A design of multichannel transmission filter at microwave is proposed. It is based on the use of the finite plasma photonic crystal operating at frequency below the plasma frequency. We consider a design structures of (AB)qA, where A is the dielectric material, B is the plasma layer, and q is the number of periods. It is found that the number of channels is equal to q-1. We show that the locations such multiple channels are in the pass band of the infinite plasma-dielectric photonic crystal. The idea of such design is thus to engineer the photonic pass band, which is fundamentally different from the usual design by engineering the photonic stop band like the multilayer Fabry-Perot transmission filter. The physical mechanism of multiple channels is also discussed.
Strong improvement in the photonic stop-band edge sharpness of a lithium niobate photonic crystal slab