# Measurement and Study of Electric Field Radiation from a High Voltage Pseudospark Switch

## TL;DR

This paper studies electric field radiation from a high voltage pseudospark switch and its impact on electromagnetic interference in pulsed power systems.

## Contribution

The study introduces a detailed characterization of electric field radiation from a pseudospark switch using a near-field scanning system.

## Key findings

- Electric field radiation peaks at 43.99 kV/m during high-frequency oscillation near the PSS.
- Radiation spectrum extends to 60 MHz with key frequencies at 1.24 MHz and harmonics at 20.14 MHz and 32.33 MHz.
- Findings guide electromagnetic compatibility design for integrated pulsed power systems.

## Abstract

The pulsed power switch serves as a critical component in pulsed power systems. The electric radiation generated by switching operations threatens the miniaturization of pulsed power systems, causing significant electromagnetic interference (EMI) to nearby signal circuits. The pseudospark switch’s (PSS) exceptionally fast transient response, a key enabler for sophisticated pulsed power systems, is also a major source of severe EMI. This study investigated the electric field radiation from a high voltage PSS within a capacitor discharge unit (CDU), using a near-field scanning system based on an electro-optic probe. The time-frequency distribution of the radiation was characterized, identifying contributions from three sequential stages: the application of the trigger voltage, the main gap breakdown, and the subsequent oscillating high voltage. During the high-frequency oscillation stage, the distribution of the peak electric field radiation aligns with the predictions of the dipole model, with a maximum value of 43.99 kV/m measured near the PSS. The spectral composition extended to 60 MHz, featuring a primary component at 1.24 MHz and distinct harmonics at 20.14 MHz and 32.33 MHz. Additionally, the impacts of circuit parameters and trigger current on the radiated fields were discussed. These results provided essential guidance for the electromagnetic compatibility (EMC) design of highly-integrated pulsed power systems, facilitating more reliable PSS applications.