All-solid-state high-power microwave source with tunable rise time based on photoconductive switch

Abstract

The invention discloses an all-solid-state high-power microwave source with tunable rise time based on a photoconductive switch, which belongs to the technical field of semiconductor devices and comprises the photoconductive switch, a variable inductor and a horn antenna. The variable inductor is electrically connected with the photoconductive switch through a wire. The horn antenna is electrically connected with the variable inductor through a radio frequency connecting line and a radio frequency coaxial connector. The photoconductive switch comprises a substrate layer, a Ni metal layer and a pair of ohmic contact electrode assemblies, the Ni metal layer is arranged above the substrate layer, and the ohmic contact electrode assemblies are arranged above the Ni metal layer. By adopting the all-solid-state high-power microwave source with the tunable rise time based on the photoconductive switch, the requirements of multiple application scenes such as tunable and ultrafast can be met, and miniaturization and practical popularization is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor devices, in particular to a full solid-state high-power microwave source with adjustable rise time based on a photoconductive switch. BACKGROUND

[0002] In the prior art, high-power microwave mainly refers to electromagnetic waves with a frequency of 100MHz-300GHz and a peak power of 100MW or more, which can be radiated through an antenna. High-power microwave has the characteristics of high light speed attack, large beam coverage area, instantaneous effect, large ammunition, all-weather, and strong concealment, which can change the form of future war. At present, higher performance requirements are put forward for the response speed, on-resistance, portability and adjustability of high-power microwave sources.

[0003] 4H-SiC photoconductive semiconductor switches can be applied to microwave generation, and the output waveform rise time depends on the rise time of the trigger laser, that is, fast front edge electrical signals can be obtained by using ultrafast picosecond laser triggering, and high-frequency microwave fields can be generated by antenna radiation. Unlike traditional high-power microwave generation technology based on relativistic vacuum electronics, 4H-SiC photoconductive switches can achieve wide frequency coverage and MHz-level repetition frequency. The above-mentioned method of using ultrafast laser triggering to realize electromagnetic pulse has limitations, and the output spectrum parameters are usually fixed or difficult to be tuned in a large range.

[0004] In view of the current problems, some related researches introduce a narrow-band high-power adjustable frequency radio frequency / microwave generation scheme of a high-power pulse cluster all-fiber laser system, for example, Chinese patent document CN114927514A. The results show that this method can modulate the trigger laser signal through the electro-optical modulator (EOM) of the arbitrary waveform generator (AWG), and then realize the continuous adjustment of the pulse output waveform. However, in actual application, the modulation of high-frequency trigger laser mode will lead to the complexity of the structure of the laser triggering system on the one hand, and the laser source needs a large device volume and is expensive. On the other hand, high repetition frequency laser pulses can cause serious damage to the photoconductive switch, thereby reducing the service life of the microwave source system. SUMMARY

[0005] The purpose of the present application is to provide a full solid-state high-power microwave source with adjustable rise time based on a photoconductive switch, which has a simple structure, small size and low cost.

[0006] In order to achieve the above-mentioned purpose, the application provides a rise time tunable all-solid-state high-power microwave source based on a photoconductive switch, comprising a photoconductive switch, a variable inductor and a horn antenna; the variable inductor is electrically connected with the photoconductive switch through a wire; the horn antenna is electrically connected with the variable inductor through a radio frequency connecting line and a radio frequency coaxial connector; the photoconductive switch comprises a substrate layer, a Ni metal layer and a pair of ohmic contact electrode assemblies, the Ni metal layer is arranged above the substrate layer, and the ohmic contact electrode assemblies are arranged above the Ni metal layer.

[0007] Preferably, the ohmic contact electrode assembly comprises a first electrode and a second electrode, and the second electrode is electrically connected with the variable inductor through a wire.

[0008] Preferably, the first electrode and the second electrode are both rectangular, and a gap is arranged between the first electrode and the second electrode to form a photoconductive switch electrode; the first electrode and the second electrode are both arranged with a rounded corner, and the size is 1mm.

[0009] Preferably, a groove is formed in the top of the substrate layer, and the Ni metal layer and the ohmic contact electrode assembly are arranged in the groove.

[0010] Preferably, the thickness of the Ni metal layer is 100-400nm.

[0011] Preferably, the ohmic contact electrode assembly is a Ti / Pt / Au composite metal layer or a Ti / Al / Ti / Au composite metal layer.

[0012] Preferably, the lower surface of the substrate layer is treated by a thinning process, so that the thickness of the substrate layer is 100μm.

[0013] Preferably, the adjustment range of the variable inductor is 0-10nH.

[0014] Therefore, the rise time tunable all-solid-state high-power microwave source based on a photoconductive switch can meet the needs of tunable, ultrafast and other application scenarios, and has the advantages of simple structure, small size, low cost, and easy miniaturization and practicality.

[0015] The technical solutions of the application will be further described in detail below with reference to the drawings and embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is a sectional view of the overall structure of the rise time tunable all-solid-state high-power microwave source based on a photoconductive switch of the application;

[0017] Figure 2This is a diagram illustrating the fabrication process of the photoconductive switch in the all-solid-state high-power microwave source with tunable rise time based on the photoconductive switch of this invention.

[0018] Figure 3 This is a comparison diagram of the output waveforms of the all-solid-state high-power microwave source with tunable rise time based on photoconductive switches under different inductor parameters.

[0019] Figure Labels

[0020] 1. Photoconductive switch; 2. Variable inductor; 3. Horn antenna; 4. Substrate layer; 5. Ni metal layer; 6. Ohmic contact electrode; 7. First electrode; 8. Second electrode; 9. N-type RF coaxial connector. Detailed Implementation

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0023] Example 1

[0024] like Figure 1 As shown, this invention provides an all-solid-state high-power microwave source with tunable rise time based on a photoconductive switch, including a photoconductive switch 1, a variable inductor 2, and a horn antenna 3. The variable inductor 2 is electrically connected to the photoconductive switch 1 via a wire, and the horn antenna 3 is electrically connected to the variable inductor 2 via an RF connection line and an RF coaxial connector. By connecting the variable inductor 2 in series in the discharge circuit of the photoconductive switch 1 for circuit parameter tuning, the output waveform of the photoconductive switch 1 can be tuned, and the rise time of the output signal of the photoconductive switch 1 can be tuned from 180ps to 500ps, which has great promotional value and broad application prospects.

[0025] Specifically as follows:

[0026] The photoconductive switch 1 comprises a substrate layer 4, a Ni metal layer 5 arranged above the substrate layer 4, and a pair of ohmic contact electrode assemblies 6 arranged above the Ni metal layer 5. In this embodiment, the substrate layer 4 is made of SiC, and a recess is formed in the top of the substrate layer 4, and the Ni metal layer 5 and the ohmic contact electrode assemblies 6 are arranged in the recess.

[0027] The specific manufacturing process of the photoconductive switch 1 is shown in Figure 2 , wherein, Figure 2 (a) in Figure 2 (b) in Figure 2 (c) in

[0028] After the Ni metal layer 5 is arranged, the ohmic contact electrode assemblies 6 are arranged, and the ohmic contact electrode assemblies 6 are evaporated on the Ni metal layer 5 by using an electron beam evaporation or a magnetron sputtering device, and a photoetching process is used to obtain a whole SiC wafer with a photoconductive switch electrode structure by acetone / ethanol stripping. The ohmic contact electrode assemblies 6 are a Ti / Pt / Au composite metal layer or a Ti / Al / Ti / Au composite metal layer.

[0029] Figure 2 (d) in

[0030] In addition, the ohmic contact electrode assemblies 6 comprise a first electrode 7 and a second electrode 8, and the second electrode 8 is electrically connected to the variable inductor 2 through a wire. The first electrode 7 and the second electrode 8 are both rectangular, and a space is arranged between the first electrode 7 and the second electrode 8 to form a photoconductive switch electrode. The first electrode 7 and the second electrode 8 are both arranged with rounded corners, and the size is 1 mm, which can reduce the peak electric field of the electrode edge and further improve the voltage resistance of the device.

[0031] The connecting structure of the whole microwave source is specifically as follows: the second electrode 8 in the light guide switch 1 is connected with the variable inductor 2 through a wire, the right side of the variable inductor 2 is electrically connected with the horn antenna 3 through a radio frequency connecting line and an N-type radio frequency coaxial connector 9, wherein the radio frequency connecting line is a high frequency transmission line, and finally a more stable and high-power microwave can be obtained.

[0032] The variable inductor 2 is externally connected to the output end of the light guide switch 1, and the purpose is to adjust the circuit inductance, change the output waveform and affect the radiation frequency band of the microwave source. Figure 3

[0033] Therefore, the application adopts the above-mentioned full solid-state high-power microwave source with adjustable rise time based on a light guide switch, which can meet the needs of multiple application scenarios such as tunable and ultrafast, has a simple structure, a small size, a low cost, and is convenient for miniaturization and practical popularization.

[0034] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application but not to limit it, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.​

Claims

1. A full solid-state high power microwave source based on a light guide switch with adjustable rise time, characterized in that: The device includes a photoconductive switch, a variable inductor, and a horn antenna. The variable inductor is electrically connected to the photoconductive switch via a wire. The horn antenna is electrically connected to the variable inductor via an RF connection line and an RF coaxial connector. The photoconductive switch includes a substrate, a Ni metal layer, and a pair of ohmic contact electrode assemblies. The Ni metal layer is disposed above the substrate, and the ohmic contact electrode assemblies are disposed above the Ni metal layer.

2. The lightguide switch based rise time tunable all-solid-state high power microwave source of claim 1, wherein: The ohmic contact electrode assembly includes a first electrode and a second electrode, the second electrode being electrically connected to the variable inductor via a wire.

3. The lightguide switch based rise time tunable all-solid-state high power microwave source of claim 2, wherein: Both the first electrode and the second electrode are rectangular, and there is a gap between the first electrode and the second electrode to form a photoconductive switch electrode; both the first electrode and the second electrode are rounded at the corners, with a size of 1mm.

4. The lightguide switch based rise time tunable all-solid-state high power microwave source of claim 1, wherein: A groove is formed on the top of the substrate layer, and the Ni metal layer and the ohmic contact electrode assembly are both disposed in the groove.

5. The lightguide switch based rise time tunable all-solid-state high power microwave source of claim 1, wherein: The thickness of the Ni metal layer is 100-400 nm.

6. The all-solid-state high-power microwave source with tunable rise time based on a photoconductive switch according to claim 1, characterized in that: The ohmic contact electrode assembly is a Ti / Pt / Au composite metal layer or a Ti / Al / Ti / Au composite metal layer.

7. The all-solid-state high-power microwave source with tunable rise time based on a photoconductive switch according to claim 1, characterized in that: The lower surface of the substrate is treated with a thinning process to make the thickness of the substrate 100 μm.

8. The all-solid-state high-power microwave source with tunable rise time based on a photoconductive switch according to claim 1, characterized in that: The adjustable range of the variable inductor is 0-10nH.

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