FCC Test Equipment & Facilities Requirements

Question 1

What is the minimum shielding effectiveness typically required for an RF shielded room used in FCC testing?

Accepted Answer

100 dB attenuation from 10 kHz to 10 GHz

Answer

10 dB attenuation across all frequencies

Answer

50 dB attenuation at 1 GHz only

Answer

No minimum is specified; it depends on the ambient RF environment

Question 2

What type of absorber material is placed on the walls, ceiling, and floor of an anechoic chamber for FCC EMC testing?

Accepted Answer

Pyramidal carbon-loaded polyurethane foam absorbers

Answer

Concrete with embedded steel mesh

Answer

Copper foil lining with no absorbers

Answer

Fibreglass panels with air gaps

Question 3

What is the purpose of a spectrum analyzer or EMI receiver in FCC radiated emissions testing?

Accepted Answer

To measure the amplitude of electromagnetic emissions at each frequency across the test range

Answer

To generate calibrated RF signals for testing device immunity

Answer

To measure the impedance of the device under test

Answer

To control the automated test turntable

Question 4

What is a 'pre-scan' in FCC radiated emissions testing and why is it performed?

Accepted Answer

A fast sweep to identify peak emission frequencies before conducting the slower, definitive final scan

Answer

A preliminary review of the test setup checklist before beginning measurements

Answer

A calibration check performed on the EMI receiver before each test

Answer

A review of the device's technical documentation before testing begins

Question 5

What power supply conditions must be verified when setting up a device for FCC conducted emissions testing?

Accepted Answer

The device must be powered from a nominal AC line voltage with the LISN inserted, operating under its worst-case emission configuration

Answer

The device must be battery powered only during conducted emissions testing

Answer

The device must be powered from a DC supply to avoid power line effects

Answer

The power supply condition is irrelevant if the LISN is properly installed

Question 6

What is the purpose of a ground plane in a radiated emissions test setup?

Accepted Answer

To provide a reference conducting plane that simulates installation on a typical metallic surface and ensures measurement repeatability

Answer

To prevent static electricity from damaging the device under test

Answer

To provide a return current path for the LISN

Answer

To shield the receive antenna from low-frequency magnetic fields