analysis_of_photonic_bandgap_surfacesAPPLICATION NOTE ANALYSIS OF PHOTONIC BANDGAP SURFACES USING ANSOFT HFSS T Fig. 1 Dielectric rod PBG crystal with waveguide simulator cell defined (Γ-X transmission direction). w he microwave industry recently foundnew uses for concepts familiar to solidstate designers in the form of photonic band gap (PBG) constructions. PBG constructions offer the ability to produce substrates, ground planes and other structures, which have a forbidden frequency range, or band gap, that does not support electromagnetic waves. This behavior arises from some form of periodicity, in either material characteristics or in a circuit layer, that reacts to electromagnetic fields in much the same way that crystal lattice structures do. PBG surfaces ― which often become magnetic conductors within their band gap……