Nonlinearity and power consumption analysis of a low-IF MEMS receiver architecture

The nonlinearity and power consumption of low-IF receiver with RF MEMS filters is analyzed and a novel architecture employing high-Q RF MEMS filters at front end is presented. The target application is for the GSM900 MHz, and the MEMS filter is used as the front-end channel selectivity filter. Tradeoffs and analysis of the newly developed architecture using the MEMS filter is discussed. The MEMS filter can be used as a front-end channel selectivity filter which reduce interferes and blockers from entering the desired signal channel in the receiver. This results in lowering the required dynamic range, linearity, IIP2 and IIP3, and the power consumption of the receiver. For the low-IF receiver, the LNA and the mixer is designed using the CMOS 0.4 μm (BSIM3 model) technology. The LNA consists of three-stages with gain of 26 dB, noise figure NF=1.5 dB, IIP3=-18 dBm with 12 mW power consumption. A Gilbert-cell mixer with single-ended input is designed. The mixer has conversion gain of 5.08 dB, NF=6.9 dB IIP3=-14.6 dBm and the power consumption is less than 5 mW.