Ultra-Wideband, Short-Pulse Electromagnetics 6 pp 299-315 | Cite as
Location and Orientation of Electrically Small Transmitting and Receiving Antenna Pairs with Common Linear Polarization and Beam Direction for Minimal Mutual Coupling
Abstract
In measurements of electromagnetic scattering (such as by a radar), one needs to transmit (from an antenna) an incident wave which in turn scatters from the object of interest (the target), the scattered field being sensed in turn via some receive antenna. The far-field amplitude decays with distance r proportional to r -1. Similarly the scattered far field is proportional to r -1 for a total decay of the received signal (voltage) proportional to r -2. If the same antenna is used for both transmission and reception (monostatic), there is then a problem in accurately measuring the scattered signal in the presence of the transmitted signal. One can use time gating to separate these if the time duration is shorter than the round-trip transit time to the target. So a short pulse in transmission offers some advantages. However, the transmitted signal should decay sufficiently rapidly in the source and antenna, noting the possibility of small reflections and resonances, which carry out in time. The decay should be sufficiently rapid such that at the round-trip time from the target the signal is negligible compared to the scattered signal in the antenna.
Keywords
Electric Dipole Magnetic Dipole Beam Direction Scattered Signal Mixed TermPreview
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