Antenna miniaturization for vehicular platforms using printed coupled lines emulating magnetic photonic crystals

A miniature printed antenna exploiting magnetic photonic crystal (MPC) modes is presented. The MPC mode is typically found in volumetric anisotropic materials and is realized here using a set of coupled printed transmission lines. The printed element is formed by a pair of unit cells, cascaded to realize a circularly periodic structure. To excite the nonreciprocal MPC mode, the coupled microstrip lines are printed on a uniform substrate with magnetic material inserts. A printed and slot (cavity-backed) version of the MPC-based element is designed and constructed. It is found that the cavity-backed version is better suited for reducing platform interactions, thus, avoiding detuning when installed on smaller platforms. Tunable magnetic biasing is also explored to improve functionality. The paper concludes by providing the in situ performance of the cavity-backed and recessed MPC antennas.