Chessboard Focal Plane Array for a CMOS-Integrated Terahertz Camera

Research output: Contribution to journalArticleScientificpeer-review

Abstract

This article presents the development of a focal plane array (FPA) for terahertz imaging applications with a near diffraction-limited resolution achieved through a very tight sampling of the focal plane. The antenna array is integrated with direct detectors in a 22-nm CMOS technology and operates from 200 to 600 GHz. The tight sampling of the focal plane is realized by using a combination of leaky-wave radiation and a dual-polarized connected array configuration that closely resembles a chessboard. By utilizing both the polarizations in the chessboard design, the number of array elements per unit area is effectively doubled. The geometry of the chessboard array was co-optimized together with that of a silicon elliptical lens to achieve both high aperture efficiency and beam overlap. Measurements in the WR2.2 band of a fabricated demonstrator showed that an aperture efficiency of −4.1 dB was realized at 400 GHz. The average gain roll-off between two diagonally adjacent array elements was measured to be −1.5 dB at 400 GHz. Compared to the reference configuration of an idealized, equivalently sampled hexagonal FPA, the improvement in gain at the edge of coverage yields 1.2 dB, which includes 1.9 dB of ohmic losses in the chessboard array. The agreement between measurements and simulations proved to be within 1 dB from 325 to 475 GHz.

Original languageEnglish
Pages (from-to)704-717
Number of pages14
JournalIEEE Transactions on Terahertz Science and Technology
Volume13
Issue number6
DOIs
Publication statusPublished - 2023

Bibliographical note

Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care
Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.

Keywords

  • Antenna arrays
  • Apertures
  • Cameras
  • CMOS antenna array
  • direct-detector
  • Feeds
  • focal plane array
  • high-resolution imaging
  • Imaging
  • leaky-wave antennas
  • lens antenna array
  • Lenses
  • passive imaging
  • Silicon
  • terahertz
  • ultra-wideband

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