A concurrent dual-band folded-cascode mixer using a LC-tank biasing circuit

In this paper, a concurrent dual-band folded-cascode mixer with a dual-band LC-tank biasing circuit is presented. The operation frequency bands of the dual-band mixer are around 2.3 GHz and 5.2 GHz, respectively. A topology of LC series-parallel resonance, which is located on the current-sinking path of the biasing circuit is used to arrive at a dual-band characteristic. An on-chip balun is designed to transform a single-ended signal, such as a radio-frequency input signal and a local oscillation signal, into a couple of differential signals for the presented mixer. The simulated/measured conversion gains are about 15.6 dB/13.4 dB and 11.3 dB/8.6 dB at 2.3 GHz and 5.2 GHz, respectively. The measured IIP3 is −6.7 dBm and −1.1 dBm at 2.3 GHz and 5.2 GHz, respectively. The RF reflection coefficients at both bands are below −8 dB. The measured single sideband noise factors, NFSSB, are about 12.1 dB and 16 dB at 2.3 GHz and 5.2 GHz, respectively. The DC power consumption of the core circuit is 7.52 mW under 1.6 V supply voltage.