Submillimeter-Wave Transceiver Chip Tunes Across 70-GHz Bandwidth
Researchers from the Institute of Microelectronics and Integrated Circuits, Universitat der Bundeswehr, Muenchen, Germany, and Infineon Technologies, Neubiberg, Germany, reported on a single-chip transceiver with on-chip antennas and continuous frequency coverage from 305 to 375 GHz that’s well-suited for high-data-rate wireless communications. The integrated circuit includes a push-pull voltage-controlled oscillator (VCO), frequency mixer, intermediate-frequency (IF) amplifier, and three-stage power amplifier in addition to the integrated antennas.
The transceiver demonstrates effective isotropic radiated power (EIRP) of +18.4 dBm at 343 GHz with phase noise of −79 dBc/Hz offset 1 MHz from the carrier. Intermediate-frequency (IF) conversion gain is 28 dB with a fundamental mixer frequency-conversion architecture.
The submillimeter-wave transceiver IC is fabricated using a 130-nm silicon-germanium (SiGe) BiCMOS semiconductor technology. The VCO handles the frequency mixing. It provides fundamental-frequency and doubled-frequency outputs, which are used with the frequency mixer, and a divide-by-64 on-chip divider as part of the frequency-conversion plan.
Separate on-chip rectangular patch antennas are used for the transmit and receive functions. These are rectangular patches with multiple metal layers and a metal ground plane for optimal radiation efficiency. They are formed by combining two quarter-wavelength resonant sections to form a half-wavelength radiating patch. An array of viaholes is used between the metal layers and the ground plane with a ground ring surrounding the patch for consistent performance. Using on-chip antennas at these high frequencies is more efficient than the high losses suffered by external antennas at such high submillimeter-wave frequencies.
The patch antenna was simulated with several modeling software tools, including the three-dimensional (3D) ANSYS High Frequency Structure Simulator (HFSS) electromagnetic (EM) simulation software and the 3D planar EM simulation software from Sonnet Software, which yielded similar results. For testing, the transceiver IC was mounted to a two-sided printed-circuit board (PCB) with a brass plate attached to the PCB using conductive epoxy glue to help with the cooling.
See “Fully Integrated Single-Chip 305-375-GHz Transceiver With On-Chip Antennas in SiGe BiCMOS,” IEEE Transactions on Terahertz Science and Technology, Vol. 8, No. 2, May 2018, p. 329.
