
Custom Search
More than 10,000 searchable pages indexed.
•−• ••−• −•−• •− ••−• •
RF Cafe Morse Code >Hear It< 

FM General Equation  
Let the carrier be x_{c}(t) = X_{c}·cos (Ω_{c}t), and the modulating signal be x_{m}(t) = β·sin (Ω_{m}t) 
Then x(t) = X_{c}·cos [Ω_{c}t + β·sin (Ω_{m}t)]  
Modulation Index  


Narrowband FM (NBFM)  
Narrowband FM is defined as the condition where β is small enough to make all terms after the first two in the series expansion of the FM equation negligible. Narrowband Approximation: β = Δω/Ω_{m} < 0.2 (could be as high as 0.5, though) BW ~ 2ω_{m} 

Wideband FM (WBFM)  
Wideband FM is defined as when a significant number of sidebands have significant amplitudes.
BW ~ 2Δω 

Carson's Rule  
J.R. Carson showed in the 1920's that a good approximation that for both very small and very large
β,
BW ~ 2 (Δω + Ω_{m/sub>)) = 2*Ωm/sub> (1 + β) } 

A Disruptive Web Presence™
Custom Search
Over 10,000 pages indexed! (none duped or pirated)

Read About RF Cafe Webmaster: Kirt Blattenberger KB3UON 
RF Cafe Software
RF Cascade Workbook 
Product & Service Directory Personally Selected Manufacturers 

RF Cafe TShirts & Mugs  
RF Cafe SoftwareCalculator WorkbookRF Workbench Smith Chart™ for Visio Smith Chart™ for Excel 
Your RF Cafe Progenitor & Webmaster  
Kirt
Blattenberger...
singlehandedly redefining what an engineering website should be. 5CCG (5th MOB): My USAF radar shop 

Airplanes and Rockets: My personal hobby website Equine Kingdom: My daughter Sally's horse riding website 