crystal oscillator vs frequency synthesizer | difference between crystal oscillator and frequency synthesizer

This page on crystal oscillator vs frequency synthesizer describes difference between crystal oscillator and frequency synthesizer. Both are used as frequency generator source, but crystal oscillator is meant for very stable fixed low frequency source mostly 10 or 100 MHz or around these frequencies. As mentioned frequency output of the crystal oscillator is fixed and are available in different output formats(square,sinewave,triangular). While frequency synthesizer is designed to generate different frequencies within the band and selection depends on step size for which it is designed.

Crystal oscillator

Crystal oscillator is used as reference input frequency source for frequency synthesizer. Crystal oscillator is mainly used in various embedded circuits as clock reference and frequency synthesizer is used for RF channel selections in various modem and rf transceivers.

Crystal oscillator is used as reference oscillator for PLL circuits used in local oscillators and synthesizers.It is used as stable reference frequency in the design of Vector Signal Generators(VSGs) and Vector Signal Analyzers(VSAs),requiring very accurate measurements. Typical crystal oscillators available as per different applications are OCXO,EMXO,TCXO,VCXO,VCSO,XO etc.

Frequency Sythesizer

RF device used to select frequency from pool of frequencies is called frequency synthesizer. It is used as variable RF frequency generator source with different tuning step size as designed. For detail design and fundamentals of frequency synthesizer refer following link mentioned in related links section.

Crystal oscillator and Frequency Synthesizer related links

RF synthesizer block diagram, equations and design example
RF Synthesizer manufacturers
Crystal Oscillator vs MEMS Oscillator
crystal oscillator manufacturers
crystal oscillator vs frequency synthesizer
Vectron OCXO
Rakon TCXO
GPS Guided TCXO Oscillator

What is Difference between

difference between FDM and OFDM
Difference between SC-FDMA and OFDM
Difference between SISO and MIMO
Difference between TDD and FDD
Difference between 802.11 standards viz.11-a,11-b,11-g and 11-n
Bluetooth vs zigbee
Fixed wimax vs mobile

RF and Wireless Terminologies