A Grating-Based Circular Polarization Duplexer for Submillimeter-Wave Transceivers

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

“…Fig. 12(a) and (b) shows photographs of the two front-end configurations on an aluminum plate that is mounted onto a radar test-bench nearly identical to that reported in [1] and [3]. That radar's subreflector illuminating the main aperture was removed, leaving only a parabolic feed reflector and a flat grating [ Fig.…”

“…1(b)], which radiates and detects circularly polarized beams of opposite handedness with near-perfect efficiency and excellent transmit/receive (T/R) isolation exceeding 90 dB [3]. While this all-quasi-optical grid/grating duplexer overcomes most of the 6-dB beam splitter loss, it still requires a polarizing grid that, like the beam splitter, is delicate and difficult to integrate with a densely spaced focal plane array of transceivers.…”

Enabling Technologies for High Performance Millimetre and Sub-millimetre Wave Radar

“…For linear cross-polarised operation a wire grid polariser offers excellent performance, for example better than -80 dB at 94 GHz (at the limit of VNA measurement) [14]. For circularly polarised operation variations on quarter-wave plates (both transmission and reflection forms) may be used including gratings [15]. Polarising interferometers may also be used such as the Martin-Puplett interferometer and the frequency-selective polariser (FSP) based duplexer [16].…”

Circular polarization analyzer with polarization tunable focusing of surface plasmon polaritons

“…The differential detection of the intensities of the two focuses can be instructive to develop CPAs with high efficiency and low noise. Compared with the traditional method for distinguishing LCP and RCP THz waves 25 and chiral THz devices based on metamaterial, 26,27 the proposed CPA is compact and easy to fabricate. Although the proposed scheme is verified in the THz range, the designed CPA can be extended to other wavebands (visible, infrared and microwave) by scaling the parameters (s, d, w, and l) of the slit.…”