CTE Wireless & RF Engineering Flashcards
6 cards from real CTE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 CTE Wireless & RF Engineering flashcards as text
What FCC regulation limits the maximum Effective Isotropic Radiated Power (EIRP) for unlicensed 2.4 GHz Wi-Fi devices in the US?
Answer: 4 W EIRP
FCC Part 15.247 limits unlicensed spread-spectrum devices at 2.4 GHz to a maximum of 4 W (36 dBm) EIRP.
Which propagation model is most appropriate for estimating path loss in dense urban macrocell environments for LTE planning?
Answer: Okumura-Hata model
The Okumura-Hata empirical model is widely used for urban macro-cell path loss prediction in the 150–1500 MHz range typical of cellular deployments.
What does the term 'noise figure' describe in an RF amplifier?
Answer: The degradation of signal-to-noise ratio caused by the amplifier
Noise figure (NF) is the ratio of input SNR to output SNR in dB, indicating how much thermal noise the amplifier itself adds to the signal.
In CDMA systems, what is the function of the Walsh codes assigned to each user?
Answer: To orthogonally separate multiple users sharing the same frequency and time resources
Walsh codes are orthogonal spreading codes that allow CDMA systems to separate simultaneous users occupying the same frequency band.
What is the primary advantage of using a parabolic reflector antenna in point-to-point microwave links?
Answer: Very high directional gain reducing interference and increasing range
Parabolic dishes focus energy into a narrow beam, producing high gain (often 30–45 dBi) that maximizes range and minimizes co-channel interference.
In 5G NR, what is the purpose of the Sub-6 GHz spectrum compared to mmWave spectrum?
Answer: Sub-6 GHz provides wider coverage and better building penetration; mmWave provides extreme capacity over short distances
Sub-6 GHz bands offer better propagation and wall penetration for broad coverage, while mmWave bands above 24 GHz deliver multi-Gbps throughput over short ranges like stadiums and dense urban hotspots.