PHOTONIC BAND GAP MATERIALS FOR MILLIMETER WAVES

RESEARCHERS ARE EXTENDING PHOTONIC BAND GAP MATERIALS FROM THE MICROWAVE FREQUENCY BAND INTO THE MILLIMETER WAVE FREQUENCY BAND. THEY HAVE IDENTIFIED POTENTIAL NEW PRACTICAL FABRICATION TECHNIQUES FOR MAKING THESE MATERIALS WITH PHOTONIC BAND GAP NEAR 100 GHZ. THE MATERIALS WOULD EMBODY A HIERARCHAL STRUCTURE CONSISTING OF A HIGH INDEX OF REFRACTION COMPOSITE WITH FINE MICROSTRUCTURE ON THE SCALE OF MICRONS WHICH IS FABRICATED INTO A COARSER STRUCTURE HAVING A PERIODIC VARIATION OF INDEX OF REFRACTION ON THE SCALE OF A MILLIMETER. THE PROJECT IS INVESTIGATING THESE FABRICATION TECHNIQUES AND CHARACTERIZING THE ELECTROMAGNETIC PROPERTIES OF THE RESULTANT MATERIALS. PHOTONIC BAND GAP MATERIALS HAVE BEEN SHOWN TO HAVE EXTRAORDINARY PROPERTIES FOR APPLICATIONS IN THE MICROWAVE RANGE. IF THESE PROPERTIES CAN BE EXTENDED TO THE MILLIMETER WAVE RANGE, THEY WOULD MAKE POSSIBLE MILLIMETER WAVE SYSTEMS IN WHICH THE DESIGNER HAS AN UNPRECEDENTED DEGREE OF CONTROL OVER RADIATION. IT WILL ALLOW DIELECTRIC WAVEGUIDE TECHNOLOGY AND MMIC TECHNIQUES TO BE EMPLOYED AT MILLIMETER WAVE FREQUENCY. THE RESULT WOULD BE PRACTICAL SYSTEMS WITH GREATLY IMPROVED CAPABILITIES AND WITH THE POTENTIAL FOR HAVING CONSIDERABLY LOWER MMW COMPONENT COST.