A dual-channel signal source

Abstract

The present invention relates to a dual-channel signal source, belonging to the technical field of microwave signal sources, and solves the problem that the frequency bands of existing microwave signal sources do not exceed two and the use of two 4U signal sources leads to an increase in test costs and volume. The signal source includes: a frequency synthesizer module that provides a broadband local oscillator signal and a frequency-agile local oscillator signal; a down-conversion module that mixes the received X, Ku, and Ka band signals with the local oscillator signal and then mixes the mixing result with the frequency-agile local oscillator signal to generate two intermediate frequency signals; a real-time control module that outputs two DDS signals to the frequency synthesizer module according to two frequency measurement signals; an intermediate frequency processing module that delays and forwards the two input intermediate frequency signals; an up-conversion module that up-converts the two delayed variable intermediate frequency signals to two X, Ku, and Ka band output signals; and two channel radio frequency output modules that output the two X, Ku, and Ka band output signals via channel A and channel B respectively. Two-channel X, Ku, and Ka signal sources that work independently are integrated in a single chassis.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave signal sources, and in particular to a dual-channel signal source. Background Art

[0002] Most of the existing microwave signal sources are mainly single-channel, and the number of frequency bands does not exceed two. In the original radar tests, single-channel and single-band signal sources are usually used for testing. For the radar tests of dual-frequency bands (for example, Ka and Ku bands), only two 4U signal sources can be used in cooperation to complete the test work, which not only increases the test cost but also increases the volume. At the same time, the instantaneous bandwidth of 500 MHz and the agile bandwidth of 1 GHz of the original signal source cannot meet the current test requirements. Therefore, it is extremely urgent to integrate two 4U microwave signal sources into a single 4U chassis and at the same time increase the instantaneous bandwidth and agile bandwidth. Summary of the Invention

[0003] In view of the above analysis, embodiments of the present invention aim to provide a dual-channel signal source to solve the problems that the number of frequency bands of the existing microwave signal source does not exceed two and the test cost and volume increase due to the cooperation of two 4U signal sources for testing.

[0004] On the one hand, embodiments of the present invention provide a dual-channel signal source, including: a frequency synthesizer module for providing a broadband local oscillator signal and an agile local oscillator signal according to a frequency measurement signal or a DDS signal; a down-conversion module for mixing the received X, Ku, and Ka band signals with the local oscillator signal and mixing the first mixing result with the agile local oscillator signal to generate two intermediate frequency signals; a real-time control module for outputting the two DDS signals to the frequency synthesizer module according to the two frequency measurement signals, so that the down-conversion module generates two variable intermediate frequency signals; an intermediate frequency processing module for delaying and adjusting the power of the two variable intermediate frequency signals to generate two intermediate frequency signals with delayed changes; an up-conversion module for up-converting the two delayed variable intermediate frequency signals to two X, Ku, and Ka band output signals; and two channel radio frequency output modules for respectively outputting the two X, Ku, and Ka band output signals via channel A and channel B.

[0005] The beneficial effects of the above technical solutions are as follows: Two channels of microwave signal sources in three frequency bands of X, Ku, and Ka are integrated in a single 4U chassis, and the intermediate frequency processing bandwidth is extended to 1 GHz, realizing a large bandwidth agility of 2 GHz. The signal sources of the two channels are independent working microwave signal sources and can meet the test requirements of dual-frequency band and dual-polarization radars.

[0006] Based on the further improvement of the above device, the real-time control module is used to generate a control signal and control the frequency synthesizer module, the down-conversion module, the intermediate-frequency processing module, the up-conversion module, and the two-channel radio-frequency output module according to the control signal.

[0007] Based on the further improvement of the above device, the broadband local oscillator signal includes two first-bandwidth local oscillator signals, the agile local oscillator signal includes two first-agile local oscillator signals, and the down-conversion module includes a receiving down-conversion module and an S-band down-conversion module. Among them, the receiving down-conversion module is used to receive two X, Ku, and Ka-band signals through two X / Ku / Ka radio-frequency input modules respectively, and mix the two X, Ku, and Ka-band signals with the two first-bandwidth local oscillator signals respectively to generate two first S-band signals; the frequency synthesizer module is used to provide two variable first-agile local oscillator signals according to the DDS signal; the S-band down-conversion module is used to mix the two first S-band signals with two first-agile local oscillator signals respectively to generate two original intermediate-frequency signals, and then mix the two first S-band signals with the two variable first-agile local oscillator signals to generate two variable intermediate-frequency signals.

[0008] Based on the further improvement of the above device, the X / Ku / Ka-band receiving down-conversion module includes: a first attenuator, a low-noise amplifier, a mixer, and a first S-band filter. Among them, the attenuator is used to control the opening or closing of the attenuator according to the control signal of the real-time control module to reduce the X, Ku, and Ka-band signals; the low-noise amplifier is used to perform low-noise amplification processing on the X, Ku, and Ka-band signals received from the attenuator; the first mixer is used to mix the low-noise amplified X, Ku, and Ka-band signals with the first-bandwidth local oscillator signal to down-convert the X, Ku, and Ka-band signals to the first S-band signal; and the first S-band filter is used to filter the first S-band signal to output the filtered S-band signal to the first S-band down-conversion module.

[0009] Based on further improvements to the above device, the S-band down-conversion module includes an amplification and power splitting module, a frequency division module, a detection module, a frequency measurement module, and a second mixer. Among them, the amplification and power splitting module is used to amplify and split the filtered first S-band signal; the frequency division module is used to perform frequency division processing on the amplified and split first S-band signal and output the frequency-divided first S-band signal to the frequency measurement module; the detection module is used to perform detection processing on the amplified and split first S-band signal and provide the detected signal to the intermediate frequency processing module; the frequency measurement module is used to perform frequency measurement processing on the frequency-divided first S-band signal based on the clock signal generated by the frequency synthesis module to generate a frequency measurement signal; and the second mixer is used to mix the amplified and split first S-band signal with the first agile local oscillator signal or the varying first agile local oscillator signal to down-convert the amplified and split first S-band signal to the intermediate frequency signal or the varying intermediate frequency signal.

[0010] Based on further improvements to the above device, the broadband local oscillator signal includes two second bandwidth local oscillator signals, the agile local oscillator signal includes two second agile local oscillator signals, and the up-conversion module includes: an S-band up-conversion module and two transmit up-conversion filtering and amplitude stabilization modules. Among them, the frequency synthesis module is used to provide two varying second agile local oscillator signals according to the DDS signal; the S-band up-conversion module is used to mix the two delay-varying intermediate frequency signals with the two second agile local oscillator signals or the two varying second agile local oscillator signals to generate two second S-band signals or two varying second S-band signals; and the two transmit up-conversion filtering and amplitude stabilization modules are used to mix the two second S-band signals or the two varying second S-band signals with the two second bandwidth local oscillator signals to generate the two X / Ku / Ka-band output signals.

[0011] Based on further improvements to the above device, the S-band up-conversion module includes a third mixer, a second S-band filter, and a first amplifier. Among them, the third mixer is used to mix the two delay-varying intermediate frequency signals with the second agile local oscillator signal or the varying second agile local oscillator signal to down-convert the two delay-varying intermediate frequency signals to the two second S-band signals or the two varying second S-band signals; the second S-band filter is used to filter the two second S-band signals or the two varying second S-band signals; and the first amplifier is used to generate saturated two second S-band signals or two varying second S-band signals according to the filtered two second S-band signals or two varying second S-band signals.

[0012] Based on further improvements to the above device, the transmitting up-conversion filtering and amplitude stabilization module includes a fourth mixer, a Ku-band filter bank, a variable attenuator, a PIN attenuator, and a step attenuator. Among them, the fourth mixer is used to mix two saturated second S-band signals or two varying second S-band signals with the two second bandwidth local oscillator signals respectively to down-convert the two saturated second S-band signals or two varying second S-band signals to the two X / Ku / Ka-band output signals respectively; the Ku-band filter bank is used to filter the two X / Ku / Ka-band output signals to generate two first X / Ku / Ka-band output signals; the variable attenuator is used to perform or not perform power attenuation processing on the two first X / Ku / Ka-band output signals, and modulate and perform power amplification processing on the attenuated or unattenuated two first X / Ku / Ka-band output signals to generate two second X / Ku / Ka-band output signals; the PIN attenuator attenuates the power of the two second X / Ku / Ka-band output signals, and then performs amplification processing to generate two third X / Ku / Ka-band output signals; and the step attenuator is used to attenuate the two third X / Ku / Ka-band output signals according to any one of four attenuation levels or any combination of the four attenuation levels to generate two fourth X / Ku / Ka-band output signals and use the two fourth X / Ku / Ka-band output signals as the two output signals of the transmitting up-conversion filtering and amplitude stabilization module.

[0013] Based on further improvements to the above device, the dual-channel signal source further includes an end switch combining component, connected to the two-channel radio frequency output modules, for closing switches A and B to achieve output of channel A, channel A+B, and channel B.

[0014] Based on further improvements to the above device, the receiving down-conversion module, the S-band down-conversion module, the frequency synthesizer module, the intermediate frequency processing module, the S-band up-conversion module, the real-time control module, and the two transmitting up-conversion filtering and amplitude stabilization modules are sequentially integrated on a board with dimensions of 160mm * 340mm.

[0015] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0016] 1. Integrated microwave signal sources of three bands, namely X, Ku, and Ka, for two channels in a single 4U chassis, which not only reduces the test cost but also decreases the volume and expands the intermediate frequency processing bandwidth to 1 GHz, achieving large bandwidth agility of 2 GHz.

[0017] 2. The signal sources of the two channels are independent operating microwave signal sources, capable of meeting the test requirements of dual-band and dual-polarization radars.

[0018] 3. The present application realizes dual-channel independent operation. Each channel integrates three bands of X, Ku, and Ka, simultaneously receives radar emission signals in the broadband X, Ku, and Ka bands, simulates information such as the delay, speed, and Doppler of the target, and is capable of emitting coherent target echo signals in the corresponding bands of microwave signal sources.

[0019] In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination schemes. Other features and advantages of the present invention will be described in the subsequent specification. Moreover, some advantages can be made obvious from the specification or understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained from the content specifically pointed out in the specification and the drawings. Description of the Drawings

[0020] The drawings are only used for the purpose of showing specific embodiments and are not considered as limitations on the present invention. Throughout the drawings, the same reference signs denote the same components.

[0021] Figure 1 It is a block diagram of a dual-channel signal source according to an embodiment of the present invention.

[0022] Figure 2 It is a principle block diagram of a dual-channel signal source according to an embodiment of the present invention.

[0023] Figure 3 It is a schematic diagram of a dual-channel signal source according to an embodiment of the present invention.

[0024] Figure 4 It is a flowchart of the RF signal flow of X, Ku, and Ka bands according to an embodiment of the present invention.

[0025] Figure 5 It is a top view of a dual-channel signal source according to an embodiment of the present invention.

[0026] Figure 6 It is a control system interface diagram of a dual-channel signal source according to an embodiment of the present invention.

[0027] Figure 7 It is the overall technical system of a dual-channel signal source according to an embodiment of the present invention.

[0028] Figure 8 It is the overall composition logic diagram of a dual-channel signal source according to an embodiment of the present invention.

[0029] Figure 9 It is a diagram showing the human-machine interface of a dual-channel signal source according to an embodiment of the present invention. Detailed Embodiments

[0030] The preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. The accompanying drawings form a part of this application and, together with the embodiments of the present invention, are used to explain the principles of the present invention, rather than to limit the scope of the present invention.

[0031] The dual-channel large-bandwidth agile microwave signal source is a radar test device for dual bands, capable of storing the phase information of the radar, simulating the static characteristics (such as distance, power, etc.) and dynamic characteristics (such as distance change, Doppler frequency shift, etc.) of a fully coherent radar target, statically setting the distance, Doppler, and radiation power, and simulating the target dynamic characteristics of a fully coherent radar (including the speed, distance, and Doppler of the target, etc.) to complete the test of various functional and performance technical indicators such as the azimuth, frequency, tracking accuracy, tracking range, and sensitivity of the radar.

[0032] A specific embodiment of the present invention discloses a dual-channel signal source. Refer to Figure 1 , the dual-channel signal source includes: a frequency synthesis module 102 for providing a broadband local oscillator signal and an agile local oscillator signal according to the frequency measurement signal or the DDS signal; a down-conversion module 104 for mixing the received X, Ku, and Ka band signals with the local oscillator signal and mixing the first mixing result with the agile local oscillator signal to generate two intermediate frequency signals; a real-time control module 106 for outputting two DDS signals to the frequency synthesis module according to two frequency measurement signals, so that the down-conversion module generates two variable intermediate frequency signals; an intermediate frequency processing module 108 for delaying and adjusting the power of the two variable intermediate frequency signals to generate two intermediate frequency signals with delayed changes; an up-conversion module 110 for up-converting the two delayed variable intermediate frequency signals to two X, Ku, and Ka band output signals; and two channel radio frequency output modules 112 for respectively outputting the two X, Ku, and Ka band output signals via channel A and channel B.

[0033] Compared with the prior art, the dual-channel signal source provided in this embodiment integrates microwave signal sources in three bands of X, Ku, and Ka for two channels in a single 4U chassis, and expands the intermediate frequency processing bandwidth to 1 GHz, achieving a large bandwidth agility of 2 GHz. The signal sources of the two channels are independent working microwave signal sources, capable of meeting the test of dual-band dual-polarization radar.

[0034] In the following, the dual-channel signal source according to the embodiment of the present invention will be described in detail with reference to Figures 1 to 5 . The dual-channel signal source includes a frequency synthesis module 102, a down-conversion module 104, a real-time control module 106, an intermediate frequency processing module 108, an up-conversion module 110, two channel radio frequency output modules 112, and an end switch and combiner assembly.

[0035] Refer to Figure 1, the frequency synthesizer module 102 is used to provide a broadband local oscillator signal and a frequency-agile local oscillator signal according to the frequency measurement signal or the DDS signal. The broadband local oscillator signal includes two first-bandwidth local oscillator signals and two second-bandwidth local oscillator signals, and the frequency-agile local oscillator signal includes two first frequency-agile local oscillator signals and two second frequency-agile local oscillator signals. The frequency synthesizer module 102 is used to provide two variable first frequency-agile local oscillator signals and two variable second frequency-agile local oscillator signals according to the DDS signal. Specifically, refer to Figure 4 , the frequency synthesizer module 102 is used to mix the DDS signal with the point source signal, and then filter and power-divide and amplify the mixing result to generate two first frequency-agile local oscillator signals and two second frequency-agile local oscillator signals.

[0036] The down-conversion module 104 is used to mix the received X, Ku, and Ka band signals with the local oscillator signal and mix the first mixing result with the frequency-agile local oscillator signal to generate two intermediate frequency signals. Specifically, refer to Figure 2 and Figure 3 , the down-conversion module includes a receiving down-conversion module and an S-band down-conversion module. The receiving down-conversion module is used to receive two X, Ku, and Ka band signals respectively through two X / Ku / Ka radio frequency input modules, and mix the two X, Ku, and Ka band signals with two first-bandwidth local oscillator signals to generate two first S-band signals. The S-band down-conversion module is used to mix the two first S-band signals with two first frequency-agile local oscillator signals respectively to generate two original intermediate frequency signals, and then mix the two first S-band signals with two variable first frequency-agile local oscillator signals to generate two variable intermediate frequency signals.

[0037] Specifically, refer to Figure 4 , the X / Ku / Ka band receiving down-conversion module includes: a first attenuator, a low-noise amplifier, a mixer, and a first S-band filter. The first attenuator is used to control the opening or closing of the attenuator according to the control signal of the real-time control module to reduce the X, Ku, and Ka band signals; the low-noise amplifier is used to perform low-noise amplification processing on the X, Ku, and Ka band signals received from the attenuator; the first mixer is used to mix the low-noise amplified X, Ku, and Ka band signals with the first-bandwidth local oscillator signal to down-convert the X, Ku, and Ka band signals to the first S-band signal; and the first S-band filter is used to filter the first S-band signal to output the filtered S-band signal to the first S-band down-conversion module.

[0038] Specifically, refer to Figure 4, The S-band down-conversion module includes an amplification and power splitting module, a frequency division module, a detection module, a frequency measurement module, and a second mixer. The amplification and power splitting module is used to amplify and split the filtered first S-band signal. The frequency division module is used to perform frequency division processing on the amplified and split first S-band signal and output the frequency-divided first S-band signal to the frequency measurement module. The detection module is used to perform detection processing on the amplified and split first S-band signal and provide the detected signal to the intermediate frequency processing module. The frequency measurement module is used to perform frequency measurement processing on the frequency-divided first S-band signal based on the clock signal generated by the frequency synthesis module to generate a frequency measurement signal. The second mixer is used to mix the amplified and split first S-band signal with the first agile local oscillator signal or the varying first agile local oscillator signal to down-convert the amplified and split first S-band signal to an intermediate frequency signal or a varying intermediate frequency signal.

[0039] The real-time control module 106 is used to output two DDS signals to the frequency synthesis module 102 according to the two frequency measurement signals. The frequency synthesis module 102 is used to provide two varying first agile local oscillator signals and two varying second agile local oscillator signals according to the DDS signals, so that the down-conversion module generates two varying intermediate frequency signals. The real-time control module 106 is used to generate control signals and control the frequency synthesis module 102, the down-conversion module 104, the intermediate frequency processing module 108, the up-conversion module 110, and the two-channel radio frequency output modules 112 according to the control signals.

[0040] The intermediate frequency processing module 108 is used to perform delay and power adjustment on the two variable intermediate frequency signals to generate two intermediate frequency signals with varying delays. Specifically, the intermediate frequency processing module 108 stores, processes, and forwards the intermediate frequency signals, and increases the signal bandwidth from the original 500 MHz to 1 GHz by oversampling, that is, it has an instantaneous bandwidth of 1 GHz. At the same time, the intermediate frequency that can be processed is 2.3 GHz.

[0041] The up-conversion module 110 is used to up-convert the two delayed variable intermediate frequency signals to two X, Ku, and Ka-band output signals. Refer to Figure 2 and Figure 3 , The up-conversion module includes: an S-band up-conversion module and two transmitting up-conversion filtering and amplitude stabilization modules. The S-band up-conversion module is used to mix the two intermediate frequency signals with varying delays with two second agile local oscillator signals or two varying second agile local oscillator signals to generate two second S-band signals or two varying second S-band signals; and two transmitting up-conversion filtering and amplitude stabilization modules, which are used to mix the two second S-band signals or two varying second S-band signals with two second bandwidth local oscillator signals to generate two X / Ku / Ka-band output signals.

[0042] Specifically, refer to Figure 4, the S-band up-conversion module includes a third mixer, a second S-band filter, and a first amplifier. The third mixer is used to mix two intermediate-frequency signals with varying delays with a second agile local oscillator signal or a varying second agile local oscillator signal to down-convert the two intermediate-frequency signals with varying delays to two second S-band signals or two varying second S-band signals. The second S-band filter is used to filter the two second S-band signals or the two varying second S-band signals. The first amplifier is used to generate two saturated second S-band signals or two varying second S-band signals based on the two filtered second S-band signals or two varying second S-band signals. By outputting a saturated signal through the first amplifier, the frequency response is reduced, and it is possible to avoid excessive frequency changes. 3V, input 34 - 35G, with a relatively large frequency response (in-band frequency response).

[0043] Specifically, referring to Figure 4 , the transmit up-conversion filtering and amplitude stabilization module includes a fourth mixer, a Ku-band filter bank, a variable attenuator, a PIN attenuator, and a step attenuator. The fourth mixer is used to mix the two saturated second S-band signals or the two varying second S-band signals with two second bandwidth local oscillator signals respectively to down-convert the two saturated second S-band signals or the two varying second S-band signals to two X / Ku / Ka-band output signals respectively. The Ku-band filter bank is used to filter the two X / Ku / Ka-band output signals to generate two first X / Ku / Ka-band output signals. The variable attenuator is used to perform or not perform power attenuation on the two first X / Ku / Ka-band output signals, and modulate and power-amplify the attenuated or non-attenuated two first X / Ku / Ka-band output signals to generate two second X / Ku / Ka-band output signals. The PIN attenuator is used to attenuate the power of the two second X / Ku / Ka-band output signals and then amplify them to generate two third X / Ku / Ka-band output signals; and the step attenuator is used to attenuate the two third X / Ku / Ka-band output signals according to any one of four levels of attenuation or any combination of the four levels of attenuation to generate two fourth X / Ku / Ka-band output signals and use the two fourth X / Ku / Ka-band output signals as the two output signals of the transmit up-conversion filtering and amplitude stabilization module.

[0044] The two-channel RF output module 112 is used to output two X, Ku, and Ka-band output signals via channel A and channel B respectively.

[0045] The end switch combining component is connected to the two-channel RF output module and is used to complete the closing of switches A and B to achieve output of channel A, channel A + B, and channel B.

[0046] Referring to Figure 5, the receiving down-conversion module, S-band down-conversion module, frequency synthesizer module, intermediate-frequency processing module, S-band up-conversion module, real-time control module, and two transmitting up-conversion filtering and amplitude-stabilizing modules are sequentially integrated on a board with a size of 160mm * 340mm.

[0047] In the following text, reference will be made to Figure 2 , and a dual-channel signal source according to an embodiment of the present invention will be described in detail by way of specific examples.

[0048] The signal source includes: a receiving down-conversion component for down-converting microwave signals in the X, Ku, and Ka bands received to the S band, while receiving a power range of 10dBm to -40dBm, and having an input power detection function and a dual-channel receiving down-conversion function. An S-band down-conversion component for down-converting the S-band signal to an intermediate-frequency processing signal, and having a detection function and a dual-channel down-conversion function. An intermediate-frequency processing component for storing and forwarding the intermediate-frequency signal, and having an instantaneous bandwidth of 1GHz. An S-band up-conversion component for up-converting the intermediate-frequency processed signal to the S band, and having a dual-channel up-conversion function. An up-conversion amplitude-stabilized output component for up-converting the S-band signal to the X band, Ku band, and Ka band, and simultaneously performing power amplitude stabilization control on the output signal. A frequency synthesizer component having two 2-20GHz broadband sources as broadband local oscillators, and also having two point sources and a DDS-based agile local oscillator to achieve fast agility. A real-time control system component for communicating with the host computer through the PXIe bus, performing task scheduling, comprehensively controlling each component, and also having a frequency measurement function.

[0049] The structural schematic diagram of the present invention is as shown in Figure 5 All modules adopt a standardized board design, including a receiving down-conversion component, an S-band down-conversion component, an intermediate-frequency processing component, an S-band up-conversion component, an A-channel amplitude-stabilized up-conversion component, a B-channel amplitude-stabilized up-conversion component, a frequency synthesizer component, a switch combining component, a real-time control system component, a PXIe chassis, and a PXIe zero-slot controller. The host computer is carried by the PXIe zero-slot controller, and the host computer communicates with the real-time control system component through the PXIe bus. The real-time control system component analyzes the commands to perform task scheduling on each component. The data and command interactions between the components are carried out through the backplane bus.

[0050] As shown in Figure 2As shown in the figure, the input X, Ku, and Ka band signals are down-converted to the S band by the receiving down-conversion component. At the same time, the S band signal is detected to monitor the strength of the input signal. The S band down-conversion component down-converts the S band signal to the intermediate frequency. Meanwhile, the radio frequency signal is detected, and the detection result is sent to the real-time control system component for processing. The intermediate frequency processing component stores, processes, and forwards the intermediate frequency signal output by the S band down-conversion component. The intermediate frequency processing component uses the oversampling method to increase the signal bandwidth from the original 500 MHz to 1 GHz. Meanwhile, the processable intermediate frequency is 2.3 GHz, reducing the front-end design pressure. The S band up-conversion component up-converts the intermediate frequency output signal of the intermediate frequency processing component to the S band. The A channel amplitude-stabilized up-conversion component up-converts the S band signal to the X, Ku, and Ka band signals, and has amplitude stabilization control at the same time. The output power range can reach 20 dBm to -100 dBm, and the output power stability is ±2 dB in the temperature range of -10°C to 40°C. The frequency synthesizer component generates a broadband local oscillator signal of 2 to 20 GHz for the first-stage up and down conversion, and the agile local oscillator composed of 1 DDS and 2 point sources is used for the second-stage up and down conversion. The switching time of the agile local oscillator is about 150 ns. The switch and combiner component performs switch and combiner control on the A channel and B channel signals. The real-time control system component analyzes the commands from the host computer, comprehensively controls the other components, and has a frequency measurement function at the same time. It measures the frequency of the 750 MHz to 1250 MHz signal and transmits the frequency measurement code to the other components for switching the frequency source and filter bank. It also has a power calibration storage function and a synchronization signal conditioning function. All components are highly integrated, and the dual-channel function is integrated on a board of 160 mm * 340 mm.

[0051] The human-computer interaction software interface. The main contents of the software include

[0052] (1) Select the signal source working mode, including guidance, normal, coherent, agile, etc.;

[0053] (2) Set and transfer parameters, such as frequency, power, delay, speed, Doppler, trigger level, etc.;

[0054] (3) Read information, such as delay, frequency measurement, pulse width, repetition frequency value, etc.;

[0055] (4) Implement command transmission, such as radio frequency switch, modulation, reference selection, trigger selection, etc.;

[0056] (5) Implement device functions, such as power calibration, frequency response calibration, frequency self-diagnosis, power on and off, etc.;

[0057] (6) Program-controlled communication via network port and serial port;

[0058] (7) And other settings related to system control and signal flow.

[0059] (8) The dual-channel broadband agile signal source realizes the reception, processing, and transmission of X / Ku / Ka dual-channel signals.

[0060] Overall Design of the Signal Source

[0061] In accordance with the design concept of "general reconfigurability", the dual-frequency signal source has the plasticity of the design framework under the technical framework of unified standards, achieving future-oriented scalability.

[0062] According to the embodiments of the present application, the signal source will insert X / Ku / Ka band functional boards in a 4U high PXIe bus chassis to achieve the functions of X / Ku / Ka band coherent and agile signal sources.

[0063] The dual-frequency signal source can realize the coherent and agile functions of the X / Ku / Ka band signal source. Under a unified control platform, it can receive the radar emission signals in the X / Ku / Ka band, simulate target delay, speed, Doppler and other information, and transmit coherent X / Ku / Ka band target echo signals. The dual-frequency signal source includes the signal source coherent and agile guiding functions and the function of actively generating X / Ku / Ka signals.

[0064] The dual-frequency signal source can receive X / Ku / Ka band signals emitted by the radar. Based on the received and collected signals, it can modulate target information through parameter settings, simulate target distance, movement, change and other information, and the RF signal channel generates X / Ku / Ka band target echo signals. It cooperates with the radar to complete tests such as target search, acquisition, tracking, and identification. The control subsystem realizes unified control, conducts human-computer interaction, parameter mode setting, and selects and configures system modules.

[0065] The dual-frequency signal source uses a modular PXIe general signal source platform and realizes the technical requirements of the microwave signal source through the combination of RF and signal processing boards. The proposed configuration is as follows.

[0066] Table 1 Composition Table of the Dual-Channel Signal Source System

[0067]

[0068]

[0069] The dual-frequency signal source includes two signal reception and transmission channels in the Ku band and the Ka band. Except for the unified control system, switch and multiplexing module, and the shared 100 MHz clock source, the signal processing modules are independent of each other. The RF signal processing processes of the Ku band and the Ka band are respectively as Figure 4 shown.

[0070] The dual-frequency signal source respectively down-converts the radar transmission signals in the X / Ku / Ka bands into intermediate-frequency signals through the microwave subsystem. The intermediate-frequency DRFM channel has the ability to receive and transmit signals with a bandwidth of 1 GHz. Combined with the agile local oscillator system, the signal source thus meets the requirement of a 2.1 GHz agile bandwidth. In the intermediate-frequency signal processing system, the target signal is simulated, and then through the microwave subsystem, the output intermediate-frequency signal is up-converted to obtain a target echo signal that is coherent in frequency with the transmission signal. The signal source includes coherent, agile guidance functions and the function of actively setting the frequency to generate signals. The coherent and agile guidance functions receive the radar transmission signals, simulate and modulate information such as target distance, speed, and Doppler in the DRFM component through radio frequency storage technology, and generate a radio frequency target signal coherent with the transmission signal through radio frequency up-conversion. The function of actively setting the frequency to generate signals actively generates intermediate-frequency continuous wave or pulse modulation signals through the DRFM component, and through radio frequency up-conversion, generates radio frequency signals in the X / Ku / Ka bands. The Ku band can achieve 12 - 18 GHz, and the Ka band can achieve 33 - 38 GHz.

[0071] The signal source can be divided into a microwave subsystem, a control subsystem, a signal processing subsystem, a software subsystem, a power supply subsystem, a structural subsystem, a wiring subsystem, etc. The microwave subsystem includes a radio frequency signal receiving unit, a radio frequency signal transmitting unit, and a frequency synthesizer unit. The radio frequency signal receiving unit includes two stages of down-conversion for each of the Ku and Ka bands, and contains functional components such as radio frequency signal down-conversion, filtering, amplification, and intermediate-frequency frequency division processing, generating detection signals, frequency measurement signals, and intermediate-frequency signals, with characteristics such as wide bandwidth and large input dynamic range; the radio frequency signal transmitting unit includes two stages of up-conversion for each of the Ku and Ka bands, and contains components such as up-conversion filtering, amplification, constant-temperature amplitude stabilization control, and power control, with characteristics such as signal coherent replication, carrier frequency agility, wide bandwidth, and large output power dynamic range. The frequency synthesizer unit provides broadband local oscillator frequencies for the radio frequency signal transceiver channels and system internal / external reference clock sources, including a broadband local oscillator system provided for the two channels of the Ku and Ka bands, and a shared reference clock source. The signal processing subsystem includes two independent DRFM intermediate-frequency signal processing channels; the control subsystem includes two independent frequency measurement modules, DDS local oscillator modules, and a shared system control platform. The structural and power supply subsystems achieve the interconnection of electrical, signal, control, and physical structures on a PXIe general-purpose signal source platform. The software subsystem also realizes system real-time control, human-computer interaction, and program-controlled communication based on the unified signal source platform.

[0072] The overall composition logic diagram of the dual-frequency signal source system is as Figure 6As shown. In this solution, each component of the dual-frequency signal source will be modularized by function. Each board is a field-replaceable unit, and each board can be customized with different functions according to user requirements. General units (such as the zero-slot controller) have high generality, and products conforming to international standard specifications can be selected. Modules shared by multiple functions (such as the real-time control unit module) are designed as general modules according to specifications to achieve reuse and future-oriented compatibility. Complex RF function modules are designed with standard interfaces, and their specific configurations can be selected by users. Through these designs, users can freely choose module combinations to form the simplest mode that meets their needs.

[0073] Reference Figure 5 , the dual-frequency signal source adopts a PXIe standard bus chassis (4U). The chassis depth is 675 mm (including front and rear panels). Inside, it includes microwave standard modules, a PXIe zero-slot controller, a power module, and a bus backplane. Among them, the PXIe zero-slot controller and the power module have a standard depth of 160 mm and are placed at the front of the chassis. Each standard microwave module is 340 mm deep and is inserted vertically at the rear of the chassis.

[0074] Through unique technical designs, the panel is also an optional component. Users can choose to install the panel or not. Through the reverse layout of the zero-slot controller and the RF system, the layout structure of the front and rear panels is naturally compatible with the previous supporting ones, and at the same time, the chassis space can be utilized to the maximum extent.

[0075] The cooling fans of the chassis are located at the bottom of the chassis, and the air flows from bottom to top to ensure the normal heat dissipation of each board and guarantee reliability.

[0076] Reference Figure 7 , the hardware part of the dual-frequency signal source mainly includes subsystems such as microwave functions, control, chassis and structure, power supply, and connection accessories. The hardware part of the signal source consists of standard boards with different functions, which are optional installation contents for user-required boards.

[0077] The microwave function subsystem is mainly divided into four parts according to functions: RF signal receiving unit, RF signal transmitting unit, and frequency synthesizer unit. It mainly realizes signal source functions such as receiving down-conversion, intermediate frequency frequency storage, transmitting up-conversion amplitude stabilization and attenuation.

[0078] The control subsystem unit mainly consists of a real-time control unit, a PXIe zero-slot controller, a display and keyboard input unit, a LAN communication unit, and a microwave function control interface, etc. The PXIe zero-slot controller interacts with the real-time control unit through the PXIe bus on the chassis backplane. The real-time control unit then, according to the RF bus specification and the signal source function requirements, performs local or external program control on the operation of each microwave function module, controls the relevant microwave function modules to receive or generate RF signals according to instructions, and conducts communication interconnection and data exchange with other external devices.

[0079] The microwave signal source selects a standard chassis using the PXIe mechanical and electrical specifications and designs the structure of the microwave function module. According to user requirements, a 4U standard radio frequency bus chassis is adopted, which contains a ventilation unit and has a certain electromagnetic shielding function. Using the microwave function subsystem module and component planning, the slot width of the component module is reasonably designed.

[0080] The power supply subsystem provides the required digital and analog power supplies for each function module such as the microwave signal source control subsystem and the microwave function subsystem. The connection accessories provide the connection functions of radio frequency, intermediate frequency and synchronous control signals for each module of the microwave function subsystem.

[0081] The signal source software consists of two major parts: the upper computer software (zero-slot controller software) and the lower computer software (embedded real-time processing software). The upper computer software has a user call interface to meet the specific needs of users. The lower computer software closely cooperates with the system hardware to achieve fast and instant signal processing of the signal source.

[0082] Microwave system

[0083] The dual-frequency signal source consists of 9 standard components, as Figure 3 shown. Among them, the receive down-conversion component down-converts the X / Ku / Ka frequency bands to the S-band intermediate frequency signal, and performs filtering, limiting and amplification. The S-band down-conversion component down-converts the S-band intermediate frequency signal (including the externally input intermediate frequency signal) to the low intermediate frequency signal, sends it to the frequency measurement and DRFM unit, and sends the extracted radar pulse envelope to the real-time control system. The real-time control system module performs instantaneous frequency measurement on the frequency measurement signal, then guides the local oscillator signal inside the frequency synthesizer component to achieve the second down-conversion, generates the L-band intermediate frequency signal, and outputs it to the intermediate frequency processing component. The intermediate frequency processing component receives the L-band intermediate frequency signal, generates the target analog information, outputs the L-band intermediate frequency signal to the S-band up-conversion component, receives the L-band intermediate frequency signal in two paths A and B, mixes it with the local oscillator signal provided by the frequency synthesizer component to generate the S-band intermediate frequency signal, and the amplitude stabilization and transmission component up-converts the S-band intermediate frequency signal respectively to generate the X / Ku / Ka frequency band radio frequency signal, and then completes the functions of filtering, amplification, modulation, amplitude stabilization and attenuation. The end switch and combining component completes the switch and combination of the two paths A and B to achieve the output functions of channels A, A + B and B.

[0084] The 9 modules of the signal source are all independent standard components. The analog signals are interconnected through the interfaces on the component panel, and the digital control signals and power supplies are interconnected through the PXIe bus backplane of the radio frequency chassis.

[0085] Power supply system

[0086] The dual - frequency signal source adopts an AC / DC power conversion module, and the input of the module selects the mains supply of 220V. The voltages and currents of each output port of the module will be designed according to the power supply requirements of the radio frequency system and the control system. The output ripple of each port is less than 100mV, and the power module is specially customized according to the internal structure characteristics of the PXIe standard chassis.

[0087] Control system

[0088] Reference Figure 8 , the control unit of this system includes a PXIe zero - slot controller and a real - time control system. The zero - slot controller executes the PXIe standard specification. The zero - slot controller uses C / C++ language as the software development tool, adopts a modular design, and the programmed control protocol can fully cover the protocol requirements of the original signal source and can further meet the new needs of users. The real - time control system uses FPGA + DSP as the hardware platform to achieve fast response requirements such as signal source agility.

[0089] Software design

[0090] Reference Figure 9 , the signal source software consists of two major parts: the upper - computer software and the lower - computer software. The upper - computer software is the zero - slot controller software, and the lower - computer software is the embedded real - time processing software.

[0091] (1) Upper - computer software

[0092] The hardware operation platform of the upper - computer software is the PXI - e zero - slot controller, the software platform is the Windows7 operating system, the software development environment is Microsoft Visual C++6.0, and it is written in C++ language.

[0093] The external interfaces of the upper - computer software mainly include a display interface, a PXIe bus interface, a DSP control interface for communication between the lower - computer and the upper - computer, a user input keyboard interface, and a programmed control interface.

[0094] The main functions required by the upper - computer software are: display function, manual / programmed control function, execution function, system parameter setting function, keyboard response function, self - diagnosis function, power calibration function, and function of being compatible with multiple signal source programmed control protocols. The reference schematic diagram is as shown in the figure

[0095] (2) Lower - computer software

[0096] The lower - computer software is divided into real - time control system DSP software, FPGA software, interface board FPGA software, and radio - frequency storage FPGA software.

[0097] Real - time control system DSP software

[0098] The DSP software is the embedded software for the real-time control system. The running hardware platform is the C6000 series DSP chips of TI Company, and the software development environment is CCS3.3 of TI Company. It is written in C language.

[0099] The external interfaces of the DSP software mainly include the communication interface between the DSP and the host computer and the communication interface between the DSP and the FPGA of the real-time control system.

[0100] The main functions of the DSP software are: parsing host computer instructions, sending control commands, frequency code calculation, and power calibration.

[0101] The FPGA software of the real-time control system

[0102] The running hardware platform of the FPGA software of the real-time control system is the cyclone IV series FPGA chips of Altera Company, and the software development environment is Quartus II of Altera Company.

[0103] The external interfaces of the FPGA software of the real-time control system mainly include the PXI-e bus interface, the communication interface between the DSP and the FPGA, the custom bus interface, and the communication interface with the frequency measurement machine.

[0104] The main functions of the FPGA software of the real-time control system are: PXI-e bus communication, receiving host computer control instructions, receiving DSP control codes, DDS frequency code calculation, frequency code calculation of the frequency measurement machine, and custom bus communication.

[0105] The FPGA software of the frequency measurement sub-card of the real-time control system

[0106] The running hardware platform of the FPGA software of the frequency measurement sub-card of the real-time control system is the FPGA chip of Xilinx Company, and the software development environment is ISE of Xilinx Company.

[0107] The external interface of the FPGA software of the frequency measurement sub-card of the real-time control system is mainly the communication interface with the frequency measurement machine.

[0108] The main functions of the FPGA software of the frequency measurement sub-card of the real-time control system are: communication through the frequency measurement machine bus interface, receiving control instructions of the real-time control system, address decoding, and completing the frequency measurement function.

[0109] The FPGA software of the interface board

[0110] The running hardware platform of the FPGA software of the interface board is the cyclone IV series FPGA chips of Altera Company, and the software development environment is Quartus II of Altera Company.

[0111] The external interfaces of the FPGA software of the interface board mainly include the custom bus interface and the external control interface.

[0112] The software functions of the interface board FPGA mainly include: custom bus communication, receiving control instructions from the real-time control system, address decoding, control code generation and transmission.

[0113] RF storage FPGA software

[0114] The hardware platform for the operation of the RF storage FPGA software is the FPGA chip of Xilinx, and the software development environment is ISE of Xilinx.

[0115] The external interfaces of the RF storage FPGA software mainly include custom bus interfaces and external control interfaces.

[0116] The software functions of the RF storage FPGA mainly include: custom bus communication, receiving control instructions from the real-time control system, address decoding, and control of the RF storage functional circuit system.

[0117] The embodiments of the present invention can achieve dual-channel independent operation. Each channel integrates three bands of X, Ku, and Ka, simultaneously receives radar emission signals in the broadband X / Ku and Ka bands, simulates information such as the delay, speed, and Doppler of the target, and can emit coherent target echo signals in the corresponding bands of microwave signal sources.

[0118] Those skilled in the art can understand that all or part of the processes for implementing the methods of the above embodiments can be completed by instructing relevant hardware through a computer program, and the program can be stored in a computer-readable storage medium. Among them, the computer-readable storage medium is a magnetic disk, an optical disc, a read-only memory, or a random access memory, etc.

[0119] As mentioned above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention.

Claims

1. A dual-channel signal source, characterized in that, Comprising: A frequency synthesizer module for providing a broadband local oscillator signal and a frequency-agile local oscillator signal according to a frequency measurement signal or a DDS signal; A down-conversion module for mixing the received X, Ku, and Ka band signals with the local oscillator signal and mixing the first mixing result with the frequency-agile local oscillator signal to generate two intermediate frequency signals; A real-time control module for outputting the two DDS signals to the frequency synthesizer module according to two frequency measurement signals, so that the down-conversion module generates two variable intermediate frequency signals; An intermediate frequency processing module for delaying and power-adjusting the two variable intermediate frequency signals to generate two intermediate frequency signals with delayed variations; An up-conversion module for up-converting the two delayed variable intermediate frequency signals to two X, Ku, and Ka band output signals; And Two-channel radio frequency output modules for outputting the two X, Ku, and Ka band output signals via channel A and channel B respectively, The frequency-agile local oscillator signal includes two first frequency-agile local oscillator signals, and the down-conversion module includes a receiving down-conversion module and an S-band down-conversion module. Among them, the receiving down-conversion module is used to receive the X, Ku, and Ka band signals through two X / Ku / Ka radio frequency input modules and mix the two X, Ku, and Ka band signals with the two first bandwidth local oscillator signals respectively to generate two first S-band signals; the frequency synthesizer module is used to provide two variable first frequency-agile local oscillator signals according to the DDS signal; the S-band down-conversion module is used to mix the two first S-band signals with two first frequency-agile local oscillator signals respectively to generate two original intermediate frequency signals, and then mix the two first S-band signals with the two variable first frequency-agile local oscillator signals to generate two variable intermediate frequency signals; Among them, the X / Ku / Ka band receiving down-conversion module includes: an attenuator, a low-noise amplifier, a first mixer, and a first S-band filter. The attenuator is used to control the opening or closing of the attenuator according to the control signal of the real-time control module to reduce the X, Ku, and Ka band signals; the low-noise amplifier is used to perform low-noise amplification processing on the X, Ku, and Ka band signals received from the attenuator; the first mixer is used to mix the X, Ku, and Ka band signals after low-noise amplification with the first bandwidth local oscillator signal to down-convert the X, Ku, and Ka band signals to the first S-band signal; and the first S-band filter is used to filter the first S-band signal to output the filtered S-band signal to the S-band down-conversion module.

2. The dual-channel signal source according to claim 1, wherein The real-time control module is used to generate a control signal and control the frequency synthesizer module, the down-conversion module, the intermediate frequency processing module, the up-conversion module, and the two-channel radio frequency output module according to the control signal.

3. The dual-channel signal source according to claim 1, wherein The S-band down-conversion module includes an amplification power splitting module, a frequency division module, a detection module, a frequency measurement module, and a second mixer. Among them, The amplification power splitting module is used to amplify and split the filtered first S-band signal; The frequency division module is used to perform frequency division processing on the amplified and split first S-band signal and output the frequency-divided first S-band signal to the frequency measurement module; The detection module is used to perform detection processing on the amplified and split first S-band signal and provide the detected signal to the intermediate frequency processing module; The frequency measurement module is used to perform frequency measurement processing on the frequency-divided first S-band signal based on the clock signal generated by the frequency synthesizer module to generate a frequency measurement signal; and The second mixer is used to mix the amplified and split first S-band signal with the first agile local oscillator signal or the varying first agile local oscillator signal to down-convert the amplified and split first S-band signal to the intermediate frequency signal or the varying intermediate frequency signal.

4. The dual-channel signal source according to claim 1, characterized in that, The broadband local oscillator signal includes two second bandwidth local oscillator signals, the agile local oscillator signal includes two second agile local oscillator signals, and the up-conversion module includes: an S-band up-conversion module and two transmit up-conversion filtering and amplitude stabilization modules, where The frequency synthesizer module is used to provide two varying second agile local oscillator signals according to the DDS signal; The S-band up-conversion module is used to mix the two delay-varying intermediate frequency signals with the two second agile local oscillator signals or the two varying second agile local oscillator signals to generate two second S-band signals or two varying second S-band signals; and The two transmit up-conversion filtering and amplitude stabilization modules are used to mix the two second S-band signals or the two varying second S-band signals with the two second bandwidth local oscillator signals to generate the two X / Ku / Ka-band output signals.

5. The dual-channel signal source according to claim 4, wherein The S-band up-conversion module includes a third mixer, a second S-band filter, and a first amplifier, where The third mixer is used to mix the two delay-varying intermediate frequency signals with the second agile local oscillator signal or the varying second agile local oscillator signal to down-convert the two delay-varying intermediate frequency signals to the two second S-band signals or the two varying second S-band signals; The second S-band filter is used to filter the two second S-band signals or the two varying second S-band signals; and The first amplifier is used to generate two saturated second S-band signals or two varying second S-band signals according to the filtered two second S-band signals or two varying second S-band signals.

6. The dual-channel signal source according to claim 5, wherein, The transmit up-conversion filtering and amplitude stabilization module includes a fourth mixer, a Ku-band filter bank, a variable attenuator, a PIN attenuator, and a step attenuator, where The fourth mixer is used to mix the two saturated second S-band signals or the two varying second S-band signals with the two second bandwidth local oscillator signals respectively to down-convert the two saturated second S-band signals or the two varying second S-band signals to the two X / Ku / Ka-band output signals respectively; The Ku-band filter bank is used to filter the two X / Ku / Ka-band output signals to generate two first X / Ku / Ka-band output signals; The variable attenuator is used to perform or not perform power attenuation processing on the two first X / Ku / Ka-band output signals, and modulate and perform power amplification processing on the attenuated or non-attenuated two first X / Ku / Ka-band output signals to generate two second X / Ku / Ka-band output signals; The PIN attenuator attenuates the power of the two second X / Ku / Ka-band output signals, and then performs amplification processing to generate two third X / Ku / Ka-band output signals; and The step attenuator is used to attenuate the two third X / Ku / Ka-band output signals according to any one of the four-step attenuations or any combination of the four-step attenuations to generate two fourth X / Ku / Ka-band output signals and use the two fourth X / Ku / Ka-band output signals as the two output signals of the transmit up-conversion filtering and amplitude stabilization module.

7. The dual-channel signal source according to claim 1, characterized in that, It further includes an end switch and combiner assembly, which is connected to two channel radio frequency output modules and is used to complete the closing of two switches, A and B, to realize the output of channel A, channel A + B, and channel B.

8. The dual-channel signal source according to claim 1 or 6, characterized in that, The receive down-conversion module, the S-band down-conversion module, the frequency synthesizer module, the intermediate frequency processing module, the S-band up-conversion module, the real-time control module, and two transmit up-conversion filtering and amplitude stabilization modules are sequentially integrated on a board with a size of 160mm * 340mm.

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