Composite signal single cable transmission front-end circuit and multi-mode satellite communication system

Abstract

The application discloses a kind of composite signal single cable transmission front-end circuit and multi-mode satellite communication system, belong to satellite communication composite signal transmission field.The front-end circuit includes main circuit, radio frequency circuit, control circuit, direct current circuit;Radio frequency circuit has three shunt ports and one combiner port, one end of main circuit is connected with the combiner port of radio frequency circuit, the other end is composite signal transceiver port, control circuit and direct current circuit are connected on main circuit, control circuit is close to the side of radio frequency circuit, direct current circuit is close to the side of composite signal transceiver port, and direct current isolation circuit is arranged between the connecting point of control circuit and direct current circuit.The application can realize multi-mode self-defined communication control protocol, power supply / control / multi-path radio frequency three-in-one signal long-distance single-core efficient transmission between multi-mode satellite communication equipment and multi-mode composite radio frequency equipment.

Description

Technical Field

[0001] This invention relates to the field of satellite communication composite signal transmission, and in particular to a composite signal single-cable transmission front-end circuit and a multi-mode satellite communication system, which can be used in multi-mode satellite communication equipment to transmit multiple composite signals such as radio frequency, power supply, and control using a single radio frequency coaxial cable. Background Technology

[0002] Currently, in multi-mode satellite communication equipment, the connection between multi-mode satellite communication equipment and multi-mode composite radio frequency equipment mainly consists of multiple multi-band radio frequency signals, control signals, and DC power supply signals. The multiple multi-band radio frequency signals are transmitted through multiple radio frequency coaxial radio frequency cables of different frequency bands, the control signals use multi-core data cables, and RS422 or RS233 are used for signal transmission. The DC power supply signals are connected through low-frequency cables that carry a large current.

[0003] Traditional methods for connecting multi-mode satellite communication equipment with multi-mode composite radio frequency equipment present several problems. First, the numerous coaxial radio frequency cables, control data cables, and power supply cables of different frequency bands make cable connection, use, installation, and maintenance difficult. Second, the transmission distance of multi-core RS422 or RS232 control data signals and DC voltage signals using low-frequency cables is limited, making it difficult to support long-distance transmissions of more than 20 meters. Third, low-frequency transmitted DC signals and control signals are prone to mutual interference with high-frequency transmitted radio frequency signals, leading to errors in control information parsing and distortion of radio frequency signals. Summary of the Invention

[0004] In view of this, the present invention proposes a composite signal single-cable transmission front-end circuit and a multi-mode satellite communication system, which can realize multi-mode custom communication control protocol, power supply / control / multi-channel radio frequency three-in-one signal long-distance single-core high-efficiency transmission between multi-mode satellite communication equipment and multi-mode composite radio frequency equipment.

[0005] The technical solution adopted in this invention is:

[0006] A single-cable transmission front-end circuit for composite signals in multi-mode satellite communication includes a backbone circuit, an radio frequency (RF) circuit, a control circuit, and a DC circuit. The RF circuit has three branch ports and one combiner port. One end of the backbone circuit is connected to the combiner port of the RF circuit, and the other end is a composite signal transceiver port. The control circuit and the DC circuit are connected to the backbone circuit, with the control circuit closer to the RF circuit and the DC circuit closer to the composite signal transceiver port. A DC isolation circuit is provided between the connection points of the control circuit and the DC circuit.

[0007] The radio frequency circuit includes a three-in-one circuit and a high-pass filter circuit. The branch side of the three-in-one circuit is the three branch ports of the radio frequency circuit, and the combining side of the three-in-one circuit is connected to the high-pass filter circuit. The external end of the high-pass filter circuit is the combining port of the radio frequency circuit.

[0008] The control circuit includes an analog modulation and demodulation circuit and a low-pass filter circuit. The low-pass filter circuit is located between the analog modulation and demodulation circuit and the main circuit. The analog modulation and demodulation circuit receives external control commands through the network port to complete parameter configuration and data transmission and reception.

[0009] The DC circuit includes a DC filter circuit and a broadband choke circuit. The broadband choke circuit is located between the DC filter circuit and the main circuit. The external end of the DC filter circuit is the DC input / output port.

[0010] Furthermore, the three-in-one circuit is composed of two-stage two-in-one circuits, wherein the combining terminal of one two-in-one circuit is connected to a branch terminal of the other two-in-one circuit.

[0011] Furthermore, the DC filter circuit includes an inductor and a grounding bypass, with a DC blocking capacitor provided on the grounding bypass, which is located between the buffer inductor and the DC input / output port.

[0012] Furthermore, the analog modulation and demodulation circuit includes an AISG on / off keyed coaxial modem transceiver and a microcontroller. The AISG on / off keyed coaxial modem transceiver and the microcontroller communicate via a serial port protocol. The microcontroller internally implements a software configuration module, a framing module, a deframing module, and an interface module. After power-on, the microcontroller's software configuration module sets the DIRMD1 and DIRMD2 pins of the AISG on / off keyed coaxial modem transceiver via GPIO to configure the communication rate. The interface module receives control commands sent by external multi-mode satellite communication equipment via Ethernet. The framing module... The Ethernet port control commands are translated into a serial port frame format that the AISG on / off keyed coaxial modem transceiver can recognize, according to the AISG on / off keyed coaxial modem transceiver frame format. The AISG on / off keyed coaxial modem transceiver uses an on / off keyed modulation transmission with a 2.176MHz sine wave carrier. The on / off keyed demodulation signal of the AISG on / off keyed coaxial modem transceiver with a 2.176MHz sine wave carrier in the opposite direction is sent to the microcontroller's frame de-framing module through the serial port frame format. The frame de-framing module translates the serial port frame format protocol into the Ethernet port protocol and sends it to the external multi-mode satellite communication equipment.

[0013] This invention also provides a multi-mode satellite communication transmission system for composite signal single-cable transmission, including a multi-mode satellite communication device and a multi-mode composite radio frequency device. Both the multi-mode satellite communication device and the multi-mode composite radio frequency device are connected to a composite signal single-cable transmission front-end circuit. The UHF, L, and S band signals of the multi-mode satellite communication device are connected to the three branch ports of the composite signal single-cable transmission front-end circuit. The DC power input of the multi-mode satellite communication device is connected to the DC input / output port of the composite signal single-cable transmission front-end circuit. The multi-mode composite radio frequency device is connected to the three branch ports of the composite signal single-cable transmission front-end circuit for UHF, L, and S band radio frequency output. The DC input / output port of the composite signal single-cable transmission front-end circuit outputs the DC power supply of the multi-mode composite radio frequency device. The composite signal transceiver ports of the two composite signal single-cable transmission front-end circuits are connected via a single-core cable.

[0014] Compared with the prior art, the present invention has the following advantages:

[0015] 1. This invention enables single-coaxial cable transmission between multi-mode satellite communication equipment and multi-mode composite radio frequency equipment. The coaxial cable has low insertion loss, high signal shielding and anti-interference performance, good electromagnetic compatibility, and features simple installation, convenience, reliability, and long-distance transmission capabilities.

[0016] 2. This invention employs composite transmission of multiple radio frequency (RF), power supply, and control signals. The RF signals can support the transmission of multiple RF signals in different frequency bands as needed, and the power supply signals support a wide DC bandwidth and can carry high current signals, making it particularly suitable for multi-band, multi-mode, and high-power composite signal transmission applications.

[0017] 3. This invention adopts AISG on / off keying modulation and demodulation technology combined with microcontroller (MCU) control signal technology, which can realize the protocol-based and formatted transmission of control signals, and flexibly configure, formulate and transmit control information. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the front-end circuit for composite signal single-cable transmission in an embodiment of the present invention.

[0019] Figure 2 yes Figure 1 A schematic diagram of the radio frequency circuit.

[0020] Figure 3 yes Figure 1 A schematic diagram of the control circuit.

[0021] Figure 4 yes Figure 1 A schematic diagram of a DC circuit. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings.

[0023] A composite signal single-cable transmission front-end circuit for multi-mode satellite communication, such as Figures 1-4 As shown, the circuit includes a main circuit, an RF circuit, a control circuit, and a DC circuit. The RF circuit, control circuit, and DC circuit are all connected to the main circuit. The RF circuit has three branch ports and one combiner port. One end of the main circuit is connected to the combiner port of the RF circuit, and the other end is a composite signal transceiver port. The control circuit is located near the RF circuit, and the DC circuit is located near the composite signal transceiver port. A DC isolation circuit is provided between the connection points of the control circuit and the DC circuit.

[0024] The radio frequency circuit includes a three-in-one circuit and a high-pass filter circuit. The branch side of the three-in-one circuit is the three branch ports of the radio frequency circuit, and the combining side of the three-in-one circuit is connected to the high-pass filter circuit. The external end of the high-pass filter circuit is the combining port of the radio frequency circuit.

[0025] The control circuit includes an analog modulation and demodulation circuit and a low-pass filter circuit. The low-pass filter circuit is located between the analog modulation and demodulation circuit and the main circuit. The analog modulation and demodulation circuit receives external control commands through the network port to complete parameter configuration and data transmission and reception.

[0026] The control circuit adopts a technology that combines an AISG on / off keyed coaxial modem transceiver with a microcontroller (MCU). The MCU manages and configures the AISG on / off keyed coaxial modem transceiver, selects OOK modulators with different center frequency carriers as needed, supports AISG signal rates of different speed levels, and performs signal conversion and protocol processing on control signals. With the corresponding peripheral crystal oscillator circuit and power supply circuit, it realizes one-line communication and control functions as needed.

[0027] The DC circuit includes a DC filter circuit and a broadband choke circuit. The broadband choke circuit is located between the DC filter circuit and the main circuit. The external end of the DC filter circuit is the DC input / output port.

[0028] This front-end circuit can be applied to multi-mode satellite communication equipment and multi-mode composite radio frequency equipment.

[0029] When used in multi-mode satellite communication equipment, the front-end circuit uses a three-way multiplexing of radio frequency (RF) circuit, control circuit, and DC circuit. The external multi-band RF input signal is combined with the RF signal through a three-in-one circuit and a high-pass filter circuit. The control signal is combined with the low-pass filter circuit using on-off keying modulation (OOK) technology. The external DC voltage is combined with the broadband choke circuit through a current filter circuit. The three components form a composite signal that combines multiple RF signals, on-off keying control signals, and DC power supply signals. This composite signal is then transmitted over a long distance to the external RF front-end via a single-core RF coaxial cable.

[0030] In multimode composite RF equipment applications, the front-end circuit receives composite signals via a single-core cable. It then extracts the DC supply voltage, control signals, and multiple RF output signals through DC circuits, control circuits, and RF circuits. Specifically, a high-current DC voltage signal is extracted using a DC circuit composed of a high-current DC filter circuit and a broadband choke circuit to power each module of the RF front-end. The control circuit, through a low-pass filter circuit and on / off key demodulation technology, analyzes the control signals and transmits them to the microcontroller (MCU) for control protocol parsing. Simultaneously, it transmits the multi-band RF signals to the RF power divider circuit. The RF power divider circuit, through a high-pass filter circuit and a 1-to-3 power divider circuit, decomposes the signals into multiple RF signals of different frequency bands and transmits them to the multi-band RF components.

[0031] This front-end circuit enables the connection between multi-mode satellite communication equipment and multi-mode composite radio frequency equipment using a single radio frequency cable, adapting to scenarios requiring high-reliability long-distance transmission of composite radio frequency signals between in-cabin multi-mode communication equipment and external multi-mode antennas.

[0032] Here is a more specific example:

[0033] A composite signal single-cable transmission front-end circuit for multi-mode satellite communication, such as Figures 1-4 As shown, it mainly consists of three parts connected to the main circuit: radio frequency circuit, control circuit, and DC circuit. A DC isolation circuit is also provided between the control circuit and the DC circuit.

[0034] The radio frequency circuit includes a three-in-one circuit and a high-pass filter circuit. The three-in-one circuit consists of two stages of two-in-one circuits. Signals from different frequency bands from the outside are combined into one output through the two stages of two-in-one circuits. The two-in-one circuit is implemented using a commercially available broadband power divider synthesizer SBTC-2-25. The high-pass filter circuit consists of capacitors C8, C9, and C10, and inductors L5 and L6.

[0035] The DC isolation circuit consists of capacitors C5 and C6 connected in parallel, which blocks DC from passing through the radio frequency, ensuring that UHF, S, and L band signals can be transmitted with low loss.

[0036] The control circuit includes a low-pass filter circuit and an analog modulation and demodulation circuit. Inductors L3, L4, and C7 form the low-pass filter circuit, which extracts the control signal. The AISG on / off keying coaxial modem circuit is implemented using a commercially available CA-IF4023. In the external circuit, C13 and C14 provide power filtering, E2 provides an external crystal oscillator with a clock speed of 8.704MHz, C15 and C16 form the crystal oscillator matching circuit, and a 7.5pF capacitor is used. R1 and R2, along with C11, form the output amplitude adjustment circuit. In practical applications, R1 can be 1KΩ, and R2 can be 10KΩ. R3 and C12 achieve analog input matching. The MCU uses a commercially available GD32 ARM Cortex-M3 as the controller, and the on / off keying coaxial modem transceiver uses a commercially available CA-IF4023 chip. The MCU and CA-IF4023 communicate via serial port for configuring modem transceiver parameters and setting the rate.

[0037] The microcontroller (MCU) internally implements a software configuration module, a framing module, a frame deframing module, and an interface module. After the device powers on, the MCU's software configuration module sets the DIRMD1 and DIRMD2 pins of the AISG on / off keyed coaxial modem transceiver via GPIO to configure the communication rate. In this case, DIRMD1 is set to 0, DIRMD2 is set to 1, and the AISG rate is 115.2 kbps. The interface module receives communication control commands sent from the Ethernet port of an external multi-mode satellite communication device. The framing module translates the Ethernet port control commands into a serial port frame format that the AISG on / off keyed coaxial modem transceiver can recognize, according to the AISG on / off keyed coaxial modem transceiver frame format. The AISG on / off keyed coaxial modem transceiver uses on / off keying (OOK) modulation with a 2.176 MHz sine wave carrier for transmission. Similarly, in the opposite direction, the demodulation carrier of the AISG on-off keying coaxial modem transceiver is a 2.176MHz sine wave on-off keying (OOK) demodulation signal, which is sent to the microcontroller (MCU) deframe module via serial frame format. The deframe module translates the serial frame format protocol into the Ethernet port protocol and sends it to the external multi-mode satellite communication equipment.

[0038] The DC circuit consists of a broadband choke circuit and a high-current DC filter circuit. The broadband choke circuit is composed of a 100nH inductor, a 10pF capacitor, a 100pF capacitor, and a 1000pF capacitor, forming a low-pass filter structure. The high-current DC filter circuit is composed of a 10uH inductor and a 10uF capacitor, forming a low-pass filter structure, which plays a role in DC voltage regulation.

[0039] A multimode satellite communication transmission system for composite signal single-cable transmission includes a multimode satellite communication device and a multimode composite radio frequency device. Both the multimode satellite communication device and the multimode composite radio frequency device are connected to a composite signal single-cable transmission front-end circuit. The UHF, L, and S band signals of the multimode satellite communication device are connected to the UHF, L, and S band radio frequency ports of the composite signal single-cable transmission front-end circuit. The DC power input of the multimode satellite communication device is connected to the +28V DC port of the composite signal single-cable transmission front-end circuit. At the other end, the multimode composite radio frequency device is connected to the UHF, L, and S band radio frequency ports of the composite signal single-cable transmission front-end circuit for radio frequency output. The +28V DC port of the composite signal single-cable transmission front-end circuit outputs the DC power required by the multimode composite radio frequency device. The composite signal transceiver ports of the two composite signal single-cable transmission front-end circuits are connected by a single-core cable.

[0040] In summary, this invention can composite external multi-band RF input signals through multiple sets of three-in-one circuits and high-pass filter circuits. It combines the control signal using on-off keying modulation (OOK) technology with the low-pass filter circuit, and combines the external DC voltage with a broadband choke circuit through a high-current DC combiner circuit. These three components form a composite signal consisting of multiple RF signals, on-off keying control signals, and DC power supply signals. This composite signal is then transmitted over a long distance to an external multi-mode satellite communication RF front-end via a single-core RF cable. Upon receiving the composite signal, the multi-mode RF front-end similarly reverses the process by using a DC separation circuit, a control separation circuit, and an RF separation circuit to extract the DC power supply voltage, control signal, and multiple RF output signals. The entire solution employs a combination of on-off keying modulation (OOK) control and MCU control strategy to achieve bidirectional transmission of the on-off keying modulation control signal and the RF signal.

Claims

1. A composite signal single-cable transmission front-end circuit for multi-mode satellite communication, characterized in that, It includes a main circuit, an RF circuit, a control circuit, and a DC circuit. The RF circuit has three branch ports and one combiner port. One end of the main circuit is connected to the combiner port of the RF circuit, and the other end is a composite signal transceiver port. The control circuit and the DC circuit are connected to the main circuit, with the control circuit closer to the RF circuit and the DC circuit closer to the composite signal transceiver port. A DC isolation circuit is provided between the connection points of the control circuit and the DC circuit. The radio frequency circuit includes a three-in-one circuit and a high-pass filter circuit. The branch side of the three-in-one circuit is the three branch ports of the radio frequency circuit, and the combining side of the three-in-one circuit is connected to the high-pass filter circuit. The external end of the high-pass filter circuit is the combining port of the radio frequency circuit. The control circuit includes an analog modulation and demodulation circuit and a low-pass filter circuit. The low-pass filter circuit is located between the analog modulation and demodulation circuit and the main circuit. The analog modulation and demodulation circuit receives external control commands through the network port to complete parameter configuration and data transmission and reception. The DC circuit includes a DC filter circuit and a broadband choke circuit. The broadband choke circuit is located between the DC filter circuit and the main circuit. The external end of the DC filter circuit is the DC input / output port.

2. The composite signal single-cable transmission front-end circuit for multi-mode satellite communication according to claim 1, characterized in that, The three-in-one circuit consists of two two-in-one circuits, wherein the combining terminal of one two-in-one circuit is connected to a branch terminal of the other two-in-one circuit.

3. The composite signal single-cable transmission front-end circuit for multi-mode satellite communication according to claim 1, characterized in that, The DC filter circuit includes an inductor and a grounding bypass. A DC blocking capacitor is provided on the grounding bypass, which is located between the buffer inductor and the DC input / output port.

4. The composite signal single-cable transmission front-end circuit for multi-mode satellite communication according to claim 1, characterized in that, The analog modulation and demodulation circuit includes an AISG on / off keyed coaxial modem transceiver and a microcontroller. The AISG on / off keyed coaxial modem transceiver and the microcontroller communicate via a serial port protocol. The microcontroller internally implements a software configuration module, a framing module, a deframing module, and an interface module. After power-on, the microcontroller's software configuration module sets the DIRMD1 and DIRMD2 pins of the AISG on / off keyed coaxial modem transceiver via GPIO to configure the communication rate. The interface module receives control commands sent by external multi-mode satellite communication equipment via Ethernet. The framing module follows the A... The AISG on / off keyed coaxial modem transceiver translates Ethernet port control commands into a serial port frame format that the AISG on / off keyed coaxial modem transceiver can recognize. The AISG on / off keyed coaxial modem transceiver uses an on / off keyed modulation transmission with a 2.176MHz sine wave carrier. The AISG on / off keyed coaxial modem transceiver sends the demodulated signal with a 2.176MHz sine wave carrier in the opposite direction to the on / off keyed demodulation signal via the serial port frame format to the microcontroller's deframe module. The deframe module translates the serial port frame format protocol into the Ethernet port protocol and sends it to the external multi-mode satellite communication equipment.

5. A multi-mode satellite communication transmission system for composite signal single-cable transmission, comprising a multi-mode satellite communication device and a multi-mode composite radio frequency device, characterized in that, Both the multi-mode satellite communication equipment and the multi-mode composite radio frequency equipment are connected to a composite signal single-cable transmission front-end circuit as described in any one of claims 1 to 4. The UHF, L, and S band signals of the multi-mode satellite communication equipment are connected to the three branch ports of the composite signal single-cable transmission front-end circuit. The DC power supply input of the multi-mode satellite communication equipment is connected to the DC input / output port of the composite signal single-cable transmission front-end circuit. The multi-mode composite radio frequency equipment is connected to the three branch ports of the composite signal single-cable transmission front-end circuit for UHF, L, and S band radio frequency output. The DC input / output port of the composite signal single-cable transmission front-end circuit outputs the DC power supply of the multi-mode composite radio frequency equipment. The composite signal transceiver ports of the two composite signal single-cable transmission front-end circuits are connected by a single-core cable.

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