New-Tech Europe Magazine | March 2018

Picture 2: Multi-channel radar sensor developed by Analog Devices.

will be able to influence the existing regulations, rather than waiting for regulators to define the way the industry should operate. To reach this point, UAV manufacturers need to take three steps: Develop a basic understanding of radar and its various modes Understand the components of the RF signal chain required for a complete radar solution Adopt radar solutions that provide a complete hardware setup with the software algorithms to allow them to get to market faster. The following discussion provides an overview of these steps and a potential solution to help UAV manufacturers adopt 24 GHz radar for collision avoidance and radio altimeter applications. Basics of Radar Radar sensors are commonly used in the automotive and industrial markets to detect, measure and track objects, e.g., blind spot detection and automotive driver assistance systems (ADAS). Compared to

optical or ultrasonic sensors, radar can accurately detect and measure objects over a much longer range and wider field of view in very difficult environments, including dust, smoke, snow, fog and poor lighting. A typical radar has various modes, each best depending on what needs to be detected and tracked. FMCW - Operating in the frequency modulated continuous wave (FMCW) mode, the radar measures the distance to stationary targets. By modulating the frequency, also referred to as an FMCW ramp or chirp, the radar measures the response of the reflected wave to derive range, velocity and the angle of the target. Figure 1 shows how the target’s range, velocity and angle are derived in FMCW mode. The range resolution depends on the transmitter’s carrier sweep bandwidth; the higher the bandwidth, the higher the resolution of the radar sensor. The velocity resolution depends on dwell time and carrier frequency; the higher the carrier frequency or dwell time, the higher

relaxing the regulations that restrict autonomous drone operation. Radar To The Rescue At Analog Devices, we believe UAV manufacturers have an opportunity to influence regulatory policies governing drone operation by embracing the RF, microwave and mmWave technology that can enable the sensors needed to prove the safe, reliable navigation of drones. A 24 GHz radar, operating in the globally recognized industrial, scientific and medical (ISM) band, is one example of a basic and versatile sensor for multiple use cases. An ISM band radar at 24 GHz can be used without regulation anywhere in the world for functions such as automatic collision avoidance and radio altimeters. In addition to measuring how high the drone is flying, the same radar can detect and track multiple objects— two of the most basic requirements for safe drone operation. By proving their solutions are technically capable of operating autonomously, UAV manufacturers

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