Defect mode in microwave waveguide Bragg structures with metal pins

A waveguide Bragg structure containing equidistant cylindrical pins that are galvanically coupled to a wide wall of the waveguide is used to implement frequency response functions characterized by the presence of a band gap. Characteristics of a defect mode of the microwave photonic crystal with a pin element as a defect with an $n$–$i$–$p$–$i$–$n$ structure with controlled conductivity placed in the capacitive gap are experimentally studied and calculated. Controlled reflectance of a microwave signal with a dynamic range of greater than 50 dB is obtained at the frequency of the defect mode.