# Practical Microwave CircuitsAnswers to RF Cafe Quiz #61

All RF Cafe quizzes would make perfect fodder in 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.

Note: Some material based on books have quoted passages.

This quiz is based on the information presented in Practical Microwave Circuits, by Stephen A. Maas.

Note: Some of these books are available as prizes in the monthly RF Cafe Giveaway.

"This book is a collection of things I learned. largely on my own, over forty years in microwave circuit design. While almost all of the material in this book existed somewhere in some form, no single source was comprehensive and accessible. I learned most of it by experience, talking to people and digging through technical papers and books. In some cases, I just had to figure it out..."

1.  Where are coupled transmission lines likely to be found?

d)  All the above.

Coupled transmission lines are useful for many types of components, most notably directional couplers,
but also for filters, baluns, and control components.
(see page 31)

2.  What is a homogeneous transmission line?

d)  A transmission line in which all of the field lines are contained within a single dielectric medium.
(see page 17)

3.  Which transmission line is an example of a non-homogeneous transmission line?

b)  Stripline.

In stripline, microstrip, coplanar waveguide, and suspended substrate are all examples of non-homogeneous
transmission lines because the field lines exist both within and outside of the substrate dielectric.
(see page 18)

4.  Which problem did the Lange coupler solve for two-strip planar couplers?

a)  The inability to achieve sufficient coupling between two edge-coupled strips to realize a 3-dB coupler.
(see page 49)

5.  Which of the following describes a balanced transmission line?

d)  Two conductors of identical cross-section surrounded by free space (isolated from ground).
(see page51)

6.  Which of the following describes an unbalanced transmission line?

c)  Uses the ground surface as one of the two conductors.
(see page 51)

7.  When did S parameters first come into common use?

b)  1960s.

They came into common use in the 1960s and 1970s as accurate automated microwave
network analyzers were created.
(see page 67)

8.  What is the main difference between microwave and lower frequency analog circuit design?

a)  Microwave design focuses more on maximum power transfer whereas lower frequency circuit
design focuses more on voltage gain.
(see page 113)

9.  What is another name for a normalized lowpass filter design?

d)  A prototype network.
(see page 134)

10.  What is meant by "de-embedding" S parameters?

b)  Removing all effects test fixture elements from the measurement of a discrete component being measured.

Effects of the test ports, their discontinuities, and transmission lines from the component must be
mathematically subtracted from the overall measurement.
(see page 202)

 About RF Cafe Copyright: 1996 - 2024Webmaster:    Kirt Blattenberger,    BSEE - KB3UON RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ... All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged. My Hobby Website:  AirplanesAndRockets.com