A Low-Power $W$ -Band SiGe-HBT Double-Balanced Up-Conversion Mixer With an Integrated Second-Order IF Low-Pass Filter

A low-power $W$ -band (75–110 GHz) double-balanced up-conversion mixer using a 0.13 $\mu$ m SiGe:C BiCMOS technology with $f_\mathrm{T}/f_\mathrm{max}=250/370~\mathrm{GHz}$ is presented. The mixer includes on-chip transformer baluns at the LO and RF ports for on-wafer characterization. At 91.3 GHz, the active mixer achieves a single sideband (SSB) power conversion gain of 4.1 dB with a 3-dB RF bandwidth (BW) of 30 GHz from 78.1 to 108.3 GHz, covering almost the entire $W$ -band. The linearity performance, characterized by $\mathrm{OP}_{1\mathrm{dB}}$ and $P_{\mathrm{sat}}$ , is 0.6 and 1.8 dBm, respectively while consuming only 11 mW from a 1.8 V supply. Moreover, a second-order IF $LC$ low-pass filter (LPF) with a cutoff frequency of 1.4 GHz is integrated to provide an additional spurious suppression of $\sim$ 12 and $\sim$ 19 dB at the second and third harmonic of the fundamental IF (i.e., 1.25 GHz). The overall chip area, including the IF LPF is 990 $\times$ 540 $\mu$ m (0.53 mm $^2$ ). To the best of authors’ knowledge, the active up-conversion mixer achieves the lowest power consumption along with the highest $\mathrm{OP}_{1\mathrm{dB}}$ / $P_{\mathrm{sat}}$ and 3-dB RF BW reported among all prior published $W$ -band SiGe-HBT up-conversion mixers.