TY - JOUR
T1 - Reception Power Pattern of Distributed Absorbers in Focal Plane Arrays
T2 - A Fourier Optics Analysis
AU - Llombart, Nuria
AU - Dabironezare, Shahab Oddin
AU - Carluccio, Giorgio
AU - Freni, Angelo
AU - Neto, Andrea
N1 - Accepted Author Manuscript
PY - 2018/8/1
Y1 - 2018/8/1
N2 - Passive imaging cameras at millimeter and submillimeter wavelengths are currently entering a new era with the development of large format arrays of direct detectors. Several of these arrays are being developed with bare absorbing meshes without any antenna coupling (lens or horn) structures. The design of such arrays is typically done resorting to geometrical considerations or basic broadside plane wave incidence analysis. This paper presents a spectral technique for the analysis of such focal plane arrays in reception using Fourier Optics, which is valid also for moderately skewed incident angles. The analysis constitutes a step improvement with respect to previously used methods by providing an accurate and efficient way to estimate the point-source angular response and the throughput from a distributed incoherent source of an absorbing mesh in the focal plane of a quasi-optical component (e.g. a parabolic reflector or lens). The proposed technique is validated with full-wave simulations. After presenting the analysis, the paper compares the performance of arrays of bare absorber in the focal plane of a quasi-optical component to those of corresponding antenna based arrays. It is found that absorbers lead to a comparable trade-off, in terms of spill-over and focusing efficiency, only for very tight samplings. For larger samplings, the focusing efficiency of absorbers is significantly lower than the one for antennas.
AB - Passive imaging cameras at millimeter and submillimeter wavelengths are currently entering a new era with the development of large format arrays of direct detectors. Several of these arrays are being developed with bare absorbing meshes without any antenna coupling (lens or horn) structures. The design of such arrays is typically done resorting to geometrical considerations or basic broadside plane wave incidence analysis. This paper presents a spectral technique for the analysis of such focal plane arrays in reception using Fourier Optics, which is valid also for moderately skewed incident angles. The analysis constitutes a step improvement with respect to previously used methods by providing an accurate and efficient way to estimate the point-source angular response and the throughput from a distributed incoherent source of an absorbing mesh in the focal plane of a quasi-optical component (e.g. a parabolic reflector or lens). The proposed technique is validated with full-wave simulations. After presenting the analysis, the paper compares the performance of arrays of bare absorber in the focal plane of a quasi-optical component to those of corresponding antenna based arrays. It is found that absorbers lead to a comparable trade-off, in terms of spill-over and focusing efficiency, only for very tight samplings. For larger samplings, the focusing efficiency of absorbers is significantly lower than the one for antennas.
KW - Quasi optics
KW - Radiometry
KW - Reflector antenna feeds
KW - Submillimeter wave detectors
UR - http://www.scopus.com/inward/record.url?scp=85050964904&partnerID=8YFLogxK
U2 - 10.1109/TAP.2018.2862359
DO - 10.1109/TAP.2018.2862359
M3 - Article
AN - SCOPUS:85050964904
SN - 0018-926X
VL - 66
SP - 5990
EP - 6002
JO - IEEE Transactions on Antennas and Propagation
JF - IEEE Transactions on Antennas and Propagation
IS - 11
ER -