CAD of Asymmetric Ortho-Mode Transducers for Single- and Dual-Band Linear Polarization with Simple Building-Blocks

摘要

Asymmetric ortho-mode transducers (OMTs) are key elements in compact antenna feeds working in orthogonal linear polarizations with moderate bandwidth. This paper presents the computer aided design (CAD) of these devices using configurations as basic as possible for operation in single and dual frequency Ku/K bands. The proposed structures have simple building blocks, avoiding elements as metallic septa which may be difficult to manufacture or to control accurately at highfrequencies. Two different scenarios for linear polarization are addressed. The first one is a single band design with both polarizations working at the same frequencies. In the second one, low-pass filter sections at the axial port are introduced into the ortho-mode transducer to cope with two well separated frequency Ku/K sub-bands, one for each polarization.