 All RF Cafe Quizzes make great 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. Bonne chance, Viel Glück, がんばろう,
buena suerte, удачи, in bocca al lupo, 행운을 빕니다,
ádh mór, בהצלחה, lykke til, 祝你好運.
Well, you know what I mean: Good luck!
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Quiz #36
 This
quiz is based on the information presented in Advanced RF MEMS, by Stepan Lucyszyn. This book is full of
cool micrographs of actual device geometries.
Cambridge University Press is the publisher. Note: Some of these books are
available as prizes in the monthly RF Cafe
Giveaway.
1. What does the acronym MEMS stand for? b) Microelectromechanical Systems
(see Preface) 2. Which material is commonly used in RF MEMS for its
superior magnetic and thermal expansion properties? c) Electroplated nickel In recent
years, electroplated nickel has been used as a structural material in microfabricated circuits, RF MEMS
switches and antennas. Its thermal expansion coefficient is 5x that of polycrystalline silicon. (see page
6) 3. What distinguishes MEMS devices from traditional integrated circuits?
d) Physical displacement of internal components Moveable, three-dimensional physical structures are
created to perform mechanical functions.
4. Which properties of a MEMS RF switch are superior to a solid state RF switch?
a) Insertion loss and bandwidth In some aspects, such as power consumption, isolation, insertion
loss and bandwidth, RF MEMS switches have and advantage over electronic PIN diode and FET devices.
(see page 37) 5. Which properties of a MEMS RF switch are
inferior to a solid state RF switch? b) Speed and size The response time of RF MEMS switches is
much longer than that of electronic switches. (see page 37) 6.
What is the purpose of a sacrificial layer during MEMS fabrication? d) Allows dry etching to reduce
undercutting and erosion common with wet etching Dry etching of with an oxygen plasma allows high
selectivity when removing materials. (see page 63) 7. Which
application would be perfect for multi-pole, multi-throw MEMS RF switch? d) All the above. Duh.
(see page 90)
8. What is the purpose of a "hold electrode?" a) To counter induced bias from a
strong RF signal power level As a way of avoiding self-actuation, through an excess in the mean RF signal
power level, a number of switches designs have incorporated a second hold electrode, in addition to
the normal pull-down electrode. (see page 95) 9. Which phenomenon is
possible in a MEMS device but not in a solid state device? a) Vibration-induced actuation
Self-actuation can occur due to vibration or shock. (see page 129) 10. What
is zero-level (0-level) packaging? c) On-wafer encapsulation Zero-level packaging creates an
on-wafer, device-scale, enclosure (or sealed cavity for) the MEMS, serving as the first protective
interface. (see page 233) |
