A 300-GHz Band Sliding-IF I/Q Receiver Front-End in 130-nm SiGe Technology

This work presents a sliding-IF mixer-first IQ receiver front-end, in 130 nm SiGe BiCMOS technology with <inline-formula> <tex-math notation="LaTeX">${f_{t}}/{f_{\mathrm { max}}}$ </tex-math></inline-formula> of 300 GHz/450 GHz, operating in 300 GHz band. For near-<inline-formula> <tex-math notation="LaTeX">$f_{\mathrm { max}}$ </tex-math></inline-formula> operation, the sliding-IF architecture eliminates the need for the local oscillator (LO) frequency to be the same as the carrier frequency. Consequently, the power consumption of the LO chain is significantly reduced with carefully optimized multiplier chain. Signal amplification is performed at the IF stage. LO frequency at two thirds and one third of the carrier frequency is generated, from an external 50 GHz LO signal using on-chip frequency doublers for RF and I/Q mixers, respectively. The receiver provides 15.2 dB of conversion gain, input-referred compression point of &#x2013;17 dBm and single sideband noise figure of 29.5 dB at 310 GHz. The 3-dB RF and BB bandwidths are measured to be 26 GHz and 10 GHz, respectively. Despite operating at 0.69x<inline-formula> <tex-math notation="LaTeX">$f_{\mathrm { max}}$ </tex-math></inline-formula>, the receiver front-end operates with 16-quadrature amplitude modulation (QAM) modulation with 4 GHz, 64-QAM with 2 GHz and 256-QAM with 0.5 GHz wide modulated signal centered at low-baseband frequency with 8.2%, 5.5%, and 2.7% error vector magnitude (EVM), respectively. In low gain mode, the receiver offers a 10 dB improvement in the dynamic range with a 30% reduction in power consumption in the signal chain, which makes it one of the most energy efficient receiver front-ends in its class.