X-band passive pulse compression device and gain preservation method

Abstract

This invention relates to the field of high-power microwave electromagnetic equipment technology, specifically to an X-band passive pulse compression device and gain maintenance method. The invention achieves a compact and space-saving overall structure through the rational arrangement of a spherical energy storage resonant cavity, a dual-polarization mode coupler, a heat dissipation channel, and a tuning aperture. This allows for easy installation and use in small HPM systems, and the resonant cavity's natural frequency is easily adjustable. Furthermore, it proposes a power gain prediction method based on microwave energy storage and release laws, which can accurately obtain the power gain of the pulse compression device at different surface temperatures. Combined with a temperature feedback control system and gain maintenance method, the temperature of the heat-conducting medium within the heat dissipation channel can be rationally adjusted to maintain the stability of the spherical cavity's natural resonant frequency, ensuring that the signal source output frequency is at the point of maximum power gain for pulse compression, thereby maximizing the system's output microwave energy.

Description

Technical Field

[0001] This invention relates to the field of high-power microwave electromagnetic equipment technology, specifically to an X-band passive pulse compression device and gain preservation method. Background Technology

[0002] With the development of high-power microwave technology, high-power microwave systems (HPM systems) have been widely used in many fields. An HPM system generally consists of a high-voltage pulse power supply, an excitation signal source, a microwave tube, and a load device (transmitting antenna). Due to the theoretical limits of microwave tube and antenna gain under specific power modes and limited dimensions, how to obtain higher output power in high-power microwave systems with limited volume and weight and unchanged power input has become a major challenge.

[0003] Pulse compression technology can compress low-power long-pulse microwaves into short-pulse microwaves with a success rate several times or even tens of times, thereby obtaining high-power output. Passive pulse compression devices can input microwave pulses into an energy storage device for storage, and then rapidly release the stored energy from the energy storage device mainly by inverting the input signal, achieving a doubling of microwave energy power peak without introducing additional power consumption.

[0004] To reduce microwave loss and achieve a higher quality factor, existing passive pulse compression devices generally use oxygen-free copper. However, copper devices are sensitive to temperature and are prone to deformation with temperature changes. In addition, the spherical energy storage cavity of the existing SLED (energy multiplier) pulse compression device is a point-frequency operating device. Temperature changes will cause the inherent resonant point (operating frequency) to shift, which will have a significant impact on its power gain.

[0005] Therefore, in order to address the issues of heat generation caused by the ohmic impedance of the X-band pulse compressor during high-power operation and the effects of ambient temperature changes, it is imperative to effectively improve its structure and rationally control its operating temperature so that the X-band pulse compressor can operate at its optimal state. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an X-band passive pulse compression device and a gain maintenance method, which enables the device to maintain the stability of the spherical cavity structure under high power operating conditions and to achieve precise temperature control, ensuring that the operating frequency and power gain are not affected, thereby maximizing the output microwave energy of the system.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0008] I. An X-band passive pulse compression device

[0009] This invention provides a structure for an X-band passive pulse compression device, mainly comprising: a spherical energy storage resonant cavity 1, a dual-polarization mode coupler 2, a heat dissipation channel 3, a tuning hole 4, and a temperature feedback control system; the outer surface of the spherical energy storage resonant cavity 1 is provided with multiple heat dissipation channels 3, and the spherical energy storage resonant cavity 1 is externally fastened with a housing 9, and the heat dissipation channels 3 are connected to the fastened housing 9 by a water pipe 10;

[0010] The spherical energy storage resonant cavity 1 and the dual-polarization mode coupler 2 are connected by a connecting plate 5, and the waveguide input terminal 6 of the dual-polarization mode coupler 2 is connected to a high-power microwave source and a signal source, and the waveguide output terminal 7 of the dual-polarization mode coupler 2 is connected to a load device.

[0011] The temperature feedback control system includes a vector network analyzer, a temperature probe, a thermally conductive medium tank, and a host computer. The vector network analyzer is connected to the dual-polarization mode coupler 2 and is used to measure the input reflection coefficient of the waveguide input terminal 6 and the forward transmission coefficient between the waveguide input terminal 6 and the waveguide output terminal 7. The temperature probe is installed on the outer surface of the spherical energy storage resonant cavity 1 and is used to measure the surface temperature of the resonant cavity. The thermally conductive medium tank is connected to the water inlet pipe 10, and a temperature control module and a flow control valve are respectively installed inside and at the outlet of the thermally conductive medium tank.

[0012] The signal source, vector network analyzer, temperature probe, temperature control module, and flow control valve are all electrically connected to the host computer.

[0013] Preferably, multiple tuning holes 4 are evenly arranged along the equatorial surface of the spherical energy storage resonant cavity 1, and each tuning hole 4 is provided with an adjusting screw. By adjusting the screwing depth of the adjusting screw, the inner diameter of the cavity in the corresponding area is changed, thereby adjusting the inherent resonant frequency of the spherical energy storage resonant cavity 1.

[0014] Preferably, the dual-polarization mode coupler 2 is provided with a flange vent 8, and the flange vent 8 is connected to a vacuum pump through a venting pipe.

[0015] Preferably, the power gain prediction method for the pulse compression device includes:

[0016] 1) By performing thermodynamic simulation on the surface of the spherical energy storage resonant cavity, the corresponding relationship between the equivalent radius of the spherical cavity and the surface temperature of the spherical cavity is obtained;

[0017] 2) By modeling the pulse compression device as a whole and performing electromagnetic simulation, the correspondence between the equivalent radius of the spherical cavity and the inherent resonant operating point was obtained;

[0018] 3) Based on the correspondence between the equivalent radius of the spherical cavity and the surface temperature and inherent resonant operating point of the spherical cavity, and combined with the preset energy multiplication formula, the theoretical gain of the pulse compression device at the non-resonant operating point is derived and calculated, and the pulse compression device at different surface temperatures T is predicted. c Power gain below

[0019] Preferably, the predictive pulse compression device is used at different surface temperatures T c Power gain below The specific formula is as follows:

[0020] The formula is as follows:

[0021]

[0022] In the formula, the coefficient α=2β / (1+β), β is the coupling coefficient, β=(1+S21) min ) / (1-S21 min ); ω0=2πf0, f0 is the inherent resonant frequency of the resonant cavity, ω=2πf, f is the actual operating frequency of the signal source; resonant cavity time constant Q0 is the inherent quality factor of the resonant cavity; t1 is the inversion time of the input signal; t2 is the energy release time of the input signal. ε = π.

[0023] Preferably, the heat dissipation channel 3 is evenly opened in multiple channels along the outer ring of the spherical energy storage resonant cavity 1, and the outer side of the heat dissipation channel 3 is covered with a liquid collection cavity end cap for preventing overflow. The inlet and outlet openings of the liquid collection cavity end cap are connected to the corresponding water inlet pipe 10.

[0024] Preferably, adjusting the inherent resonant frequency of the spherical energy storage resonant cavity 1 includes:

[0025] 1) Obtain the forward transmission coefficient between the waveguide input and output ends using a vector network analyzer, and determine the resonant frequency corresponding to the current minimum value of the forward transmission coefficient;

[0026] 2) If the resonant frequency is lower than the signal source operating frequency, slowly screw the tuning screw in the tuning hole inward while observing the real-time monitored positive transmission coefficient waveform, so that the resonant point slowly shifts to a higher frequency until it reaches the preset frequency range.

[0027] 3) If the resonant frequency is higher than the signal source operating frequency, slowly unscrew the tuning screw in the tuning hole and observe the real-time monitoring of the forward transmission coefficient waveform, so that the resonant point slowly shifts to a lower frequency until it reaches the preset frequency range.

[0028] Preferably, during the inherent frequency adjustment process, the tuning pins at opposite corners of the spherical cavity adopt the same tuning measures. When adjusting, the tuning pin with a large adjustment range is first turned to coarsely adjust the resonant frequency, and then the tuning pin with a small adjustment range is turned to finely adjust the resonant frequency until the resonant frequency matches the operating frequency of the signal source.

[0029] II. A gain preservation method for an X-band passive pulse compression device

[0030] Based on the same inventive concept, the present invention also provides a gain maintenance method for the X-band passive pulse compression device as described above, comprising the following steps:

[0031] S1, in a room temperature environment without turning on the high-power microwave source and signal source, the host computer controls the temperature control module in the heat transfer medium water tank to change the temperature of the heat transfer medium, and monitors the relationship between the inherent resonant frequency of the pulse compression device and the surface temperature of the ball cavity in real time through the temperature probe and vector network analyzer, forming a resonant frequency-temperature database and storing it in the host computer.

[0032] S2, In a room temperature environment without turning on the high-power microwave source and signal source, adjust the inherent resonant frequency of the spherical energy storage resonant cavity according to the preset signal source operating frequency, so that the inherent resonant frequency matches the signal source operating frequency.

[0033] S3, turn on the high-power microwave source and signal source. Under high-power working conditions, the pulse compression device gradually heats up. The temperature probe monitors the surface temperature of the ball cavity in real time and feeds it back to the host computer. The host computer controls the temperature control module in the heat transfer medium water tank and the flow control valve at the outlet of the water tank to perform adaptive control of the temperature and flow of the heat transfer medium.

[0034] S4, the vector network analyzer monitors the change of the inherent resonant frequency of the pulse compression device in real time, and predicts the power gain of the pulse compression device at the current inherent resonant frequency in real time according to the preset power gain prediction method.

[0035] S5, if the difference between the predicted power gain in step S4 and the expected maximum power gain exceeds a preset threshold, the host computer directly calls the resonant frequency-temperature database and adjusts the output frequency of the signal source so that the output frequency of the signal source corresponds to the natural resonant frequency of the spherical cavity at the current temperature.

[0036] Preferably, the adaptive control of the temperature and flow rate of the heat transfer medium includes:

[0037] 1) Monitor the temperature change range of the spherical cavity surface and its deviation from room temperature in real time;

[0038] 2) If the current ball cavity surface temperature minus room temperature is greater than the preset deviation threshold, the temperature of the heat transfer medium in the water tank will be reduced to the preset temperature through the temperature control module, and the flow control valve will be increased to the preset opening degree.

[0039] 3) If the detected change in the surface temperature of the ball cavity is greater than the preset threshold, the opening of the flow control valve is reduced to the preset opening of two.

[0040] Compared with the prior art, the present invention has the following main advantages:

[0041] 1. The X-band passive pulse compression device of the present invention has a compact overall structure and saves space through the reasonable arrangement of the spherical energy storage resonant cavity, dual polarization mode coupler, heat dissipation channel and tuning hole. It can be adapted to the installation and use of small HPM systems, and the natural frequency of the resonant cavity is easy to adjust.

[0042] 2. This invention takes into account the material, wall thickness and pressure conditions of the resonant cavity, and designs a heat dissipation channel structure. Combined with a temperature feedback control system, it can efficiently adjust the surface temperature of the spherical cavity and ensure that the cavity structure remains stable.

[0043] 3. This invention proposes a power gain prediction method based on the laws of microwave energy storage and release, which can accurately obtain the power gain of the pulse compression device at different surface temperatures. At the same time, combined with the gain maintenance method proposed in this invention, the temperature of the heat-conducting medium in the heat dissipation channel can be reasonably adjusted to keep the natural resonant frequency of the spherical cavity stable, ensuring that the output frequency of the signal source is at the maximum power gain point of pulse compression, thereby maximizing the output microwave energy of the system. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the structure of the X-band passive pulse compression device in an embodiment of the present invention;

[0045] Figure 2 This is a schematic diagram showing the specific arrangement of the heat dissipation channel structure in an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of the surface temperature distribution of the resonant cavity in an embodiment of the present invention;

[0047] Figure 4 This is a schematic diagram of the temperature feedback control system in an embodiment of the present invention.

[0048] In the figure: 1-Spherical energy storage resonant cavity; 2-Dual polarization mode coupler; 3-Heat dissipation channel; 4-Tuning hole; 5-Connecting plate; 6-Waveguide input end; 7-Waveguide output end; 8-Flange vent; 9-Fixed housing; 10-Water inlet pipe. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0050] It should be noted that, depending on the implementation needs, the various steps / components described in this application can be broken down into more steps / components, or two or more steps / components or parts of the operation of steps / components can be combined into new steps / components to achieve the purpose of this invention.

[0051] In this invention, unless otherwise expressly specified and limited, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise expressly and specifically limited.

[0052] Example 1: This example provides an X-band passive pulse compression device, such as... Figure 1 As shown, it mainly includes: a spherical energy storage resonant cavity 1, a dual-polarization mode coupler 2, a heat dissipation channel 3, a tuning hole 4, a connecting plate 5, a waveguide input end 6, a waveguide output end 7, a flange vent 8, a fastening housing 9, a water inlet pipe 10, and a temperature feedback control system, which features miniaturization and adjustable frequency.

[0053] The outer surface of the spherical energy storage resonant cavity 1 is provided with multiple heat dissipation channels 3, and the spherical energy storage resonant cavity 1 is externally fastened with a housing 9. The heat dissipation channels 3 are connected to the fastening housing 9 by a water pipe 10.

[0054] The spherical energy storage resonant cavity 1 and the dual-polarization mode coupler 2 are connected by a connecting plate 5. The waveguide input terminal 6 of the dual-polarization mode coupler 2 is connected to a high-power microwave source and a signal source, and the waveguide output terminal 7 of the dual-polarization mode coupler 2 is connected to a load device. The signal source provides a low-power radio frequency signal with inverted phase from the high-power microwave source. The high-power microwave source amplifies the signal to form a microwave pulse, which is then multiplied by an X-band pulse compression device and matched and absorbed by the load device.

[0055] The spherical energy storage resonant cavity, with an outer diameter of 210 mm, is primarily used to form a standing wave and store the input inverted microwave pulse signal. The dual-polarization mode coupler simultaneously excites the two energy storage modes of the spherical energy storage resonant cavity, integrating the functions of a 3dB directional coupler, mode converter, and polarizer. The fastening housing is used for pressing and fastening the upper and lower hemispheres of the spherical energy storage resonant cavity. The connecting plate connects the spherical energy storage resonant cavity to the dual-polarization mode coupler. Eight tuning holes are alternately distributed on the equatorial plane of the upper and lower hemispheres. Adjusting the depth of the internal adjusting screws changes the inner diameter of the cavity in that area, thereby adjusting the cavity's natural frequency. The heat dissipation channel carries a heat-conducting medium to ensure the resonant cavity operates at a suitable temperature. The evacuation port is a CF35 flange evacuation port, connected to a vacuum pump via an evacuation pipe, used to ensure the vacuum level of the X-band pulse compression device, providing megawatt-level power capacity. The input / waveguide output interface uses a BJ100 interface.

[0056] Furthermore, the power gain prediction method for the X-band passive pulse compression device includes:

[0057] 1) First, the relationship between the surface temperature of the spherical energy storage cavity and the equivalent radius of the cavity is obtained through thermodynamic simulation of the spherical energy storage cavity surface;

[0058] 2) Then, the relationship between the equivalent radius of the spherical cavity and the inherent resonant operating point is obtained by modeling and electromagnetic simulation of the X-band pulse compression device;

[0059] 3) Finally, the theoretical gain of the X-band pulse compressor device at the non-resonant operating point is derived and calculated using the SLED (Signal-Energy Multiplier) formula, and then the gain of the pulse compressor device at different surface temperatures T is predicted. c Power gain below The specific calculation formula is as follows:

[0060]

[0061] Wherein, coefficient α=2β / (1+β), β is the coupling coefficient, β=(1+S21min) / (1-S21min); ω0=2πf0, f0 is the inherent resonant frequency, ω=2πf, f is the actual operating frequency (i.e., the signal source frequency);

[0062] Resonant cavity time constant Q0 is the inherent quality factor of the resonant cavity;

[0063] t1 is the inversion time of the input signal (the charging time of the input), and t2 is the discharging time of the input;

[0064] ε = π.

[0065] Based on the above derivation, after inputting parameters such as the resonant cavity's natural frequency, the signal source's operating frequency, and the pulse width, the corresponding peak power gain can be calculated.

[0066] Actual measurements show that, for this X-band passive pulse compression device, the error between the calculated power gain prediction method and the actual test results is no more than 15%.

[0067] like Figure 2 As shown, this application comprehensively considers the material, wall thickness and pressure conditions of the resonant cavity sphere and designs a heat dissipation channel structure. The structure is evenly distributed on both sides of the clamp along the surface of the sphere. A liquid collection chamber end cap is installed on the outside of the channel to prevent coolant from overflowing from the channel. Inlet and outlet openings are provided on the liquid collection chamber end cap.

[0068] In this example, the specific structure of the heat dissipation channel is as follows: the channel width is 3mm, the rib width is 0.82mm, the height is 4mm, and the inner diameter of the inlet and outlet pipes is 4mm; the total number of channels is 16, and the channels are evenly distributed along the surface of the spherical shell on both sides of the clamp, with a total width not exceeding 30mm. A liquid collection chamber end cap is installed on the outside of the channel to prevent coolant from overflowing from the channel. The liquid collection chamber end cap is provided with inlet and outlet openings, and the diameter of the openings is adjusted according to the flow resistance and inlet pressure requirements. The inlet and outlet pipes of the channel are connected to the end cap by brazing or argon arc welding, and the number and position of the water inlet pipes are adapted to the inlet and outlet of the channel. It is necessary to ensure the distance and clearance between the liquid collection chamber end cap and the clamps on both sides to avoid affecting the installation and fixation.

[0069] like Figure 3 As shown, through thermodynamic simulation, when the cooling water mass flow rate is 0.1 kg / s, the average pressure drop inside the pipe is 15.24 kPa, and the average outlet temperature is 20.45℃; the highest temperature on the inner surface of the ball cavity is located at both ends of the ball cavity, both at 23.79℃; when the cooling water mass flow rate is 0.025 kg / s, the average pressure drop inside the pipe is 1.1 kPa, and the average outlet temperature is 21.63℃; thus, it can achieve good temperature control.

[0070] Example 2: This example provides an X-band passive pulse compression device, such as... Figure 4 As shown, the temperature feedback control system includes: a vector network analyzer, a temperature probe, a heat transfer medium water tank, and a temperature control host computer.

[0071] The vector network analyzer is used to measure the input reflection coefficient (S11 parameter) and forward transmission coefficient (S21 parameter) of the X-band pulse compression device in real time to determine the inherent resonant frequency of the pulse compression device at different surface temperatures, and input the data into the host computer to establish a resonant frequency-temperature database.

[0072] The temperature probe is installed on the equatorial surface of the spherical energy storage resonant cavity of the pulse compression device to monitor the surface temperature of the cavity in real time and feed it back to the host computer.

[0073] The heat transfer medium water tank provides heat transfer medium for the heat dissipation channel of the pulse compression device. The water tank is equipped with a temperature control module (including electric heating tube and cooling chip in this example) and a flow control valve is provided at the outlet of the water tank. It can receive instructions from the host computer to dynamically adjust the temperature and flow rate of the heat transfer medium.

[0074] The host computer has frequency adjustment and temperature control functions, and can dynamically adjust the signal source frequency and device heat dissipation temperature by calling the resonant frequency-temperature database.

[0075] This temperature feedback control system can ensure the stability of the natural resonant frequency of the spherical cavity, ensuring that the output frequency of the signal source is at the maximum power gain point of pulse compression (i.e., the natural resonant operating point of the spherical cavity), thereby maximizing the microwave energy output by the system.

[0076] Furthermore, the method for adjusting the inherent frequency of the resonant cavity includes:

[0077] 1) Use a vector network analyzer to obtain the input reflection coefficient (S11 parameter) and forward transmission coefficient (S21 parameter);

[0078] 2) If the resonant point (the frequency corresponding to the minimum value of S21) is lower than the operating frequency of the signal source, the tuning hole should be squeezed inward to make the inner diameter of the ball cavity in this area smaller: Slowly screw the tuning screw in the tuning hole inward and observe the waveform of the S21 parameter to make the resonant point slowly shift to the high frequency to achieve the desired state.

[0079] 3) If the resonant point is higher than the operating frequency of the signal source, adjust the position of the tuning hole to increase the inner diameter of the ball cavity: slowly unscrew the tuning screw in the tuning hole and observe the waveform of the S21 parameter to make the resonant point slowly shift to a lower frequency until the desired state is achieved.

[0080] 4) During the adjustment process, the tuning pins at opposite corners of the spherical cavity should be tuned using the same tuning measures. When adjusting, prioritize the tuning pin with the larger adjustment range of the resonance point, and then turn the tuning pin with the larger adjustment range until the desired state is achieved.

[0081] Example 3: Based on the same inventive concept, this example also provides a gain maintenance method for the X-band passive pulse compression device as described above, including the following steps:

[0082] Step S1: In a room temperature environment without turning on the high-power microwave source and signal source, the temperature control module in the heat transfer medium water tank is controlled by the host computer to change the temperature of the heat transfer medium. The relationship between the inherent resonant frequency of the pulse compression device and the surface temperature of the spherical cavity is monitored in real time by the temperature probe and vector network analyzer to form a resonant frequency-temperature database and store it in the host computer.

[0083] Step S2: In a room temperature environment without turning on the high-power microwave source and signal source, adjust the inherent resonant frequency of the spherical energy storage resonant cavity according to the preset signal source operating frequency so that the inherent resonant frequency matches the signal source operating frequency, at which point the maximum power gain can be obtained.

[0084] Step S3: Turn on the high-power microwave source and signal source. Under high-power operating conditions, the pulse compression device gradually heats up. The temperature probe monitors the surface temperature of the ball cavity in real time and feeds it back to the host computer. The host computer controls the temperature control module in the heat transfer medium water tank and the flow control valve at the outlet of the water tank to perform adaptive control of the temperature and flow of the heat transfer medium, so as to ensure that the ball cavity size of the pulse compression device remains relatively stable.

[0085] Step S4: At this time, the vector network analyzer can be used to monitor the change of the inherent resonant frequency of the pulse compression device in real time, and the power gain of the pulse compression device can be predicted in real time according to the above-mentioned gain prediction method.

[0086] Step S5: If the maximum power gain minus the power gain predicted in the previous step is greater than the preset threshold or the current power gain does not meet the usage requirements, the host computer can call the spherical cavity natural resonant frequency-temperature relationship database and directly issue instructions to the signal source to adjust the output frequency of the signal source to correspond to the spherical cavity natural resonant frequency, thereby ensuring the maximum power gain. This method is mainly used when the ambient temperature changes drastically or the cooling efficiency is difficult to meet the requirements. It is a supplementary means to ensure power gain by temperature and flow adaptive control.

[0087] Furthermore, the implementation of adaptive control of the temperature and flow rate of the heat transfer medium includes:

[0088] 1) Monitor the temperature change range of the spherical cavity surface and its deviation from room temperature in real time;

[0089] 2) If the current ball cavity surface temperature minus room temperature is greater than the preset deviation threshold, the temperature of the heat transfer medium in the water tank will be reduced by the temperature control module, and the opening of the flow control valve will be increased to make the ball cavity surface temperature drop back to the expected stable state quickly.

[0090] 3) If the temperature change of the ball cavity surface is detected to be greater than the preset threshold, the opening of the flow control valve will be reduced to prevent the device material from deforming due to excessively rapid temperature changes.

[0091] Actual measurements show that when applied to a high-power microwave system, this application can effectively maintain the peak gain of the microwave system's output power at more than 4 times, reduce the output loss under high-power microwave operating conditions by more than 50%, effectively improve microwave energy utilization efficiency, and has high application value.

[0092] Furthermore, all parts of this application that are not described in detail are the same as or implemented using existing technology.

[0093] In summary:

[0094] 1. The X-band passive pulse compression device of the present invention has a compact overall structure and saves space through the reasonable arrangement of the spherical energy storage resonant cavity, dual polarization mode coupler, heat dissipation channel and tuning hole. It can be adapted to the installation and use of small HPM systems, and the natural frequency of the resonant cavity is easy to adjust.

[0095] 2. This invention takes into account the material, wall thickness and pressure conditions of the resonant cavity, and designs a heat dissipation channel structure. Combined with a temperature feedback control system, it can efficiently adjust the surface temperature of the spherical cavity and ensure that the cavity structure remains stable.

[0096] 3. This invention proposes a power gain prediction method based on the laws of microwave energy storage and release, which can accurately obtain the power gain of the pulse compression device at different surface temperatures. At the same time, combined with the gain maintenance method proposed in this invention, the temperature of the heat-conducting medium in the heat dissipation channel can be reasonably adjusted to keep the natural resonant frequency of the spherical cavity stable, ensuring that the output frequency of the signal source is at the maximum power gain point of pulse compression, thereby maximizing the output microwave energy of the system.

[0097] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0098] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0099] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An X-band passive pulse compression device, characterized by: It includes a spherical energy storage resonant cavity (1), a dual-polarization mode coupler (2), a heat dissipation channel (3), a tuning hole (4), and a temperature feedback control system; the spherical energy storage resonant cavity (1) has multiple heat dissipation channels (3) on its outer surface, and the spherical energy storage resonant cavity (1) is externally fastened to a housing (9), and the heat dissipation channels (3) are connected to the housing (9) by water pipes (10); The spherical energy storage resonant cavity (1) is connected to the dual-polarization mode coupler (2) via a connecting plate (5), and the waveguide input end (6) of the dual-polarization mode coupler (2) is connected to a high-power microwave source and a signal source, and the waveguide output end (7) of the dual-polarization mode coupler (2) is connected to a load device. The temperature feedback control system includes a vector network analyzer, a temperature probe, a thermal medium tank, and a host computer; the vector network analyzer is connected to the dual-polarization mode coupler (2) and is used to measure the input reflection coefficient of the waveguide input end (6) and the forward transmission coefficient between the waveguide input end (6) and the waveguide output end (7); the temperature probe is installed on the outer surface of the spherical energy storage resonant cavity (1) and is used to measure the surface temperature of the resonant cavity; the thermal medium tank is connected to the water inlet pipe (10), and a temperature control module and a flow control valve are respectively provided inside the thermal medium tank and at the outlet end; The signal source, vector network analyzer, temperature probe, temperature control module, and flow control valve are all electrically connected to the host computer. The power gain prediction method for the pulse compression device includes: 1) By performing thermodynamic simulation on the surface of the spherical energy storage resonant cavity, the corresponding relationship between the equivalent radius of the spherical cavity and the surface temperature of the spherical cavity is obtained; 2) By modeling the pulse compression device as a whole and performing electromagnetic simulation, the correspondence between the equivalent radius of the spherical cavity and the inherent resonant operating point was obtained; 3) According to the corresponding relationship between the equivalent radius of the spherical cavity and the surface temperature and the natural resonance working point, the theoretical gain of the pulse compression device at the non-resonance working point is derived and calculated by combining the preset energy multiplication formula, and the power gain of the pulse compression device at different surface temperatures T c is predicted ; The predictive pulse compression device at different surface temperatures T c Power gain below The specific formula is as follows: The formula is as follows: In the formula, the coefficients , β The coupling coefficient is... β= (1+S21) min ) / (1-S21 min ); , f 0 is the natural resonant frequency of the resonant cavity. , f The actual operating frequency of the signal source; the time constant of the resonant cavity. , Q 0 represents the intrinsic quality factor of the resonant cavity; t 1 represents the inversion time of the input signal. t 2 represents the energy release time of the input signal; , ε=π.

2. The X-band passive pulse compression device according to claim 1, characterized in that, Multiple tuning holes (4) are evenly arranged along the equatorial surface of the spherical energy storage resonant cavity (1), and each tuning hole (4) is provided with an adjusting screw. By adjusting the screwing depth, the inner diameter of the cavity in the corresponding area is changed, thereby adjusting the inherent resonant frequency of the spherical energy storage resonant cavity (1).

3. The X-band passive pulse compression device according to claim 1, characterized in that, The dual-polarization mode coupler (2) is provided with a flange vent (8), and the flange vent (8) is connected to a vacuum pump through a venting pipe.

4. The X-band passive pulse compression device according to claim 1, characterized in that, The heat dissipation channel (3) is evenly opened in multiple channels along the outer ring of the spherical energy storage resonant cavity (1), and the outside of the heat dissipation channel (3) is covered with a liquid collection chamber end cap for preventing overflow. The inlet and outlet openings of the liquid collection chamber end cap are connected to the corresponding water inlet pipe (10).

5. The X-band passive pulse compression device according to claim 2, characterized in that, The adjustment of the inherent resonant frequency of the spherical energy storage resonant cavity (1) includes: 1) Obtain the forward transmission coefficient between the waveguide input and output ends using a vector network analyzer, and determine the resonant frequency corresponding to the current minimum value of the forward transmission coefficient; 2) If the resonant frequency is lower than the signal source operating frequency, slowly screw the tuning screw in the tuning hole inward while observing the real-time monitored positive transmission coefficient waveform, so that the resonant point slowly shifts to a higher frequency until it reaches the preset frequency range. 3) If the resonant frequency is higher than the signal source operating frequency, slowly unscrew the tuning screw in the tuning hole and observe the real-time monitoring of the forward transmission coefficient waveform, so that the resonant point slowly shifts to a lower frequency until it reaches the preset frequency range.

6. The X-band passive pulse compression device according to claim 5, characterized in that, During the adjustment of the inherent resonant frequency, the tuning pins at opposite corners of the spherical cavity adopt the same tuning measures. When adjusting, the tuning pin with a large adjustment range is first turned to coarsely adjust the resonant frequency, and then the tuning pin with a small adjustment range is turned to finely adjust the resonant frequency until the resonant frequency matches the operating frequency of the signal source.

7. A gain-preserving method for the X-band passive pulse compression device as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1, in a room temperature environment without turning on the high-power microwave source and signal source, the host computer controls the temperature control module in the heat transfer medium water tank to change the temperature of the heat transfer medium, and monitors the relationship between the inherent resonant frequency of the pulse compression device and the surface temperature of the ball cavity in real time through the temperature probe and vector network analyzer, forming a resonant frequency-temperature database and storing it in the host computer. S2, In a room temperature environment without turning on the high-power microwave source and signal source, adjust the inherent resonant frequency of the spherical energy storage resonant cavity according to the preset signal source operating frequency, so that the inherent resonant frequency matches the signal source operating frequency. S3, turn on the high-power microwave source and signal source. Under high-power working conditions, the pulse compression device gradually heats up. The temperature probe monitors the surface temperature of the ball cavity in real time and feeds it back to the host computer. The host computer controls the temperature control module in the heat transfer medium water tank and the flow control valve at the outlet of the water tank to perform adaptive control of the temperature and flow of the heat transfer medium. S4, the vector network analyzer monitors the change of the inherent resonant frequency of the pulse compression device in real time, and predicts the power gain of the pulse compression device at the current inherent resonant frequency in real time according to the preset power gain prediction method. S5. If the difference between the predicted power gain in step S4 and the expected maximum power gain exceeds a preset threshold, the host computer directly calls the resonant frequency-temperature database and adjusts the output frequency of the signal source so that the output frequency of the signal source corresponds to the natural resonant frequency of the spherical cavity at the current temperature.

8. The gain preservation method according to claim 7, characterized in that, The adaptive control of the temperature and flow rate of the heat transfer medium includes: 1) Real-time monitoring of the temperature change range of the spherical cavity surface and its deviation from room temperature; 2) If the current ball cavity surface temperature minus room temperature is greater than the preset deviation threshold, the temperature of the heat transfer medium in the water tank will be reduced to the preset temperature through the temperature control module, and the flow control valve will be increased to the preset opening degree. 3) If the detected change in the surface temperature of the ball cavity is greater than the preset threshold, the opening of the flow control valve is reduced to the preset opening of two.

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