Modular Nanosecond Pulser Topology for Low-Stray High-Voltage Output
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Solution Overview
Problem
Current nanosecond pulsers face challenges in generating high peak voltage and power with short pulse widths and fast rise times while maintaining low stray inductance and capacitance, which limits their efficiency and versatility.
Innovation Solution
A nanosecond pulser design incorporating a transformer with low stray inductance and capacitance, coupled with solid state switches such as IGBTs or MOSFETs, and a snubber diode circuit, allowing for high peak voltage and power output with pulse widths less than 1000 nanoseconds and rise times under 50 nanoseconds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional nanosecond pulser designs are used, then high peak voltage and power output can be achieved, but stray inductance and capacitance increase, limiting efficiency and versatility
Solution Approach 1:
The pulser is divided into multiple independent switch modules (e.g., 8 modules) that can be selectively activated. Each module contains its own solid state switch, capacitor, and connection to the transformer primary windings. This segmentation allows parallel operation of multiple modules to achieve high peak power while maintaining low stray inductance through distributed architecture.
Solution Approach 2:
The switch modules are arranged radially around the transformer core in a three-dimensional configuration rather than in a planar layout. This spatial arrangement minimizes the loop areas for current paths, thereby reducing stray inductance. The radial geometry optimizes the magnetic coupling between switches and transformer while keeping parasitic elements low.
2Power
If high peak voltage output is achieved, then pulse power capability increases, but pulse width control precision decreases
Solution Approach 1:
The system employs dynamic control of the switch modules where each solid state switch can be independently turned on and off with precise timing control. The gate drive circuits provide fast switching transitions (rise times under 50 nanoseconds) allowing dynamic adjustment of pulse width while maintaining high peak voltage. The selective activation of different numbers of modules enables variable pulse widths from single-module to multi-module operation.
3Speed
If fast rise time is achieved, then pulse generation speed increases, but device complexity increases
Solution Approach 1:
The system achieves fast rise times by optimizing key parameters: using solid state switches with low junction capacitance, minimizing stray inductance through radial geometry and short current paths, and employing low-inductance capacitors. The rise time is controlled by the RC time constant where R is the load impedance and C is the total capacitance (stray plus intentional). By keeping stray inductance low (less than 100 nH) and capacitance controlled, rise times under 50 nanoseconds are achieved without excessive complexity.
4Power
If multiple switch modules are used, then power output capability increases, but stray inductance increases
Solution Approach 1:
The pulser is divided into multiple independent switch modules (e.g., 8 modules) that can be selectively activated. Each module contains its own solid state switch, capacitor, and connection to the transformer primary windings. This segmentation allows parallel operation of multiple modules to achieve high peak power while maintaining low stray inductance through distributed architecture.
Solution Approach 2:
The switch modules are arranged radially around the transformer core in a three-dimensional configuration rather than in a planar layout. This spatial arrangement minimizes the loop areas for current paths, thereby reducing stray inductance. The radial geometry optimizes the magnetic coupling between switches and transformer while keeping parasitic elements low.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The design achieves high peak voltage and power output with rapid pulse generation, enabling variable pulse widths and frequencies, and reduces energy loss through efficient energy storage and switching.
Implementation Method 1
The transformer may include a core, a plurality of primary windings wound at least partially around a portion of the core, each of the plurality of switch modules may be coupled with a subset of the primary windings, and a plurality of secondary windings wound at least partially around a portion of the core
Data Source
AI summary
A nanosecond pulser may include a plurality of switch modules, a transformer, and an output. Each of the plurality of switch modules may include one or more solid state switches. The transformer may include a core, at least one primary winding wound around at least a portion of the core, each of the plurality of switch modules may be coupled with the primary windings, and a plurality of secondary windings wound at least partially around a portion of the core. The output may output electrical pulses having a peak voltage greater than about 1 kilovolt and having a pulse width of less than about 1000 nanoseconds. The output may output electrical pulses having a peak voltage greater than about 5 kilovolts, a peak power greater than about 100 kilowatts, a pulse width between 10 nanoseconds and 1000 nanoseconds, a rise time less than about 50 nanoseconds, or some combination thereof.