Experimental measurements of the microwave properties of co‐axial 2D Bragg structures and 3D PIC code MAGIC simulations of these same structures are reported. Two‐dimensional coaxial Bragg structures, which can be obtained by providing shallow bi‐periodic corrugation of either the inner or the outer conductor, or by coating the conductors with dielectric material having bi‐periodic refractive index, are recognized as having useful properties for applications in high power microwave electronics. The influence of distributed RF power losses and the parameters of the corrugation on the transmission coefficient and the field distribution inside the 2D Bragg structure were studied and the results obtained are presented and discussed. The simulations of the RF field evolution inside the 2D Bragg coaxial structure using the 3D PIC code MAGIC were undertaken. For the experimental studies several different co‐axial 2D Bragg structures were designed and constructed. A microwave vector network analyzer was used to measure the RF properties of the co‐axial 2D Bragg structures. The transmission coefficient and RF fluxes associated with the near cut‐off modes of a coaxial waveguide were measured and compared with the MAGIC simulations. Good agreement was obtained between the experimental measurements and the MAGIC simulations, which has enabled the suitability of 2D Bragg structures in different applications such as input and output mirrors of a cavity, narrow band filters, active RF sources and pulse compressors to be ascertained. © 2003 American Institute of Physics