Evaluation of the Radiated Electric Field of a Tri-band Circularly Polarized Antenna Integrating a Ferrite Material using Infrared Thermography

This paper evaluates the radiated electric field (E-field) intensity of a tri-band circularly polarized antenna using infrared thermography (IRT). The radiated fields at each operational band are measured and compared with electromagnetic simulations. We demonstrate how IRT measurements’ fast, non-invasive nature enables rapid validation of the antenna’s operating modes. Additionally, the antenna performance is analyzed for the case of biased and unbiased ferrite, demonstrating how ferrite substrates allow for obtaining radiation characteristics unavailable on conventional dielectric substrates. Furthermore, we show how a proper interpretation of the E-field cartography obtained at a very short distance from the antenna provides insight into the radiated polarization state and gives enough information to evaluate the on-axis gain of the antenna.