While most people can identify a radar detector hanging from someone’s windshield, most people don’t understand what radar jammers are and how they work.
Radar vs. Laser
The first step to understanding a radar jammer is to understand the difference between the two main types of police speed enforcement. Police use both Radar and Laser (LIDAR) guns. You can read more about how both work at our other articles, How Police Laser Works and How Police Radar Works. Simply put, Radar uses radio waves bouncing off of an object to measure its speed, while laser uses a light beam.
Radar Jammer vs. Laser Jammer
Be sure not to confuse radar jammers and laser jammers! While radar jammers are not for sale in the US, and are illegal nationwide, laser jammers are widely available and are totally legal in 41 of 50 states.
Related: USA Laser Jammer Laws
How Radar Jammers Work
Radar works on a few different frequency range (or ‘bands’); for the US, these are X-Band, K-Band, and Ka band. Radar jammers, usually installed in the front of a vehicle, will detect a radar source operating on one of these ranges and begin sending out radio waves at the same wavelength. In theory, this will cause the radar source (a police officer’s radar gun) to be jammed and to show no reading, or a very incorrect reading. However, in practice, results very often vary for a few different reasons.
One reason that there are no widely available radar jammers in the US is because they are illegal. The FCC regulates the broadcast of radio waves and only approved devices are allowed to emit radio waves. Operating a radar jammer in the US is against federal law and violators can face stiff fines or jail time. Conversely, laser jammers (mentioned above) fall under the jurisdiction of the FDA since they are emitting light, not radio waves. Laser jammers are legal under federal law, but nine states and Washington, DC have passed state laws banning their use.
Other Issues: Sources of Radar and Tuning
Though you cannot see it, much of our world is awash in radio waves and, particularly, radar waves. Anyone with a decent radar detector knows that many automatic doors at convenience stores and grocery stores run on K-band radar; if a radar jammer attempted to jam every automatic door, they would be jamming all day! Ka band, however, is usually reserved for law enforcement radar usage, so some jammers (like the Scorpion Radar Jammer) focus solely on this band. So, there is no ‘miracle jammer’ that is programmed to detect and jam all frequencies of police radar. Finally, just like radar guns, radar jammers must be tuned correctly so that they identify and emit radar signals on the correct wavelengths. Scorpion radar jammer owners have reported that the units are both expensive and fall out of tune quickly.
Learn more about Laser Jammers from our Beginner’s Guide to Laser Jammers