Jeff Postupack and Sam Weinstein explain how integrated radar systems can apply high-end technology to economic cars This article refers to the address: http:// A 25-year-old male driver is looking at his smartphone, when the traffic jam begins to move. Just as he stepped on the gas pedal, the vehicle in front was suddenly braked due to congestion. Seeing that there is a collision, fortunately, the on-board radar system is intervening with lightning speed. The adaptive cruise control system with automatic stop function detects that the car in front is decelerating, in order to maintain the preset distance and avoid collision. , decided to stop immediately. Welcome to the era of smart cars with ever-changing technology! Since the airbags became standard safety configurations for the past two decades, automotive safety technology has made great strides. "Passive safety" represented by seat belts, airbags and collision detection systems has evolved into "active safety" - anti-lock braking (ABS), electronic stability control, adaptive suspension and rudder angle / roll control. The latest phase is "driver assisted" safety, including adaptive cruise control (ACC), blind spot detection (BSD) and lane change assist (LCA). These systems are beginning to merge with in-vehicle communication systems to make cars more autonomous and intelligent. Radar is a promising driver assistance technology. Radar systems can greatly reduce the frequency and severity of accidents, especially those that are distracting from the driver. In many countries, car safety legislation promotes driving safety, driver mortality has fallen to historically low levels, and the development of smart cars has been promoted. Until recently, radar was limited to use in airplanes and luxury cars, but it has now become a technology of interest for ordinary cars. The challenge for designers is how to integrate multiple security features while meeting the demanding quality and cost requirements of the automotive industry. These goals are not destined to conflict. For the first time ever, highly integrated systems have been continuously produced, integrating adaptive cruise control (ACC) and other radar-based detection and collision avoidance applications into a tiny package that is only smartphone-sized. Advances in on-chip signal conditioning technology allow designers to write the required settings for different driving conditions, whether it's urban roads or highway cruising, all in an affordable package. As a result, radar system designers now need to make choices: whether to use discrete devices or to use integrated solutions. Electronic integration has been adopted in many industries, such as medical imaging, communication infrastructure, consumer electronics, etc., and now it is finally the turn of automotive radar. Regardless of the solution, designers must consider the pros and cons. Size and cost Radar is changing from the standard equipment of luxury cars to the optional equipment of mid-range cars. It is expected to become a safety feature commonly used by cars in five years. The speed of popularization will accelerate with the introduction of cheap radar, and the target classification of the radar will be more perfect, and the range resolution will be higher. The design method of the analog front end (AFE) is critical. Discrete devices can be used to build top-level custom solutions, and there are always some perfectionists who want to optimize each parameter. However, building a radar system with discrete components takes more time, takes up more space, and costs more. Integrated ICs provide most of the functionality that automakers want, even for ACC and BSD applications, and their size and cost are just a fraction of discrete solutions. Signal conditioning and data acquisition circuits are now fully integrated into a single IC. Dimensions are important because radar sensor modules must be suitable for installation in tight areas, such as behind shock absorbers, which are not designed to accommodate such electronic devices. With an integrated solution, the installation area can be reduced by at least half. The integrated device is cost effective while providing the level of performance required by radar system designers. Of course, you can build a discrete system yourself, so that it exactly meets the needs, but the cost can be prohibitively high and it is impossible to achieve large-scale production. The integrated solution means that the radar system can be used in more cars at a lower cost, thereby improving the safety of all vehicles as a whole. Ease of use The integrated device adds several built-in innovations such as programmable gain and flexible filters. These features support the platform design methodology, which not only speeds up the time-to-market of the first system, but also shortens the development time of all subsequent systems using the same platform. For example, filters need to be fine-tuned for different driver safety applications. Discrete designs make it difficult to reprogram the filter. To change the filter characteristics, designers must manually change resistors and capacitors. An integrated device with a tunable filter can easily solve this problem, all adjustments are done by reprogramming the chip through the serial port. This adjustment can even be done in real time, allowing designers to make multiple adjustments quickly, reducing design time. Multiple channels on the same chip also help to simplify the design because the channels are well matched and beneficial to the driver because the sensor has a wider detection range. The ideal radar system is able to detect objects within a 180 degree viewing angle around the car, just like human vision. A receiving system with 6 channels can do this, and the angular resolution is better because it can receive more transmitted signals. This means that the target positioning time is more abundant, and the radar is more capable of resolving the target's approximate size. Although designers can use discrete devices to accomplish the same task, the structure may be bloated. The latest integrated solution automatically adjusts the characteristics of the radar sensor based on the length of the distance. When the radar signal is reflected back into the car, the designer must prevent the system from being overloaded. If the target is directly in front of the car, the amplitude of the return signal will be very high and must be attenuated. If the target is 120m away from the car, the return signal will be weak, and the microprocessor will constantly try to optimize the signal-to-noise ratio to help identify the target, determine its position in the field of view, and how far it is from the car. Many of these features are implemented with programmable gain amplifiers. Designers can use discrete PGAs, but they are never as easy and economical as PGAs controlled by the same serial port as programmable filters. Given the variability of radar system requirements, flexibility is naturally another attractive highlight of integrated solutions. The highway ACC requires a wide dynamic range, while the ACC automatic parking start function requires a narrower range, a larger field of view and faster response times to respond quickly to traffic ahead. With user-programmable settings for integrated products, a single platform can provide enhanced performance under different operating conditions, adapting to both highway and severely crowded driving conditions. Obviously, platform design methods using dedicated integrated devices can simplify the design process, reduce the size of the radar system, and more importantly, make more cheap cars safer. Substation Transformer,Prefabricated Substation,High Quality Prefabricated Substation,European Type Substation Hangzhou Qiantang River Electric Group Co., Ltd.(QRE) , https://www.qretransformer.com