TDS SNI System

The Time Domain Sensor SNIffer (TDS SNI) probes are miniaturized, active, fully isolated magnetic and electric near-field probes that perform over a very broad frequency range, from 10 MHz –10 GHz. SPEAG’s TDS technology operates in both the frequency and time domains, delivering unparalleled sensitivity and spatial resolution for precise amplitude and phase measurements. TDS provides tremendous advantages over traditional conductive EMC probes in all near-field applications where EM transparency and noise and interference immunity are essential. All TDS systems are calibrated in SPEAG’s ISO17025-certified calibration laboratory.



TDS SNI is composed of one or more TDS SNI probes for electric or magnetic near-field sniffing and a TDS Remote Unit.


The TDS SNI system is optimized for near-field  EMC/EMI/ESD sniffing using SPEAG's novel time-domain sensor technology, including:

  • Measurements in EM-harsh environments
  • EMC/EMI/ESD near-field quantitative measurements
  • EMC/EMI/ESD pre-compliance tests
  • Measurement of the full complex-valued vector field in the very close near-field of radiators
  • In situ base station compliance measurements
Basic Configuration

The basic configuration of a TDS SNI system is composed of:

  • a TDS Standalone Remote Unit
  • a TDS SNI H1TDS magnetic or E1TDS electric field probe
  • 3.5 mm RF coaxial cable (length 0.6 m)
  • ClickCleaner (optical connector cleaner)
  • USB cable
  • USB power supply
  • TDS Professional Handbook
TDS Remote Unit

TDS Remote Unit specifications:

  • input: TDS MU8 optical interconnect
  • output: 3.5mm RF connector
  • frequency range: 100kHz (10Hz) to 6 GHz
  • dynamic range: > 130 dB
  • P1dB: > 0dBm
  • return loss: > 10 dB
  • power and control: USB
TDS SNI Probes

Specifications of H1TDS SNI magnetic field probes:

  • frequency range: 10 MHz to 6 GHz
  • dynamic range: 1 μA/m - ≥1 A/m (2 GHz)
  • E-field suppression: > 20dB (2 GHz)
  • sensor size: 2 × 2 mm2
  • tip size:  4 × 4 mm2

Specifications of E1TDS SNI electric field probes:

  • frequency range: 10 MHz to 6 GHz
  • dynamic range: 0.3 mV/m - ≥150 V/m 
  • sensor size: 2.8 mm
  • tip size:  4 × 4 mm2
Software TDS SNI comes with a remote control capability via SCPI commands over the USB link for measurement and test automation.
Calibration Calibration is performed in SPEAG's ISO17025-certified calibration laboratory.

see ICEy verification sources

Standard Compatibility

TDS SNI can be used for tests in compliance with:

  •  IEC TS 61967-3
Unique Features

Frequency range

Active optical technology

Miniature near-field probes



10 MHz - 6 GHz

non-disturbing EM measurements with unparalleled sensitivity

enables separation of magnetic and electric field coupling with a high spatial resolution

flat wideband  RF signal transmission

only EMC probe with a traceable calibration on the market


Wide-band sensors

Miniature EM near-field sensors

Fully isolated using optical technology

Traceable calibration

ability to measure all mobile communications bands with one probe

unique probe design for accurate resolution of both magnetic and electric fields in the reactive near-field

no disturbance of the measurement from the probe on the device under test

delivering calibrated datasheet-ready results

Compatibility DASY8 Module R&D
Product History see Product Lifetime

Latest News
Z43 Glowing Night
Sep 21, 2023