Radar Bands Reference: X, K, Ka, and Ku

Radar detectors are described by the bands they can receive. The band list on a specification sheet is one of the first fields a buyer compares, and it is also one of the most commonly overstated. This reference explains what each band name means and what to confirm before you repeat a band list in your own catalog.

X band

X band sits near 10.5 GHz. It was widely used for speed measurement in earlier decades and is still named on most band lists. In daily driving, signals in this range also come from non-automotive sources such as door openers and some industrial equipment. A unit that receives X band can therefore produce alerts in shopping areas that have nothing to do with a driver's situation. Sensitivity to X band is often adjustable for exactly this reason.

K band

K band sits near 24 GHz. It has been used for speed measurement and is also the range used by many vehicle blind-spot and collision-avoidance systems. That double use is the main reason K band is associated with false alerts in dense traffic: a detector set to full K band sensitivity in city traffic will hear other cars, not only measurement devices. Filtering and adjustable K band sensitivity are the controls that matter here.

Ka band

Ka band covers roughly 33.4 to 36 GHz and is split into narrower segments. It carries most of the modern speed-measurement use in the United States. Band lists often describe Ka coverage as a set of segments rather than one number. When you compare two quotes, ask which segments each unit covers and how the coverage was tested, rather than comparing the word Ka alone.

Ku band

Ku band sits between X and K. It is named on some band lists because a small number of devices in some markets have used it. Coverage of Ku is uncommon in units sold for the United States market, and a Ku entry on a band list should be treated as a question to ask rather than a feature to assume.

Laser

Laser is not a radar band at all. Speed measurement by laser uses short pulses of infrared light, and some detector units include a laser receiver alongside the radar receiver. Laser receiving is listed separately on every specification sheet. See the laser receiving page for details.

What to confirm on a band list

• Which bands the unit receives, named band by band, not as a general claim.
• Whether the list comes from a bench test of the SKU or from a design description.
• Which Ka segments are covered, if Ka is listed.
• Which sensitivity or filtering controls the driver can adjust per band.
• Whether the band list differs between firmware versions.

A band list you cannot source to a test is a marketing sentence. Keep it pending in your catalog until the supplier documents it, and write band coverage in your own listings in the same measured way.