Wideband turnstile junction coaxial waveguide orthomode transducer

Abstract

A wideband turnstile junction coaxial waveguide orthomode transducer (OMT) is presented in this paper, featuring coaxial waveguide input and orthogonal rectangular waveguide outputs. It primarily comprises of a turnstile junction, bending stepped impedance transformers and power combiners. The symmetrical geometry helps achieve wide operating bandwidth and balanced output phases. The OMT covers the whole Ku band from 12 to 18 GHz, which aims at wideband dual‐polarized signal combination and separation within coaxial‐type multi‐band antenna systems. An experimental prototype is manufactured and the measured results confirm that the reflection coefficient is lower than −15 dB within the whole band, and the port isolation is better than 35 dB. Turnstile junction coaxial waveguide OMTs can be adopted widely in circular/coaxial waveguide hybrid feeding networks for multi‐band satellite communication/remote sensing antenna systems.

Computer‐aided development and experimental investigation of a double‐ridged orthomode transducer for modern satellite and space communication systems

“…Besides, an OMT can be used as a separate microwave waveguide device without a polarizer, if the operation of an antenna system at circular polarizations is not required. Several main types of OMTs were analyzed in scientific articles and conference papers 74–92 . Let us compare some of the practical designs of OMTs.…”

“…A combination of a waveguide polarization converter [67][68][69][70][71][72][73] 73 and an orthomode transducer (OMT) [74][75][76][77][78][79] provides possibility of wideband functionality of an antenna system operating at two circular polarizations simultaneously. Besides, an OMT can be used as a separate microwave waveguide device without a polarizer, if the operation of an antenna system at circular polarizations is not required.…”

“…Several main types of OMTs were analyzed in scientific articles and conference papers. [74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91][92] Let us compare some of the practical designs of OMTs.…”

Ultra‐compact taper branching orthomode transducer

“…However, the presence of a higher order mode TM 01 often limits the OMT bandwidth. 3 The symmetric structure [4][5][6][7][8][9][10] is an effective method to obtain the wideband solutions (>70%). Although these wide band designs can achieve high performance by avoiding the excitation of higher order modes, they must be implemented with complex and bulky structure due to the requirement of utilizing 2-fold symmetries.…”