@article{24227,
  abstract     = {{This work describes an electrical interferometer for contactless permittivity measurements working at 120 GHz. It was fabricated in a 130 nm SiGe process featuring an ft and fmax of 240 and 330 GHz. The on-chip system contains a 120 GHz VCO with a tuning range of 7 GHz featuring a divide-by-64 circuit to enable external PLL operation. The subsequent buffer provides 7 dBm of output power at 120 GHz. Additionally, the IC contains high-precision and high-resolution phase shifters based on a slow-wave transmission line approach with digital control for direct readout ability. A 120 GHz LNA with 17 dB gain and a power detector to provide DC output signals were realized on chip. It enables sample emulation capability by phase shift inducement in the measurement as well as a reference transmission line. In terms of phase detection, the system shows a sensitivity of 907.36 MHz/°.}},
  author       = {{Wessel, Jan and Schmalz, Klaus and Scheytt, Christoph and Kissinger, Dietmar}},
  issn         = {{1558-1764}},
  journal      = {{IEEE Microwave and Wireless Components Letters}},
  number       = {{2}},
  pages        = {{198--200}},
  title        = {{{A 120-GHz Electrical Interferometer for Contactless Permittivity Measurements With Direct Digital Read-Out}}},
  doi          = {{10.1109/LMWC.2017.2649384}},
  volume       = {{27}},
  year         = {{2017}},
}