A low-voltage high-linearity ultra-wideband down-conversion mixer in 0.18-μm CMOS technology

This paper presents a wideband mixer chip covering the frequency range from 3.4 to 6.8 GHz using TSMC 0.18 μm CMOS technology. The linearity can be improved using multiple-gated-transistors (MGTR) topology. The measured 3-dB RF frequency bandwidth is from 3.1 to 6.8 GHz with an IF of 10 MHz. The measured results of the proposed mixer achieve 7.2–4.3 dB power conversion gain and 2–3 dBm input third-order intercept point (IIP3), and the total dc power consumption of this mixer including output buffers is 2.9 mW from a 1 V supply voltage. The current output buffer is about 2.17 mW, and the excellent LO–RF isolation achieved up to 54 dB at 5 GHz. The paper presents a mixer topology that is very suitable for low-power in ultra-wideband system applications.