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.Some of these books used in quizzes
are available as prizes in the monthly
RF Cafe Giveaway
Note: Many answers contain passages quoted from the text.
quiz is based on the information presented in
Microwave Mixer Technology and Applications, by Bert Henderson and Edmar Camargo.
Note: Some of these books are available as prizes in the monthly
RF Cafe Giveaway.
1. What is the name given to a receiver circuit whose oscillator
circuit is biased just shy of the oscillation point in order to increase signal sensitivity?
What is the name given to a mixer configuration that cancels out received signal frequencies that are equidistant
from the oscillator frequency as the intended signal, but on the opposite side of the oscillator; i.e., on the opposite
a) Image reject
b) Sideband reject
c) Mirror reject
3. What is Error Vector Magnitude (EVM)?
The magnitude expected vector
b) The magnitude of the measured vector
c) The difference between
the expected vector magnitude and the measured vector magnitude
d) The sum of the expected vector magnitude
and the measured vector magnitude
4. What is a "cold FET?"
A FET bathed in a cryogenic fluid
b) Slang for a burnt-out FET
c) An insensitive FET
A FET circuit without DC bias
5. Why might a Lange coupler be preferred
over a 3 dB hybrid coupler?
a) Lower insertion loss
b) Higher power handling
Wider bandwidth for impedance matching
d) Narrower bandwidth for impedance matching
6. What are mixer spurious products comprised of?
a) Small signal LO and small
signal RF inputs
b) Small signal LO and large signal RF inputs
c) Large signal LO and small signal
d) Large signal LO and large signal RF inputs
does the mechanism of noise generation in a mixer differ than that of an amplifier?
a) Because the
device parameters vary in time in response to the LO signal
b) Because of passive versus active operation
c) Because diodes are noisier than transistors
d) Because a two-port component is different than
a 4-port component
8. Why does a cascode amplifier provide higher gain
than a single stage?
a) Because of a higher bias current
b) Because of a lower supply voltage
c) Because of higher output impedance and higher reverse isolation
d) Because of its
smaller physical size
9. What is the equivalent of a triply-balanced mixer?
a) A combination of three singly balanced mixers
b) A combination of two doubly balanced mixers
c) Three diodes in a star configuration
d) Three diodes in a ring configuration
10. What is a major advantage of the Gilbert cell topology?
a) It has a
much lower implementation cost
b) It uses fewer components required
c) It has a smaller circuit
d) It multiplies the input and output currents to avoid improve linearity
Need some help? Click here for the
answers and explanations.