comprises an RF connector, an array antenna, a composite cable, and an anti-interference processing unit. The array antenna comprises seven B1 / B3 RF receiving antennas and one short message transceiver antenna. Six of the B1 / B3 RF receiving antennas are connected to six peripheral RF units of the airborne channel front-end module via the RF connector, and the remaining B1 / B3 RF receiving antennas are connected to the B3 / B1 RF receiving circuit of the central RF unit of the airborne channel front-end module via the RF connector. The short message transceiver antenna is connected to the short message B2b / S receiving circuit and the short message L RF transmitting circuit of the central RF unit via the RF connector. The airborne channel front-end module is connected to the anti-interference processing unit via the integrated cable.

10. An antenna according to claim 9, characterized in that, The integrated cable has an 8-core structure, of which 7 cores are used for RNSS radio frequency signals and provide 5V power to the circuit; 1 core is used for RDSS radio frequency signals and provides 12V or 28V power to the circuit. When 12V is provided, no radio frequency signal is transmitted, and when 28V is provided, a radio frequency signal is transmitted.

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