EM RECIPROCITY BASED CALCULATION OF TD RADIATION CHARACTERISTICS

A systematic use of the electromagnetic (EM) reciprocity theorem of the time‐convolution type results in the (self‐)reciprocity relation facilitating the construction of equivalent Kirchhoff's network antenna representations. This relation can also be applied to calculating the time domain (TD) EM radiation characteristics of an antenna system from its load response to a uniform EM plane wave in reception. The transmitting and receiving states of one and the same wire antenna are mutually interrelated. In the transmitting situation, the antenna is activated by a voltage pulse applied in its excitation gap. Consequently, the antenna radiates into its embedding, where people may calculate the TD far‐field radiated amplitude at a given angle of observation. The TD radiation characteristics can be calculated either from the electric‐current distribution along the radiating wire or, alternatively, using the induced load voltage and current quantities in the receiving state in which the antenna is irradiated by an impulsive EM plane wave.