Test Equipment and Measurements Flashcards
6 cards from real GROL practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Test Equipment and Measurements flashcards as text
What is the purpose of an attenuator pad in RF measurements?
Answer: To reduce signal levels by a known amount to protect instruments or improve impedance matching
An attenuator reduces signal power by a precise, known amount (in dB) while maintaining characteristic impedance, protecting sensitive instruments and improving measurement accuracy.
What is the primary purpose of a time-domain reflectometer (TDR)?
Answer: To locate faults, breaks, or impedance discontinuities in a transmission line
A TDR sends a fast pulse down a transmission line and measures the time and character of reflections, allowing precise location of faults or impedance mismatches.
What does the term 'dynamic range' mean when applied to a receiver?
Answer: The ratio between the largest signal the receiver can handle and the smallest signal it can detect
Dynamic range is the difference in dB between the minimum detectable signal (sensitivity) and the maximum input level before significant distortion occurs.
What is meant by the 1 dB compression point of an amplifier?
Answer: The input power level at which the amplifier's gain drops 1 dB below its linear value due to saturation
The 1 dB compression point indicates the onset of amplifier nonlinearity — above this input power level, the amplifier enters saturation and produces increased distortion.
What is the purpose of a calibration standard (open, short, load) when using a VNA?
Answer: To remove systematic errors from the measurement by establishing reference conditions
Calibrating with known standards (open circuit, short circuit, and 50-ohm load) allows the VNA software to mathematically correct for errors caused by the test cables and connectors.
What unit is most commonly used to express receiver sensitivity?
Answer: dBm (decibels referenced to 1 milliwatt)
Receiver sensitivity is typically expressed in dBm, representing the minimum signal power (relative to 1 mW) that produces a usable output at a specified signal-to-noise ratio.