RF Voltage-Current Probe for Plasma Processing Applications (analog vi probe)


  • Customized to your application
  • High sensitivity
  • High power rating




R&D engineers

Equipement maintenance engineers



Study of RF discharges

Development of processing tools

Troubleshooting of RF systems

The Vigilant Sensor covers the main excitation frequencies used in plasma applications (2, 4, 13.56, 27.12, 40.68, 60MHz) and their harmonics thanks to the amazing flat frequency response of its sensors. This is a handy probe for your R&D projects or for the troubleshooting of RF systems. This is also the ideal RF diagnostic tool for multi-frequency capacitive discharges.


This analog vi probe can be used before or after the matching unit inside your plasma system. Both ports can be either equipped with standard coaxial connectors or a rod adapter to connect the probe to copper straps for easy integration into your reactor.


The probe uses two innovative sensors to achieve accurate simultaneous measurements of both the voltage and current waveforms without significant distortions and with a minimum perturbation. It delivers two analogs signals optimized for analysis by your test instrument (oscilloscope, spectrum analyzer).


You can trust the waveforms displayed on your oscilloscope with this high fidelity probe.

The graph on the left shows the voltage and current waveforms measured with an oscilloscope. The probe output is connected to a 50-ohm attenuator load while excited with a complex RF voltage waveform full of harmonics as typically met in plasma processes. The fundamental frequency is 13.56MHz.

The voltage and current waveforms are identical and in phase as expected with a pure resistive load. They are also well superposed with the waveform measured at the output of the wideband attenuator (serving as the reference).


We combine many proprietary innovations to offer what is probably the most advanced analog RF voltage-current probe commercially available today:

- Customizable high performance electrical sensors: flat wideband response, robust, low-perturbative and compact voltage and current sensors developed through extensive experimental work and electromagnetic modeling. The settings of these sensors are customized during calibration to maximize performance for your application (maximized sensitivity and power rating while minimizing the perturbation).


- Automated highly accurate calibration process to ensure the best measurement accuracy and probe-to-probe repeatability. Our calibration process is NIST-traceable and uses the best electronic test instruments available today in a temperature and EMI controlled environment. Each probe is provided with its own certificate of calibration. The calibration is performed with the non-detachable signal cable.


Frequency band (with flat response +/-10%)


Max voltage

Max current


Calibration factors accuracy
Insertion Loss
Signal cable

Voltage sensor: 2-200MHz

Current sensor: 2-100MHz

8kV peak-to-peak

200A peak-to-peak

All standard coaxial connectors available, Strap connector (Rod)

+/- 2% (typical)
<0.5% (typical at 13.56MHz)
Pair of shielded 50Ω coaxial cables terminated with BNC connectors
90mm x 120mm x 45mm (without the signal cable)            


The sensitivity of the voltage and current sensors are customized separately during production to fit your needs (low to high power applications).


Ordering information

In order to provide you with the best suitable probe for your application, please use the following model numbering:


VSN - ATT - ZT - IN - OUT - LEN              Example: VSN-1000X-50-1F-1M-100


Code Details                             Values    C: Custom (if not listed)
 ATT Attenuation of the voltage sensor 500X, 1000X, 1500X, 2000X
ZT Sensitivity of the current sensor in mV/A (transfer impedance) 25, 50, 75, 100



Input connector type and gender

Output connector type and gender

0: Rod (with M5 threaded hole)

    1F: N Female                     1M: N Male      

2F: HN Female                   2M: HN Male

   3F: 7/16 Female                  3M: 7/16 Male

4F: LC Female                    4M: LC Male
LEN Length of the signal cable in cm Between 0 (no cable) and 300 (100 by default)

Datasheet   &   Certificate of Calibration

Vigilant Sensor Datasheet (older version)
Analog RF vi probe for plasma processing applications
VSN Datasheet.pdf
Adobe Acrobat Document 2.7 MB
Certificate of calibration (example)
Voltage Attenuation: 500X
Current Sensor Sensitivity: 50 mV/A
(Model Number: VSN-500X-50-1M-1F-100)
Adobe Acrobat Document 317.6 KB