This article discusses how frequency hopping describes a method in which communication systems rapidly change their operating frequency for purposes specific to their application. Applications such as communications, radar and electronic warfare use frequency hopping in order to avoid interference or detection, or to detect cloaked signals.
The faster these systems can change frequencies, or frequency hop, the more agile they become, making it easier to avoid interference and detection.
Traditional frequency hopping uses an analogue mixer and a phase-locked loop/voltage-controlled oscillator, and changing frequencies can take quite a long time.
As radio-frequency (RF) sampling has become more prevalent, frequency hopping has moved toward a numerically controlled oscillator (NCO)-based hopping technique; however, the frequency hop time can still be limited by a slow Serial Peripheral Interface (SPI) and the multiple register writes required to update the NCO.
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