A 1.8V 2.4 GHz Folded-Switch Mixer for Direct Conversion Receiver

In the literature, a Folded Switch Mixer (FSM) which uses self-bias current reuse technique at the transconductance stage is proposed for achieving high Conversion Gain (CG), good linearity and low Noise Figure (NF). In order to increase the CG and reduce the NF of Folded Switch Mixer (FSM) further, two FSMs denoted as S-FSM and P-FSM are proposed in this paper. Both of them use dynamic Current Injection (DCI) technique. S-FSM and P-FSM uses an inductor in series and across the current injection path respectively. For the purpose of comparison, FSM, P-FSM and S-FSM are implemented in UMC 180 nm CMOS process Technology and studied through simulation at 2.4 GHz. From the study, it is found that the CG of (S-FSM, P-FSM) are higher by (2 dB, 6 dB) and NF of (S-FSM, P-FSM) approximately lower by (1.0 dB, 1.0 dB) respectively compared to that of the FSM. But S-FSM has better linearity (4 dBm) compared to P-FSM (-26 dBm) at the cost of increase in area.