For the last thirty years, radar detector manufacturers have struggled to stay one jump ahead of police radar, and vice versa. Radar for speed enforcement applications has been around since 1954; while the technology has evolved, the principle has remained the same. The policeman’s radar gun transmits microwaves, then receives the reflected pulses from your moving car. Using the Doppler effect, the difference in frequency of transmitted waves and returned waves are translated by a circuit that counts the number of cycles per second of each signal, then calculates speed and displays it on a digital readout.
Early radar guns used X-band frequencies strictly, but X-band radar became obsolete when motion detectors, amateur radio and many other applications started using the same frequencies (and when X-band technology was topped by consumer radar detectors). In addition, radar detector manufacturers soon stepped up their own technology, making X-band a less-effective choice. Newer radar units use K- or Ka-band radar frequencies , and the battle of measures and countermeasures continues with police units that can pick up a radar detector in your own car. Not to be outdone, manufacturers now are including features that can detect that detector as well, and will allegedly shut down the main radar receiver when that signal is picked up. Borrowing from military ELINT surveillance countermeasures, radar detector manufacturers changed the frequency of the oscillators in their units; almost every radar detector is now immune to the VG-2 Interceptor detector-detector.
Don’t be fooled, however, by radar detectors that are purported to ‘scramble” or “absorb” police radar. Tests have shown that these are useless, and furthermore, it’s illegal to actively jam radar equipment.
The best detectors scan constantly across X, K, Ka, and SuperWide Ka bands, as well as featuring low-noise laser sensors. Also, good quality radar detectors will have great auto-sensitivity to block out spurious signals and eliminate false alarms (a big problem with older units); a City/Highway setting is usually included for sensitivity. Newer units are also taking GPS technology into account, using input from other users to identify known speed traps. Cobra’s iRadar combines these features (along with red light camera detection), with all settings and preferences controllable from an iPhone or Android app. Long a popular name in the business, Escort radar detectors are still a popular and reliable brand, with affordable units that offer great filtering for false alarms, laser and full-band radar detection, voice alerts, long-range detection, and much more.
The upshot is this: as long as police radar continues to evolve, radar detector manufacturers will keep trying to stay one step ahead of the game. Your radar detector from ten years ago may still work, but it’s far from being up to date and in step with the times. If you’re planning on driving more than 5 or 10 MPH over the speed limit, investing in a quality radar detector may be a good idea (and much cheaper than a speeding ticket and jacked-up insurance rates)