A 225 GHz Circular Polarization Waveguide Duplexer Based on a Septum Orthomode Transducer Polarizer

作者：Leal Sevillano Carlos A^*; Cooper Ken B; Ruiz Cruz Jorge A; Montejo Garai Jose R; Rebollar Jesus M

来源：IEEE Transactions on Terahertz Science and Technology, 2013, 3(5): 574-583.

DOI：10.1109/TTHZ.2013.2264317

• Circular polarization
• duplexer
• orthomode transducer
• terahertz

In this paper, we present the modeling and experimental validation of an efficient, compact, and high-isolation waveguide duplexer operating at 225 GHz. While duplexers based on ferrite circulators are key components of many monostatic radar systems, at W-band frequencies and above the performance of waveguide circulators rapidly deteriorates. The design presented here uses a ferrite-free duplexing concept based on transmitting and receiving in orthogonal circular polarizations. The circular polarization is efficiently generated in waveguide using a septum orthomode transducer polarizer, leading to a compact device with a single horn antenna. The complete duplexer is designed using efficient numerical algorithms, resulting in a fabricated device with a measured 10% fractional bandwidth, a return loss better than 20 dB, isolation of 30 dB, and insertion loss below 1 dB.

• 出版日期2013-9