Improvement of planar antenna efficiency when integrated with a millimetre-wave photonic crystal

In this work a silicon-based coplanar waveguide (CPW)-fed slot dipole antenna has been integrated with a silicon micromachined three-dimensional woodpile photonic bandgap crystal (PBG) in the W-band regime (67-110GHz). A slot dipole antenna optimired for operation at 94GHz shows significant radiation through the subsirate as expected. Combination of the slotline antenna and the PEG shows a strong interaction between the two, with complete suppression of backside radiation. In addition, the resonant frequency of the 94 G l h antenna was found to he dependent on its positioning on the PEG. Also shown in this work is the experimental optimisation of the slotline dipole geometry to produce resonant behaviour at 94 GHz when placed on the PBG. As a consequence, the radiation efficiency of the combined antennalPBG is significantly enhanced at 94 GHz.