Characterizing Physically Transient Antennas

A physically transient (PT) antenna changes its properties over a predefined lifespan due to its time-varying dimension and shape. The PT antenna technology has attracted much attention in the areas of biomedical, environmental, and military applications. It is also a fundamental building block of transient communications, where certain components of the communication link are degradable. In this paper, we revisit the classical antenna figures-of-merit such as resonant frequency and input impedance, and propose a novel immersion-time-dependent description framework to characterize this class of antennas, taking into account their PT nature. Subsequently, we present the notions of average and outage antenna characteristics over all realizations of the random antenna degeneration process occurring in a solvent. To the best of our knowledge, this is the first attempt in the open literature to quantify stochastically the properties of a PT antenna. Finally, we look into the specific application scenario of a degradable circular patch to demonstrate the principles and applicability of the proposed methodology. The analytical approach may also find important applications in the design and evaluation of other PT wireless devices and systems.