An ultra low power MICS band receiver for implantable wireless body area networks

Abstract

The wireless body area networks WBANs consists of a network of implanted or a wearable sensor node to monitor the bio signals of human beings. The design of the implantable sensor node is critical as these nodes should consume very low power. In this work, an efficient low power CMOS receiver is designed for implantable medical devices in the MICS band. The receiver RF front-end consists of a low noise amplifier and down-conversion mixer. As the low noise figure is a major concern in the LNA, with the use of the complementary current reuse technique a noise figure of 1.06dB is obtained and there is a reduction of 1.7dB noise figure compared with the existing work. In order to improve the linearity, the source degeneration technique is incorporated into the down conversion mixer. The proposed mixer incorporates the resistive source degeneration topology into the folded approach architecture to obtain low power consumption. The proposed mixer achieves −12.6dB improvement in linearity and 34% reduction in power consumption compared to the existing folded mixture. The results were obtained using cadence RF spectre tools with 180 nm technology and the receiver front-end found to consume 485 µW for the MICS band.