Results 71 to 80 of about 229,198 (350)
An investigation of a frequency diverse array [PDF]
, 2009 This thesis presents a novel concept for focusing an antenna beam pattern as a function of range, time, and angle. In conventional phased arrays, beam steering is achieved by applying a linear phase progression across the aperture.
Antonik, P.
core
Advances on Frequency Diverse Array Radar and Its Applications
Leida xuebao, 2018 Unlike the conventional phased array that provides only angle-dependent transmit beampattern, Frequency Diverse Array (FDA) employs a small frequency increment across its array elements to produce automatic beam scanning without requiring phase shifters ...
Wang Wenqin +3 more
doaj +1 more source
Advanced Materials, EarlyView.The performance of Cu‐based photocathodes in photoelectrochemical CO2 reduction is not governed by catalytic sites alone, but by the dynamic journey of photogenerated carriers. This review decodes how carrier generation, recombination, transport, accumulation, extraction, and electrolyte coupling shape catalytic activity, selectivity, and stability ...
Yi‐Cheng Wang +5 more
wiley +1 more source
TECHNIQUES AND INSTRUMENTATION FOR PHASED ARRAY CALIBRATION [PDF]
, 2020 Active phased arrays suffer the inherent problem of excitation errors, i.e., incorrect phase and amplitude excitation of the antenna elements. Excitation errors degrade critical performance parameters since they increase sidelobe level and reduce antenna
Lebron Garcia, Rodrigo
core
Photocatalytic Water Splitting on the Lunar Surface: Prospects for In Situ Resource Utilization
Advanced Materials Interfaces, EarlyView.Water has been found in craters on the moon nearby locations which are illuminated >80% of the time. Photocatalysis uses energy from sunlight to drive chemical reactions such as water splitting to produce oxygen and hydrogen. It is a scalable technology that requires lighter equipment and utilizes resources available on the moon. ABSTRACT The discovery
Ranjani Kalyan +6 more
wiley +1 more source
Advanced Materials Technologies, EarlyView.ABSTRACT Real‐time insight into local chemistry is critical for reliable part quality in additive manufacturing, especially laser powder bed fusion (PBF‑LB/M), where rapid thermal cycles and localized evaporation can undermine part performance. Optical emission spectroscopy (OES) offers non‑intrusive, in situ plume monitoring, but detection geometry ...
Philipp Gabriel +4 more
wiley +1 more source
Target recognition techniques for multifunction phased array radar [PDF]
, 2010 This thesis, submitted for the degree of Doctor of Philosophy at University College London, is a discussion and analysis of combined stepped-frequency and pulse-Doppler target recognition methods which enable a multifunction phased array radar designed
French, A.
core
A Two-Dimensional Electronically-Steerable Array Antenna for Target Detection on Ground [PDF]
, 2011 Target-detection with a proof-of-concept electronically-steerable array (ESA) antenna is demonstrated in this paper. First, the clutter level is investigated by using vertically-and horizontally-polarized electric fields.
Chen, Kenle +9 more
core +2 more sources
Beamforming for a Fast Scanning Phased Array Weather Radar [PDF]
, 2023 At the airports, fast-scanning phased array radars are used to detect point-like targets, e.g., birds and drones. However, these radars do not possess Doppler processing and thus are not used for observation of the weather targets like precipitation ...
Gîrdianu, Alexandru (author) +3 more
core +1 more source
Development of RF Hardware and Point Cloud Processing Method for Phased Array Millimeter Wave Radar
IET Signal ProcessingThe development of smart transportation has raised the demand for perception and detection of vehicle targets on the road, and compared to traditional methods, such as video cameras, millimeter wave radar applications are becoming increasingly widespread.
Zihang Yan +3 more
doaj +1 more source