Wide-IF-bandwidth CMOS Down-conversion Mixer MMIC

Abstract

A wide-Intermediate-Frequency (IF) down-conversion mixer operating in millimeter-wave band is proposed. The mixer is designed based on a passive double-balanced structure integrating Radio-Frequency (RF) and Local-Oscillator (LO) baluns. To optimize the performances in terms of the Conversion Gain (CG), bandwidth and isolations of the mixer, the gate-inductive technique is employed. The measured results show that the mixer features a wide IF bandwidth from 0.5 to 12 GHz. A measured CG of –8.5～–5.5 dB is achieved within such a wide IF band at a LO power (PLO) of 4 dBm and a LO frequency (fLO) of 30 GHz. The proposed mixer also achieves a CG with a ripple of 2 dB from –7.9 to –5.9 dB in a wide RF band (fRF) from 25 to 45 GHz at a PLO of 4 dBm and a fixed IF frequency (fIF) of 0.5 GHz. The measured LO-to-IF, LO-to-RF and RF-to-IF isolations are better than 42, 50 and 43 dB, respectively. The chip is fabricated in TSMC 90 nm CMOS process with an area of 0.4 mm2.