High-reliability large-power nanosecond narrow pulse generating circuit

Abstract

The invention discloses a high-reliability large-power nanosecond narrow pulse generating circuit. The circuit employs a broadband radiofrequency transformer to synchronously feed trigger signals into position between the base electrode and the emitter electrode of each avalanche triode cascaded with a Marx circuit, a protection circuit is arranged between a trigger pulse generating circuit and a trigger pulse shaping circuit, and an isolation circuit is arranged between the trigger pulse shaping circuit and the Marx circuit, wherein the protection circuit is used for protecting the trigger pulse generating circuit, the isolation circuit is used for protecting the trigger pulse shaping circuit, and a high-voltage large-resistance charging resistor is employed in the Marx circuit. Under the condition that large peak power (more than 30kW) and nanosecond narrow pulses (less than 8ns, 10%-10%) are generated, the circuit of the invention solves the problems in the prior art including that the avalanche triode is easy to lose efficacy, and the output large-power nanosecond pulses tend to damage the trigger pulse generating circuit; and the reliability of the circuit is effectively improved.

Description

technical field [0001] The invention relates to the technical field of ultra-broadband microwave detection, in particular to a highly reliable and high-power nanosecond pulse generation circuit applicable to ground-penetrating radar transmitters. Background technique [0002] Large-amplitude nanosecond narrow pulses are widely used in ground-penetrating radar, high-speed photography, optical communication, high-power laser array drive, and ultrasonic detection. [0003] Using Marx circuit to generate high-power nanosecond pulse is one of the commonly used methods in ground-penetrating radar transmitters. The ground penetrating radar transmitter based on Marx circuit generally consists of four parts: trigger pulse generation circuit, trigger pulse shaping circuit, Marx circuit and power supply circuit. The trigger pulse generation circuit is generally a digital integrated circuit, which is used to generate a trigger signal to trigger the work of the Marx circuit. The trigge...

AI Technical Summary

Problems solved by technology

[0004] In practical engineering applications, the above-mentioned narrow pulse generation circuit generally has relatively low reliability (working time) due to the following reasons. First, because the static operating point of the avalanche transistor is located near the breakdown point, and the number of avalanches is limited, Unreasonable settings will seriously affect the life of the avalanche triode; secondly, because the parameters of the avalanche triode are relatively discrete, the same circuit and the same static operating point cannot adapt to every avalanche triode in the cascaded circuit. Especially for the situation where there are many cascaded avalanche transistors in the high-power narrow pulse generating circuit; the third is that because the circuit works in a high-voltage state, for the high-power narrow pulse generating circuit, the output narrow pulse peak voltage is as high as thousands of volts or even several Kilovolts, even when the average power is small, instantaneous high voltage may cause the failure of components in the circuit

The invention proposes a high-reliability high-power narrow pulse generation circuit, which solves the problems in the prior art that the avalanche triode is easy to fail, the output high-power nanosecond pulse is easy to damage the trigger pulse generation circuit, etc., and effectively improves the reliability of the circuit.

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