AbstractUltra‐wideband (UWB) antenna is indispensable in impulse radar that transmits and receives short electromagnetic pulse signals and preserves the waveform well. Phased array antenna systems cannot meet the demand of the system. Optical true‐time delay techniques open the possibility of ultra‐wide bandwidth antenna systems, while at the same time meeting the stringent weight and size requirements. Continuously tunable true‐time delay techniques can provide continuous beam scanning. With advanced optoelectronic technique, fast wavelength tuning speed is possible. To detect and track moving‐target [Bi and Ren, Prog Electomagn Res 87 (2008), 15–41)], UWB time‐domain antenna array beam scanning is studied in this article. First, the theory of time‐domain antenna array scanning is analyzed, some useful conclusions are achieved. Then, an experiment system of UWB time‐domain antenna array scanning is built, which includes an antenna array, fiber‐optic true‐time delay device, and other equipments. Finally, the theoretical and experimental results combined to are made to validate the theory of UWB time‐domain antenna array beam scanning. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1110–1112, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25102