Design of RF front end receiver for biomedical applications

This paper presents RF front end receiver circuit for biomedical applications especially for ECG acquisition systems. The RF front end system consists of Low Noise Amplifier (LNA), Differential Power Splitter (DPS) and a quadrature mixer. The three stage LNA with body biasing technique is introduced to improve the noise and gain and the differential power splitter is used to provide the differential signals to the quadrature mixer. The down conversion mixer gives I/Q output which will be further reduced by an off chip filter. The circuit is implemented in 0.18μm technology using cadence to meet the zigbee standard of 2.4-5.5GHz. The metrics achieved include noise figure of 7dB and the conversion gain of 13.54dB. Further the power consumption is 6mW for the 1V supply voltage.