1,721,035 research outputs found
Tackling Technical Research
No full textAt the end of their studies, master's degree students can get very close to solving research problems, but sometimes they can be very easily discouraged, dropping the option to earn a Ph.D. degree. Their listlessness and disorientation might be due to their lack of knowledge of what is research, science, and engineering (and innovation). The lack of understanding combined with 1) the impact of deal ing with heavy research subjects (the analysis of the state of the art, the understanding of the problem, and the project development) and 2) the memory of their just-finished, often-boring laboratory sessions, reporting activities can be disappointing and cause students to lose interest, especially if some basic ideas are not clea
Implementation-Aware System-Level Simulations for IR-UWB Receivers: Approach and Design Methodology
No full textA 0.07 mm2 asynchronous logic CMOS pulsed receiver based on radio events self-synchronization
No full textThis paper presents an ultra-low-power radio receiver implemented only with CMOS logic gates used as basic building blocks and proves its operation. The self-timed duty-cycled system is self-synchronized with the input radio signal, runs a noise-robust baseband detection and does not require any reference besides power supply. Based on S-OOK modulation, the 350-450 MHz digital radio RX occupies an area of 0.07 mm 2 in a 130 nm RFCMOS technology and achieves a 0.1% sensitivity of -63 dBm at 95 kbps, 380 MHz center frequency and 40 μW active power consumption at 1.1 V power supply. At 1.0 V it achieves -62 dBm sensitivity and 33 μW active power at ~ 0.1% error rate. The compact receiver, whose architecture is parametric and technology scalable, suits energy harvested and miniaturized biomedical applications. The paper also presents the potential advantages of asynchronous logic pulse radio and introduces an ad-hoc VHDL model demonstrating RTL-/gate-level accurate error-rate predictions capabilities based on digital simulation only, i.e., without requiring electrical-level co-simulation
A microbial fuel cell powering an all-digital piezoresistive wireless sensor system
No full textMicrobial fuel cells (MFcs) are energy sources, which generate electrical charge thanks to bacteria metabo- lism. We report on a full custom pressure wireless sensor node especially designed to operate with MFcs, comprising an ultra-low-power Impulse-radio Ultra-Wide-Band Transmit- ter operating in the low 0-960 Mhz band, a nanostructured piezoresistive pressure sensor connected to a discrete com- ponent digital read-out circuit, and an MFc energy supply system. The sensor device comprises an insulating matrix of polydimethylsiloxane and nanostructured multi-branched copper microparticles as conductive filler. Our prototype sys- tem comprises two MFcs connected in series to power both the UWB transmitter, which consumes 40 μW, and the read- out circuit. The two MFcs generate an open circuit voltage of 1.2 ± 0.1 V. each MFc prototype has a total volume of 0.34 l and comprises two circular poly(methyl methacrylate) chambers (anode and cathode) separated by a cation exchange membrane. The paper reports measurements on a fully work- ing prototype that enables the separate transmission of pres- sure information and MFc voltage level at the same time. The complete sensor node powered by the MFc, thanks to its nature can be located either in harsh environments where there is no connection to energy grids, or in environments where the MFc, hence the complete node, can self-sustai
A Mixed-Signal Demodulator for a Low-Complexity IR-UWB Receiver: Methodology, Simulation and Design
Full text linkThis works presents an integrated 0.18μm CMOS 2-PPM demodulator based on a switched capacitor network for an Energy Detection Impulse-Radio UWB receiver. The circuit has been designed using a top-down methodology that allows to discover the impact of low-level non-idealities on system-level performance. Through the use of a mixed signal simulation environment, performance figures have been obtained which helped evaluate the influence at system-level of the non-idealities of the most critical block. Results show that the circuit allows the replacement of the ADC typically employed in Energy Detection receivers and provides about infinite equivalent quantization resolution. The demodulator achieves 190 pJ/bit at 1.8V
A Flexible Low-Power 130 nm CMOS Read-Out Circuit With Tunable Sensitivity for Commercial Robotic Resistive Pressure Sensors
No full textAn analog-mode impulse radio system for ultra-low power short-range audio streaming
No full textThis paper introduces and analyzes an ultra-low power and low-complexity analog IR-UWB radio system for unlicensed audio streaming which achieves continuous wave FM performance but exploiting aggressively duty-cycled signaling. At the TX, signal is modulated using a VCO which generates pulses with variable rate (PRF modulation), for an average of 600 kHz. At the RX an asynchronous and interference-robust detector regenerates the modulated signal at half frequency without requiring phase-locking, which is successively processed by a passive FM detector. The obtained demodulated signal is filtered using a fourth order Sallen-Key cell. The TX and RX modules based on commercial components draw 1.89 and 10 mA from 100 mAh Lithium-ion rechargeable batteries (1 TX and 2 RX) and include an integrated TX/RX chipset in a 130 nm RFCMOS technology which operates at 3.5 GHz center frequency and 1.2 V supply. The radio system transmits audio with THD 1%, provides an SNR of 64 dB (aligned with FM radio and compact cassettes) and has a frequency response 110 Hz-17 kHz, for a continuous play time of 50 h (TX) and 12 h (RX), and 2.5 m radio rang
Energy Detection UWB Receiver Design using a Multi-resolution VHDL-AMS Description
Full text linkUltra Wide Band (UWB) impulse radio systems are appealing for location-aware applications. There is a growing interest in the design of UWB transceivers with reduced complexity and power consumption. Non-coherent approaches for the design of the receiver based on energy detection schemes seem suitable to this aim and have been adopted in the project the preliminary results of which are reported in this paper. The objective is the design of a UWB receiver with a top-down methodology, starting from Matlab-like models and refining the description down to the final transistor level. This goal will be achieved with an integrated use of VHDL for the digital blocks and VHDL-AMS for the mixed-signal and analog circuits. Coherent results are obtained using VHDL-AMS and Matlab. However, the CPU time cost strongly depends on the description used in the VHDL-AMS models. In order to show the functionality of the UWB architecture, the receiver most critical functions are simulated showing results in good agreement with the expectations
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