Tester integrating airborne AIS detection inspection and responder inspection

Abstract

The invention provides a tester integrating airborne AIS detection inspection and responder inspection, and relates to an avionics test and guarantee technology. The tester comprises a signal processing module and a transmitting and receiving module. The transmitting and receiving module is integrated with a radio frequency front-end circuit covering a plurality of standard frequency points; the plurality of standard frequency points comprise a first working frequency point and a second working frequency point of the AIS, and an inquiry frequency point and a response frequency point of the responder; the signal processing module responds to user operation, generates corresponding coded data and sends the coded data to the transmitting and receiving module; the coded data is AIS coded data or responder inquiry coded data; the transmitting and receiving module generates and transmits a radio frequency signal on a corresponding standard frequency point based on the coded data; the transmitting and receiving module receives a response signal from a responder at a response frequency point, down-converts the response signal into an intermediate frequency signal, and sends the intermediate frequency signal back to the signal processing module. According to the tester, AIS detection inspection and responder inspection can be realized, so that the detection efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of avionics test and support technology, in particular to a test instrument integrating airborne AIS interception inspection and transponder inspection. BACKGROUND

[0002] The airborne automatic identification system (AIS) interception device is a device for receiving broadcast information from sea vessels to realize maritime awareness and collision avoidance. The airborne transponder is a device for communicating with ground air traffic control radar and other aircraft to realize air traffic control and air collision avoidance. To ensure the reliability of these devices, frequent maintenance and inspection must be carried out in the field.

[0003] Currently, the detection of airborne AIS interception devices and transponders generally uses mutually independent special test instruments. Ground maintenance personnel need to use two independent devices, an airborne transponder detector and an airborne AIS interception tester, to complete the inspection of the corresponding devices on the aircraft in two operations. Because the two sets of test equipment are single-function and independent of each other, ground personnel must carry two instruments, perform two connection operations, two test operations, and two result interpretations when performing routine maintenance or pre-flight inspection. This repetitive process not only is cumbersome to operate, but also greatly increases the workload of ground personnel and prolongs the ground maintenance time of the aircraft, which cannot meet the urgent needs of high efficiency and fast response in modern aviation support. SUMMARY

[0004] The technical problem to be solved by the present application is the low detection efficiency of airborne AIS interception devices and transponders in the prior art. The present application provides a test instrument integrating airborne AIS interception inspection and transponder inspection to solve the above problems.

[0005] The present application is implemented by the following technical solutions:

[0006] In a first aspect, the present application provides a test instrument integrating airborne AIS interception inspection and transponder inspection, comprising a signal processing module and a transmitting and receiving module which are physically separated and connected through a unified interface; the transmitting and receiving module is integrated with a radio frequency front-end circuit covering multiple standard frequencies; the multiple standard frequencies include a first working frequency and a second working frequency of AIS, an interrogation frequency of a transponder, and a response frequency;

[0007] The signal processing module is configured to generate corresponding coded data in response to user operation and send the coded data to the transmitting and receiving module; the coded data is AIS coded data or transponder interrogation coded data;

[0008] The transmitting and receiving module is configured to generate and transmit a radio frequency signal on a corresponding standard frequency point based on the encoded data.

[0009] The transmitting and receiving module is further configured to receive a response signal from a transponder on the response frequency point, and send the response signal to the signal processing module after down-conversion of the response signal into an intermediate frequency signal.

[0010] Optionally, the tester further comprises a key module, and the signal processing module comprises a master control chip, the master control chip is connected with 2N keys of the key module through a group of high-level output lines and a group of low-level output lines, the number of key switches of the master control chip is N, and the total number of pins of the master control chip is N+2.

[0011] The key module is configured to generate key data in response to user operations on the plurality of keys.

[0012] The master control chip is configured to receive the key data, determine a modulation mode based on the key data, and further generate corresponding encoded data.

[0013] Optionally, the encoded data comprises modulation data, a frequency control signal and a gate signal, and the transmitting and receiving module comprises a direct digital frequency synthesis (DDS) source and a radio frequency processing unit.

[0014] The DDS source is configured to generate a carrier signal on a standard frequency point corresponding to the frequency control signal, modulate the carrier signal by using the modulation data, and output a modulated radio frequency signal.

[0015] The radio frequency processing unit is connected with the DDS source and is configured to sequentially perform filtering and program-controlled amplification processing on the modulated radio frequency signal, and perform pulse emission on the processed radio frequency signal under the control of the gate signal.

[0016] Optionally, the DDS source is controlled by a field programmable gate array (FPGA).

[0017] The FPGA is configured to generate a frequency control word, a phase control word and an amplitude control word according to the encoded data, and provide the DDS source with the frequency control word, the phase control word and the amplitude control word.

[0018] The DDS source is specifically configured to modulate the carrier signal by using the modulation data based on the frequency control word, the phase control word and the amplitude control word, and output a modulated radio frequency signal.

[0019] Optionally, the modulation mode is ASK modulation mode, DPSK modulation mode or MSK modulation mode; the ASK modulation mode is used to generate an interrogation signal for a normal mode; the DPSK modulation mode is used to generate an interrogation signal for an S mode; the MSK modulation mode is used to generate an interrogation signal for M5 or an AIS broadcast signal; the normal mode is one of M1, M2, M3 / A, MC and M4.

[0020] Optionally, the radio frequency processing unit is further configured to:

[0021] receive a reply signal from a transponder at the reply frequency 1090MHz;

[0022] sequentially perform amplitude limiting, attenuation, filtering, amplification and down-conversion processing on the reply signal to obtain an intermediate frequency signal;

[0023] send the intermediate frequency signal back to the signal processor module.

[0024] Optionally, the signal processor module further comprises an analog-to-digital converter.

[0025] The analog-to-digital converter is configured to perform analog-to-digital conversion on the intermediate frequency signal to output a digital intermediate frequency signal.

[0026] The main control chip is connected with the analog-to-digital converter and is further configured to perform digital down-conversion, signal detection, demodulation and protocol analysis on the digital intermediate frequency signal to obtain protocol data.

[0027] Optionally, the tester further comprises a display screen configured to visually display the protocol data; the protocol data comprises an identification code, a geographical position and altitude information reported by the transponder.

[0028] Optionally, the tester further comprises a power module configured to:

[0029] receive a first direct current from an adapter of an external power supply or a second direct current from an external battery box;

[0030] perform filtering and DC / DC conversion on the received direct current to generate a plurality of direct currents required for the operation of the tester.

[0031] Optionally, the power module comprises a power conversion unit, a filtering circuit and a DC / DC conversion circuit.

[0032] The power conversion unit is configured to automatically switch to the first direct current and use the adapter as a power supply input when the first direct current and the second direct current exist simultaneously.

[0033] The filtering circuit is configured to filter the first direct current.

[0034] DC / DC conversion circuit, for DC / DC conversion of the filtered first DC, to generate +5V, +12V and-12V DC voltage required for the operation of the tester.

[0035] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0036] The present application provides a tester integrating airborne AIS interception inspection and transponder inspection, integrates the working frequency point of the AIS signal and the interrogation frequency point and the response frequency point of the transponder in a transmitting and receiving module, and controls through a unified signal processing module, so that the airborne AIS interception inspection and the transponder inspection are realized through one tester, the convenience of testing and the miniaturization of the equipment are realized, and the convenience and efficiency of the ground service test personnel can be improved. Moreover, the tester separates the internal signal processing module from the transmitting and receiving module, the modules are independent of each other and a unified communication interface is established, when a single module fails, the single independent module can be replaced to quickly locate the fault, the maintenance speed can be improved, the maintenance cost can be reduced, and the tester has the ability of subsequent expansion and upgrading. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions of the example embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without paying creative labor. In the drawings:

[0038] Figure 1 A structure schematic diagram of a tester integrating airborne AIS interception inspection and transponder inspection provided by the present application embodiment;

[0039] Figure 2 A composite key logical relationship diagram provided by the present application embodiment;

[0040] Figure 3 A cross-linking relationship diagram of a transmitting unit in a transmitting and receiving module provided by the present application embodiment;

[0041] Figure 4 A cross-linking relationship diagram of a receiving unit in a transmitting and receiving module provided by the present application embodiment;

[0042] Figure 5 A structure schematic diagram of a power module provided by the present application embodiment. DETAILED DESCRIPTION

[0043] In order to make the objects, technical solutions and advantages of the present application clearer, further detailed description will be made to the present application with reference to the embodiments and drawings, the illustrative embodiments and the description thereof are only used to explain the present application, and do not limit the present application.

[0044] In the field of avionics test and support, the detection of airborne AIS interception equipment and transponder generally uses special test instruments independent of each other. This independent test scheme has the following problems.

[0045] 1. Low maintenance efficiency: When performing daily inspection, the ground maintenance personnel must carry two different test devices and complete the test process in two separate times, which not only increases the physical burden and work complexity of the maintenance personnel, but also significantly prolongs the ground maintenance time and reduces the overall support efficiency. In wartime or emergency transfer and other special situations, the ground maintenance efficiency is directly related to the sortie rate and combat effectiveness of the warplane.

[0046] 2. Difficult fault positioning and high support cost: Since the internal architecture and design principles of the independent test devices are different, when the device itself fails, it is difficult to quickly and accurately locate the fault in the field, especially in the field environment lacking professional and precise detection tools. The maintenance personnel usually cannot determine the fault module and can only adopt the overall replacement strategy, which not only leads to high cost of device spare parts, but also makes the fault repair cycle long.

[0047] 3. Waste of human resources: The accurate positioning of faults in the field often requires the dispatch of maintenance personnel with different professional backgrounds to cooperate in troubleshooting, which causes serious waste of human resources. At the same time, the efficiency and effect of fault troubleshooting are limited to a great extent by the personal technical level and experience of the on-site maintenance personnel, further increasing the uncertainty and time cost of the maintenance work.

[0048] Therefore, the embodiments of the present application provide a test instrument integrating airborne AIS interception inspection and transponder inspection. Please refer to Figure 1 The structure schematic diagram of the test instrument integrating airborne AIS interception inspection and transponder inspection provided by the embodiments of the present application. The test instrument includes a signal processing module and a transmitting and receiving module which are physically separated and connected through a unified interface.

[0049] The transmitting and receiving module is integrated with a radio frequency front-end circuit covering multiple standard frequency points; the multiple standard frequency points include a first working frequency point and a second working frequency point of AIS, an interrogation frequency point of a transponder, and a response frequency point;

[0050] The signal processing module is used to generate corresponding coded data in response to user operation, and send the coded data to the transmitting and receiving module; the coded data is AIS coded data or transponder interrogation coded data;

[0051] The transmitting and receiving module is configured to generate and transmit radio frequency signals on corresponding standard frequency points based on the encoded data;

[0052] The transmitting and receiving module is further configured to receive the response signal from the airborne transponder on the response frequency point, and send the response signal to the signal processing module after down-converting the response signal to an intermediate frequency signal.

[0053] In the specific implementation process, the standard frequency points covered by the transmitting and receiving module specifically include:

[0054] (1) the first working frequency point of AIS: 161.975MHz ± 2KHz;

[0055] (2) the second working frequency point of AIS: 162.025MHz ± 2KHz;

[0056] (3) the interrogation frequency point of the transponder: 1030MHz;

[0057] (4) the response frequency point of the transponder: 1090MHz.

[0058] The transmitting and receiving module is configured to generate standard AIS radio frequency signals on the first working frequency point or the second working frequency point of AIS, and transmit the AIS radio frequency signals out through the antenna port. The AIS radio frequency signals are used to simulate the broadcast signals transmitted by real maritime AIS base stations or ships, to send test information to the detected airborne AIS detection equipment, so as to verify whether the receiving sensitivity, signal demodulation capability, and data analysis and display functions of the airborne AIS detection equipment are normal.

[0059] Meanwhile, the transmitting and receiving module is configured to generate standard interrogation signals on the 1030MHz frequency point, and transmit the interrogation signals out through the antenna port. The interrogation signals are used to simulate the mode instructions transmitted by the ground secondary radar interrogator, to trigger the detected airborne transponder to generate corresponding response signals, so as to verify whether the receiving, decoding and response functions of the airborne transponder in different modes are normal.

[0060] In the embodiments of the present application, the test instrument integrates the AIS signal frequency points and the transponder signal frequency points originally belonging to different communication systems in the same transmitting and receiving module, and through the unified hardware architecture and the configurable signal generation mechanism, the detection of two types of different airborne avionics equipment (AIS detection equipment and transponder) can be completed using a single test instrument, which significantly improves the integration and guarantee efficiency of the field test.

[0061] In a possible embodiment, please continue to refer to Figure 1, the tester further comprises a key module, and the signal processing module comprises a master control chip. The master control chip is connected with 2N keys of the key module through a group of high-level output lines and a group of low-level output lines, the number of key switches of the master control chip is N, and the total number of pins of the master control chip is N+2.

[0062] The key module is configured to generate key data in response to operations of the user on the plurality of keys.

[0063] The master control chip is configured to receive the key data, determine a modulation mode based on the key data, and generate corresponding coded data.

[0064] In the specific implementation process, the user can input to-be-sent coded information and select a test mode (an AIS detection mode or a transponder detection mode) through the key module. When the transponder detection mode is selected, the user can further formulate an interrogation mode (any one of M1, M2, M3 / A, MC, M4, M5, and S mode).

[0065] The master control chip (such as a ZYNQ chip) can determine a corresponding standard frequency point according to the test mode selected by the user after receiving the key data. If the test mode selected by the user is the AIS detection mode, the corresponding standard frequency point is an AIS working frequency point (161.975 MHz / 162.025 MHz). If the test mode selected by the user is the transponder detection mode, the corresponding standard frequency point is an interrogation frequency point (1030 MHz).

[0066] Further, the master control chip can determine a modulation mode according to the test mode and the interrogation mode selected by the user, and further generate corresponding coded data. If the interrogation mode selected by the user is a regular mode (M1, M2, M3 / A, MC, or M4), the corresponding modulation mode is an amplitude shift keying (ASK) modulation mode. If the interrogation mode selected by the user is the S mode, the corresponding modulation mode is a differential phase shift keying (DPSK) modulation mode. If the interrogation mode selected by the user is M5 or the test mode is the AIS detection mode, the corresponding modulation mode is a minimum shift keying (MSK) modulation mode. If the test mode selected by the user is the AIS detection mode, the coded data generated by the master control chip is AIS coded data. If the test mode selected by the user is the transponder detection mode, the coded data generated by the master control chip is transponder interrogation coded data.

[0067] Please refer to Figure 2A composite key logic relationship diagram is provided for the embodiment of the present application. Among them, B1-B8 represent 8 keys of the key module, K1-K4 represent 4 key switches of the master chip, and L1 and L2 represent high-level output lines and low-level output lines, respectively.

[0068] In a specific connection relationship, the keys B1 and B5 are connected in series with the key switch K1 and then connected between L1 and L2; the keys B2 and B6 are connected in series with the key switch K2 and then connected between L1 and L2; the keys B3 and B7 are connected in series with the key switch K3 and then connected between L1 and L2; and the keys B4 and B8 are connected in series with the key switch K4 and then connected between L1 and L2.

[0069] The master chip first controls the key switches K1-K4 to be closed in turn, and simultaneously monitors the level state of the low-level output line L2. When a key is pressed and the corresponding key switch is closed, the level signal of the high-level output line L1 will be transmitted to the low-level output line L2 through the key. The master chip can uniquely determine the specific key triggered among the eight keys through the level jump of the low-level output line L2 and in combination with the number of the key switch currently in the closed state.

[0070] In the embodiment of the present application, this composite connection scheme only needs to use 1 high-level output line + 1 low-level output line + 4 key switch control lines, that is, a total of 6 I / O pins can realize the identification of 8 keys, which significantly saves hardware resources compared with the traditional independent connection scheme (which needs 8 I / O pins).

[0071] In a possible embodiment, please continue to refer to Figure 1 The transmitting and receiving module includes a direct digital frequency synthesizer (DDS) source and a radio frequency processing unit.

[0072] The DDS source is used to generate a carrier signal at a standard frequency corresponding to a frequency control signal; the carrier signal is modulated using modulation data, and a modulated radio frequency signal is output.

[0073] The radio frequency processing unit is connected with the DDS source, and is used to sequentially perform filtering and program-controlled amplification processing on the modulated radio frequency signal, and perform pulsed transmission on the processed radio frequency signal under the control of a gate signal.

[0074] In the implementation process, the DDS source is connected with the master chip, and can receive the encoded data sent by the master chip, and parse the modulation data, the frequency control signal and the gate signal from the encoded data. The modulation data contains baseband encoding information and modulation control parameters, and the modulation control parameters are digital commands for accurately controlling the DDS source to change the carrier characteristics according to a specific modulation mode (ASK, DPSK, MSK). The frequency control signal is used to indicate the working frequency (161.975MHz / 162.025MHz, 1030MHz) corresponding to the test mode selected by the user. The gate signal is used to generate a corresponding pulse timing control signal according to the test mode, and is used to accurately control the transmission time window and the pulse period of the radio frequency signal.

[0075] The DDS source can generate a carrier signal at a corresponding standard frequency based on the frequency control signal, and use a specified modulation mode (ASK / DPSK / MSK) to perform real-time modulation on the carrier signal by loading the modulation data, and finally output a radio frequency signal with specific modulation characteristics.

[0076] Please refer to Figure 3 The cross-linking relationship diagram of the transmitting unit in the transmitting and receiving module provided in the embodiment of the application.

[0077] The frequency source (i.e. the DDS source) outputs the modulated radio frequency signal, which first enters the filter for filtering processing, and then enters the power amplifier for preliminary amplification. The power controller controls the working state of the power amplifier in real time according to the target power value set by the system. The signal after twice amplification and power control is fed through the coupler, which feeds the signal to the subsequent link and provides a sampling signal for power detection to form a closed-loop power control. The signal then passes through the circulator, which is used to isolate the transmitting signal and the receiving signal to prevent the high-power transmitting signal from entering the sensitive receiving channel. After passing through the circulator, the signal is further purified by the filter to further ensure the spectral purity of the output signal. Finally, the purified signal is radiated by the antenna.

[0078] In the embodiment of the application, the DDS source generates signals in a digital manner, has extremely high frequency accuracy and stability, and can quickly switch to different standard frequencies (such as 1030MHz, 1090MHz, 161.975MHz, 162.025MHz) by changing the frequency control word, realizes seamless switching of multi-mode testing, and meets the requirements of frequency flexibility in complex field testing. And the gate signal is used to control the pulse transmission of the radio frequency signal, to ensure that the signal format strictly conforms to the timing specification of the aviation secondary radar and AIS communication.

[0079] In a possible embodiment, the DDS source is controlled by a Field-Programmable Gate Array (FPGA); the FPGA is configured to generate a frequency control word, a phase control word and an amplitude control word according to the coded data, and provide the DDS source with the frequency control word, the phase control word and the amplitude control word; and the DDS source is specifically configured to modulate the carrier signal with the modulation data based on the frequency control word, the phase control word and the amplitude control word, and output the modulated radio frequency signal.

[0080] In the embodiments of the present application, the FPGA precisely controls the signal generation and modulation process of the DDS source in a full-digital manner by generating three control words of frequency, phase and amplitude, and can flexibly implement multiple modulation schemes such as ASK, DPSK and MSK. The digital control manner avoids problems such as temperature drift and component aging existing in traditional analog modulation circuits, and significantly improves the quality and long-term stability of the signal.

[0081] In a possible embodiment, the radio frequency processing unit is further configured to:

[0082] receive a reply signal from the transponder at a reply frequency of 1090 MHz; sequentially perform amplitude limiting, attenuation, filtering, amplification and down-conversion processing on the reply signal to obtain an intermediate frequency signal; and send the intermediate frequency signal back to the signal processor module.

[0083] Please refer to Figure 4 for a cross-linking relationship diagram of the receiving unit in the transmitting and receiving module provided in the embodiments of the present application.

[0084] The radio frequency signal (such as the 1090 MHz reply signal) received by the antenna first enters the circulator, and the one-way transmission characteristic of the circulator is used to realize the isolation of transmission and reception. Subsequently, the signal sequentially passes through the amplitude limiter, the filter and the amplifier, the amplitude limiter limits the power of the input high-power interference signal to protect the subsequent sensitive receiving circuit; the filter selects the frequency band of the received signal to effectively suppress the out-of-band interference; and the amplifier preliminarily amplifies the useful signal to improve the receiving sensitivity of the system. The amplified radio frequency signal is sent to the mixer and mixed with the local oscillator signal generated by the oscillator; the frequency of the oscillator is precisely controlled by the frequency control signal, so that the radio frequency signal is down-converted to a fixed 70 MHz intermediate frequency signal. The intermediate frequency signal obtained by down-conversion is then subjected to amplitude adjustment by the subsequent amplifier (intermediate frequency amplifier), and further filtered to remove the noise by the filter, and finally sent to the digital-to-analog converter of the signal processing module.

[0085] In a possible embodiment, please continue to refer to Figure 1 , the signal processor module further includes an analog-to-digital converter. The analog-to-digital converter is configured to perform analog-to-digital conversion on the intermediate frequency signal and output a digital intermediate frequency signal; and the master control chip is connected with the analog-to-digital converter and is further configured to perform digital down-conversion, signal detection, demodulation and protocol analysis on the digital intermediate frequency signal to obtain protocol data.

[0086] In the implementation process, the analog-to-digital converter samples and quantizes the received intermediate frequency signal, converts it into a digital intermediate frequency signal, and transmits it to the master control chip. The master control chip performs digital down conversion on the digital intermediate frequency signal, that is, shifts the digital intermediate frequency signal to the baseband, and separates the in-phase component and the quadrature component. Then, the effective signal is identified through energy detection or correlation detection algorithm, and the signal type is judged. Then, according to the signal type, the corresponding demodulation algorithm (ASK demodulation, DPSK demodulation or MSK demodulation) is adopted, and the baseband data stream is restored. Finally, the baseband data stream is subjected to frame synchronization, decoding and checking according to the aviation secondary radar or AIS communication protocol, and finally the protocol data containing target identity, position, height and other information is extracted.

[0087] In the embodiment of the present application, the intermediate frequency signal is converted into a digital signal by the analog-to-digital converter, so that the subsequent processing is completely carried out in the digital domain, effectively avoiding the inherent problems of analog circuits such as temperature drift, gain instability, etc., and significantly improving the stability and consistency of the system. Based on the powerful processing capability of the master control chip, various demodulation algorithms such as ASK, DPSK and MSK can be realized through software configuration, without the need to change the hardware to adapt to the needs of different communication systems, greatly enhancing the adaptability of the system.

[0088] In a possible embodiment, please continue to refer to Figure 1 The tester further comprises a display screen. The display screen is used for visual display of the protocol data. The protocol data includes but is not limited to the following information:

[0089] 1. Identification code: 24-bit aircraft address code from the transponder, used for uniquely identifying the target identity;

[0090] 2. Geographical position information: containing longitude and latitude coordinates;

[0091] 3. Height information: current barometric altitude of the aircraft.

[0092] In the embodiment of the present application, the display screen displays the above protocol data in real time through a graphical interface, displays all test information in a centralized manner, realizes real-time visualization of test results, enables maintenance personnel to intuitively and quickly obtain test results without the aid of external equipment, simplifies the operation process, quickly judges the working state of the airborne equipment, and improves the convenience of field testing.

[0093] In a possible embodiment, please continue to refer to Figure 1 The tester further comprises a power module, and the power module is used for:

[0094] receiving first direct current from an adapter of an external power supply or second direct current from an external battery box;

[0095] The received direct current is filtered and DC / DC converted to generate various direct current voltages required for the operation of the tester.

[0096] In the implementation, the power module supports two power supply modes:

[0097] 1. External AC 220V AC power is converted into DC 19V direct current input through a power adapter.

[0098] 2. An external battery box provides DC 16.8V direct current input.

[0099] The power module filters the input direct current to suppress electromagnetic interference and ensure power quality. The filtered direct current is then DC / DC converted, which is a technology for converting one direct current (DC) voltage into another direct current (DC) voltage, to provide stable and reliable power supply for modules with different working voltage requirements in the tester (such as signal processing modules, transmitting and receiving modules, etc.).

[0100] In the embodiments of the present application, the power module supports two power supply modes of AC adapter and battery, which can meet the requirements of fixed place use and mobile testing in the field, thereby adapting to different working environments.

[0101] In a possible embodiment, the power module includes a power conversion unit, a filter circuit, and a DC / DC conversion circuit. The power conversion unit is used to automatically switch to the first direct current and use the adapter as the power input when the first direct current and the second direct current exist at the same time. The filter circuit is used to filter the first direct current. The DC / DC conversion circuit is used to DC / DC convert the filtered first direct current to generate +5V, +12V, and -12V direct current voltages required for the operation of the tester.

[0102] Please refer to Figure 5 for the structural schematic diagram of the power module provided in the embodiments of the present application.

[0103] The externally input direct current voltage (Vin) first passes through the lightning protection and reverse protection circuit to provide basic protection against transient high voltage impact and reverse connection of the power supply polarity. Then, the power supply enters the surge current suppression circuit to prevent excessive current generated during the power-on of the device from damaging the subsequent circuit. The voltage after the primary protection passes through the input filter circuit to suppress electromagnetic interference and noise from the power grid or battery, and to provide clean input for the subsequent DC / DC conversion circuit.

[0104] The filtered voltage is sent to multiple independent DC / DC conversion circuits for high-efficiency voltage conversion. The output of each DC / DC converter is connected to an output filter circuit to further filter out switching noise and stabilize the output voltage, ultimately generating +5V, +12V, and -12V DC voltages required for the operation of the tester, to power different units such as the signal processing module and the transmitting and receiving module.

[0105] In the embodiments of the present application, the power supply unit automatically selects the optimal power supply source, preferentially uses grid power supply, effectively prolongs the service life of the battery, effectively suppresses power supply noise through the filter circuit to provide clean input for the subsequent conversion circuit, and ensures that each circuit module obtains stable and reliable operating voltage through multiple groups of DC / DC conversion circuits.

[0106] It should be noted that in this document, the terms "comprising", "containing" or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or systems that include a series of elements not only include those elements, but also include other elements not explicitly listed, or include elements inherent to such processes, methods, articles or systems. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or system that includes the element.

[0107] The above sequence numbers of the embodiments of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0108] The above detailed description further describes the purpose, technical solutions and advantages of the present application. It should be understood that the above is only a specific embodiment of the present application, and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A tester that fuses airborne AIS intercept checking and transponder checking, characterized in that, The signal processing module and the transmitting and receiving module are physically separated and connected through a unified interface; the transmitting and receiving module is integrated with a radio frequency front-end circuit covering multiple standard frequency points; the multiple standard frequency points include a first working frequency point and a second working frequency point of the AIS, an interrogation frequency point of the transponder, and a response frequency point; The signal processing module is configured to generate corresponding coded data in response to a user operation and send the coded data to the transmitting and receiving module; The coded data is AIS coded data or transponder interrogation coded data; The transmitting and receiving module is configured to generate and transmit a radio frequency signal on a corresponding standard frequency point based on the coded data; The transmitting and receiving module is further configured to receive a response signal from a transponder on the response frequency point, down-convert the response signal into an intermediate frequency signal, and send the intermediate frequency signal back to the signal processing module.

2. The test set of claim 1, wherein, The tester further includes a key module, and the signal processing module includes a master control chip connected with 2N keys of the key module through a group of high-level output lines and a group of low-level output lines; the number of key switches of the master control chip is N, and the total number of pins of the master control chip is N+2. The key module is configured to generate key data in response to user operations on multiple keys. The master control chip is configured to receive the key data, determine a modulation mode based on the key data, and then generate corresponding coded data.

3. The test set of claim 2, wherein the test set is configured to perform a test of the AIS receiver and the transponder receiver simultaneously. The coded data includes modulation data, a frequency point control signal, and a gate signal; the transmitting and receiving module includes a direct digital frequency synthesis (DDS) source and a radio frequency processing unit; The DDS source is configured to generate a carrier signal on a standard frequency point corresponding to the frequency point control signal, modulate the carrier signal with the modulation data, and output a modulated radio frequency signal; The radio frequency processing unit is connected with the DDS source and is configured to sequentially perform filtering and program-controlled amplification processing on the modulated radio frequency signal and pulse-transmit the processed radio frequency signal under the control of the gate signal.

4. The test set of claim 3, wherein the test set is configured to perform a test of the AIS receiver and the transponder receiver simultaneously. The DDS source is controlled by a field programmable gate array (FPGA); The FPGA is configured to generate a frequency control word, a phase control word, and an amplitude control word according to the coded data and provide the DDS source with the frequency control word, the phase control word, and the amplitude control word; The DDS source is specifically configured to modulate the carrier signal with the modulation data based on the frequency control word, the phase control word, and the amplitude control word and output a modulated radio frequency signal.

5. The test set of claim 2, wherein the test set is configured to perform a test of the AIS receiver and the transponder receiver simultaneously. The modulation mode is an ASK modulation mode, a DPSK modulation mode, or an MSK modulation mode; the ASK modulation mode is used to generate an interrogation signal for a conventional mode; the DPSK modulation mode is used to generate an interrogation signal for an S mode; the MSK modulation mode is used to generate an interrogation signal for M5 or an AIS broadcast signal; the conventional mode is one of M1, M2, M3 / A, MC, and M4.

6. The test set of claim 3, wherein the test set is configured to perform a test of the airborne AIS receiver and the transponder receiver simultaneously. The radio frequency processing unit is further configured to: receive a response signal from a transponder on the response frequency point 1090 MHz; perform amplitude limiting, attenuation, filtering, amplification, and down-conversion processing on the response signal in sequence to obtain an intermediate frequency signal; and The intermediate frequency signal is sent back to the signal processor module.

7. The test set of claim 6, wherein the test set is configured to perform a test of the AIS receiver and the transponder receiver simultaneously. The signal processor module further comprises an analog-to-digital converter; The analog-to-digital converter is used for analog-to-digital conversion of the intermediate frequency signal to output a digital intermediate frequency signal; The main control chip is connected with the analog-to-digital converter and is further used for digital down conversion, signal detection, demodulation and protocol analysis of the digital intermediate frequency signal to obtain protocol data.

8. The test instrument for integrating airborne AIS detection and transponder inspection as described in claim 7, characterized in that, The tester further comprises a display screen used for visual display of the protocol data; the protocol data comprises identification code, geographical position and altitude information reported by the transponder.

9. The test set of claim 1, wherein, The tester further comprises a power module used for: receiving first direct current from an adapter of an external power supply or second direct current from an external battery box; filtering and DC / DC converting the received direct current to generate various direct current voltages required for operation of the tester.

10. The test set of claim 9, wherein the test set is configured to perform a test of the AIS receiver and the transponder receiver simultaneously. The power module comprises a power conversion unit, a filter circuit and a DC / DC conversion circuit; The power conversion unit is used for automatically switching to the first direct current when the first direct current and the second direct current exist simultaneously and taking the adapter as a power supply input; The filter circuit is used for filtering the first direct current; The DC / DC conversion circuit is used for DC / DC conversion of the filtered first direct current to generate +5V, +12V and -12V direct current voltages required for operation of the tester.

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