Two-Element Biomimetic Antenna Array Design for Power Extraction / Phase Amplification Tradeoff

Two-element arrays composed of closely-spaced antennas with mutual coupling have recently been investigated in conjunction with electrical coupling networks that amplify the phase difference in the measurements. These systems have biomimetic analogies to the hearing mechanism in small insects that exhibit exceptional direction finding capabilities. Several coupling networks have been considered with varying complexity and performance relative to the fundamental tradeoff between power extraction and phase difference amplification. In this paper we present a general design method that establishes the achievable region for the power extraction/ phase amplification tradeoff, and we present a four-port Pi coupling network that realizes the entire achievable region. An example illustrates the design method for two closely-spaced dipole antennas at 40 MHz.