A radar sensor is an electronic module that uses radio waves to detect objects, measure distance, speed, and angle. Its model and specification determine whether it fits automotive, industrial, security, or IoT use. Common radar sensor models are grouped by frequency: 24 GHz for short-range sensing, 60 GHz for high-resolution indoor detection, and 77/79 GHz for automotive ADAS. Model numbers often encode band, channels, antenna style, interface, and package. When selecting a radar sensor, review key specifications. Frequency and bandwidth affect resolution and accuracy. Detection range defines maximum reliable distance, while field of view shows horizontal and vertical coverage. Range resolution separates close targets. Speed accuracy and update rate matter for moving objects. Antenna gain and beamwidth shape the sensing zone. Interface options include UART, CAN, SPI, I2C, and Ethernet. Power consumption, supply voltage, and operating temperature affect integration. Environmental ratings such as IP67 protect against dust and water. A good radar sensor specification lists modulation, MIMO channels, output data, latency, and dimensions. Compare models against the application. For example, a 24 GHz radar module may suit parking and level sensing, while a 77 GHz sensor supports long-range adaptive cruise control. Always validate datasheet values in the final enclosure, because mounting, cover material, and interference can change performance. Use a model that fits size and cost.