Speed Cameras

Feared by many motorists (let those who have never driven too fast cast the first stone), the speed camera, usually containing a radar, is an electronic device whose workings are still a mystery to most electronics hobbyists. In this article we take the covers of these curious devices and describe their operation in detail, also considering a few ideas to guard against their actions.A little bit of historyMany, many years ago, the investigations carried out on electromagnetic radiation in the thirties revealed that RF waves appeared to be reflected back from some objects. This property became more discernible as the frequency was increased (above 100 MHz). It wasn’t until the end of the thirties that SHF (f > 1 GHz) waves could be generated easily, thanks to the introduction of the magnetron (which is still used in modern microwave ovens).