Broadband pulse radiator integrating high-voltage pulse generation circuit and microstrip antenna

Abstract

The present invention discloses a broadband pulse radiation device integrating a high-voltage pulse generation circuit and a microstrip antenna, belonging to the field of electronic circuits. The device comprises a trigger signal input circuit, an N-stage Marx circuit, and N / 3 microwave radiation modules. Each three-stage Marx circuit is connected in series with a microwave radiation module capable of electromagnetic emission, and the operating frequency of the microstrip patch antenna in each microwave radiation module increases step by step. The present invention can generate high-frequency pulse sequences at multiple frequencies in the far field, facilitating signal coverage over a wider bandwidth. Furthermore, during the discharge conduction process, the device can directly emit energy into space, eliminating the need for transmission line coupling, synthesizers, and other structures, thus avoiding the loss and complexity associated with signal synthesis.

Description

Technical Field

[0001] The present invention belongs to the field of electronic circuits and relates to high-power microwave technology. Specifically, it provides a broadband pulse radiation device integrating a high-voltage pulse generating circuit and a microstrip antenna. Background Art

[0002] As the core component of ultra-wideband systems, the design and development of ultra-wideband pulse signal sources has always been a research focus in this field. These sources are capable of generating nanosecond or even sub-nanosecond transient electromagnetic pulses with a rich spectrum covering frequency bands ranging from hundreds of MHz to several GHz. Due to their high peak power, low average power, strong penetration, and high temporal resolution, ultra-wideband pulse signals have broad application prospects in high-speed short-range communications, wall-penetrating detection, medical imaging, geological exploration, electronic countermeasures, and other fields.

[0003] Currently, the most common method for achieving ultra-wideband, high-power signal output is the traditional Marx generator. Its basic principle is to discharge high-voltage pulses in a short period of time by charging and discharging multiple capacitors in parallel. It is widely used in pulsed power technology and high-voltage excitation systems. However, the design goals of a Marx generator are primarily to increase the voltage amplitude and pulse front speed, but its inherent electromagnetic emission efficiency is low, making it difficult to directly use it as an efficient microwave source. Furthermore, traditional Marx generators often use discrete capacitors and mechanical switches, which are bulky and have a low repetition rate, hindering integration and system miniaturization. While currently mainstream microwave signal sources, such as vacuum electronic devices like magnetrons, traveling wave tubes, and klystrons, can provide high transmission power, they suffer from high power consumption, limited modulation bandwidth, short lifespan, bulk, weight, and poor system integration. These drawbacks make them difficult to meet the development needs of future electronic warfare systems, vehicle-mounted / airborne platforms, and portable electronic devices for lightweight, broadband, and efficient microwave sources. Summary of the Invention

[0004] To address the shortcomings of the existing technology, the present invention provides a broadband pulse radiator that integrates a high-voltage pulse generating circuit and a microstrip antenna to further enhance electromagnetic emission efficiency and signal coverage. This invention improves upon the traditional Marx circuit by designing a multi-stage Marx circuit. A microwave radiator module with electromagnetic emission capability is inserted into the next stage of each three-stage Marx circuit. The microstrip patch antenna in each microwave radiator module operates at a progressively higher frequency, generating high-frequency pulse sequences at multiple frequencies in the far field, facilitating wider bandwidth signal coverage. Furthermore, during the discharge conduction process, the device can directly radiate energy into space, eliminating the need for transmission line coupling, synthesizers, and other structures, thus avoiding the loss and complexity associated with signal synthesis.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A broadband pulse radiation device integrating a high-voltage pulse generating circuit and a microstrip antenna, characterized by comprising: a trigger signal input circuit, an N-level Marx circuit, and N / 3 microwave radiation modules, wherein N is an integer multiple of 3;

[0007] The trigger signal input circuit is used to input the square wave pulse signal into the N-level Marx circuit after amplification and differentiation as the external excitation signal of the N-level Marx circuit;

[0008] The N-level Marx circuit is composed of N Marx circuits in cascade; wherein the trigger signal of the first-level Marx circuit is an external excitation signal, and the remaining Marx circuits use a step-by-step conduction mechanism to complete the cascade triggering, so that the Marx circuits at each level output pulse signals;

[0009] The microwave radiation module is arranged in series after the mth Marx circuit, where m=3, 6, 9, ..., N; and is used to transmit the pulse signal directly to the far field, thereby forming a broadband linear frequency modulated Gaussian pulse train in the far field.

[0010] Furthermore, in the N-level Marx circuit, each level of the Marx circuit is composed of avalanche transistors Q n , current limiting resistor R 2n , capacitor C n and current limiting resistor R 2n-1 constitute;

[0011] Among them, the avalanche transistor Q n The collector of the 2n-1 Connect the boost bias power supply VCC and pass the capacitor C n Connect the avalanche transistor Q n-1 The emitter is connected to the base through the current limiting resistor R 2n grounding;

[0012] In particular, in the first-stage Marx circuit, a trigger signal input circuit is connected in series between the emitter and base of the avalanche transistor Q1, and the other end of the capacitor C1 is grounded; in the m-th-stage Marx circuit, m=3,6,9,...,N, the avalanche transistor Q m The emitter is connected to the microwave radiation module; in the m+1th level Marx circuit, m=3,6,9,...,N-3, the capacitor C m+1 The other end is connected to the microwave radiation module.

[0013] Furthermore, the microwave radiation module is composed of a microstrip patch antenna A k , avalanche transistor Q A,k , current limiting resistor RA,2k-1 and current limiting resistor R A,2k Composition, k = 1, 2, ..., N / 3; where the microstrip patch antenna A k The feed end is connected to the avalanche transistor Q A,k The collector of the avalanche transistor Q 3k The emitter of the avalanche transistor Q A,k The collector of the A,2k-1 Connected to the boost bias power supply VCC, the emitter and base are connected, and through the current limiting resistor R A,2k Grounded and also connected to capacitor C 3k+1 the other end;

[0014] In particular, in the N / 3-stage microwave radiation module, the avalanche transistor Q A,N / 3 The emitter and base are connected and connected in parallel with the current limiting resistor R A,2N / 3 and the load resistor R L Ground.

[0015] Furthermore, by adjusting the microstrip patch antenna A in each level of microwave radiation module k The size of the microwave radiation module increases the resonant frequency in each level step by step, thereby forming a broadband linear frequency modulated Gaussian pulse train in the far field.

[0016] Furthermore, the trigger signal input circuit is composed of a transformer, a capacitor, and a resistor; the square wave pulse trigger signal is input to the primary side of the transformer, and the secondary side of the transformer is connected to an RC differential circuit composed of a capacitor and a resistor, so that the square wave pulse signal is differentiated to obtain a peak pulse and is input to the N-level Marx circuit.

[0017] Furthermore, the output power P of the boost bias power supply VCC is e Determined by:

[0018] After the external excitation signal is input to the N-level Marx circuit, each microwave radiation module will emit a Gaussian signal to the far field. Assume that the peak voltage of the Gaussian signal emitted by the N / 3-level microwave radiation module is U e , half-peak pulse width is T e , the repetition frequency is f, and the load resistance is R L , then the output power P of the bias power supply is obtained e for:

[0019]

[0020] Where t represents the continuous time variable of the pulse distribution over time.

[0021] Furthermore, the microwave radiation module and the multi-stage Marx circuit use the same avalanche transistor model.

[0022] The working principle of the present invention is:

[0023] The present invention designs a multi-stage Marx circuit, which uses switching devices and energy storage devices to be alternately connected in series to achieve parallel charging and series discharge of the energy storage devices, thereby outputting a pulse signal with high peak power. At the same time, a microwave radiation module with a microstrip patch antenna is interspersed in the multi-stage Marx circuit, enabling pulses to be directly emitted into the far field during signal propagation.

[0024] During the charging phase, the boost bias power supply VCC provides bias voltage to the avalanche transistor through a current-limiting resistor. Since the avalanche transistor does not receive a trigger signal, the base voltage is lower than the critical threshold and the device is in a high-resistance state. The boost bias power supply VCC charges the energy storage capacitor and the microstrip patch antenna.

[0025] When the trigger signal is input, under high voltage bias conditions, the avalanche transistor Q1 will operate in the avalanche zone. When it is broken down by avalanche, the potential of the left end of capacitor C2 will be equal to the potential of the right end of capacitor C1, and the potential difference between the two ends of capacitor C2 has not changed, then the collector potential of the avalanche transistor Q2 will become 2VCC; similarly, the potential of the third avalanche transistor will reach 3VCC at the moment of breakdown, the right end of capacitor C3 will discharge, and the emitter of the avalanche transistor Q3 will inject a large current to the microstrip patch antenna A1. The microstrip patch antenna A1 will radiate part of the pulse signal to the far field, and the signal that is not radiated will continue to propagate to the subsequent stage, forming an automatic cascade trigger chain.

[0026] Since each microstrip patch antenna transmits high-frequency pulses in sequence at short time intervals, the signal received by the far-field receiving antenna appears as a pulse sequence composed of multiple pulses in the time domain; since the operating resonant frequency of the microstrip patch antenna increases step by step, the effect received in the far field is a Gaussian-like pulse train with increasing frequency at sub-nanosecond intervals.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] (1) The present invention adopts a microstrip patch antenna to replace the traditional capacitor element. On the basis of energy storage, it can directly transmit energy to the far field during signal transmission, thereby improving the system integration and functional reusability.

[0029] (2) The present invention constructs an automatic cascade trigger link through avalanche transistors, avoiding the reliance on complex timing control or multi-channel drive in traditional systems, so that pulse triggering can be achieved step by step without the need for external timing control logic, thereby improving the system's working efficiency and response speed.

[0030] (3) The present invention utilizes multi-stage microwave radiation modules to form a time domain superposition effect in the far field, which can output electromagnetic pulse signals with wider frequency and higher energy density, and has better far-field emission performance, and is suitable for scenarios such as electromagnetic compatibility testing and broadband excitation.

[0031] (4) The present invention has a simple structure and is easy to process and package. It is suitable for promotion and application in on-chip systems or high-frequency microwave integrated modules, and has good engineering feasibility and industrialization prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is the overall workflow diagram of the present invention.

[0033] Figure 2 Schematic diagram of the circuit structure of the embodiment.

[0034] Figure 3 FIG. 4 is a waveform diagram of an external excitation signal according to an embodiment.

[0035] Figure 4 3 is a fitting diagram of the output voltage amplitude and the Marx circuit series of the embodiment.

[0036] Figure 5 1 is the pulse waveform input to the first-stage microwave radiation module of the embodiment.

[0037] Figure 6 1 is the pulse waveform input to the second-stage microwave radiation module of the embodiment.

[0038] Figure 7 FIG. 4 is a waveform of a pulse sequence radiated into the far field by the device of the embodiment. DETAILED DESCRIPTION

[0039] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, the specific implementation methods of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art may make similar modifications without departing from the scope of the invention. Therefore, the present invention is not limited to the specific implementation methods disclosed below.

[0040] This embodiment provides a broadband pulse radiation device integrating a high-voltage pulse generating circuit and a microstrip antenna. The overall working process is shown in the following figure. Figure 1 As shown, the circuit structure diagram is as follows Figure 2 As shown, it includes: a trigger signal input circuit, a 30-level Marx circuit, and 10 microwave radiation modules.

[0041] The trigger signal input circuit is composed of a transformer, a capacitor C0, and a resistor R0. The square wave pulse trigger signal is input to the primary side of the transformer, and the secondary side of the transformer is connected to an RC differential circuit composed of a capacitor C0 and a resistor R0. After differentiation, the square wave pulse signal is obtained as a spike pulse and input to the N-level Marx circuit as the external excitation signal of the first-level Marx circuit. The waveform of the external excitation signal is shown in FIG. Figure 3 shown.

[0042] The 30-level Marx circuit is composed of 30 cascaded Marx circuits; the trigger signal of the first-level Marx circuit is an external excitation signal, and the remaining Marx circuits use a step-by-step conduction mechanism to complete the cascade triggering, so that the Marx circuits at each level output pulse signals.

[0043] The microwave radiation module is arranged in series after the mth-stage Marx circuit and is used to transmit the pulse signal directly to the far field, thereby forming a broadband linear frequency modulated Gaussian pulse train in the far field, where m=3, 6, 9..., 30.

[0044] Specifically, each level of Marx circuit is composed of avalanche transistors Q n , current limiting resistor R 2n , capacitor C n and current limiting resistor R 2n-1 Composition, n=1,2,...,30; each level of microwave radiation module is composed of microstrip patch antenna A k , avalanche transistor Q A,k , current limiting resistor R A,2k-1 and current limiting resistor R A,2k Composition, k = 1, 2, ..., 10.

[0045] Among them, the avalanche transistor Q n The collector of the 2n-1 Connect the boost bias power supply VCC and pass the capacitor C n Connect the avalanche transistor Q n-1 The emitter is connected to the base through the current limiting resistor R 2n grounded; in particular, in the first-stage Marx circuit, a trigger signal input circuit is connected in series between the emitter and base of the avalanche transistor Q1, and the other end of the capacitor C1 is grounded.

[0046] The microstrip patch antenna A k The feed end is connected to the avalanche transistor Q A,k The collector of the avalanche transistor Q 3k The emitter of the avalanche transistor Q A,k The emitter is connected to the base and connected through the current limiting resistor R A,2k Ground and connected to capacitor C3k+1 , the collector passes through the current limiting resistor R A,2k-1 Connected to the boost bias power supply VCC; in particular, in the 10th stage microwave radiation module, the avalanche transistor Q A,10 The emitter and base are connected and connected in parallel with the current limiting resistor R A,20 and the load resistor R L Ground.

[0047] In this embodiment, the operating parameters of each component are selected as follows:

[0048] To achieve a narrow pulse output in an RC differentiator circuit, the product of capacitor C0 and resistor R0 (the RC time constant) must be significantly smaller than the period of the square wave pulse trigger signal. In this embodiment, the maximum repetition frequency of the Marx circuit is 50 kHz, so the RC time constant of the differentiator circuit is set to less than 1 / 10 of the square wave period—here, 2.2 μs—to ensure effective differentiation and trigger accuracy.

[0049] In selecting avalanche transistors, this embodiment uses the FMMT415 for circuit design, taking into account the technical specifications of avalanche transistors, peak output performance requirements, and device cost factors. Based on the device parameter characteristics of the FMMT415, the maximum bias voltage VCC in the device is set to no more than 260V.

[0050] All current limiting resistors are R 2n =R 2n-1 =R A，2k =R A，2k-1 =20kΩ.

[0051] When determining the number of Marx circuit stages in the specific implementation process, since the microwave radiation module still has the function of Marx circuit in addition to the radiation function during the charging and discharging stage, the number of microwave radiation modules is included in the total number of Marx circuit stages, that is, there are a total of class.

[0052] Ideally, the total output peak value of the last microwave radiation module is N′·VCC. As the number of Marx circuit stages increases, the resistance of the avalanche transistor and the energy storage capacitor in series increases, causing the output peak voltage to grow slower and gradually saturate after the number of Marx circuit stages increases. Therefore, the peak voltage of the last stage output is:

[0053]

[0054] Among them, R L is the output load impedance, VCC is the DC bias voltage, r is the equivalent internal resistance of the Marx circuit, r A is the equivalent internal resistance of the microwave radiation module.

[0055] Sequentially label the Marx circuits and microwave radiation modules at each level, and perform curve fitting on the above equation; where the boost bias voltage is VCC = 240V, and the load resistance R L =50Ω, circuit order n' is the independent variable, n'=1,2,...,N', output peak value U e is the dependent variable, the equivalent internal resistance r and r A is the fitting parameter; the value of N′ is determined by fitting, such as Figure 4 As shown in the figure, according to the trend of the curve, the device is designed to have 40 stages, including 30 stages of Marx circuits and 10 microwave radiation modules.

[0056] After determining the number of circuit stages, further determine the parameters of the energy storage capacitor, taking the circuit stage N′=40, the load impedance R L =50Ω, radiation pulse falling edge τ d =0.5ns, the upper and lower limits of the energy storage capacitance are obtained as 44.5pF and 154pF, and the value of this device is 68pF during implementation.

[0057] The microstrip patch antenna A k It consists of a rectangular feed layer and a radiating element on its upper surface, a dielectric layer and a reference ground on its lower surface. The antenna size is designed based on the relationship between the antenna feed layer size and the resonant frequency. The resonant frequency is the -3dB cutoff frequency of the antenna radiation pulse. Here, the first and second microwave radiation modules are taken as examples:

[0058] The spike pulse obtained by the RC differential circuit is input into the Marx circuit and input into the first microwave radiation module after three amplifications. The peak voltage V1 of the pulse s1(t) is 3VCC. At this time, the input 0th order Gaussian pulse signal is as follows: Figure 5 As shown in the figure, the -3dB cutoff frequency is calculated to be 0.11 GHz by the formula. Therefore, the center frequency of the microstrip patch antenna A1 in the first microwave radiation module is set to 0.11 GHz. Therefore, the antenna size (i.e., the feed layer size) is 410.7 mm long and 500.5 mm wide. The energy of the pulse transmitted to the far field by the first microwave radiation module is:

[0059]

[0060] Where t represents the continuous time variable of the pulse distribution over time, D1 is the effective bandwidth radiation energy ratio of the microstrip patch antenna A1, α0=4ln2 / T0 2 , T0 is the half-peak pulse width.

[0061] The remaining energy is E 2，in =(1-D1)·E1 continues to be transmitted to the subsequent Marx circuit, and the pulse signal s2(t) input to the second microwave radiation module is as follows Figure 6 As shown, its peak voltage is:

[0062]

[0063] The -3dB cutoff frequency is 0.19 GHz, so the center frequency of microstrip patch antenna A2 is set to 0.19 GHz. The antenna dimensions (i.e., the dielectric layer dimensions) are 237.7 mm long and 289.8 mm wide. The energy of the pulse emitted by the second microwave radiation module into the far field is:

[0064]

[0065] Wherein, D2 is the effective bandwidth radiation energy ratio of the microstrip patch antenna A2.

[0066] Since each level of microwave radiation module not only has the radiation function, but also has the ability of partial voltage storage and cascade discharge, during the operation of the system, after the pulse signal transmits part of its energy through the first-level microwave radiation module, its remaining energy continues to be transmitted along the subsequent Marx circuit and is further increased. Finally, it is radiated in turn at each level of microwave module to form a step-by-step superposition waveform in the time domain, such as Figure 7 shown.

[0067] Experimental tests demonstrate that this structure achieves effective voltage superposition and broadband pulse radiation when subjected to a positive pulse input voltage of 3.5V. The output pulse waveforms of each microwave radiation module exhibit distinct step-by-step delay and amplitude increase, and the superimposed waveform exhibits a time-domain morphology characterized by enhanced oscillation and multi-peak accumulation. The maximum amplitude of the total pulse waveform measured in the far field is approximately ±8kV, the total pulse train width is approximately 100ns, and the main frequency range extends from hundreds of MHz to several GHz, meeting the requirements for broadband pulse sources.

[0068] In summary, to achieve high-amplitude, wide-bandwidth microwave pulse signal radiation, the present invention provides a broadband pulse radiation device that integrates a high-voltage pulse generator circuit with a microstrip antenna. This device boasts a compact structure and high radiation efficiency, making it suitable for applications in pulse radar, electromagnetic compatibility testing, and electromagnetic weaponry.

[0069] It should be noted that the configuration of a 30-stage Marx circuit and 10 microwave radiation modules is a preferred structure in this embodiment. In practical applications, the number of Marx circuit stages, the capacitance parameters of each stage, the insertion spacing of the microwave radiation modules, and the structural parameters of the microstrip patch antenna can be flexibly adjusted to control the output waveform characteristics based on the specific requirements of different scenarios for pulse amplitude, radiation directivity, pulse width, and frequency range.

[0070] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they may modify the embodiments or make equivalent replacements for some of the technical features therein without departing from the spirit and scope of the present invention. Such modifications or replacements should also fall within the scope of protection of the present invention.

Claims

1. A broadband pulse radiating device integrating a high-voltage pulse generating circuit and a microstrip antenna, characterized in that: include: A trigger signal input circuit, an N-level Marx circuit, and N / 3 microwave radiation modules, where N is an integer multiple of 3; The trigger signal input circuit is used to input the square wave pulse signal into the N-level Marx circuit after amplification and differentiation as the external excitation signal of the N-level Marx circuit; The N-level Marx circuit is composed of N Marx circuits in cascade; wherein the trigger signal of the first-level Marx circuit is an external excitation signal, and the remaining Marx circuits use a step-by-step conduction mechanism to complete the cascade triggering, so that the Marx circuits at each level output pulse signals; The microwave radiation module is arranged in series after the m-th Marx circuit, where m=3, 6, 9, ..., N; and is used to transmit the pulse signal directly to the far field, thereby forming a broadband linear frequency modulated Gaussian pulse train in the far field; In the N-level Marx circuit, each level of the Marx circuit is composed of avalanche transistors Q n , current limiting resistor R 2n , capacitor C n and current limiting resistor R 2n-1 constitute; Among them, the avalanche transistor Q n The collector of the 2n-1 Connect the boost bias power supply VCC and pass the capacitor C n Connect the avalanche transistor Q n-1 The emitter is connected to the base through the current limiting resistor R 2n grounding; In the first-stage Marx circuit, a trigger signal input circuit is connected in series between the emitter and base of the avalanche transistor Q1, and the other end of the capacitor C1 is grounded; in the m-th-stage Marx circuit, m=3,6,9,...,N, the avalanche transistor Q m The emitter is connected to the microwave radiation module; in the m+1th level Marx circuit, m=3,6,9,...,N-3, the capacitor C m+1 The other end is connected to a microwave radiation module; The microwave radiation module is composed of a microstrip patch antenna A k , avalanche transistor Q A,k , current limiting resistor R A,2k-1 and current limiting resistor R A,2k Composition, k = 1, 2, ..., N / 3; where the microstrip patch antenna A k The feed end is connected to the avalanche transistor Q A,k The collector of the avalanche transistor Q 3k The emitter of the avalanche transistor Q A,k The collector of the A,2k-1 Connected to the boost bias power supply VCC, the emitter and base are connected, and through the current limiting resistor R A,2k Grounded and also connected to capacitor C 3k+1 the other end; In the N / 3 level microwave radiation module, the avalanche transistor Q A,N / 3 The emitter and base are connected and connected in parallel with the current limiting resistor R A,2N / 3 and the load resistor R L Ground.

2. A broadband pulse radiating device integrating a high-voltage pulse generating circuit and a microstrip antenna according to claim 1, characterized in that: Microstrip patch antenna A in each level of microwave radiation module k The size of the microwave radiation module is gradually reduced, so that the resonant frequency in each level of microwave radiation module is gradually increased, thereby forming a broadband linear frequency modulated Gaussian pulse train in the far field.

3. A broadband pulse radiating device integrating a high-voltage pulse generating circuit and a microstrip antenna as claimed in claim 2, characterized in that: The trigger signal input circuit is composed of a transformer, a capacitor, and a resistor; a square wave pulse trigger signal is input to the primary side of the transformer, and the secondary side of the transformer is connected to an RC differential circuit composed of a capacitor and a resistor, so that the square wave pulse signal is differentiated to obtain a peak pulse and input it to the N-level Marx circuit.

4. A broadband pulse radiating device integrating a high-voltage pulse generating circuit and a microstrip antenna as claimed in claim 3, characterized in that: The output power P of the boost bias power supply VCC e Determined by: After the external excitation signal is input to the N-level Marx circuit, each microwave radiation module will emit a Gaussian signal to the far field. Assume that the peak voltage of the Gaussian signal emitted by the N / 3-level microwave radiation module is U e , half-peak pulse width is T e , the repetition frequency is f, and the load resistance is R L , then the output power P of the bias power supply is obtained e for: Where t represents the continuous time variable of the pulse distribution over time.

5. The broadband pulse radiating device integrating a high-voltage pulse generating circuit and a microstrip antenna according to claim 4, characterized in that: The microwave radiation module and the N-level Marx circuit use the same avalanche transistor model.

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