FCC RF Emissions & Electromagnetic Compatibility 2

Question 1

What test site is considered the reference standard for FCC radiated emissions measurements?

Accepted Answer

Open Area Test Site (OATS)

Answer

The Open Area Test Site (OATS) is the reference test environment specified in FCC rules and ANSI C63.4, against which all alternative test sites must validate their performance.

Question 2

What is 'site attenuation' and why is it important in EMC testing?

Accepted Answer

A measure of how well a test site replicates free-space propagation, used for site validation

Answer

Site attenuation is the insertion loss between a transmit and receive antenna at a test site, measured to validate that the site performs within 4 dB of theoretical free-space values per ANSI C63.4.

Question 3

Which standard does FCC reference for measuring radiated and conducted emissions from digital devices?

Accepted Answer

ANSI C63.4

Answer

FCC references ANSI C63.4 as the primary measurement standard for radiated and conducted emissions from unlicensed digital devices under Part 15 subpart B.

Question 4

What is the purpose of a LISN (Line Impedance Stabilization Network) in conducted emissions testing?

Accepted Answer

To provide a defined impedance on the power line and couple emissions to the measurement receiver

Answer

A LISN provides a standardized 50-ohm impedance at the power input of the device under test and couples the conducted RF emissions from the power line to the measurement receiver.

Question 5

What does 'quasi-peak' detector mean in the context of FCC emissions measurements?

Accepted Answer

A detector whose output rises quickly with pulses but decays slowly, weighted by pulse repetition rate

Answer

A quasi-peak detector charges quickly on signal peaks but discharges slowly, producing a reading that is weighted by the repetition rate of impulsive interference, as specified in CISPR publications.

FCC - Federal Communications Commission Certified Laboratory Practice Test

FCC - Federal Communications Commission Certified Laboratory Practice Test

FCC RF Emissions & Electromagnetic Compatibility 2