Radar is a compact electronic gadget that is able to detect and inform the owner about the presence of direction finding systems of the traffic police. Such systems emit laser beams or radio waves, the determination of which he is tuned. That is, a radar is a kind of receiver that works with incoming signals.
There are passive and active models. The latter are called radar detectors and their main feature is the generation of high-power interference for traffic police detection systems. Such devices work in certain radio frequency spectra or directly modulate the response signal, which is much superior in power to the original bearing.
As a result, either a modulated result will appear on the traffic police systems / radars, or nothing will be detected at all. Such a radar is a direct violation of the law, where at best you will face a fine with confiscation of the gadget, and at worst - criminal liability. Therefore, we will not consider them, but will talk about the allowed models, which are called detectors.
A conventional radar detector is a passive receiver that does not muffle or modulate the signals from direction-finding systems of the traffic police as a radar detector, but only lets the owner know about their approach / presence.
Manufacturers
Less than a dozen brands are leading the market for this type of vehicle technology. Here you can note the company Whistler, Escort, radar detector Sho Me, Cobra and Beltronics. This, in fact, is the backbone of manufacturers with a decent history, whose name has become a household name for gadgets of this kind.
There are other less well-known companies whose assortment includes smart devices, but here you need to look carefully and weigh a lot of things before buying. These include Uniden, STR (Street Storm), Rocky Mountain and PNI.
As for our territory, the domestic consumer prefers more or less high-quality adapted models for our realities from Moongoose, Simikon, Invisible and past generations of the venerable Cobra. The Radartech brand, whose devices can detect the notorious Strelka, is rapidly gaining popularity in the Russian Federation.
There are more exotic instances of such gadgets that do not play a special role for the motorist, like the 24-Flight radar model, which can track aircraft online. The thing is useful in some situations, but too narrowly focused.
Principle of operation
The traffic police bearing systems work according to the reflection scheme, that is, the speed is measured by the radiation that is reflected from your car. Such a signal is noticeably slower than a direct one that uses a radar detector, which means that the driver will be notified in advance of the presence of the bearing along the line.
If the weather is good, as well as the terrain, then you can find the traffic police system at a distance of up to 5000 meters, and the best premium radar is able to pick up a signal up to 10,000 m even on hilly terrain.
Considering the fact that most traffic police direction finders are designed for 300-500 meters for stable readings, the radar, you can say, without straining, will warn you about the presence of a traffic police post.
There is also another kind of this kind of technology - this is a GPS radar. Here the principle of operation is completely different. If the detector is engaged in direct bearing of the up-to-date traffic police detection system, then the GPS device takes into account map data, that is, accurate marks on posts and cameras along the route of the vehicle online.
Such a radar requires constant (or close to this) communication with the satellite to display the most reliable data. The option is quite functional, but only if the signal is stable and does not disappear for a long time when you are moving along the highway. If the connection with the satellite is often interrupted or there is none at all, then you just get a nice gadget on the panel, not a radar.
Responses of owners to such equipment are motley, and depend mainly on the climatic nuances of a particular region. You have sunny and steppe terrain - almost any radar detector is suitable, often drive in the mountains or in the rain - a GPS device will be the best option.
As for the reviews on specific models of radars, it is very difficult to classify them due to the variety of manufacturers, rulers, series and gadgets themselves. Nevertheless, one can trace one tendency of reviews, which is best expressed by the expression: "The more expensive, the better."
Amplifiers
All radar detectors (on radio waves), due to their characteristics, use signal amplifiers, which greatly increase their range of operation. In total, 2 types of such amplifications can be designated - direct and based on the local oscillator (sometimes with the prefix "super").
Direct gain
This is the oldest and most common way of reinforcing for the budget sector. One of the advantages of this method is absolute passivity, that is, the radiation of the module itself is as close to zero as possible. In countries where such equipment is prohibited, a gadget with such an amplifier does not require the presence of any blocking protocols on board the car, such as VG-2.
In addition, the direct amplification of the detector eliminates most of the interference, which is due to the small sensitivity of the device. Devices of such a plan are very easy to configure and have a very affordable price tag.
European manufacturers have long begun to abandon such decisions, due to their low efficiency, but domestic leaders still continue to replenish the automotive market with gadgets with such amplifiers.
Heterodyne amplifier
This amplification method is much more advanced and most advanced technically. It is common to see such modules in mid-budget and premium models of radar detectors. An indisputable plus of such amplification is its high sensitivity and a good selection of operating frequencies.
Critical is the fact that a device with such a heterodyne module is active, that is, the radar during operation starts emitting characteristic waves. In addition, the presence of interference during use sometimes greatly interferes with the normal functionality of the device. Setting up such a device turns into a real adventure along the branch of complex circuits and frequency selectivity.
It is also worth noting separately that devices of this kind are prohibited by law in a number of countries. Such trends have not yet reached Russia, therefore, on our territory, a heterodyne radar detector can be used without fear of being fined. These gadgets are expensive, but, what is noteworthy, they pay off very quickly, especially if you very often drive along highways, autobahns and generally travel around the country.
Signal processing unit
This block, in fact, is the heart of any radar. Here, the processing of incoming signals from antennas and sensors takes place. That is, relying on some of its own algorithms, the device processes the information and gives it to the user in the proper form. Today, several variants of such signal classifiers are used - analog, digital and hybrid.
Analog
The simplest analogue method is slowly becoming a thing of the past, giving way to hybrids and digital devices. Such processing is built according to the already embedded circuits in the chip, that is, according to the prescribed algorithms.
Cons here are obvious and critical: a high rate of interference and errors, a very low speed and high current consumption.
Digital
The digital method is the most promising in terms of versatility. Radar detectors of this kind are equipped with a microprocessor and many VLSIs (ultra-large integrated circuits), where a lot of scenarios are laid down along with a set of algorithms, and the principle of operation of such a device is based on heuristics, which allows you to significantly increase the speed of the device.
The software that is used in digital radars can be updated, and therefore improve the performance of the detector, adding new algorithms to the existing list. In addition, the method is characterized by minimal false positives, and the amount of interference is reduced to zero. Here you can add a significantly increased scope of the device and parallel processing (up to eight simultaneous signals). According to drivers, devices of this type are much more efficient than analog ones.
Hybrid
Hybrid gadgets are the most common in our territory. The principle of operation of such a device is quite simple and clear from the name. That is, we have some kind of analog block, but with the capabilities of the “digit”. Such devices are characterized by a more or less fast response and a small amount of false signals, that is, interference.
Almost all the radars on the shelves of domestic stores in the mid-budget sector operate using hybrid technology. As the reviews of many users say, the “figure” is, of course, good, but it is expensive and needs to be serviced more often, and hybrids are unpretentious and universal.