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International audience; This paper presents a single-bit RF transmitter based on single-bit switched-capacitor RF digital-to-analog converters (DACs) embedded in an finite-impulse response (FIR) filter (FIR-DACs). The transmitter system comprises a single-bit quadrature delta-sigma modulator (M), a digital mixer, and a 109-tap RF FIR-DAC stage with a single external inductor, combining D-A conversion with discrete-and continuous-time filtering. The on-chip part of the FIR-DAC is built exclusively with CMOS inverters and metal-oxide-metal capacitors, which are implemented in the interconnect layers to propose a compact fully digital solution, suitable for advanced CMOS nodes. A method for canceling redundant switching in the FIR-DAC is proposed to reduce its complexity and power consumption. Combining discrete-and continuous-time filtering, the out-of-band quantization noise of the 1-bit RF signal is strongly attenuated below the level required by emission masks. The RF FIR-DAC prototype is implemented in a 28-nm FD-SOI CMOS technology with ten metal layers and occupies a total active area of only 0.047 mm 2. The overall power consumption is 38 mW at 4.6-dBm peak output power, 900-MHz carrier frequency, and 1-V supply. FD-SOI body bias V t tuning is used to effectively correct mixing clock duty-cycle errors in order to perform precise high-frequency I/Q interleaving, which enables high image and local oscillator rejections. The resulting power consumption, surface, and performance of the measured prototype make the proposed circuits and concepts particularly appropriate for use in emerging Internet of Things (IoT) applications. Index Terms-28-nm FD-SOI, all-digital transmitter, body bias, delta-sigma modulation (M), finite-impulse response filter (FIR), finite-impulse response digital-to-analog converter (FIR-DAC), switched-capacitor (SC) DAC.

International audience; This paper presents a versatile chip-level wireless driving method for microelectromechanical system (MEMS) actuators. A MEMS actuator is integrated as an electrical component of a coupled LCR resonant circuit, and it rectifies the energy sent through an ultrahigh-frequency (UHF) radio frequency (RF) wave. Two types of actuators were remotely driven using the proposed method: thermal (bimorph) actuators used as the R component and capacitive (comb-drive) actuators used as the C component of a resonant receiver circuit. We demonstrated the remote actuation of a 13 Ω thermal actuator transferring 7.05 mW power with a power efficiency of 15.8%. This was achieved using coupled 500 μm diameter 5.5-turn planar coil antennas over a distance of 90 μm. When an impedance-matching configuration (Zo = 50 Ω) was used, the efficiency over a distance of 65 μm was measured to be 55.6%, which was 8.2 times greater than that of simple inductor coupling. The proposed method can be applied to future deployment scenarios, where fragile MEMS are placed on top of a system and must directly interface with the environment (thus, being prone to break). The authors propose to fabricate MEMS and energy receiver circuits monolithically on a chip, and place them on another energy transmitter chip. Thereby, the MEMS chip can avoid electrical feedthrough so that (a) the MEMS chip is easily replaceable if it breaks, and (b) the MEMS chip can move beyond wiring cable limitations. Four features are underlined in the article: (1) MEMS itself can rectify the RF energy owing to the fact that the governing equation of the MEMS actuator involves the square of the voltage and/or current, thereby, ensuring higher system-level efficiency than any other RF transceiver circuits using additional rectifying components (e.g., diodes). (2) Both the transmitter and receiver use coils of the same design, whose sizes are equivalent to those of the MEMS actuators (hundreds of micrometers). Moreover, they can be operated at UHF, owing to the much higher self-resonant frequency (fs &gt GHz) when compared to conventional transmitters (fs ≈ MHz). In addition, by using LCR resonant circuits, it is possible to not only (3) increase the transmission efficiency but also (4) multiply the driving voltage of the capacitive MEMS actuator, because of LC resonance. Voltage multiplication is quite useful for electrostatic MEMS operations because the movement is proportional to the square of the voltage across the MEMS capacitance. Comprehensive designs, implementations, and demonstrations of wireless operation are presented in this paper, for both thermal (resistive) and electrostatic (capacitive) actuators. Remote operation includes on–off-keying for MEMS without mechanical resonance and amplitude modulation of sinusoidal signals to stimulate the mechanical resonant frequency of MEMS.

This paper presents the design and measurement of a 4 × oversampled 18th order digital low-pass FIR filter. It is a key building block in the proposed digitally enhanced transmitter architecture for 60 GHz wireless high-data rate links. Spectrum mask requirements are fully satisfied for OFDM modulated signals without requiring additional analog filtering. Pipelined CPL adders and TSPC flip-flops are used to enable a very high operation frequency. The core area is 0.1 mm2 in a standard GP 65 nm CMOS process. Measured power consumption is 400 mW at 9.6 GS/s with a 1.4 V power supply voltage.

A complete UMTS transmitter is proposed. It is composed of a radiofrequency (RF) signal generator, a power stage, and a bulk acoustic wave (BAW) duplexer. The 90-nm CMOS digital RF signal generator is based on a third-order delta-sigma modulator using innovative design techniques to increase work frequency and a BAW filter to get rid of out-of-band quantization noise. The filter exhibits very high rejection, 3 dB of insertion losses at 1.95 GHz for a 3% fractional bandwidth. The 0.25-μm BiCMOS power stage feeds a BAW duplexer that allows to share a common between W-CDMA emission and reception. This 4 × 4 mm2 duplexer, built with flip-chipped BAW on glass substrate, ensures good isolation. The full transmitter measurements show the compliance with respect to spurious emissions in the different frequency bands and an EVM measurement at the state of the art (

International audience; In this paper, we address issues and solutions for micro-electro-mechanical-systems (MEMS) powering through semiconductor devices towards one-chip MEMS, especially those with microactuators that require high voltage (HV, which is more than 10 V, and is often over 100 V) for operation. We experimentally and theoretically demonstrated that the main reason why MEMS actuators need such HV is the tradeoff between resonant frequency and displacement amplitude. Indeed, the product of frequency and displacement is constant regardless of the MEMS design, but proportional to the input energy, which is the square of applied voltage in an electrostatic actuator. A comprehensive study on the principles of HV device technology and associated circuit technologies, especially voltage shifter circuits, was conducted. From the viewpoint of on-chip energy source, series-connected HV photovoltaic cells have been discussed. Isolation and electrical connection methods were identified to be key enabling technologies. Towards future rapid development of such autonomous devices, a technology to convert standard 5 V CMOS devices into HV circuits using SOI substrate and a MEMS postprocess is presented. HV breakdown experiments demonstrated this technology can hold over 700 to 1000 V, depending on the layout. (C) 2018 The Japan Society of Applied Physics.

An all-digital RF signal generator using DeltaSigma modulation and targeted at transmitters for mobile communication terminals has been implemented in 90 nm CMOS. Techniques such as redundant logic and non-exact quantization allow operation at up to 4 GHz sample rate, providing a 50 MHz bandwidth at a 1 GHz center frequency. The peak output power into a 100 Omega diff. load is 3.1 dBm with 53.6 dB SNDR. By adjusting the sample rate, carriers from 50 MHz to 1 GHz can be synthesized. RF signals up to 3 GHz can be synthesized when using the first image band. As an example, UMTS standard can be addressed by using a 2.6 GHz clock frequency. The measured ACPR is then 44 dB for a 5 MHz WCDMA channel at 1.95 GHz with output power of -16 dBm and 3.4% EVM. At 4 GHz clock frequency the total power consumption is 120 mW (49 mW for DeltaSigma modulator core) on a 1 V supply voltage, total die area is 3.2 mm2 (0.15 mm2 for the active area).

This paper reports successful wireless drive of a 100 µm × 500 µm × 5 µm MEMS thermal actuator via micro-scale coupled magnetic resonances. Receiver inductor is 500 µm × 500 µm, which is the same scale as the actuator. There is no need for rectifier circuit to drive the actuator, enabling power transmission with zero conversion loss. The transmission efficiency of the system was also evaluated and the efficacy of magnetic resonant coupling for micro-scale power transmission was verified. The system using downsized transmitter inductor was also evaluated and we verified that it has capability of driving the actuator wirelessly.

Sudden cardiac death (SCD) in the young tends to occur in individuals with undiagnosed heart disease and has a devastating impact on families and communities. Such events tend to draw substantial public and media attention, particularly when a young athlete is involved. Heightened awareness of SCD has led to anxiety regarding youth athletics as well as debate regarding appropriate and cost-effective screening. It is important to note that many pediatric, nonathletic cardiopulmonary arrests are either of a respiratory or traumatic etiology. Nonetheless, sudden cardiac arrest (SCA) is the leading cause of death in young athletes and may be preventable in many cases. However, current screening methods in the USA are inadequate to identify those at risk with sufficient sensitivity or specificity, or in a practical or cost-effective manner.

Mutations in sarcomeric proteins can lead to either hypertrophic or dilated cardiomyopathy depending on their effects on the structural and functional properties of the contractile unit of the heart. Mutations in cardiac troponin T, which binds the calcium-responsive troponin complex to α-tropomyosin, have been shown to result in cardiac hypertrophy or cardiac dilatation and heart failure, depending on the nature of the specific mutation. In this study, we report the identification of a novel cardiac troponin T mutation (A171S) leading to dilated cardiomyopathy and sudden cardiac death. In contrast to prior described mutations, the A171S mutation results in a significant gender difference in the severity of the observed phenotype with adult males (over 20 years of age) demonstrating more severe ventricular dilatation [left ventricular end diastolic dimension (LVEDD) 7.1 vs. 5.1cm; P =0.01, t test] and left ventricular dysfunction [left ventricular shortening fraction (LVSF) 21 vs. 34%; P =0.04, t test] than adult females. The described mutation substitutes a hydrophilic amino acid for a hydrophobic one in a highly conserved domain involved in the interaction between troponin T and α-tropomyosin. Interestingly, four previously described mutations within 12 amino acids of A171 lead to a hypertrophic phenotype, suggesting that further characterization of the functional consequences of the A171S mutation may lead to a better understanding of the pathophysiology of DCM and of the functional differences between HCM- and DCM-causing mutations in cardiac troponin T.

Objectives: This study examined the indicat- ions, efficacy and outcomes of implantable cardioverter defibrillator (ICD) use in the pediatric population. Background: ICDs are first-line therapy for adults re- suscitated from sudden cardiac death (SCD) or at high risk for life-threatening ventricular arrhythmias. Use of ICDs in children and young adults is infrequent and there are few data regarding this group. Methods: We abstracted and analyzed data for all patients in whom ICDs were implanted.

We have developed a flexible station for probing and testing microelectromechanical systems (MEMS) and relative integrated circuits. The system allows testing devices under vacuum condition ranging from 10−6 to 760 Torr and at variable temperatures from −100 to +150 °C. Electrical measurements up to 3 GHz and optical measurements through glass windows can be performed simultaneously on MEMS devices. Either packaged devices mounted on printed circuit boards or diced or undiced chips are acceptable. Chips are probed using manual probe heads or probe cards. If needed, two separable parts of a MEMS device, for example, an electromechanical part and an electronic integrated circuit, can be tested simultaneously in different temperature conditions. The setup has been successfully used to characterize electromechanical resonators which exhibit quality factors close to 100 000 in high vacuum.

A fifth-order elliptic low-pass continuous-time filter based on triode transconductors for applications in the video frequency range is presented. Fabricated in a standard 2- mu m CMOS technology, the circuit occupies 6 mm/sup 2/ of silicon area including the automatic tuning circuitry. The filter achieves a 7-MHz cutoff frequency using a parasitic pole compensation scheme. The dynamic range is 40 dB and power consumption is 30 mW for a 5-V supply. A transconductor biasing strategy which allows a continuous tuning range for the cutoff frequency of one decade is presented. >

A CMOS preamplifier optimized for piezoelectric transducers is presented. The extensive use of CMOS-compatible lateral bipolar transistors (CLBTs) and careful layout leads to a very low noise along with good untrimmed DC and AC characteristics. These features make it competitive with bipolar and JFET realizations. In addition, long coaxial lines can be driven without significant alteration of performance using the two uncommitted on-chip buffers. This circuit was fabricated in a standard 3- mu m p-well CMOS technology, opening perspectives to monolithic integration of data acquisition subsystems. >

This paper presents the first demonstration of a complete CMOS 90nm digital RF signal generator for wireless communication systems including a BAW (Bulk Acoustic Wave) based filter. A 1-bit delta-sigma signal generator is assembled with a BAW band pass filter for the UMTS TX-band at 1.95GHz. The system satisfies UMTS specifications for ACPR and spurious emissions as defined in the IST MOBILIS project. The CMOS and BAW chip sizes are respectively 3.2mm² and 4.7mm².

OBJECTIVE To detail changes in adrenocorticotropic hormone (ACTH), cortisol, and aldosterone levels following cardiac surgery and to test the hypothesis that postcardiotomy infants requiring excessively high-dose vasopressor support will demonstrate adrenal insufficiency which will be proportional to cardiopulmonary bypass (CPB)/circulatory arrest times and vasopressor requirements. DESIGN Prospective observational pilot study. SETTING A tertiary care pediatric cardiac intensive care unit. PATIENTS Prospectively enrolled infants were divided into three subgroups: CPB, CPB with deep hypothermic circulatory arrest (DHCA), and control subjects. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS A representative patient sample from each surgical group underwent preoperative synthetic ACTH testing. Postoperative serum samples for cortisol, ACTH, and inotrope score (IS) were collected at discrete intervals over 48 hrs along with patient demographics, surgical procedure, and CPB/DHCA times. Fifty-eight patients were classified by subgroup: 31 CPB, 22 DHCA, and 5 controls. Ten patients with DHCA, analyzed separately, received intraoperative steroids. Tested patients demonstrated preoperative adrenal competence. Cortisol peaked within 2 hrs of surgery without differences among groups. ACTH inversely correlated with bypass time in patients with DHCA (p = .03) but not with circulatory arrest time. Peak cortisol level did not correlate with simultaneous IS. Although not noted in any DHCA-steroid patients, nine patients had increased ACTH/cortisol ratios in association with elevated ISs suggesting inadequate adrenal responsiveness to endogenous ACTH. CONCLUSIONS The majority of infants with congenital heart disease and intact hypothalamic-pituitary-adrenal axes demonstrated an appropriate adrenocortical stress response to cardiac surgery. Peak serum cortisol was unrelated to CPB/DHCA time and did not predict the level of inotrope support. However, a subset of patients with elevated ACTH/cortisol ratios seemed to have a clinical status consistent with adrenal insufficiency and may be a target group for early postoperative steroid therapy.

This paper presents an all-digital approach to the generation of the modulated radio-frequency carrier and its application to a multimode transmitter in today’s communication systems and draws a possible picture of tomorrow’s systems. We will first analyze how digital transmitters will progressively replace their analog counterparts and what are the main issues associated with this trend. The combination of Δ​Σ modulation and digital mixing is proposed as an innovative approach enabling multimode operation of transmitters with low power consumption and chip area, easy configurability, and good performance. A 90 nm CMOS chip has been designed to demonstrate the feasibility of the concept and its potential in multimode transmitter architectures. Techniques such as redundant arithmetic and non-exact quantization are used in the high-speed Δ​Σ modulator implementation. Furthermore, approaches to antenna filtering using BAW filters and reconfigurable semi-digital RF FIR filters will be introduced. Finally, a review of recent outstanding transmitter designs will allow a comparison between the presented approach and architectures based on digital-to-RF conversion.

A differential digital to 60 GHz quadrature mixer on a 65 nm SOI CMOS process from STMicroelectronics has been designed. Two 5 GS/s 4-bit quadrature base band signals are fully decoded and fed into an unary-weighted current DAC. The DAC output is fed to two RF Gilbert cell mixers driven by an off-chip 60 GHz LO signal. The simulated P1dB output power is −22.5 dBm for an LO power of −2 dBm at 60 GHz for a 6 mA current consumption at 1.2 V. The chip size is 1.54 × 2.6 mm2.

The presented digital RF signal generator in 90 nm CMOS uses 1-bit DeltaSigma modulation and targets mobile communication terminals. A 50 MHz bandwidth centered on 1 GHz can be achieved when the circuit is clocked at 4 GHz. Signals up to 3 GHz can be synthesized when using the first image band. The peak output power into a 100 Omega diff. load is 3.1 dBm with 53.6 dB SNDR. The digital core employs redundant arithmetic, precomputed non-exact quantization and differential dynamic logic. The digital core consumes 49 mW at maximum clock frequency. Active area is 0.15 mm2.

This paper presents a reconfigurable semi-digital RFFIR filter suitable for digital transmitters using 1-bit DeltaSigma signal generation. A transmission line based 5-channel power combiner allows both increase of output power and programmable filtering of the signal. A prototype has been built with 65 nm CMOS and Integrated Passive Devices (IPD) technologies. The system exhibits a 14 dB power gain for a peak power of 17 dBm at 1.2 GHz and an attenuation of out-of band noise of up to 15 dB. CMOS and IPD chip size are respectively 2.05 mm2 and 17.78 mm2.

International audience; This paper presents a very high-speed delta-sigma modulator for achieving digital generation of radio-frequency signals. About 68 dB of ACLR (adjacent channel leakage ratio) is obtained on the 7.8 GS/s output of the delta-sigma modulator for WCDMA standard. This is achieved by using original concepts like borrow-save arithmetic, non-exact quantization and differential dynamic logic.

Digital generation of radio-frequency signals is a key concept of software defined radios. This paper presents a digital transmitter chain including a very high-speed delta-sigma modulator. It comprises also baseband processing, sample rate conversion, digital upconverter and output stages (switching- mode amplifier and BAW filters). About 74 dB of ACLR (adjacent channel leakage ratio) is obtained on the 7.8 GS/s output of the delta-sigma modulator for the WCDMA standard.

For the first time a high-voltage IC, specially dedicated to the remote powering and the control by inductive coupling of electrostatic actuators, has been designed and successfully tested. Four actuators can be controlled simultaneously with a maximum actuation voltage of 100 V. As a preliminary test, a capacitive load of 220 pF has been driven at a frequency of 100 Hz with an output voltage of 30 V and a distance of 2.5 cm between emitter and receiver antennas. To avoid the electrostatic stiction of mobile parts, the IC alternates the polarity of the actuation voltage. The possibility to control 4 highly capacitive actuators independently makes this circuit suitable for the remote control of a two degrees of freedom electrostatic Ciliary Motion System (CMS). The chip has been fabricated using European multi-chip service (EUROPRACTICE) in the Alcatel-Mietec I2T100 technology. Its dimensions are 5*3 mm/sup 2/.

Objective. Patient-activated transtelephonic electrocardiographic event monitors (TTMs) are often used for the evaluation of children and adolescents with suspected arrhythmias. Since their introduction 25 years ago, there has been little inquiry quantifying the usefulness of TTMs for pediatric patients. The objective of this study was to measure the utility of TTMs for children and adolescents with symptoms of a possible cardiac rhythm disturbance. Methods. Medical records of all patients who received TTMs from C.S. Mott Children’s Hospital Electrocardiography Laboratory between February 1, 1993, and October 31, 2000, were reviewed. Patients with pacemakers, known arrhythmias, or age older than 18 years were excluded. Indications for monitoring included palpitations with or without other symptoms (N = 420), chest discomfort (N = 43), and presyncope or syncope (N = 32). Results. A total of 495 studies (patient mean age: 10.2 ± 4.3 years; range: 0.1–17.9 years; 48% male) met inclusion criteria. Monitoring was performed for 1 to 1021 consecutive days (mean: 103 ± 97). Fifty-two percent (N = 257) of patients failed to transmit an electrocardiogram while experiencing symptoms. Fewer boys transmitted electrocardiograms (N = 100/238). Of 238 symptomatic patients, 15% (N = 35; mean age: 11.4 ± 4.7 years; range: 0.1–17.4 years; 51% male) had supraventricular tachycardia (SVT). No other significant arrhythmia that may warrant treatment was identified. All patients with SVT had palpitations. No patients with isolated chest discomfort, presyncope, or syncope had SVT (N = 75). SVT was documented more frequently in patients with postevent (N = 35/464) than loop recorders (N = 0/31). Of those with SVT, 71% (N = 25) and 91% (N = 33) transmitted events within 4 and 16 weeks, respectively. Follow-up for 1 to 108 months (mean: 32 ± 25; median: 26) in 53% (243 of 460) of patients without SVT uncovered a 3% (N = 7) rate of subsequent SVT detection. The overall sensitivity of the TTM test was 83% (35 of 42) for detection of SVT. The sensitivity of studies theoretically limited to 4 and 16 weeks would be 60% (25 of 42) and 79% (33 of 42), respectively. The negative predictive value of the TTM study was 99% in our patient population. The negative predictive value of tests theoretically limited to 4 and 16 weeks would be 96% and 98%, respectively. TTM studies of 2 weeks’ duration were most cost-effective in terms of total diagnostic yield. In contrast, studies of 4 weeks’ duration were most cost-efficient for SVT detection. Conclusions. TTMs are useful for the evaluation of children and adolescents with palpitations but not with isolated chest pain, syncope, or presyncope. In this study, girls were more likely to transmit events. The sensitivity of TTMs for detection of SVT was 83%. The negative predictive value of the TTM test was 99%. Monitoring for longer than 16 weeks did not increase test sensitivity. Studies of 4 weeks’ duration proved most cost-effective for SVT detection.

This paper summarizes research towards the realization of a fully-integrated, compact, intelligent MEMS (Smart MEMS). The system performs the cooperative function of microactuators by integration with sensors and processors. By using a cooperative operation the weak force of each microactuator is gathered so the system can produce a strong force, in preserving the precise motion control thanks to the high resonant frequency of microactuators and short feedback cycle of the integrated processor. The design of a demonstration system is presented in this paper.

This study examined the indications, efficacy and outcomes of implantable cardioverter defibrillator (ICD) use in the pediatric population.ICDs are first-line therapy for adults resuscitated from sudden cardiac death (SCD) or at high risk for life-threatening ventricular arrhythmias. Use of ICDs in children and young adults is infrequent and there are few data regarding this group.We abstracted and analyzed data for all patients in whom ICDs were implanted.A total of 38 devices were implanted in 27 patients. Age ranged from 6 to 26 years (mean, 14) and weight ranged from 16 to 124 kg (mean, 47). Diagnoses included long QT syndrome (9), hypertrophic cardiomyopathy [6], repaired congenital heart disease [5];, and idiopathic ventricular tachycardia/fibrillation [4]. Indications comprised resuscitated SCD [15], syncope [9], and life-threatening ventricular arrhythmia [3]. Initial device placement was infraclavicular in 13, abdominal in 13 and intrathoracic in 1. Epicardial leads were used with 5 systems. A single coil lead was used in 17. Seven patients, all previously resuscitated from SCD, experienced 88 appropriate successful discharges. There were 6 inappropriate discharges in 3 patients. Mean time to device replacement was 3.1 years (n = 11). Complications included 2 infected systems, 2 lead dislodgments, 2 lead fractures, 1 post-pericardiotomy syndrome, 1 adverse event with defibrillation threshold (DFT); testing, and 1 patient with psychiatric sequelae. No deaths occurred with implanted ICDs.These data demonstrate that ICDs provide safe and effective therapy in young patients. The indications for ICDs as primary preventive therapy remain uncertain.

Anomalous origin of the left main coronary artery from the right sinus of Valsalva with retropulmonary course is a rare congenital abnormality. It is associated with a high incidence of sudden cardiac death, particularly among young, athletic individuals. Many of these individuals do not have symptoms before sudden death, and the diagnosis is usually made at postmortem examination. We present a case of a 15-year-old boy who was evaluated for a systolic click with routine 2-dimensional echocardiography. The anomalous coronary artery was serendipitously identified, allowing surgical intervention. Coronary artery origin and proximal course should be visualized on routine echocardiography in the pediatric population. (J Am Soc Echocardiogr 1999;12:769-72.)

It was previously reported from Italy that all patients with Kawasaki disease had a positive tuberculin intradermal test. In this study from Seattle, WA, nine patients with Kawasaki disease showed no reaction to intradermal tuberculin. The difference in results might be caused by the different tuberculin products.

A 5th order elliptic low-pass continuous-time filter based on triode transconductors for applications in the video frequency range is presented. Fabricated in a standard 2μm CMOS technology, the filter achieves a 7 MHz cut-off frequency using a simple parasitic pole compensation scheme. A new transconductor biasing strategy is also presented, which allows the tuning of the transconductance over a decade.

A CMOS triode transconductor using a novel bias scheme is described. The bias circuit is based on an auxiliary transistor and ensures optimum bias conditions over the entire tuning range. This makes it possible to design low-noise integrated continuous-time filters with a wide tuning range.