A 1.42-mm2 0.45-0.49 THz Monostatic FMCW Radar Transceiver in 90-nm SiGe BiCMOS

• Published in: IEEE transactions on terahertz science and technology 2022-11, Vol.12 (6), p.592-602
• Main Authors: Mangiavillano, Christoph, Kaineder, Alexander, Aufinger, Klaus, Stelzer, Andreas
• Format: Article
• Language: English
• Subjects: CMOS; Continuous radiation; Couplers; Down-converters; Emitters; Frequency multipliers; Frequency-modulated continuous-wave (FMCW) radar; Insertion loss; mixer; Mixers; multiplier; on-chip antenna; Patch antennas; Radar; Radar antennas; Radar measurement; Receiving antennas; SiGe bipolar CMOS (BiCMOS); Signal to noise ratio; Silicon germanides; Single sideband transmission; terahertz (THz); Terahertz frequencies; Transceivers; Transmitting antennas
• ISSN: 2156-342X; 2156-3446
• DOI: 10.1109/TTHZ.2022.3208069

Terahertz frequency-modulated continuous-wave (FMCW) radars operating close to and beyond f_{\max} often use gain-enhancing lenses to improve the signal-to-noise ratio. A compact single-chip transceiver benefits a lot from the alignment of the lens to the single on-chip antenna in a monostatic system. The typically required coupler for monostatic operation adds an insertion loss. The proposed multiply-by-24 frequency multiplier-based FMCW radar transceiver removes the coupler and integrates both the final 0.48-THz doubler and subharmonic downconverter into a single common collector push-push doubler. The common emitter is the only port at 0.48 THz in this monostatic system, feeding the top-metal on-chip patch antenna using a direct via stack. The 1.42-mm 2 monostatic FMCW radar transceiver, manufactured in a 90-nm SiGe bipolar CMOS (BiCMOS) technology with an f_\text{T}/f_{\max} of 300/480 GHz consumes 85 mA when connected to a 3.3-V supply. At 0.48 THz, the output power is -12 dBm and the single-sideband noise figure is measured as 36.3 dB. FMCW radar measurements with operating bandwidths of up to 55 GHz, corresponding to a theoretical range resolution of 2.73 mm are performed using an on-board frequency source of a credit card sized demonstrator.