LPDA Calibration Using an UAV for Synthesizing UWB Impulses

In this letter, the possibility of synthesizing ultra-wideband (UWB) impulses with a conventional log-periodic dipole antenna (LPDA) mounted on a quadrotor unmanned aerial vehicle (UAV) was demonstrated. The formation of impulses using LPDA (bandwidth from 427 MHz to 1.01 GHz) with duration of 1.9 ns, containing one period of field oscillations, became possible due to compensation of amplitude and phase-frequency distortions introduced by the antenna into radiated and received impulses. Compensation for these distortions was carried out by the inverse filtering method after calibrating the antenna-feeder path at various heights with the UAV hovering above the reference reflector (brass mesh). The conductive carbon elements of the UAV, located in the near field of the antenna, are indirectly taken into account during the calibration of antenna-feeder path parameters and do not introduce significant distortions into the generated impulses. The suggested method of synthesizing UWB impulses can find application in environmental remote sensing and can also be used to sharpen the fronts of impulses radiated\received with LPDA.