A car radar detector is a 12 volt DC electronic device employed by
drivers, to alert them if their vehicle's speed is being acquired. Radar (short for
Radio Detection And Ranging) detectors comes
from the first speed measurement
technologies where radio waves around 10.5Ghz in frequency (X-band) were fired
from a law enforcement officer at a moving vehicle. The radar beam would
bounce off the moving car and the change in the wave's frequency (known as the
Doppler effect) could be electronically be calculated to determine the vehicles
speed.
Most car radar detectors are windshield mounted via a bracket
with suction cups that presses onto the glass, although some stealthier packages
are designed to be hidden upon installation, mounting in the front bumper, grill
or other discrete positions. A separate antenna is usually mounted
somewhere to the front of the vehicle, whilst the control box and/or visual
alert component is mounted in the cabin, whereby the driver has easy access to
control the volume and hear or see the alerts.
Many companies specialize in custom installations, mounting the
radar detector kit in vehicles so as you couldn't tell they were there.
Some companies can blend them in to things like rear view mirrors, clocks behind
the dashboard, or concealing the entire package except for a single LED light.
The radar detector works by picking up the police frequency at a
distance, and alerting the driver by visual and/or auditory signals. In theory, microwave from radar guns will travel forever. This
is the case in the vacuum of space, but not the case on earth. Materials
such as humidity, dust, pollution, buildings, and competing microwave signals
absorb and disperse the signal, reducing the effective range of a police radar gun.
It is at this distance, before the radar beam is strong enough to bounce back to
the police car, that a driver equipped with a radar detector stands the greatest
chance of an early warning.
Whilst some users wanted to detect radar, others wanted a
radar detector jammer, which would
block a Police radar gun from acquiring your speed.
