Micromachines (Oct 2021)

Graphene/AlGaN/GaN RF Switch

  • Yevhen Yashchyshyn,
  • Paweł Bajurko,
  • Jakub Sobolewski,
  • Pavlo Sai,
  • Aleksandra Przewłoka,
  • Aleksandra Krajewska,
  • Paweł Prystawko,
  • Maksym Dub,
  • Wojciech Knap,
  • Sergey Rumyantsev,
  • Grzegorz Cywiński

DOI
https://doi.org/10.3390/mi12111343
Journal volume & issue
Vol. 12, no. 11
p. 1343

Abstract

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RF switches, which use a combination of graphene and two-dimensional high-density electron gas (2DEG) in the AlGaN/GaN system, were proposed and studied in the frequency band from 10 MHz to 114.5 GHz. The switches were integrated into the coplanar waveguide, which allows them to be used in any system without the use of, e.g., bonding, flip-chip and other technologies and avoiding the matching problems. The on-state insertion losses for the designed switches were measured to range from 7.4 to 19.4 dB, depending on the frequency and switch design. Although, at frequencies above 70 GHz, the switches were less effective, the switching effect was still evident with an approximately 4 dB on–off ratio. The best switches exhibited rise and fall switching times of ~25 ns and ~17 ns, respectively. The use of such a switch can provide up to 20 MHz of bandwidth in time-modulated systems, which is an outstanding result for such systems. The proposed equivalent circuit describes well the switching characteristics and can be used to design switches with required parameters.

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