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RF Cafe Quizzes.
Note: Some material based on books have quoted passages.
This quiz is based on the information presented in
Handbook of RF and Microwave Power Amplifiers, by John L. B. Walker.
Cambridge
University Press graciously provided the book.
Whether you are an RF transistor designer, an amplifier designer or a system designer, this
is your one-stop guide to RF and microwave transistor power amplifiers. A team of expert authors
brings you up to speed on every topic, including: devices (Si LDMOS and VDMOS, GaAs FETs, GaN
HEMTs), circuit and amplifier design (discrete, hybrid and monolithic), CAD, thermal design, reliability,
and system applications/requirements for RF and microwave transistor amplifiers. Covering state-of-the-art
developments and emphasizing practical communications applications, this is the complete professional
reference on the subject.
1. What are the two primary parasitic components of a ceramic package for
an RF power amplifier?
a) Thermal resistance and lead inductance b) Thermal
resistance and lead capacitance c) Lead frame capacitance and wire bond inductance
d) Lead frame inductance and wire bond capacitance
2.
What change to coaxial connectors is necessary to accommodate higher frequencies?
a)
Physical size decreases b) Physical size increases c) Metallurgical compositions
changes are needed d) No change is required
3.
What are the ramifications of the results of Question 2?
a) Costs increase b) Power
handling increases c) Power handling decreases d) There are none
4. What is(are) the broad class(es) of RF power transistor(s)?
a) Bipolar junction transistors (BJTs) b) Metal oxide semiconductor field effect
transistors (MOSFETs) c) Gallium devices (GaAs and GaN) d) All the above
5. How is the average efficiency of a Class B amplifier
affected by power back-off?
a) Degrades as the square root of the power back-off
level b) Increases as the square root of the power back-off level c) Degrades
linearly with the power back-off level d) Increases linearly with the power back-off
level
6. What breakdown condition(s) is(are) typically
specified for FETs?
a) Gate-source (BVgs) b) Gate-drain (BVgd)
c) Drain-source (BVds) d) All the above
7.
How is the crest factor (CF) related to peak signal-power-to-average-signal-power (PAPR)?
a) CF = √(PAPR) b) CF = PAPR c) CF = PAPR2 d)
CF is not related to PAPR
8. What is the primary limitation
of RF power transistor applications?
a) Physical size b) Parasitic elements
c) Heat dissipation d) Cost
9. What is
a fundamental problem with using Newton's Method in a harmonic-balance simulation?
a)
Newton's Method relies on the classical model b) Newton's Method is useful only in linear
simulations c) Newton's Method is not guaranteed to converge on a solution d)
There is no issue with using Newton's Method
10. What
is a limitation on RF power amplifier (RFPA) design margin requirements?
a) Test
equipment precision and accuracy b) Schedule constraints c) Power handling
d) Bias voltage variation
Need some help? Click here for the
answers and explanations.
Posted August 3, 2013
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