Wideband Tunable N-Path Mixer With Calibrated Harmonic Rejection Including the 7th LO Harmonic

In this study, a harmonic-rejection N-path mixer is designed, implemented, calibrated, and measured. The proposed mixer features a wide bandwidth suitable for low-power multi-standard RF front-end receivers while keeping low complexity by opting for only 5 paths rather than 10 and only one stage to perform harmonic rejection up to the $7<^>{th}$ local oscillator (LO) harmonic. This work employs a calibration strategy to prevent mismatches due to the fabrication process from affecting the system performance. The 0.17-1.2-GHz RF front-end mixer is fabricated in a 28-nm FDSOI technology. Measurements show a harmonic rejection higher than 45 dB for the 3(rd), 5(th) , and 7(th) LO harmonics, 13 dB gain, 13.3 dB NF, -3.5 dBm in-band IIP3. The total power consumption is only 22 mW for a surface area of 0.62 x 0.22 mm(2) .