Design and Simulation of a Microstrip 16x16 Butler Matrix for NR-IFF Radar Application

In this paper, a new microstrip design for the 16x16 Butler matrix is presented. It is well-known that as the number of input/output ports of the Butler matrix increases, so does the number of internal crossovers and thus the complexity of the whole structure increases impractically. Therefore, most reports have been limited to the design and realization of 4x4 and 8x8 Butler matrices. However, in this paper and through the relocation of input/output ports and also by using a two-layer substrate, a new 16x16 Butler matrix is designed to be used in a Non-Rotating IFF radar for the commutation of the active sector of its cylindrical antenna array.