A 2.4-GHz low power polar transmitter for wireless body area network applications

Abstract

A 2.4 GHz low power polar transmitter is proposed in this paper. A dynamic biasing circuit, controlled by a digital envelope signal, is used as a direct digital-to-RF envelope converter. It effectively linearizes the input-output characteristic of the overdriven cascode class-C power amplifier used as the output stage, by dynamically adjusting the bias voltage of the cascode transistor. An equivalent baseband model of the transmitter is presented and used to optimize system parameters and give initial assessment of the achievable performance in terms of efficiency and linearity. Based on these simulations, parameters for transistor-level implementation of the bias circuit are derived. The transmitter is designed in a 65 nm CMOS technology. The post layout simulations indicate that the transmitter successfully meets the requirements of the IEEE 802.15.6 standard for wireless body area networks. The simulated amplifier consumes 4.75 mA from a 1.2 V supply while delivering 1.45 dBm of output power with a peak efficiency of 24 %. The entire transmitter, including the PLL, consumes 7.5 mA.

Channel estimation and transmit power control in wireless body area networks

“…The RF subsystem accounts for more than 75% of total power consumed when the transmit power is − 10 dBm [3]. Some investigations have focused their attention on the design of more energy efficient hardware for wireless healthcare monitoring [10] and WSNs [11]. Here we do not propose new hardware, but address an efficient interoperable ATPC algorithm.…”

Design Considerations for a Sub-mW Wireless Medical Body-Area Network Receiver Front End

“…In wearable devices, the radio typically consumes most of the energy [ 2 , 3 ]. In a typical WBAN radio, both transmitter and receiver consume a few mWs [ 2 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. However, while the transmitter is typically operated with a very low duty cycle, since data transmission is operated in bursts, the receiver is continuously operating, and is therefore the element primarily responsible for the average power dissipation [ 12 ].…”

Routing Design and Simulation of Body Area Network Based on Node Energy Consumption Control Strategy

“…Consequently, because of too fast energy consumption these nodes will die, and thus the original route will fail. To restore the communication, other nodes will again initiate route discovery process, resulting in the increase of packages communicated in the network, congestion or conflicts in the network, and the reduction of efficiency of network communication [4] [5] .…”