How to select and apply radar for sensing in harsh environments
Range and material sensitivity are also heavily influenced by the operating frequency. Lower frequencies are better for long-range detection and work well with materials that have high dielectric constants, such as metals and water. Higher frequencies offer greater accuracy and are better suited for detecting smaller objects and a wider variety of materials. Beam patterns and sensing zones Radar sensors can be optimized to focus on specific areas of interest and track one or multiple objects. Key parameters include the beam pattern, sensing zones, and dead zones.
Radar sensors emit radio waves in a specific pattern, defined by horizontal and vertical angles. Narrow beam patterns offer precise detection and longer range, while wide beam patterns cover larger areas and better detect irregularly shaped objects. Many radar sensors allow the configuration of multiple sensing zones within their beam pattern. This feature enables more complex detection scenarios, such as setting different parameters for near and far zones in collision avoidance applications. The dead zone is the area immediately in front of the sensor where detection is unreliable. Higher-frequency sensors generally have shorter dead zones.
Identifying the optimal radar sensor: start with the basics There are numerous factors to consider when selecting a radar sensor. In addition to the basic operating parameters, radar sensors have various features that impact their cost, durability, and ease of use. Figure 1 provides a flow chart that illustrates some of these decision points using radar sensors from Banner Engineering as examples. The Q90R series from Banner Engineering is a useful starting point. These FMCW sensors operate at 60 gigahertz (GHz) to balance range, accuracy, and material detection capabilities. They have a sensing range of 0.15 meters (m) to 20 m, a dead zone of 150 millimeters (mm), and two configurable sensing zones.
Figure 1: Shown is a flowchart that illustrates the process of choosing a radar sensor. (Image source: Banner Engineering)
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