Radar jamming is the intentional emission of radio frequency signals to interfere with the operation of a radar by saturating its receiver with false information. There are two types of radar jamming: noise jamming and deception jamming. This long range radar antenna (approximately 40m (130ft) in diameter) rotates on a track to observe activities near the horizon. ... The term Jamming can refer to several things: Jamming as an electronic warfare (EW) - a technique to limit the effectiveness of an opponents communications and/or detection equipment, like Radio Jamming and Radar Jamming E-Mail Jamming- used by electronic political activists or hackers to disable e-mail systems... Sine waves of various frequencies; the lower waves have higher frequencies than those above. ...

A noise jamming system is designed to delay or deny target detection. Noise jamming attempts to mask the presence of targets by substantially adding to the level of thermal noise received by the radar. Noise jamming usually employs high power signals tuned to the same frequency of the radar. The most common techniques include barrage, spot, swept spot, cover pulse, and modulated noise jamming. Noise jamming is usually employed by stand-off jamming (SOJ) assets or escort jamming assets.

Deception jamming systems (also called repeat jammers) are designed to offer false information to a radar to deny specific information on either bearing, range, velocity, or a combination of these. A deception jammer receives the radar signal, modifies it and retransmits the altered signal back to the radar.

Initially, the challenge was simple: tune in to the fixed frequencies of the radar, and then start jamming on those frequencies. However, as radars became more sophisticated they used irregular noise superimposed on the radar signal to cloak it, and the signals were broken up into short bursts, and the frequencies used were changed rapidly and constantly.

Radar jamming for the purposes of defeating speed detection radar is simpler than for military application, although it is often illegal.