Compact Duplexing for a 680-GHz Radar Using a Waveguide Orthomode Transducer

作者：Leal Sevillano Carlos A^*; Cooper Ken B; Decrossas Emmanuel; Dengler Robert J; Ruiz Cruz Jorge A; Montejo Garai Jose R; Chattopadhyay Goutam; Rebollar Jesus M

来源：IEEE Transactions on Microwave Theory and Techniques, 2014, 62(11): 2833-2842.

DOI：10.1109/TMTT.2014.2359636

• Duplexer
• orthomode transducer
• terahertz radar

A compact 680-GHz waveguide orthomode transducer (OMT) and circular horn combination has been designed, tested, and characterized in a radar transceiver%26apos;s duplexer. The duplexing capability is implemented by a hybrid waveguide quasi optical solution, combining a linear polarization OMT and an external grating polarizer. Isolation between the OMT%26apos;s orthogonal ports%26apos; flanges was measured with a vector network analyzer to exceed 33 dB over a %26gt;10% bandwidth between 630 and 710 GHz. Calibrated Y-factor measurements using a mixer attached to the OMT ports reveal losses through the transmit and receive paths that sum to an average of 4.7 dB of two-way loss over 660-690 GHz. This is consistent with radar sensitivity measurements comparing the new OMT/horn with a quasi-optical wire grid beam splitter. Moreover, the radar performance assessment validates the OMT as a suitable compact substitute of the wire grid for the JPL%26apos;s short-range 680-GHz imaging radar.

• 出版日期2014-11