frequency shift

A frequency shift is the switching from one frequency to another or also the shift from one frequency to another.

Any change in the frequency of a receiver or oscillator is referred to as a frequency shift, although the term frequency shift does not indicate the rate at which the frequency shift occurs. Frequency shift is often referred to in connection with the various frequency shift keying techniques, which are modulation techniques in which the frequency changes abruptly from one frequency to another.

The frequency shift method was already used in facsimile. Here, one frequency corresponded to a black pixel, the other to a light one. Frequency shifts also occur in radar technology due to the Doppler effect. Likewise, when a transmitter changes position rapidly. This can be the case when making a phone call with a smartphone in a fast-moving motor vehicle or train.