A Reusable Superheterodyne Dual-Band Down-Conversion Mixer With Hybrid Linearity-Enhanced Technique for 5G Non-Contiguous Multiband NR

This article presents a dual-band high-linearity down-conversion mixer that covers the frequency range of 24–30 and 36–42 GHz and enables 5G millimeter-wave (mm-wave) non-contiguous multiband operations in the major parts of the <tex-math notation="LaTeX">K</tex-math> -and <tex-math notation="LaTeX">$Ka$</tex-math> -bands. A reusable superheterodyne mixer with local oscillator (LO)-reusable technique allows dual-band spectrum shifting. A hybrid linearity-enhanced technique (HLET) is proposed to improve linearity, which combines optimum bias, feedback, and feedforward. On-chip passive edge-coupled or stack-coupled networks are utilized for impedance matching, signal conversion, and compact size. The mixer prototype is fabricated on the 55-nm bulk CMOS process. The proposed mixer achieves the input 1-dB compression point ( <tex-math notation="LaTeX">IP_1\,dB</tex-math> ) of 11.32/11.06/9.85 dBm and third-order input intercept point (IIP3) of 22.8/23.6/20.8 dBm at 28/37/39 GHz. The measured LO-to-RF and LO-to-IF isolation is better than 32.7 and 58.6 dBc. The implementation used is a high-IF topology with 6-GHz IF frequency, which supports additional sideband rejection. The measurement results show that the mixer exhibits high <tex-math notation="LaTeX">IP_1\,dB</tex-math> and IIP3 simultaneously among all designs with the same band and is suitable for high-linearity communication systems.