Alan Freedman -- The Computer Language Company - Computer Desktop Encyclopedia
Computer Desktop Encyclopedia
Longest-Running Tech Reference on the Planet

A CDE Definition

You'll love The Computer Desktop Encyclopedia (CDE) for Tech Term of the Day (TTOD)

LOOK UP ANOTHER TERM


FSK

(Frequency Shift Keying) A simple digital modulation technique that uses two frequencies for 0 and 1. See frequency modulation.




Frequency Shift Keying
FSK is a simple technique that uses two frequencies to represent 0 and 1.






frequency modulation

(1) An earlier magnetic disk encoding method that places clock bits onto the medium along with the data bits. It was superseded by MFM and RLL.

(2) Varying the frequency of the waves of a carrier in order to transmit analog or digital data. Frequency modulation (FM) is widely used in audio transmission, not only for its namesake FM radio, but for the audio channels in television. See modulation and carrier.




Vary the Angle
In FM modulation, the frequency of the carrier wave is varied by the incoming signal. In this example, the modulating wave implies an analog signal.






Digital Frequency Shift Keying (FSK)
For digital signals, frequency shift keying (FSK) uses two frequencies for 0 and 1 as in this example.





A Sad Tale of FM Origins
FM radio was invented in the early 1930s by Edwin Howard Armstrong, who years earlier had made a fortune selling RCA his amplifier technology. When he asked RCA to license his FM in 1933, RCA turned it down and pursued its own research. Seven years later, RCA offered him USD $1 million for outright purchase, but Armstrong declined. He was angry at the long hiatus and thought the offer too low. Later, Armstrong sued for patent infringement when he discovered RCA was using his technology, but RCA's legal tactics kept him at bay for so many years that the patents expired. Fighting the company also depleted his wealth. In 1954, Armstrong wrote a note to his wife, walked over to his bedroom window and jumped 13 stories to his death. Eventually, his wife received millions in back royalties from the company.



Personal Use Only

Before/After Your Search Term
BeforeAfter
frozenFSM
FRUFSN
frustrumFSO
frustumFSR
FSFSS
FSANFST
FSBFSTN
FSFFT-1
FSGFT-CCD
FSIOPFT1

Terms By Topic
Click any of the following categories for a list of fundamental terms.
Computer Words You Gotta KnowSystem design
Job categoriesUnix/Linux
Interesting stuffPersonal computers
InternetIndustrial Automation/Process Control
Communications & networkingAssociations/Standards organizations
HistoryDesktop publishing
Audio/VideoGraphics
MainframesSecurity
ProgrammingHealthcare IT
System design