Search:                        
Please support my efforts by ADVERTISING!
Serving a Pleasing Blend of Yesterday, Today, and Tomorrow™

Vintage Magazines

Electronics World
Popular Electronics
Radio & TV News
QST | Pop Science
Popular Mechanics
Radio-Craft
Radio-Electronics
Short Wave Craft
Electronics | OFA
Saturday Eve Post
Electronics Illustrated

Formulas | Data

Electronics | RF
Mathematics
Mechanics
Physics

Calvin & Phineas

Archive | Sitemap
kmblatt83@aol.com

Resources

Radar | AI
Cogitations
RF Museum
Videos | Pics |
Things | Logos
Radio Datashts
WJ Tech Notes
Day in History

Entertainment

Crosswords
Humor | Podcasts
Quotes | Quizzes
Tech Comics

Parts | Services

1000s of Listings

About RF Cafe
Software: RF Cascade Workbook | RF Symbols for Office | RF Symbols & Stencils for Visio | Espresso Workbook
Johanson Technology Hi-Q Porcelain Capacitors - RF Cafe

Frequency Synthesizers: Concept to Product
Answers to RF Cafe Quiz #35

RF Engineering Quizzes - RF Cafe WebsiteAll 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. Good luck!

A complete list of RF Cafe Quizzes.

Return to RF Cafe Quiz #35

RF Cafe FEatured Book - Frequency Synthesizers: From Concept to ProductThis quiz is based on the information presented in Frequency Synthesizers: From Concept to Product, by Alexander Chenakin (Phase Matrix). Artech House is the publisher. Note: Some of these books are available as prizes in the monthly RF Cafe Giveaway.

 

1.  What would the spectrum analyzer display for an ideal sinewave output look like?

d)  A single vertical line at the center frequency that has no width.

     See page 3.

 

2.  For a fundamental frequency of 100 MHz, what is the first harmonic frequency?

b)  100 MHz

     By definition, the first harmonic is the fundamental (1f), the second harmonic is 2f, the third

     is 3f, etc. The first overtone frequency is the same as the second harmonic (2f). See page 5.

 

3.  Increasing the oscillator signal-to-thermal noise ratio has what effect on the noise curve?

b)  The entire curve shifts down.

      Maintaining a higher power level in front of the resonator and/or reducing the active device

      noise factor while setting the active device gain to its optimum value will increase the oscillator

      signal-to-thermal noise ratio. See page 44.

 

4.  When is harmonic mixing typically used?

a)  When the LO signal needs to be multiplied.

      A lower fundamental frequency oscillator can be used for cost and simplicity reasons, and then

      a harmonic of the fundamental is used for mixing. For example the 3LO x 1 RF product might be

      the preferred mixer output rather than the more common 1LO x 1RF product. See page 71.

 

5.  What distinguishes a lumped element from a distributed element?

b)  The physical length of the component compared to signal wavelength.

      A loose rule-of-thumb is that if an element is greater in length than 1/10 of a wavelength of

      the highest frequency, analyze it as a distributed element. See page 96.

 

6.  Which circuit is most likely to be found in a

      feed-through EMI filter?

d) 

      An EMI filter is designed to block high frequency signals will passing DC bias and relatively low

      frequency control signals. That dictates a lowpass filter topology. The series inductor chokes off

      high frequencies while the parallel capacitor shunts high frequencies to ground. See page 106.

 

7.  Why might resistors be added in series to

      control ports on a synthesizer's control port?

a)  Current limiting to protect the input circuitry

     against a short or overvoltage.

     See Figure 4.13, on page 121.

 

8.  What PCB layout strategy is required for synthesizer design?

c)  Each component must be located and oriented based on how other components are placed.

     Many components are sensitive to cross-coupling with other components and much be situated

     to minimize the interference. For example, inductors should not me placed parallel to each other

     when in close proximity in order to avoid effectively creating a transformer. See page 133.

 

9.  What is the phase noise degradation of a 1 GHz synthesizer that uses a 10 MHz reference

     oscillator?

c)  40 dB

     Phase noise is degraded according to the equation 20 * log (fc/fRef).

     So 20 * log (1000/10) = 40 dB. See page 149.

 

10.  What advantage does a Fractional-N synthesizer have over Integer-N?

d)  Fractional-N permits output frequency steps that are small that the input reference source.

     See page 151.

Quizzes from vintage electronics magazines (and many custom RF Cafe-generated quizzes) such as Popular Electronics, Electronics-World, QST, Radio-Electronics, and Radio News were published over the years - some really simple and others not so simple. Robert P. Balin created most of the quizzes for Popular Electronics. This is a listing of all I have posted thus far.

RF Cafe Quizzes

Vintage Electronics Magazine Quizzes

Vintage Electronics Magazine Quizzes
Anritsu MA25211A P25 Radio Auto Test & Alignment System - RF Cafe

About the RF Cafe™ Website ©1996-2026

Kirt Blattenberger - RF Cafe WebmasterRF 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 World Wide Web (Internet) was largely an unknown entity at the time and bandwidth was a scarce commodity. Dial-up modems blazed along at 14.4 kbps while tying up your telephone line, and a lady's voice announced "You've Got Mail" when a new message arrived...

Webmaster: Kirt Blattenberger  |     BSEE - KB3UON - AMA92498  |  USAF Radar Technician

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  | My Daughter's Website: EquineKingdom
Please Support My Advertisers!
Aegis Power | Centric RF | RFCT
Empower RF | Reactel | SF Circuits
Alliance Test | Isotec
Werbel Microwave power dividers, couplers - RF Cafe

Windfreak Technologies Frequency Synthesizers - RF Cafe

Johanson Technology Antennas - RF Cafe		 Windfreak Technologies Frequency Synthesizers - RF Cafe

Innovative Power Products (IPP) CoolChips - RF Cafe

Innovative Power Products (IPP) Directional Couplers - RF Cafe

Please Support RF Cafe by purchasing my ridiculously low-priced products, all of which I created.

RF Cascade Workbook for Excel

RF & Electronics Symbols for Visio

RF & Electronics Symbols for Office

RF & Electronics Stencils for Visio

RF Workbench

These Are Available for Free

Espresso Engineering Workbook™

Smith Chart™ for Excel