Synthesizing of Ultra-Wide Band Impulse by means of a Log-Periodic Dipole Antenna. Case Study for a Radar Stand Experiment

In this work, the approach of ultra-wide band pulses synthesizing is proposed using a broadband low-cost log-periodic dipole antenna and a vector network analyzer. Synthesis of UWB pulse (duration of 2.2ns) became possible due to minimization of antenna dispersion by compensation of amplitude and phase-frequency distortions introduced by the antenna into radiated and received pulse. The method had been developed for a down-looking antenna in a monostatic radar configuration. The antenna return loss was calculated using the model of two-port linear network with S-parameters. To calibrate the model, an original amplitude-phase method was proposed that requires measuring the antenna’s return loss when the antenna is located only at several heights above the reflecting surface (metal sheet). In this case, the antenna return loss in an empty room does not need to be measured. The proposed method for synthesizing UWB pulses does not require changes in the design of the antenna and can be implemented as an additional software calibration of the antenna-feeder path. The proposed method of UWB pulses synthesizing can be implemented using miniature, low-cost vector network analyzers for environment remote sensing from unmanned aerial vehicle using the UWB impulses.