This work presents a simple differentially BPSK receiver front-end using a novel schema without the need of an explicit carrier recovery system. The main principle of operation is the conversion of the incoming BPSK signal into an ASK signal having the same modulation pattern. Two versions of the system have been designed. One is intended to work at the 433.92 MHz ISM band and the other at 2 GHz frequency band. Accordingly, two prototypes of the system core, the BPSK to ASK converter circuit, have been implemented and tested. First a hybrid version for the low frequency operation and, second a multi chip module (MCM) for the 2 GHz frequency band. The system performance has been evaluated using Agilent Technologies Advanced Design System (ADS) platform. The ability to jointly perform system, circuit and EM simulations and co-simulations is the main advantage of this design tool. Obtained results indicate that modulation rates up to 20 Mbits/s for the hybrid version and up to 80 Mbits/s for the MCM version can be reached.
Emerging technologies like ZigBee or Ultra Wide Band (UWB) Radio, based on the new standards of the IEEE 802.15 family, will, in a near future, compete with and/or complement Bluetooth technology in the development of Wireless Personal Area Networks (WPAN’s), capable to satisfy the increasing demand of high bit rate data transfer links as well as low power and small size constrains. Nowadays coexistence and interconnectivity of Wireless Local Area Networks (WLAN’s), WPAN’s and mobile phones is just the first step towards the implementation of the so called Ambient Intelligence. The main characteristics of this new paradigm are: ubiquity, transparency, and intelligence. In this context, sensor networks are the first front of the communication chain. Thus, most of the wireless data transfers will take place at very short distances and most of the information flow will be performed at very low rates. To implement the RF transceiver devices constituting sensor networks in an Ambient Intelligence environment, several challenges still need to be solved, among them: packaging (SoP vs. SoC approaches), powering (low power, batteryless systems, energy scavenging) and system architecture (new simplified direct conversion approaches). All these matters will be considered in this work.
On-chip passives, such as inductors, transformers, are key components in the design of RF building blocks when using VLSI technologies. Most of the time of the design cycle is used in the simulation of passives, trying to obtain the maximum performance. Recently, work on modelling of passives has been directed to pursuit fast computation algorithms due to the need to handle several passives in a complete RF circuit. However, small attention has been paid in the optimization of passives. The work presented tries to fill this gap. The algorithm is based on three steps: the split of the magnetic and electric modelling problem based in a PEEC description; a model order reduction, based on plausible arguments; and the use of analytical formulae to keep scalability. Fast computation is achieved thanks to both the separation of the magnetic and electric problem, and the model order reduction. By keeping an analytical formulation, the optimization of the layout for minimum losses is driven by a physical algorithm, instead of a mathematical one. The tool has been checked with experimental data from inductors fabricated in different VLSI technologies, showing its possibilities in the design of RF building blocks.
An electronic circuitry is proposed and implemented to optimize the ignition process and the robustness of a microthruster. The principle is based on the integration of propellant material within a micromachined system. The operational concept is simply based on the combustion of an energetic propellant stored in a micromachined chamber. Each thruster contains three parts (heater, chamber, nozzle). Due to the one shot characteristic, microthrusters are fabricated in 2D array configuration. For the functioning of this kind of system, one critical point is the optimization of the ignition process as a function of the power schedule delivered by electronic devices. One particular attention has been paid on the design and implementation of an electronic chip to control and optimize the system ignition.
Ignition process is triggered by electrical power delivered to a polysilicon resistance in contact with the propellant. The resistance is used to sense the temperature on the propellant which is in contact. Temperature of the microthruster node before the ignition is monitored via the electronic circuitry. A pre-heating process before ignition seems to be a good methodology to optimize the ignition process. Pre-heating temperature and pre-heating time are critical parameters to be adjusted. Simulation and experimental results will deeply contribute to improve the micropyrotechnic system. This paper will discuss all these point.
The development of tools for a multi-microrobot manipulating system prototype to handle cells and biomolecules is proposed. The system will be based on a cluster (5 to 10) of small (cm3) mobile autonomous robots. The proposed system comprises several essential subsystems such as a global positioning system to provide accurate position information of each microrobot, advanced manipulating tools and a wireless power supply unit. It also includes user interfaces as well as systems for transporting objects into and out of the working range of the robots. Additional bio-handling arms must be integrated on the robots. Actuators for the positioning and moving of cells must be compatible with their living conditions. The application of non-uniform electric fields to non-charged particles suspended in aqueous medium produces a force over the particle due to the induced dipole moment.