A 3.5-to-6.2-GHz Mixer-First Acoustic-Filtering Chipset with Mixed-Domain Asymmetric IF and Complex BB Recombination Achieving 170 MHz BW and +27 dBm IIP3 at $1\times \text{BW}$ offset

This paper presents a 3.5-to-6.2-GHz high-linearity mixer-first superheterodyne receiver chipset that utilizes gigahertz intermediate-frequency (IF) acoustic filters and a Weaver-like mixed-domain recombination architecture. The proposed mixed-domain recombination architecture enables a high IF (2.6 GHz) with a wide (170 MHz) instantaneous bandwidth (BW) and reduces the number of IF lossy passive components. Leveraging inherent quadrature down-conversion in the IF receiver, we adopt complex baseband signal processing to compensate in-phase and quadrature mismatch. Also, we identify that the IF integrated transformer loss is asymmetrical with respect to primary and secondary winding quality factors, and hence utilize stacked transformers for low loss and compact size. The chipset is fabricated using a 65-nm CMOS process and demonstrates, in measurement, an out-of-band IIP3 of +27 dBm at
$\mathrm{1}\times \text{BW}$
offset with a 9.7-dB NF at 3.5-GHz RF.