Wideband Dual-Mode Waveguide Bends for Linear and Circular Polarizations

This paper demonstrates the feasibility of very compact and broadband square waveguide bends able to transmit both linear and circular polarizations. A careful control of the bend profile for dual-linear polarization or the use of a new septum-polarizer-like geometry for dual-circular polarization allows to reach full band operation ~34% in the first case and broadband operation ~20% for the second application. Experimental validations show excellent agreement with the theoretical predictions thus effectively extending the previous bandwidth limitations.