On the Fundamental Relationship Between the Transmitting and Receiving Modes of General Antenna Systems: A New Approach

The goal of this letter is to set the stage for a general analysis of the fundamental interrelationship between the transmitting and receiving modes of antenna systems by working within the proposed framework of the antenna current Greens function formalism. A new reciprocity theorem is derived and analyzed in order to delimit the exact relation between the two operational modes. Our approach is different from the conventional methods found in literature, which take their point of departure in the classical Lorentz reciprocity theorem applied directly to sets of sources and fields. Instead, in this work the Lorentz reciprocity theorem is applied to the antenna system current Greens function itself. The new reciprocity theorem is used to construct the antenna current Greens function rigorously in the sense of distribution theory. Finally, the traditional methods are compared to the approach proposed by the antenna current Greens function formalism.