A C-band broadband ortho-mode transducer for radioastronomy polarimetry

作者：Ferreira Ivan S; Tello Camilo; Bergano Miguel^*; Villela Thyrso; Barbosa Domingos; Smoot George F

来源：SpringerPlus, 2016, 5(1): 2069.

DOI：10.1186/s40064-016-3761-5

• Radioastronomy
• Polarimeters
• Ortho-mode transducers

Background: We describe the design, the construction and performance of a narrow band ortho-mode transducer, currently used in the 5 GHz polarimetric receiver of the Galactic Emission Mapping project.
Results: The ortho-mode transducer was designed to achieve a high degree of transmission within the 400 MHz of the GEM band around the 5 GHz (4.8-5.2 GHz). It is composed of a circular-to-square waveguide transition, a septum polarizer, a thin waveguide coupler and a smooth square-to-rectangular waveguide transition with custom waveguide bends to the output ports.
Conclusion: Our simulations and measurements show a very low level of cross-polarization of about -60 dB and a good impedance match for all three ports (S11; S22; S33 < -30 dB) with only 0: 25 dB of insertion loss offset across the 400 MHz (4.8-5.2 GHz) of the reception bandwidth.

• 出版日期2016-12-2