Nuestros investigadores

This letter presents the design of a compact, wideband, and high-efficiency E-band power amplifier, integrated in a 0.13-mu m BiCMOS process and occupying 0.3 mm(2). It consists of a single-stage balanced amplifier, with HBT transistors in cascode configuration. The power amplifier (PA) is biased in class AB, with a dc consumption of 156 mW. A compact bias circuit is employed to achieve temperature robustness, while the layout is optimized for wideband and highly efficient operation. Measurements show a peak power gain of 15.3 dB at 83 GHz, with a 29.3% fractional bandwidth and less than 1-dB degradation over a 25 degrees C-85 degrees C temperature range. The peak output power at saturation and 1-dB compression is 18.6 and 13.6 dBm, respectively, and the maximum power-added efficiency (PAE) is 30.7%.

This work presents a nonius time to digital converter (TDC) adapted to a passive RF identification (RFID) pressure sensor tag. The proposed converter exploits the characteristics of time-based sensor interfaces and allows reducing voltage supply and power consumption while maintaining resolution and conversion efficiency. The nonius TDC has been designed and fabricated using the TSMC 90 nm standard CMOS technology. The main blocks of the converter are described and both the resolution adjustment and measurement processes are explained in detail. Measurement results show 10.49 bits of effective resolution for an input time range from 28.19 to 42.93 mu s. With a sampling rate of 19 KS/s the converter has a conversion efficiency of 0.395 pJ/bit with a voltage supply of only 0.6 V. This characteristics in the proposed nonius TDC enables an increased reading range of the passive RFID pressure sensor tag.

This paper presents an ultra low-power and low-voltage pulse-width modulation based ratiometric capacitive sensor interface. The interface was designed and fabricated in a standard 90 nm CMOS 1P9M technology. The measurements show an effective resolution of 10 bits using 0.5 V of supply voltage. The active occupied area is only 0.0045 mm(2) and the Figure of Merit (FOM), which takes into account the energy required per conversion bit, is 0.43 pJ/bit. Furthermore, the results show low sensitivity to PVT variations due to the proposed ratiometric architecture. In addition, the sensor interface was connected to a commercial pressure transducer and the measurements of the resulting complete pressure sensor show a FOM of 0.226 pJ/bit with an effective linear resolution of 7.64 bits. The results validate the use of the proposed interface as part of a pressure sensor, and its low-power and low-voltage characteristics make it suitable for wireless sensor networks and low power consumer electronics.

The four physiological measures of body temperature, pulse rate, respiration rate and blood pressure have for a long time been considered as vital signs in the diagnosis of a patient¿s health. It is also widely accepted that the routine measurement of other physiological or biological signals, possibly pathology specific, would help considerably in diagnosis and early stage treatment. Such measurements might include, for example, heart activity, brain activity, blood glucose level or mobility. Furthermore, the development of portable systems that can make a number of different health related measurements would prove beneficial in the monitoring of patients during treatment, recovery or rehabilitation. Technologies and instruments that can make these measurements have existed for some time, but factors such as their cost, lack of portability and in some instances, a requirement for expert knowledge, have restricted their wide scale use. Today, however, advances in information technology, communications and microfabrication techniques have made possible the realisation of truly portable systems for the measurement of a wide range of physiological signs at any medical intervention. This chapter describes the sensing technologies and systems currently being developed, or that are in use, for the measurement of a new, larger range of vital signs