Tunable ultra-high repetition rate microwave generating device and generating method based on photoconductive device

Abstract

The present invention discloses a tunable ultra-high repetition rate microwave generating device and generating method based on photoconductive devices, the device comprising: a laser modulation module and a microwave extraction module; the laser modulation module comprises a wide bandgap photoconductive semiconductor device and an ultra-high repetition rate laser driving source; the microwave extraction module comprises a high-voltage charging power supply, a microwave radio frequency transmission structure and an ultra-high repetition rate microwave radiation output component; the wide bandgap photoconductive semiconductor device is respectively connected to the ultra-high repetition rate laser driving source, the high-voltage charging power supply and the microwave radio frequency transmission structure, and the ultra-high repetition rate microwave radiation output component is connected to the microwave radio frequency transmission structure. The present invention can realize the output of MHz ultra-high repetition rate electromagnetic pulses with adjustable frequency, and the output microwave signal can be either a wide spectrum signal or a narrow spectrum signal. At the same time, the photoelectric conversion efficiency is improved, and the efficient extraction of tunable ultra-high repetition rate electromagnetic pulses is realized, which provides technical support for the development of ultra-high repetition rate high-power microwave integrated systems.

Description

Technical Field

[0001] The present invention relates to the technical field of high-power microwaves, and in particular to a tunable ultra-high repetition rate microwave generating device and a generating method based on a photoconductive device. Background Art

[0002] Electromagnetic pulse generation systems with flexible and adjustable parameters have important application value in military and civilian fields. In recent years, high power, high repetition rate and wider parameter tuning are important directions for the development of high-power electromagnetic pulses. Among them, high-power RF microwave generation systems with ultra-high repetition rate and adjustable main frequency have potential applications in interference, suppression and even damage to radar systems, electronic warfare systems, information data links, etc. At present, the generation of time-domain impulse narrow pulses based on solid-state fast switches is a major form of achieving ultra-high repetition rate electromagnetic pulses. The switch is required to have a turn-on or turn-off time of tens to hundreds of ps. In recent years, with the development of semiconductor technology and laser technology, the use of solid-state photoconductive devices to generate ultra-high repetition rate (repetition rate greater than 100kHz) electromagnetic pulses has gained more widespread attention.

[0003] Photoconductive semiconductor devices are one of the key components in the field of pulse power technology, used to generate high-power ultra-short ps pulses. Photoconductive devices not only have the advantages of compact structure of solid devices, but also have their own unique advantages, such as extremely fast conduction time, extremely small time jitter, excellent synchronization accuracy, low conduction inductance, photoelectric isolation, etc., especially in terms of repetition frequency, photoconductive devices have great development prospects. These unique advantages make photoconductive semiconductor devices have broad application prospects in solid-state compact pulse power sources, high-power ultra-wideband microwave radiation sources, dielectric wall accelerators, trigger systems of large pulse power devices, terahertz radiation and other pulse power research fields. With the development of science and technology, especially the rise of optoelectronic technology, microwave technology and laser technology, people have put forward higher requirements on the performance indicators of photoconductive semiconductor devices such as response speed, volume and weight, working accuracy, power capacity, and on-resistance.

[0004] At present, the generation mode of high-power or even high-power microwaves is changing from traditional electric vacuum devices to solid-state devices. The use of wide-bandgap photoconductive semiconductors to generate ultra-high repetition rate radio frequency microwaves with adjustable parameters is a new attempt with important application prospects. In the application of ultra-wideband sources and compact pulse power systems, it is found that photoconductive semiconductor devices made of SiC materials have good practicality because they have many excellent characteristics such as wide bandgap, high critical breakdown electric field, high carrier mobility, high electron saturation drift velocity, and high thermal conductivity. However, current research focuses on using the fast conduction characteristics of photoconductive devices to directly generate wide-spectrum or ultra-wide-spectrum electromagnetic pulses (switching oscillators). The output spectrum parameters are usually fixed or difficult to adjust, and it is impossible to achieve MHz ultra-high repetition rate electromagnetic pulse output, unable to generate wide-spectrum microwave signals, and the system photoelectric conversion efficiency is low. Under high voltage and high current conditions, the ultra-high repetition rate working life of wide bandgap photoconductive semiconductor devices is limited; in addition, for wide bandgap photoconductive semiconductor devices with large on-resistance, considering the impedance matching with the back-end output antenna, how to reasonably design the RF transmission extraction structure is also a key issue in generating ultra-high repetition rate microwaves. At present, there is no technology based on wide bandgap photoconductive semiconductor devices to generate tunable ultra-high repetition rate microwaves.

[0005] Therefore, there is an urgent need for a device and method that can provide tunable ultra-high repetition rate microwaves. Summary of the invention

[0006] The purpose of the present invention is to provide a tunable ultra-high repetition rate microwave generating device and a generating method based on a photoconductive device, so as to solve the technical problems existing in the prior art, and to realize the output of MHz ultra-high repetition rate electromagnetic pulses with adjustable frequency. The output microwave signal can be either a wide-spectrum signal or a narrow-spectrum signal. At the same time, the photoelectric conversion efficiency is improved, and the efficient extraction of tunable ultra-high repetition rate electromagnetic pulses is realized, which provides technical support for the development of ultra-high repetition rate high-power microwave integrated systems.

[0007] To achieve the above-mentioned purpose, the present invention provides the following scheme: The present invention provides a tunable ultra-high repetition rate microwave generating device based on a photoconductive device, comprising: a laser modulation module and a microwave extraction module; the laser modulation module comprises a wide bandgap photoconductive semiconductor device and an ultra-high repetition rate laser driving source; the microwave extraction module comprises a high-voltage charging power supply, a microwave radio frequency transmission structure and an ultra-high repetition rate microwave radiation output component; the wide bandgap photoconductive semiconductor device is respectively connected to the ultra-high repetition rate laser driving source, the high-voltage charging power supply and the microwave radio frequency transmission structure, and the ultra-high repetition rate microwave radiation output component is connected to the microwave radio frequency transmission structure.

[0008] Preferably, the ultra-high repetition rate laser driving source adopts a laser driving source system of continuous chirped pulse amplification, and the ultra-high repetition rate laser driving source comprises a high repetition rate seed source, a large stretching amount pulse stretcher, a multi-stage chirped pulse amplifier and a high-power pulse compressor connected in sequence.

[0009] Preferably, the wide bandgap photoconductive semiconductor device comprises a substrate, on the upper surface of which a transparent conductive layer and a high-voltage resistant passivation layer are sequentially arranged from bottom to top; a metal ring is sleeved on the transparent conductive layer and the high-voltage resistant passivation layer, the lower end face of the metal ring is connected to the substrate, and the upper end face of the metal ring is connected to a hollow metal electrode; a silver-plated layer is provided on the lower surface of the substrate, and the silver-plated layer is connected to a solid metal electrode.

[0010] Preferably, the substrate is made of high-resistance semiconductor material, the high-resistance semiconductor is a thin sheet with a thickness of 0.01 mm to 10 mm, the thin sheet is square or circular, the side length of the square is 1 mm to 50 mm, and the diameter of the circle is 1 mm to 50 mm.

[0011] Preferably, the substrate is made of wide bandgap SiC material.

[0012] Preferably, the wide bandgap photoconductive semiconductor device comprises a photoconductive semiconductor wafer, a positive contact electrode, a negative contact electrode, an insulating packaging box, and an insulating potting compound.

[0013] Preferably, the microwave radio frequency transmission structure comprises an input port, a transmission section, an impedance matching section, and an output port which are connected in sequence.

[0014] Preferably, the microwave radio frequency transmission structure is a solid-state pulse transmission line, the transmission section and the impedance matching section are the outer tube of the solid-state pulse transmission line, and the input port, the wide bandgap optical semiconductor device, and the output port together constitute the inner tube of the transmission line.

[0015] Preferably, the ultra-high repetition frequency microwave radiation output component is a flat broadband radiation horn whose impedance is matched with the microwave radio frequency transmission structure. The ultra-high repetition frequency microwave radiation output component radiates the tunable ultra-high repetition frequency electromagnetic pulse output by the wide bandgap photoconductive semiconductor device to generate and output a tunable ultra-high repetition frequency microwave signal.

[0016] The present invention provides a method for generating tunable ultra-high repetition rate microwaves based on a photoconductive device, comprising the following steps:

[0017] S1, obtaining ultra-high repetition rate laser modulation signal;

[0018] S2, inputting a high voltage and the ultra-high repetition rate laser modulation signal into a wide bandgap photoconductive semiconductor device to obtain a tunable ultra-high repetition rate electromagnetic pulse;

[0019] S3, extracting the tunable ultra-high repetition rate electromagnetic pulse;

[0020] S4. radiate the extracted tunable ultra-high repetition rate electromagnetic pulse to obtain a tunable ultra-high repetition rate microwave signal.

[0021] The present invention discloses the following technical effects:

[0022] The present invention utilizes the linear working mode of wide bandgap photoconductive semiconductor devices. Under the action of an external bias voltage, the wide bandgap photoconductive semiconductor devices are irradiated by an ultra-high repetition rate laser driving source to generate ultra-high repetition rate electrical signals, and the microwave signals are radiated and output. The output ultra-high repetition rate microwave signals can achieve frequency-adjustable MHz ultra-high repetition rate electromagnetic pulse output; by controlling the output time domain pulse width, the output microwave signal can be adjusted in width and narrow spectrum; at the same time, the present invention transmits the tunable ultra-high repetition rate electromagnetic pulses generated by the wide bandgap photoconductive semiconductor devices to the ultra-high repetition rate microwave radiation output components through a microwave radio frequency transmission structure, thereby improving the photoelectric conversion efficiency and realizing the efficient extraction of tunable ultra-high repetition rate electromagnetic pulses. The present invention provides technical support for the development of ultra-high repetition rate high-power microwave integrated systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 It is a schematic structural diagram of a tunable ultra-high repetition rate microwave generating device based on a photoconductive device of the present invention;

[0025] Figure 2 This is a flow chart of a method for generating tunable ultra-high repetition rate microwaves based on a photoconductive device according to the present invention;

[0026] Figure 3 A physical diagram of a wide bandgap photoconductive semiconductor device packaging structure in an embodiment of the present invention;

[0027] Figure 4 Schematic diagram of the packaging structure of a wide bandgap photoconductive semiconductor device according to an embodiment of the present invention;

[0028] Figure 5 This is a physical diagram of the microwave radio frequency transmission structure in an embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of a microwave radio frequency transmission structure in an embodiment of the present invention;

[0030] Figure 7It is a waveform diagram of the MHz repetition rate output by the tunable ultra-high repetition rate microwave device in an embodiment of the present invention;

[0031] In the figure, 201 is a photoconductive semiconductor chip, 202 is a positive contact electrode, 203 is a negative contact electrode, 204 is an insulating packaging box, 205 is an insulating potting compound, 401 is an input port, 402 is a transmission section, 403 is an impedance matching section, and 404 is an output port. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Reference Figure 1 As shown, this embodiment provides a tunable ultra-high repetition rate microwave generating device based on a photoconductive device, comprising: a laser modulation module and a microwave extraction module; the laser modulation module comprises a wide bandgap photoconductive semiconductor device and an ultra-high repetition rate laser driving source; the microwave extraction module comprises a high-voltage charging power supply, a microwave radio frequency transmission structure and an ultra-high repetition rate microwave radiation output component; the repetition frequency of the ultra-high repetition rate laser driving source is of the order of MHz; in this embodiment, the output laser wavelength of the ultra-high repetition rate laser driving source is 1030nm, the laser pulse width includes two gears of 300ps and 500ps, the maximum average power is 100W, and the repetition frequency is 1MHz; the high-voltage charging power supply adopts a commercial 30kV high-voltage continuous charging power supply.

[0035] The wide bandgap photoconductive semiconductor device is respectively connected to the ultra-high repetition rate laser driving source, the high-voltage charging power supply, and the microwave radio frequency transmission structure. The wide bandgap photoconductive semiconductor device is connected to the ultra-high repetition rate laser driving source through an optical fiber or an optical waveguide; the wide bandgap photoconductive semiconductor device is connected to the high-voltage charging power supply through a surface-coated zinc oxide transparent electrode; the ultra-high repetition rate microwave radiation output component is connected to the microwave radio frequency transmission structure through a coaxial line.

[0036] The ultra-high repetition rate laser driving source is used to generate continuous laser pulses with adjustable pulse width, pulse main frequency and pulse repetition rate, and input the laser pulses into the wide bandgap photoconductive semiconductor device through an optical fiber or an optical waveguide. The ultra-high repetition rate laser driving source adopts a laser driving source system for continuous chirped pulse amplification, and the ultra-high repetition rate laser driving source comprises a high repetition rate seed source, a large stretching amount pulse stretcher, a multi-stage chirped pulse amplifier and a high-power pulse compressor connected in sequence; the repetition frequency of the high repetition rate seed source is in the order of MHz, the stretching amount of the large stretching amount pulse stretcher is in the order of hundreds of ps, and the power of the high-power pulse compressor is in the order of hundreds of W. The high repetition rate seed source, the large stretching amount pulse stretcher and the high-power pulse compressor are the core parts of the ultra-high repetition rate laser driving source, providing the chirped pulse amplifier with quasi-continuous light or continuous light input, ensuring that the chirped pulse amplifier achieves stable laser amplification output with large energy, high average power and high repetition rate.

[0037] The wide bandgap photoconductive semiconductor device generates MHz tunable ultra-high repetition rate electromagnetic pulses under the simultaneous action of the continuous laser pulses generated by the ultra-high repetition rate laser driving source and the high voltage generated by the high-voltage charging power supply. The wide bandgap photoconductive semiconductor device uses a high-resistance semiconductor as a substrate, and a transparent conductive layer and a high-voltage resistant passivation layer are sequentially prepared from bottom to top on the upper surface of the substrate, and the passivation layer has an anti-reflection effect; a metal ring is sleeved on the transparent conductive layer and the high-voltage resistant passivation layer, and the lower end face of the metal ring is connected to the substrate, and the upper end face of the metal ring is connected to a hollow metal electrode; a silver-plated layer is provided on the lower surface of the substrate, and the silver-plated layer has high reflectivity, and the silver-plated layer is connected to a solid metal electrode. The high-resistance semiconductor uses a thin sheet with a thickness of 0.01mm to 10mm, and the thin sheet is square or round, the side length of the square is 1mm to 50mm, and the diameter of the circle is 1mm to 50mm. The material of the substrate is a wide bandgap SiC material, and 4H-SiC or 6H-SiC material is used in this embodiment.

[0038] The packaging structure of the wide bandgap photoconductive semiconductor device is as follows Figure 3 , Figure 4As shown, it includes a photoconductive semiconductor wafer 201, a positive contact electrode 202, a negative contact electrode 203, an insulating packaging box 204, and an insulating potting glue 205; wherein the insulating packaging box 204 is a hollow cube composed of two insulating plates, and through holes are opened on the two sides of the cube, and the positive contact electrode 202 and the negative contact electrode 203 are fixed in the deep groove through the through holes of the insulating plates; the positive contact electrode 202 and the negative contact electrode 203 are both cylindrical structures, and hollow cylindrical contact electrodes are arranged on the side contacting the photoconductive semiconductor wafer 201, and the photoconductive semiconductor wafer 201 is pressed and electrically contacted well by the two hollow cylindrical contact electrodes. The hollow part of the insulating packaging box 204 is filled with insulating potting glue 205 to ensure that the two contact electrodes and the photoconductive semiconductor device are immersed in the insulating potting glue 205 to prevent electrical breakdown. In this embodiment, the insulating packaging box 204 is made of nylon or polytetrafluoroethylene; the positive contact electrode 202 and the negative contact electrode 203 are both made of brass; and the photoconductive semiconductor chip 201 is a SiC photoconductive semiconductor device covered with a zinc oxide transparent electrode.

[0039] The microwave radio frequency transmission structure is as follows Figure 5 , Figure 6 As shown, it includes an input port 401, a transmission section 402, an impedance matching section 403, and an output port 404 connected in sequence. The microwave radio frequency transmission structure is substantially a solid-state pulse transmission line, the transmission section 402 and the impedance matching section 403 are equivalent to the outer cylinder of the solid-state pulse transmission line, and the input port 401, the wide bandgap optical semiconductor device, and the output port 404 together constitute the inner cylinder of the transmission line, thereby realizing the transmission of electrical signals and the formation of square wave pulses.

[0040] The ultra-high repetition frequency microwave radiation output component is a flat broadband radiation horn with impedance matching with the microwave radio frequency transmission structure. The ultra-high repetition frequency microwave radiation output component radiates the tunable ultra-high repetition frequency electromagnetic pulse output by the wide bandgap photoconductive semiconductor device to generate and output a tunable ultra-high repetition frequency microwave signal. This embodiment also provides a tunable ultra-high repetition frequency microwave generation method based on a photoconductive device, such as Figure 2 As shown, the specific steps include:

[0041] S1, obtaining ultra-high repetition rate laser modulation signal;

[0042] This embodiment uses an ultra-high repetition rate laser driving source to obtain an ultra-high repetition rate laser modulation signal; the ultra-high repetition rate laser driving source generates continuous laser pulses with adjustable pulse width, pulse main frequency and pulse repetition rate, which is an ultra-high repetition rate laser modulation signal.

[0043] S2. Inputting a high voltage and the ultra-high repetition rate laser modulation signal into a wide bandgap photoconductive semiconductor device to obtain a tunable ultra-high repetition rate electromagnetic pulse.

[0044] S3, extracting the tunable ultra-high repetition rate electromagnetic pulse;

[0045] This embodiment uses a microwave radio frequency transmission structure to extract the tunable ultra-high repetition rate electromagnetic pulse.

[0046] S4. radiate the extracted tunable ultra-high repetition rate electromagnetic pulse to obtain a tunable ultra-high repetition rate microwave signal.

[0047] This embodiment further verifies the tunable ultra-high repetition rate microwave generating device and generating method based on photoconductive device of the present invention. The MHz repetition rate waveform output by the tunable ultra-high repetition rate microwave device is as follows: Figure 7 As shown by Figure 7 It can be seen that the tunable ultra-high repetition rate microwave generating device and generating method based on photoconductive devices of the present invention can obtain stable MHz repetition rate microwave output, which proves the effectiveness of the tunable ultra-high repetition rate microwave generating device and generating method based on photoconductive devices of the present invention.

[0048] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A tunable ultra-high repetition rate microwave generator based on a photoconductive device, characterized in that: include: Laser modulation module, microwave extraction module; The laser modulation module includes a wide bandgap photoconductive semiconductor device and an ultra-high repetition rate laser driving source; the microwave extraction module includes a high-voltage charging power supply, a microwave radio frequency transmission structure and an ultra-high repetition rate microwave radiation output component; the wide bandgap photoconductive semiconductor device is respectively connected to the ultra-high repetition rate laser driving source, the high-voltage charging power supply and the microwave radio frequency transmission structure, and the ultra-high repetition rate microwave radiation output component is connected to the microwave radio frequency transmission structure; The microwave radio frequency transmission structure comprises an input port (401), a transmission section (402), an impedance matching section (403), and an output port (404) which are connected in sequence; The microwave radio frequency transmission structure is a solid-state pulse transmission line, the transmission section (402) and the impedance matching section (403) are the outer tube of the solid-state pulse transmission line, and the input port (401), the wide bandgap optical semiconductor device, and the output port (404) together constitute the inner tube of the transmission line; The wide bandgap photoconductive semiconductor device comprises a photoconductive semiconductor wafer (201), a positive contact electrode (202), a negative contact electrode (203), an insulating packaging box (204), and an insulating potting glue (205).

2. The tunable ultra-high repetition rate microwave generating device based on a photoconductive device according to claim 1, characterized in that: The ultra-high repetition rate laser driving source adopts a laser driving source system of continuous chirped pulse amplification, and the ultra-high repetition rate laser driving source comprises a high repetition rate seed source, a large stretching amount pulse stretcher, a multi-stage chirped pulse amplifier and a high-power pulse compressor connected in sequence.

3. The tunable ultra-high repetition rate microwave generating device based on a photoconductive device according to claim 1, characterized in that: The wide bandgap photoconductive semiconductor device comprises a substrate, on the upper surface of which a transparent conductive layer and a high-voltage resistant passivation layer are arranged in sequence from bottom to top; a metal ring is sleeved on the transparent conductive layer and the high-voltage resistant passivation layer, the lower end surface of the metal ring is connected to the substrate, and the upper end surface of the metal ring is connected to a hollow metal electrode; a silver-plated layer is provided on the lower surface of the substrate, and the silver-plated layer is connected to a solid metal electrode.

4. The tunable ultra-high repetition rate microwave generating device based on a photoconductive device according to claim 3, characterized in that: The substrate is made of high-resistance semiconductor material, the high-resistance semiconductor is a thin sheet with a thickness of 0.01mm to 10mm, the thin sheet is square or circular, the side length of the square is 1mm to 50mm, and the diameter of the circle is 1mm to 50mm.

5. The tunable ultra-high repetition rate microwave generating device based on a photoconductive device according to claim 4, characterized in that: The substrate is made of wide bandgap SiC material.

6. The tunable ultra-high repetition rate microwave generating device based on a photoconductive device according to claim 1, characterized in that: The ultra-high repetition frequency microwave radiation output component is a flat broadband radiation horn whose impedance is matched with the microwave radio frequency transmission structure. The ultra-high repetition frequency microwave radiation output component radiates the tunable ultra-high repetition frequency electromagnetic pulse output by the wide bandgap photoconductive semiconductor device to generate and output a tunable ultra-high repetition frequency microwave signal.

7. A method for generating tunable ultra-high repetition rate microwaves based on photoconductive devices, characterized in that: The tunable ultra-high repetition rate microwave generating device based on a photoconductive device for implementing any one of claims 1 to 6 comprises the following steps: S1, obtaining ultra-high repetition rate laser modulation signal; S2, inputting a high voltage and the ultra-high repetition rate laser modulation signal into a wide bandgap photoconductive semiconductor device to obtain a tunable ultra-high repetition rate electromagnetic pulse; S3, extracting the tunable ultra-high repetition rate electromagnetic pulse; S4. radiate the extracted tunable ultra-high repetition rate electromagnetic pulse to obtain a tunable ultra-high repetition rate microwave signal.

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