MPB : Shielding Effectiveness Measurements

Shielded environment need a good shielding in order to work correctly.
Normally they require a Shielding Effectiveness (SE) more than 100dB. The SE cabin has to be regularly verified to guarantee that performances are achieved and maintained over time.

SE-Measurements with RF generators and spectrum analyzers

The system must have the required dynamic range in order to fulfil the requirement. Boosting the generator can be done up to a level after which it becomes unfeasible and unsafe. RX sensitivity can be improved by reducing the Resolution Bandwidth (RBW) but this technique has some restrictions such as scan speed, spurs and accuracy and drift of frequencies. The use of a narrow RBW create the requisite that tunings of both transmitter and receiver must be very accurate and stable, TX and RX must be “aligned” for every single frequency used, and that requires skill and takes time. Tests require a long time to be performed and the problem is that in such a long time the drift maybe have taken place making the result worthless.

SE measurements with the SEMS The SEMS

is a kit that includes both TX and RX, which are specifically designed for SE measuring. All the test phases (frequency alignment, level calibration, tuning TX and RX differently) are quickly and automatically done.
The use of a very narrow RBW is possible: fast fully self-alignment in frequency and fine tuning separated for both TX and RX. SE measurements with the SEMS require short times (in the order of tens of second) to be performed as the operator does not have to set anything. The setup are guaranteed. A typical test performed with the SEMS starts with its calibration.
For every frequency of the test the SEMS
•Tunes both TX and RX automatically.
•Gets a spectrum around the tuned frequency
•Records the frequency offset.
•Records the power level

After the operator closes the door
For every frequency of the test the SEMS
•Tunes both TX and RX automatically
•Gets the power level at the tuned frequency.
•Subtracts this level from the reference recorded.

The operator can now browse the results frequency by frequency and can store them. SE measurements with the SEMS are very fast and easy, and do not require particular skills.
Conclusion The SEMS makes everything automated so that little actions are needed by the operator. No particular skill or RF experience is required.

The SEMS is made by MPB srl (