Issue 45 | Uncrewed Systems Technology Aug/Sept 2022 Tidewie USV Tupan | Performance monitoring | Bayonet 350 | UAVs insight | Xponential 2022 | ULPower UL350i and UL350iHPS | Elroy Air Chaparral | Gimbals | Clogworks Dark Matter

10 Platform one Engineers at Plextek in the UK have developed a low-cost millimetre-wave radar on a single PCB (writes Nick Flaherty). “Radar operating in the 60 GHz band offers detection ranges of many tens of metres, and is able to detect very small targets regardless of the time of day or adverse weather, including fine targets such as powerlines,” said Aled Catherall, CTO at Plextek. ”We have engineered a millimetre-wave radar so that it incorporates a phased array capable of fast scanning and the supporting electronics to achieve real- time data capture and processing. The 60 GHz band takes advantage of technology advances in consumer telecoms such as reduced antenna size as well as Low Probability of Intercept/Low Probability of Detection analyses.” For millimetre-wave radar applications, the antenna is a key component to enable scanning of a narrow beam rapidly in different directions. Phased array technology is a good approach but achieving an efficient implementation, such that the total sensor power consumption is only a few watts and within a small physical size, requires careful design and optimisation. Advances such as low-cost SiGe chipsets provide most of the required millimetre-wave functionality. Combining this technology with an electronically scanning, small, integrated and highly directional antenna offers a high- performance, low-SWaP-C solution suitable for UAV sense & avoid applications. “A high-resolution millimetre-wave radar may lack the fine detail that a camera creates, but it much more readily reflects the geometry of the world it views, since it directly provides range estimates to each object in the scene,” Catherall said. “Our radar also measures Doppler, which can provide a rapid estimate of how quickly something is moving toward the drone to support avoidance measures. A radar that scans in both azimuth and elevation provides a direct, 3D estimate of its location. “Test results of our radar demonstrate successful detection of small, static obstacles above ground clutter, such as metal poles, people and cars, at sufficient ranges to enable evasive action and route planning. In addition, Doppler processing enables discrimination of moving objects such as other, small UAVs or birds. Low-cost radar on one PCB Radar August/September 2022 | Uncrewed Systems Technology Plextek’s millimetre-wave radar incorporates a phased array to achieve real-time data capture MKS Instruments has developed a motorised infrared zoom lens optimised for the new generation of 10 µm pixel SXGA/ HD FPA (focal plane array) and 15 µm VGA FPA detectors (writes Nick Flaherty). The LightIR 18-225 mm MWIR f/4 lens takes advantage of the smaller pixels to reduce the size of the optical elements. That significantly decreases the length and weight of the lens to 84 mm long, 61.4 mm in diameter and 326 g, making it 19% smaller than similar lenses. The optics are designed to operate near the diffraction limit of the sensors at wavelengths of 3.4 to 4.9 µm and maintain focus throughout the entire zoom range. “The lens addresses the new market shift toward smaller pixel-size detectors,” said Dr Kobi Lasri, general manager, Ophir Optics Group. “It combines low- SWaP capabilities and a detection range of more than 16 km. That makes it an enabler for advanced UAV and small gimbal thermal imaging applications.” The lens is powered by a 6-12 VDC line with a peak current of 1.0 A. An RS- 422 interface is used to connect to most gimbals and camera systems. IR lens for new-gen sensors Imaging