Return to RF Cafe Quiz #6
All RF Cafe quizzes would make perfect fodder for employment interviews for technicians or engineers - particularly those who are fresh out
of school or are relatively new to the work world. Come to think of it, they would make equally excellent study material for the same persons
who are going to be interviewed for a job.
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Note: Many answers contain passages quoted in whole or in part from the text.
1. Which of the following
WLAN standards is on a different frequency band than the others?
802.11b/g/n are all in
the 2.4 GHz ISM band, 802.11a is in the 5 GHz ISM band.
2. What does the term "ruggedness" refer to
in wireless power amplifiers?
c) Ability to withstand load mismatch
A typical ruggedness spec is no
damage into a 10:1 VSWR load
3. Which FCC regulation governs the unlicensed ISM band?
FCC Part 15 governs the unlicensed ISM band for intentional, unintentional, and incidental
4. In which semiconductor technology are the majority of cellphone PAs manufactured?
Many WLAN PAs are built in SiGe and Si, and one or two experimental phone PAs are being built in Si, but the
vast majority of phone PAs are built in GaAs HBT or InGaP HBT.
5. What is a major advantage of LTCC
d) All the above
Because of the high dielectric constant of the material, relatively large distributed
components can be integrated into the substrate, which decreases the number of discrete components needed. The
higher thermal conductivity also helps with heat dissipation.
6. Which phone standard supports the
highest data rate?
iDEN=64kbps, GPRS=21.4kbps/time slot, EDGE=384kbps, GSM=14.4kbps
7. Which component is typically not part of a front-end module (FEM)?
a) Power amplifier
modules (TxM) incorporates a FEM + PA
8. Which two systems are most likely to experience concurrent
b) Bluetooth + WLAN
Bluetooth and WLAN (802.11b/g/n) both operate on the 2.5
GHz ISM band.
9. An isolator is typically required at the output of the PA for which transmitter system
CDMA/W-CDMA power amplifiers, due to their highly linear region of operation, cannot tolerate a very high
mismatch (VSWR) and must be protected with an isolator.
10. What is the commonly claimed nominal
operational range for Bluetooth?
d) All the above
Sure it's stupid (and true), but a little levity
in an interview can lighten the load.