7. Applications. A few examples

The ability to produce low-cost, integrated versions of synthesis devices has led to their widespread use in many consumer electronics systems. In particular, a frequency synthesizer can be found in every modern radio or television receiver. The local oscillator signal used for signal demodulation is generated by synthesis (DDS, PLL or fractional synthesis). The flexibility of modern synthesis devices has made it possible to extend receiver functionality. One example is the RDS (Radio Data System) found on some car radios. Thanks to this system, it is possible to follow a broadcast station whatever the reception conditions, and to pick up warning messages broadcast by the French road safety authorities.

Military applications make extensive use of frequency synthesis. Doppler radar, for example, used for long-range detection, requires good spectral purity from the...