Testable variable input and output frequency transponder ring downconverter and switching method

Abstract

The application provides a test forwarding small loop down converter with variable input and output frequencies and a switching method, which comprises a down mixing circuit, a variable high local oscillator circuit, an intermediate frequency processing circuit, an up mixing circuit, a variable low local oscillator circuit, a single-pole double-throw switch module and an X frequency band output filter; the down mixing circuit combines a V frequency band input signal and a variable high local oscillator signal to perform down mixing and generate an intermediate frequency signal; the single-pole double-throw switch module sends the intermediate frequency signal to the X frequency band output filter or the up mixing circuit; the V frequency band signal is converted and moved to an X frequency band signal or a Q frequency band signal through one-time frequency conversion or two-time frequency conversion; the input frequency and the output frequency within an arbitrary configuration band are realized; the small loop test and the ground loop test are realized; when switching, the inherent phase difference of two working links is eliminated through a deep reinforcement learning model, then the switching is performed at the zero-crossing moment of the intermediate frequency signal, seamless connection is realized, and the signal continuity under the related test scene is ensured.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a test forwarding small loop downconverter with variable input and output frequencies and a switching method. Background Technology

[0002] Existing satellite communication ground stations include uplink and downlink, with different frequencies, both significantly higher than baseband signal frequencies, especially the V-band uplink and Q-band downlink. To enable loopback testing of the uplink and downlink RF signals, as well as small-loop testing of the uplink, it is necessary to convert the V-band uplink signal to the Q-band and the uplink signal to the X-band or lower frequency band. Existing upconverters or downconverters have the same input and output frequency bandwidth, or a fixed intermediate frequency signal frequency, with the RF signal frequency changed via a local oscillator. It can only upconvert baseband signals to very high frequencies or downconvert received high-frequency satellite signals to very low baseband frequencies. Even multi-channel frequency conversion devices use the same link or two independent frequency conversion links, and cannot share the local oscillator, intermediate frequency, and frequency conversion modules. When the satellite signal or the satellite signal received by the ground is abnormal, it is impossible to determine whether the problem is with the ground equipment or the satellite itself. Therefore, a frequency relay device is needed to test the ground loopback signal or, more importantly, to determine whether the uplink is abnormal through a small loop link to locate whether the abnormality comes from the satellite itself. Summary of the Invention

[0003] In view of this, the present invention proposes a test forwarding small loop downconverter and switching method with variable input and output frequencies, which can convert V-band input signals into X-band or Q-band input signals, thereby realizing loopback testing and small loop testing of ground equipment, and ensuring seamless connection during link switching.

[0004] The technical solution of this invention is implemented as follows: A test forwarding loop downconverter with variable input and output frequencies, positioned between the uplink and downlink, includes a downconverter mixer circuit, a variable high local oscillator circuit, an intermediate frequency (IF) processing circuit, an upconverter mixer circuit, a variable low local oscillator circuit, a single-pole double-throw (SPDT) switch module, and an X-band output filter. The variable high IF circuit generates a variable high IF signal. The downconverter mixer circuit downconverts and mixes the V-band input signal from the uplink with the variable high IF signal to generate an IF signal. The IF processing circuit processes the IF signal. The SPDT switch module sends the processed IF signal to the X-band output filter or the upconverter mixer circuit. The X-band output filter outputs an X-band output signal. The variable low IF circuit generates a variable low IF signal. The upconverter mixer circuit upconverts and mixes the processed IF signal with the variable low IF signal to generate a Q-band output signal, which is then sent to the downlink.

[0005] Preferably, it further includes an input filter and a Q-band output filter. The input filter filters the V-band input signal of the uplink and then sends it to the downconverter mixer circuit. The Q-band output filter filters the Q-band output signal and then sends it to the downlink.

[0006] Preferably, it also includes an internal and external parameter reference circuit, which is electrically connected to the variable high local oscillator circuit and the variable low local oscillator circuit, respectively.

[0007] Preferably, the variable high local oscillator circuit includes a high local oscillator phase-locked loop, a high local oscillator frequency multiplier, and a high local oscillator filter. The high local oscillator phase-locked loop is electrically connected to the high local oscillator frequency multiplier and the internal and external parameter reference circuits, respectively. The high local oscillator frequency multiplier is electrically connected to the down-conversion mixer circuit, and the high local oscillator filter is electrically connected between the high local oscillator phase-locked loop and the high local oscillator frequency multiplier.

[0008] Preferably, the variable low local oscillator circuit includes a low local oscillator phase-locked loop, a low local oscillator frequency multiplier, and a low local oscillator filter. The low local oscillator phase-locked loop is electrically connected to the low local oscillator frequency multiplier and the internal and external parameter reference circuits, respectively. The low local oscillator frequency multiplier is electrically connected to the down-conversion mixer circuit, and the low local oscillator filter is electrically connected between the low local oscillator phase-locked loop and the low local oscillator frequency multiplier.

[0009] Preferably, the internal and external parameter reference circuit provides a reference power divider signal to the high local oscillator phase-locked loop and the low local oscillator phase-locked loop via a built-in temperature-controlled crystal oscillator or by an externally provided reference power divider signal.

[0010] A switching method for a small-loop down-converter using variable input and output frequencies is described. The switching of the working link is performed via a single-pole double-throw switch module. The working link includes a small-loop test link and a loopback test link. The switching method includes the following steps: Step S1: After receiving the link switching instruction, collect the operating condition data of the current working link. The operating condition data includes the intermediate frequency signal phase, output power, local oscillator frequency parameters, and ambient temperature. Step S2: Perform calculations on the collected operating data using deep reinforcement learning to solve for the local oscillator phase fine-tuning parameters of the working link to be connected; Step S3: Perform phase pre-synchronization calibration on the local oscillator signal of the working link to be accessed based on the local oscillator phase fine-tuning parameters. If the calibration fails, repeat steps S2-S3 until the calibration passes. Step S4: Monitor the zero-crossing time of the intermediate frequency signal in real time and determine the optimal switching node. At the optimal switching node time, trigger the single-pole double-throw switch module to switch the working link.

[0011] Preferably, the specific steps of step S1 are as follows: Monitor system switching commands in real time, distinguish between small loop test link switching commands and loopback test link switching commands, and mark the type of working link to be connected; The phase detection unit acquires the real-time phase value of the intermediate frequency signal of the current working link and outputs the instantaneous power value, while reading the real-time frequency and phase reference parameters of the variable high local oscillator circuit and the variable low local oscillator circuit. Real-time ambient temperature data is collected by a temperature sensor array and combined with the real-time phase value of the intermediate frequency signal, the instantaneous output power value, the real-time frequency of the variable high local oscillator circuit, the variable low local oscillator circuit, and the phase reference parameters to form operating condition data.

[0012] Preferably, the specific steps of step S2 are as follows: The real-time phase error between the current working link and the working link to be connected is calculated using the following formula:

[0013] in For real-time phase error, This is the current working link phase. The phase of the working link to be connected. This is the temperature phase shift coefficient. This represents the difference between the real-time ambient temperature and the reference ambient temperature. Construct the state space of the deep reinforcement learning model, and use real-time phase error, output power, local oscillator frequency parameters and ambient temperature as input state variables of the deep reinforcement learning model; The reward function for constructing a deep reinforcement learning model is expressed as follows:

[0014] in This is the model reward value. For output power stability, Due to the switching time, Preset weighting coefficients; The deep reinforcement learning model aims to minimize phase error, switching power consumption, and power fluctuation, and iteratively solves the local oscillator phase fine-tuning parameters of the working link to be connected.

[0015] Preferably, the specific steps of step S3 are as follows: The frequency division ratios of the high local oscillator phase-locked loop and the low local oscillator phase-locked loop are adjusted respectively based on the local oscillator phase fine-tuning parameters to complete the single-round local oscillator signal phase fine-tuning; The real-time phase error, output power, and cumulative time after this round of adjustment are collected and fed back into the deep reinforcement learning model to solve the local oscillator phase fine-tuning parameters in the next round of iteration. When the real-time phase error between the working link to be connected and the current working link is less than the preset error threshold, the iteration stops and the phase pre-synchronization calibration is completed.

[0016] Compared with the prior art, the beneficial effects of the present invention are: The variable input and output frequency test forwarding small-loop downconverter of this invention receives the V-band signal transmitted from the uplink and then performs downconversion mixing with the variable high local oscillator signal through a downconversion mixer circuit to obtain a lower intermediate frequency signal. After processing, the intermediate frequency signal can be sent to a single-pole double-throw switch module. The single-pole double-throw switch module can switch between loopback test link and small-loop test link as needed. When the output is switched to the X-band output filter, the X-band signal can be filtered and output. When the output is switched to the upconversion mixer circuit, the upconversion mixer circuit can perform upconversion mixing with the intermediate frequency signal and the variable low local oscillator signal to output a higher Q-frequency output signal. The single-pole double-throw switch module can switch the output signal frequency band, thereby realizing loopback testing and small-loop testing of ground equipment, improving testing efficiency and reducing testing costs.

[0017] The present invention provides a switching method for a test forwarding small-loop downconverter using variable input and output frequencies. During the switching of the working link, phase pre-synchronization calibration and zero-crossing switching are combined to eliminate phase step and power surges at the moment of switching, ensuring the phase continuity and power stability of the output signal. This achieves seamless switching between the small-loop test link and the loopback test link, avoiding test link lockout or test data failure caused by link switching. It is suitable for high-order test scenarios such as phased array calibration and coherent communication testing. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only preferred embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the test forwarding small loop downconverter with variable input and output frequencies according to the present invention. Figure 2 This is a schematic diagram illustrating the application of the variable input and output frequency test forwarding small loop downconverter of the present invention. Figure 3 A flowchart of the switching method for the variable input and output frequency test forwarding small loop inverter of the present invention; In the diagram, 101 is the input filter; 102 is the down-converter mixer circuit; 20 is the variable high-LO circuit; 201 is the high-LO frequency multiplier; 202 is the high-LO filter; 203 is the high-LO phase-locked loop; 301 is the internal and external parameter reference circuit; 40 is the variable low-LO circuit; 401 is the low-LO frequency multiplier; 402 is the low-LO filter; 403 is the low-LO phase-locked loop; 501 is the intermediate frequency processing circuit; 601 is the up-converter mixer circuit; 701 is the Q-band output filter; 801 is the single-pole double-throw switch module; and 901 is the X-band output filter. Detailed Implementation

[0020] To better understand the technical content of this invention, a specific embodiment is provided below, and the invention will be further described in conjunction with the accompanying drawings.

[0021] See Figures 1 to 2 The present invention provides a test forwarding small-loop downconverter with variable input and output frequencies, positioned between the uplink and downlink. It includes a downconverter mixer circuit 102, a variable high-frequency local oscillator circuit 20, an intermediate frequency processing circuit 501, an upconverter mixer circuit 601, a variable low-frequency local oscillator circuit 40, a single-pole double-throw switch module 801, and an X-band output filter 901. The variable high-frequency local oscillator circuit 20 generates a variable high-frequency local oscillator signal. The downconverter mixer circuit 102 processes the V-band input signal transmitted from the uplink and the variable high-frequency local oscillator signal... The intermediate frequency (IF) signal is generated by downconversion mixing. The IF processing circuit 501 processes the IF signal. The single-pole double-throw switch module 801 sends the processed IF signal to the X-band output filter 901 or the upconversion mixing circuit 601. The X-band output filter 901 outputs the X-band output signal. The variable low local oscillator (LOO) circuit 40 generates a variable LOO signal. The upconversion mixing circuit 601 upconverts and mixes the processed IF signal and the variable LOO signal, and generates an output signal that is sent to the downlink.

[0022] The variable input and output frequency test forwarding loop downconverter provided by this invention connects to the uplink and downlink, enabling loopback testing of ground equipment. The loopback test converts the coupled output signal of the uplink to the coupled input signal of the downlink. The coupled output signal of the uplink is the V-band signal transmitted uplink, and the coupled input signal of the downlink is the Q-band signal received downlink. During the loopback test, the coupled output signal is used as the input signal, and the V-band signal is shifted to the Q-band signal through two frequency conversions. The final output signal is then used as the coupled input signal of the downlink. This achieves loopback testing of the uplink and downlink of the satellite ground station, enabling full-link self-testing, indicator verification, fault location, and routine maintenance without consuming satellite resources, thus improving system commissioning efficiency, maintenance convenience, and operational safety.

[0023] Specifically, the V-band signal, as the input signal, is sent to the down-conversion mixer circuit 102 for down-conversion mixing. The signal mixed with the input signal is the variable high-frequency local oscillator signal generated by the variable high-frequency local oscillator circuit 20. The down-conversion mixing yields a lower intermediate frequency (IF) signal, which then enters the IF processing circuit 501. The IF processing circuit 501 performs noise suppression, signal amplification, and attenuation adjustments on the IF signal. The adjusted signal then enters the single-pole double-throw (SPDT) switch module 801, which can switch to the X-band output filter 901 or... The up-conversion mixer circuit 601, when switched to, simultaneously receives the variable low local oscillator signal from the variable low local oscillator circuit 40, and after up-conversion mixing, obtains a higher radio frequency signal that is different from the transmitted signal, i.e., the required Q-band signal. Based on this, loopback testing can be realized. The independently configured variable high local oscillator circuit 20 and variable low local oscillator circuit 40 can realize arbitrary configuration of the in-band input frequency and output frequency, realizing the conversion of any uplink frequency band signal into any downlink frequency band signal.

[0024] When the single-pole double-throw switch module 801 switches to the X-band output filter 901, the output of the variable low local oscillator circuit 40 can be turned off. The processed intermediate frequency signal can be sent to the X-band output filter 901, which suppresses out-of-band clutter in the small loop frequency band and outputs a relatively pure X-band signal that the back-end equipment link can process or receive. By converting the V-band signal to the X-band signal in a single conversion, the small loop test of the ground equipment can be realized. Without adding too many additional links, the frequency conversion function of the small loop test link can be realized with the lowest cost by using the existing down-conversion mixer circuit 102, variable high local oscillator circuit 20 and intermediate frequency processing circuit 501.

[0025] The test forwarding small loop downconverter of the present invention can realize the forwarding of small loop and loopback links, greatly simplifying the implementation method and reducing cost, size and labor. At the same time, after adding this device to the uplink and downlink, the entire link self-test, indicator verification, fault location and routine operation and maintenance can be completed without occupying satellite resources, improving system commissioning efficiency, operation and maintenance convenience and operation security.

[0026] Preferably, it also includes an input filter 101 and a Q-band output filter 701. The input filter 101 filters the input signal of the uplink and then sends it to the downconverter mixer circuit 102. The Q-band output filter 701 filters the output signal and then sends it to the downlink.

[0027] The input filter 101 can filter the input signal, removing the image frequency and other out-of-band spurious signals before it enters the down-conversion mixer circuit 102. The output signal generated by the up-conversion mixer circuit 601 carries out-of-band spurious signals such as local oscillator leakage. The Q-band output filter 701 can suppress out-of-band spurious signals, remove local oscillator and other spurious signals, and output a purer radio frequency signal.

[0028] Preferably, it also includes an internal and external parameter reference circuit 301, which is electrically connected to the variable high local oscillator circuit 20 and the variable low local oscillator circuit 40, respectively.

[0029] The internal and external parameter reference circuit 301 can provide a reliable reference signal for the variable high local oscillator circuit 20 and the variable low local oscillator circuit 40, so that the variable high local oscillator circuit 20 and the variable low local oscillator circuit 40 can generate variable high local oscillator signals and variable low local oscillator signals that are synchronized with the reference.

[0030] Preferably, the variable high local oscillator circuit 20 includes a high local oscillator phase-locked loop 203, a high local oscillator frequency multiplier 201, and a high local oscillator filter 202. The high local oscillator phase-locked loop 203 is electrically connected to the high local oscillator frequency multiplier 201 and the internal and external parameter reference circuit 301, respectively. The high local oscillator frequency multiplier 201 is electrically connected to the down-conversion mixer circuit 102, and the high local oscillator filter 202 is electrically connected between the high local oscillator phase-locked loop 203 and the high local oscillator frequency multiplier 201.

[0031] The intermediate frequency (IF) signal is a fixed-frequency output. When different input V-band signals are configured, the high local oscillator (LO) signal can be calculated using the known IF signal frequency and the output frequency required by the small loop. Then, the LO fundamental signal required for the high LO phase-locked loop (PLL) 203 to output can be calculated. Therefore, the LO fundamental signal frequency can be automatically calculated based on the input signal frequency and the predefined IF signal frequency or the output frequency required by the small loop. The LO fundamental signal is then phase-locked onto the reference signal by the LO filter 202 to suppress out-of-band spurious signals and filter out the redundant components generated by the LO 203. The LO frequency multiplier 201 then multiplies the frequency of the LO 203 to a local oscillator signal that can drive the down-conversion mixer. Thus, the down-conversion mixer circuit 102 can down-convert the input V-band signal to the IF signal.

[0032] Preferably, the variable low local oscillator circuit 40 includes a low local oscillator phase-locked loop 403, a low local oscillator frequency multiplier 401, and a low local oscillator filter 402. The low local oscillator phase-locked loop 403 is electrically connected to the low local oscillator frequency multiplier 401 and the internal and external parameter reference circuit 301, respectively. The low local oscillator frequency multiplier 401 is electrically connected to the down-conversion mixer circuit 102, and the low local oscillator filter 402 is electrically connected between the low local oscillator phase-locked loop 403 and the low local oscillator frequency multiplier 401.

[0033] Similarly, the low local oscillator fundamental signal can be calculated based on the configured output signal frequency and intermediate frequency signal. Then, the low local oscillator phase-locked loop 403 locks the low local oscillator fundamental signal onto the reference signal. After being filtered by the low local oscillator filter 402, the low local oscillator frequency multiplier 401 multiplies the calculated low local oscillator phase-locked loop 403 frequency to the local oscillator signal that drives the up-conversion mixer. Thus, the up-conversion mixer circuit 601 can perform up-conversion mixing to generate the Q-band output signal.

[0034] Preferably, the internal and external parameter reference circuit 301 provides a reference power divider signal to the high local oscillator phase-locked loop 203 and the low local oscillator phase-locked loop 403 via its own temperature-controlled crystal oscillator or by an externally provided reference power divider signal.

[0035] The reference signals for both the high-LO phase-locked loop 203 and the low-LO phase-locked loop 403 come from the internal and external reference circuit 301. The internal and external reference circuit 301 can have its own temperature-controlled crystal oscillator or can be externally provided with reference power divided to the high-LO phase-locked loop 203 and the low-LO phase-locked loop 403. When the internal temperature-controlled crystal oscillator is present and there is no external reference signal input, the signal of this temperature-controlled crystal oscillator is divided into two paths by the power divider circuit of the reference circuit and given to the high-LO phase-locked loop 203 and the low-LO phase-locked loop 403. When there is an external reference signal input, the phase-locked loop circuit inside this reference circuit performs phase-locking of the internal and external reference signals. After locking, it stably outputs the reference signal required by the high-LO phase-locked loop 203 and the low-LO phase-locked loop 403 to be synchronized with the external reference.

[0036] Reference Figure 3 As shown, the present invention applies a switching method for a test forwarding small-loop downconverter using variable input and output frequencies. The switching of the working link is performed through the single-pole double-throw switch module 801. The working link includes a small-loop test link and a loopback test link. The switching method includes the following steps: Step S1: After receiving the link switching instruction, collect the operating condition data of the current working link. The operating condition data includes the intermediate frequency signal phase, output power, local oscillator frequency parameters, and ambient temperature. Step S2: Perform calculations on the collected operating data using deep reinforcement learning to solve for the local oscillator phase fine-tuning parameters of the working link to be connected; Step S3: Perform phase pre-synchronization calibration on the local oscillator signal of the working link to be accessed based on the local oscillator phase fine-tuning parameters. If the calibration fails, repeat steps S2-S3 until the calibration passes. Step S4: Monitor the zero-crossing time of the intermediate frequency signal in real time and determine the optimal switching node. At the optimal switching node time, trigger the single-pole double-throw switch module 801 to switch the working link.

[0037] The single-pole double-throw (SPDT) switch module 801 is used for switching the working link, which includes a small-loop test link and a loopback test link. The small-loop test link is the overall link when the SPDT switch module 801 switches to the X-band output filter 901, including the input filter 101, down-converter mixer circuit 102, variable high-frequency local oscillator circuit 20, intermediate frequency processing circuit 501, SPDT switch module 801, and X-band output filter 901. The loopback test link is the overall link when the SPDT switch module 801 switches to the up-converter mixer circuit 601, including the input filter 101, down-converter mixer circuit 102, variable high-frequency local oscillator circuit 20, intermediate frequency processing circuit 501, SPDT switch module 801, and up-converter mixer circuit 601. 01. Variable low local oscillator circuit 40 and Q-band output filter 701. In the testing and maintenance of V / Q band satellite communication ground stations, the test forwarding small loop downconverter needs to be switched between the small loop test link and the ground loopback test link through the single-pole double-throw switch module 801 to complete the uplink self-test and full link loopback test. If the direct switching method is adopted, the power surge at the moment of switching is suppressed by the intermediate frequency zero-crossing detection alone. It is impossible to eliminate the inherent phase difference between the two working links caused by the difference in transmission path length, the initial phase shift of the local oscillator, the ambient temperature drift and the aging of the components. After switching, there will be a significant phase step, which can easily lead to the loss of lock of the coherent communication test link and the failure of the phased array antenna calibration data. It is difficult to meet the usage requirements of high-precision and high-continuity test scenarios.

[0038] To this end, the present invention also provides a switching method for a test forwarding small loop inverter with variable input and output frequencies. After receiving a link switching command, the operating condition data of the current working link can be collected. Then, a deep reinforcement learning model is introduced to perform calculations based on the collected operating condition data, outputting local oscillator phase adjustment parameters that satisfy phase convergence speed, power stability, and switching time. Based on the local oscillator adjustment parameters, the local oscillator signal of the working link to be connected can be pre-calibrated to eliminate the inherent phase difference between the two working links. Then, the zero-crossing moment of the intermediate frequency signal is used as the optimal switching node, which can further suppress amplitude fluctuations and power surges at the moment of switching. Finally, the single-pole double-throw switch module 801 is triggered at the optimal switching node to achieve no phase step before and after switching and no power spikes at the moment of switching. Without significantly increasing hardware costs, the signal continuity of link switching is significantly improved, which can support high-order test scenarios such as phased array calibration and coherent communication testing, and improve test efficiency and data reliability.

[0039] Preferably, the specific steps of step S1 are as follows: Monitor system switching commands in real time, distinguish between small loop test link switching commands and loopback test link switching commands, and mark the type of working link to be connected; The phase detection unit acquires the real-time phase value and output instantaneous power value of the intermediate frequency signal of the current working link in real time, and reads the real-time frequency and phase reference parameters of the variable high local oscillator circuit 20 and the variable low local oscillator circuit 40. Real-time ambient temperature data is collected by a temperature sensing array and combined with the real-time phase value of the intermediate frequency signal, the instantaneous output power value, the real-time frequency of the variable high local oscillator circuit 20, the variable low local oscillator circuit 40, and the phase reference parameters to form operating condition data.

[0040] The system monitors switching commands in real time to determine if a link switching command has been issued. The small-loop test link switching command switches the loopback test link to the small-loop test link, and the loopback test link switching command switches the small-loop test link to the loopback test link. Upon receiving the corresponding switching command, the type of the working link to be connected is identified. Then, the intermediate frequency signal phase, output power, local oscillator frequency parameters, and ambient temperature are collected as operating condition data. The intermediate frequency signal phase can be used to calculate the phase difference between the current working link and the working link to be connected. The output power is used to monitor the power fluctuation amplitude during the link operation and switching process in real time. The local oscillator frequency parameters are used as input state variables for subsequent deep reinforcement learning algorithms. The ambient temperature is used to correct the phase offset caused by temperature drift, improving the accuracy and stability of phase pre-synchronization under different operating conditions.

[0041] Preferably, the specific steps of step S2 are as follows: The real-time phase error between the current working link and the working link to be connected is calculated using the following formula:

[0042] in For real-time phase error, This is the current working link phase. The phase of the working link to be connected. This is the temperature phase shift coefficient. This represents the difference between the real-time ambient temperature and the reference ambient temperature. Construct the state space of the deep reinforcement learning model, and use real-time phase error, output power, local oscillator frequency parameters and ambient temperature as input state variables of the deep reinforcement learning model; The reward function for constructing a deep reinforcement learning model is expressed as follows:

[0043] in This is the model reward value. For output power stability, Due to the switching time, Preset weighting coefficients; The deep reinforcement learning model aims to minimize phase error, switching power consumption, and power fluctuation, and iteratively solves the local oscillator phase fine-tuning parameters of the working link to be connected.

[0044] First, the phase difference between the two links is calculated based on the current working link phase and the working link to be connected, combined with the temperature drift correction. Then, the phase difference and operating condition data are used as the input state of the deep reinforcement learning model. The action space of the deep reinforcement model is used to output the local oscillator phase fine-tuning parameters. Its reward function aims to minimize the phase error, the switching power consumption, and the power fluctuation. The optimal local oscillator phase fine-tuning parameters can be obtained through continuous iteration.

[0045] Preferably, the specific steps of step S3 are as follows: Based on the local oscillator phase fine-tuning parameters, the frequency division ratios of the high local oscillator phase-locked loop 203 and the low local oscillator phase-locked loop 403 are adjusted respectively to complete the single-round local oscillator signal phase fine-tuning; The real-time phase error, output power, and cumulative time after this round of adjustment are collected and fed back into the deep reinforcement learning model to solve the local oscillator phase fine-tuning parameters in the next round of iteration. When the real-time phase error between the working link to be connected and the current working link is less than the preset error threshold, the iteration stops and the phase pre-synchronization calibration is completed.

[0046] Phase pre-synchronization calibration is a multi-round iterative process. First, the frequency division ratio of the high local oscillator phase-locked loop 203 and the low local oscillator phase-locked loop 403 is adjusted based on the local oscillator phase fine-tuning parameters output by the deep reinforcement learning model in the first round. After the adjustment is completed, the real-time phase error, output power and cumulative time are collected and fed back to the deep reinforcement learning model in a closed loop to trigger the iterative solution of the local oscillator phase fine-tuning parameters in the next round. Then, the iterative process of solving the local oscillator phase fine-tuning parameters, adjusting the frequency division ratio and feedback the effect is repeated to continuously reduce the phase difference between the two working links until the phase difference is ≤1° of the preset threshold. Then, the phase pre-synchronization calibration is completed and the system waits for the switching command to be triggered.

[0047] When a switching command is received, the pre-processed intermediate frequency signal can be sampled in real time by the zero-crossing detection circuit to capture the zero-crossing critical point where the signal voltage amplitude changes from positive to negative or from negative to positive. Then, false zero-crossing signals caused by signal noise are filtered out. The effective zero-crossing moment is confirmed by three consecutive amplitude samplings to avoid instantaneous noise interference. The timestamp of the effective zero-crossing moment is recorded and the node is marked as the optimal switching node. The trigger waiting state of the single-pole double-throw switch module 801 is locked synchronously. At the optimal zero-crossing switching node, the switch trigger signal is output synchronously to drive the single-pole double-throw switch module 801 to complete the link path switching. During the switching process, the local oscillator circuit and the intermediate frequency processing circuit 501 continue to work to avoid interrupting the signal transmission link and avoid signal disconnection and power drop. Finally, it can switch to the X-band output filter 901 path to realize small loop test, or switch to the up-converter mixer circuit 601 path to realize Q-band ground loopback test.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A test forwarding small-loop downconverter with variable input and output frequencies, positioned between the uplink and downlink, characterized in that, The system includes a down-conversion mixer circuit, a variable high local oscillator circuit, an intermediate frequency (IF) processing circuit, an up-conversion mixer circuit, a variable low local oscillator circuit, a single-pole double-throw (SPD) switch module, and an X-band output filter. The variable high local oscillator circuit generates a variable high local oscillator signal. The down-conversion mixer circuit down-converts and mixes the V-band input signal from the uplink with the variable high local oscillator signal to generate an IF signal. The IF processing circuit processes the IF signal. The SPD switch module sends the processed IF signal to the X-band output filter or the up-conversion mixer circuit. The X-band output filter outputs an X-band output signal. The variable low local oscillator circuit generates a variable low local oscillator signal. The up-conversion mixer circuit up-converts and mixes the processed IF signal with the variable low local oscillator signal to generate a Q-band output signal, which is then sent to the downlink.

2. The variable input and output frequency test forwarding small loop downconverter according to claim 1, characterized in that, It also includes an input filter and a Q-band output filter. The input filter filters the V-band input signal of the uplink and then sends it to the downconverter mixer circuit. The Q-band output filter filters the Q-band output signal and then sends it to the downlink.

3. The variable input and output frequency test forwarding small loop downconverter according to claim 1, characterized in that, It also includes an intrinsic and extrinsic parameter reference circuit, which is electrically connected to the variable high local oscillator circuit and the variable low local oscillator circuit, respectively.

4. The variable input and output frequency test forwarding small loop downconverter according to claim 3, characterized in that, The variable high local oscillator circuit includes a high local oscillator phase-locked loop, a high local oscillator frequency multiplier, and a high local oscillator filter. The high local oscillator phase-locked loop is electrically connected to the high local oscillator frequency multiplier and the internal and external parameter reference circuits, respectively. The high local oscillator frequency multiplier is electrically connected to the down-conversion mixer circuit, and the high local oscillator filter is electrically connected between the high local oscillator phase-locked loop and the high local oscillator frequency multiplier.

5. The variable input and output frequency test forwarding small loop downconverter according to claim 4, characterized in that, The variable low local oscillator circuit includes a low local oscillator phase-locked loop, a low local oscillator frequency multiplier, and a low local oscillator filter. The low local oscillator phase-locked loop is electrically connected to the low local oscillator frequency multiplier and the internal and external parameter reference circuits, respectively. The low local oscillator frequency multiplier is electrically connected to the down-conversion mixer circuit, and the low local oscillator filter is electrically connected between the low local oscillator phase-locked loop and the low local oscillator frequency multiplier.

6. The variable input and output frequency test forwarding small loop downconverter according to claim 5, characterized in that, The internal and external parameter reference circuits provide reference power division signals to the high local oscillator phase-locked loop and the low local oscillator phase-locked loop via a built-in temperature-controlled crystal oscillator or externally.

7. A switching method for a test forwarding small loop inverter using the variable input and output frequencies described in any one of claims 1-6, characterized in that, The switching of the working link is performed through the single-pole double-throw switch module. The working link includes a small-loop test link and a loopback test link. The switching method includes the following steps: Step S1: After receiving the link switching instruction, collect the operating condition data of the current working link. The operating condition data includes the intermediate frequency signal phase, output power, local oscillator frequency parameters, and ambient temperature. Step S2: Perform calculations on the collected operating data using deep reinforcement learning to solve for the local oscillator phase fine-tuning parameters of the working link to be connected; Step S3: Perform phase pre-synchronization calibration on the local oscillator signal of the working link to be accessed based on the local oscillator phase fine-tuning parameters. If the calibration fails, repeat steps S2-S3 until the calibration passes. Step S4: Monitor the zero-crossing time of the intermediate frequency signal in real time and determine the optimal switching node. At the optimal switching node time, trigger the single-pole double-throw switch module to switch the working link.

8. The switching method according to claim 7, characterized in that, The specific steps of step S1 are as follows: Monitor system switching commands in real time, distinguish between small loop test link switching commands and loopback test link switching commands, and mark the type of working link to be connected; The phase detection unit acquires the real-time phase value of the intermediate frequency signal of the current working link and outputs the instantaneous power value, while reading the real-time frequency and phase reference parameters of the variable high local oscillator circuit and the variable low local oscillator circuit. Real-time ambient temperature data is collected by a temperature sensor array and combined with the real-time phase value of the intermediate frequency signal, the instantaneous output power value, the real-time frequency of the variable high local oscillator circuit, the variable low local oscillator circuit, and the phase reference parameters to form operating condition data.

9. The switching method according to claim 7, characterized in that, The specific steps of step S2 are as follows: The real-time phase error between the current working link and the working link to be connected is calculated using the following formula: in For real-time phase error, This is the current working link phase. The phase of the working link to be connected. This is the temperature phase shift coefficient. This represents the difference between the real-time ambient temperature and the reference ambient temperature. Construct the state space of the deep reinforcement learning model, and use real-time phase error, output power, local oscillator frequency parameters and ambient temperature as input state variables of the deep reinforcement learning model; The reward function for constructing a deep reinforcement learning model is expressed as follows: in This is the model reward value. For output power stability, Due to the switching time, Preset weighting coefficients; The deep reinforcement learning model aims to minimize phase error, switching power consumption, and power fluctuation, and iteratively solves the local oscillator phase fine-tuning parameters of the working link to be connected.

10. The switching method according to claim 9, characterized in that, The specific steps of step S3 are as follows: The frequency division ratios of the high local oscillator phase-locked loop and the low local oscillator phase-locked loop are adjusted respectively based on the local oscillator phase fine-tuning parameters to complete the single-round local oscillator signal phase fine-tuning; The real-time phase error, output power, and cumulative time after this round of adjustment are collected and fed back into the deep reinforcement learning model to solve the local oscillator phase fine-tuning parameters in the next round of iteration. When the real-time phase error between the working link to be connected and the current working link is less than the preset error threshold, the iteration stops and the phase pre-synchronization calibration is completed.

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