Relevance. In recent decades, a new direction of radar has emerged. Temporarily and spatially limited signals with different types of envelope and the wide width of the spectrum have found their application here. The use of such ultra-wideband (UWB) electromagnetic pulses in subsurface sounding requires changes in the principles of designing of equipment for radar systems, including receiving antenna systems. The urgent task remains to build compact pulsed UWB receiving antennas that have high sensitivity and do not distort the shape of the received signal. As such antennas, ferrite loop antennas can be used. The use of ferrite rods in receiving antennas allows to increase their sensitivity, leaving the dimensions small. Methods of designing UWB pulsed ferrite antennas are still in the initial stage of their development and require comprehensive fundamental and applied research.
The purpose of work is to investigate the shape of the induced current in the receiving antenna consisting of a ferrite rod with a loop of a conductor when the antenna is excited by a pulsed electromagnetic field of the form of the most common carrier-free signals.
Methods. To calculate the currents induced in a conductor that encloses a ferrite rod, the finite difference time domain method (FDTD) was used.
Results. There were revealed the relationships between optimal from the point of view of effective undistorted signal reception, the electrodynamic parameters of the ferrite element of the antenna, and the time-frequency parameters of the exciting pulse field in the form of the most common carrier-free functions, namely, the Gaussian functions, the 1st and 2nd derivatives in time of the Gauss function.
Conclusions. The parameters of the ferrite element of the pulsed receiving antenna and the carrier-free exciting pulsed electromagnetic field, at which the receiving antenna in the form of a ferrite rod with a loop of conductor provides sensitive undistorted reception of the pulse signals were determined.
A Large Aperture UWB Antenna Array for Real Beam Radar Imaging
