Power-aware architecting for data-dominated applications

The task of the system architect is to take the correct early decisions despite the uncertainties. Power-Aware Architecting provides a systematic way to support the system architect in this job. Therefore, an iterative system-level design approach is defined where iterations are based on fast and accurate estimations or predictions of area, performance and energy consumption. This method is illustrated with a concrete real life example of multi-carrier communication. This book is the result of a Ph.D. thesis, which is part of the UbiCom project at Delft University of Technology. I strongly recommend it to any engineer, expert or specialist, who is interested in designing embedded systems-on-a-chip. © 2007 Springer. All Rights Reserved

Nanopower sampled data wavelet filter design using Switched Gain Cell technique

In order to realize a nano-power wavelet filter for biomedical applications, this paper applies the Singular Value Decomposition approximation to transform the time domain 1st-derivative of a Gaussian (gauss1) wavelet base into a 5th-order z-domain transfer function. Consequently, to realize the approximated transfer function in CMOS technology employing circuitry that operates from a low supply voltage, a sampled data circuit technique, coined 'Switched Gain Cell, (SGC),' is introduced. Using the SGC technique, standard MOS switches, simple subthreshold (nonlinear) transconductors and their associated parasitic capacitances suffice to constitute the filter, while the scale of the filter can be controlled by the clock frequency. This renders the filter architecture to be simple, modular, and area efficient. Simulation results, using 0.13μm CMOS model parameters, show that the wavelet filter implements the gauss1 wavelet base well, operates from a 1V supply and consumes less than 0.47 μW quiescent power. ©2009 IEEE

An RF-Powered DLL-Based 2.4-GHz Transmitter for Autonomous Wireless Sensor Nodes

This paper presents the system and circuit design of a compact radio frequency (RF)-powered 2.4-GHz CMOS transmitter (TX) to be used for autonomous wireless sensor nodes (WSNs). The proposed TX utilizes the received dedicated RF signal for both energy harvesting as well as frequency synthesis. A TX RF carrier is derived from the received RF signal by means of a delay locked loop and XOR-based frequency multiplier. The 50-Ω load is subsequently driven by a tuned switching RF power amplifier (PA) with 25% duty cycle input for high global efficiency. The design is fabricated in 40-nm CMOS technology and occupies a die area of 0.16 mm2. Experimental results show a rectifier with 36.83% peak efficiency and power management circuit with 120-nA current consumption that enables a low start-up power of -18.4 dBm. The TX outputs a continuous 2.44-GHz RF signal at -2.57 dBm with 36.5% PA drain efficiency and 23.9% global efficiency from a 915-MHz RF input and supports ON-OFF keying modulation.Accepted Author ManuscriptBio-Electronic

Codesign of Electrically Short Antenna-Electronics Interfaces in the Receiving Mode

The aim of this brief is to point out the importance of codesigning electrically short antenna-electronics interfaces as a way to improve the system performance. This can be achieved if both the antenna and electronic circuit designer have a common optimization target. In this brief, the codesign principles are presented for antenna systems in the receiving mode, which includes reception of wireless information and wireless power. A general interface analysis is carried out, suggesting that the choice of interface impedance plays a crucial role in the optimization procedure and depends on the preferred signal quantity of the electronic circuit. This allows to effectively improve design criteria such as noise figure, power efficiency and sensitivity without increasing the power consumption. Finally, two examples are treated to demonstrate the antenna-electronics codesign for the reception of wireless information (low-noise amplifier) and wireless power (radio-frequency energy harvesting)