Reception of Signals from a Distant Transmitting Half-Wave Dipole Excited by aSingle-Cycle Sinusoid

摘要

Characteristics of the time-dependent received voltage across the terminals of athin dipole situated in the radiation zone of a thin transmitting dipole excited by a single-cycle sinusoidal voltage are investigated. In order to study this problem analytically, the zero-order approximate solution for the currents along the antennas in the frequency domain is used. Each of the four distinct incident electric field pulses induces four distinct (although overlapping) voltage pulses through the discontinuities of the receiving dipole antenna. When these two dipoles are mutually at the broadside of the other, the time duration of the incident electric field and the induced received voltage are lengthened by 1.5 cycles and up to 2 cycles respectively. It is observed that the time variation of the induced received voltage is smoother than the inducing (or incident) electric field. This shows that the receiving dipole behaves like an integrating circuit. Unlike a CW field, the spectrum of a short pulse incident electric field as well as the received voltage have peak values at frequencies higher than the carrier frequency fo of the exciting single-cycle sinusoid. Both the transmitting and the receiving dipoles attenuate lower frequencies of the spectra of the exciting single-cycle sinusoidal voltage. Ultra wideband antenna.