Calibration of Pulsed Fields according to some US (and other) Automotive EMC Standards
Automotive Radar Pulse Testing
- General Motors GMW 3097
- Ford EMC-CS-2009.1
- FCA (Fiat Chrysler) CS.0054
- VOLVO 515-0003
Autonomous Driving (Preliminary)
8.5 - 10.5 GHz, 600 V/m at 1 m and 50% Duty
15.7 - 17.7 GHz, 600 V/m at 1 m and 50 % Duty
Military & Aerospace
- RTCA/DO-160 Section 20: Radio Frequency Susceptibility (Radiated and Conducted), Category R
- MIL 461 RS103
APP NOTE - Utilizing Solid State and CW Amplifiers for Radiated Pulse Immunity Testing
CW E Field Probe Method (Dual Mode)
Peak RMS forward power is the reference parameter for characterization of the field using peak envelope power (PEP) sensors or a spectrum analyzer (not recommended by some standards).
Characterization at the required field strengths is performed in CW mode.
If the CW E Field probe is not capable of measuring the final field levels required, or if a pulsed only amplifier is used, then it is acceptable to calibrate at a lower CW level using CW power sensors plus CW amplifier and scale up the forward power levels with a PEP sensor accordingly to the corresponding target E Field during actual testing.
Pulsed E Field Probe Method
The ability for field probes to take reliable pulsed measurements has significantly improved over recent years and is close to being established, but not (yet) recommended by most standards. Manufacturers included Lumiloop, ETS-Lindgren/DARE, Amplifier Research, EMC Test Design, and others. The EMC Shop stocking e-field probes with pulse (and CW for some models) from the aforementioned four.
Antenna Method
This method may be applicable when using either CW or pulsed power amplifiers. Simultaneously measure the pulse with multiple antennas, apply a time-gating algorithm to isolate the desired response. Peak RMS forward power is used as a reference parameter for characterization of the field using peak envelope power (PEP) sensors or a spectrum analyzer.
Different Test Methods Help Establish Tried & Trusted Methods
While we use a radiated susceptibility test system with measurement uncertainty, there are other techniques that are being used to ensure consistent measurements as well as push the capability of the field probes further.
See Lumiloops experiment utilizing a GTEM and getting meaninful pulse field measurements up to 600kV/m on pulses at a 500 Hz frequency with 150ps rise time.