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Inductor current in the high speed switching converters is used as a feedback signal for current mode control and over current fault protection. Sensing inductor current for the use of digital controllers require high bandwidth current sensors and also need high speed Analog to Digital Converter (ADC) to convert the sensed current into digital domain. Use of high bandwidth current sensors and high...
This paper aims to offer insight into the topic of discrete-time ΣΔ ADCs. More specifically, we investigate the impact of non-ideal analog subcircuit parameters on the performance of a 16-bit, 1 kHz, differential second order, 1-bit quantizer, sigma-delta modulator in a 180 nm technology. The parameters in question are OPAMPs slew rate and gain which fulfill the role of fully differential, discrete-time...
This paper presents a fast-response full-wave inductor current sensor for a DC-DC converter operating in 10 MHz switching frequency. It can achieve high sensing accuracy better than 93% with inductor current varying from 100mA to 2.1 A. Also, the time response of proposed current sensor has been greatly improved and achieved < 8 ns for sensing full wave inductor current with a low transition spiking.
This paper shall present the design, simulation and implementation of a sensorless observer for three-phase permanent magnet synchronous machines which can be used for automotive steer-by-wire applications. The observer tracks steering transients enabling the sensorless speed/position estimates to be used for backup in case of encoder failure. The sensorless method is based on a high frequency injection...
Cognitive radio network (CRN) is regarded as an emerging technology for better spectrum efficiency where unlicensed secondary users (SUs) sense RF spectrum to find idle channels and access them opportunistically without causing any harmful interference to licensed primary users (PUs). However, RF spectrum sensing and sharing along with reconfigurable capabilities of SUs bring severe security vulnerabilities...
The Internet of Things revolution requires long-battery-lifetime, autonomous end-nodes capable of probing the environment from multiple sensors and transmit it wirelessly after data-fusion, recognition, and classification. Duty-cycling is a well-known approach to extend battery lifetime: it allows to keep the hardware resources of the micro-controller implementing the end-node (MCUs) in sleep mode...
The paper presents the design and implementation of an integrated wireless network that support to the multiparametric geophysical monitoring network of the Campi Flegrei volcanic area. The wireless network is equipped with a tool for real-time monitoring and fault detection. The enhancement of the transmission system with respect to the previously existing one has been realized in view of the increased...
In this study, metamaterial absorber structures that operate in the mid-wave infrared (MWIR) region are presented. The advantage of the design stems from the high absorptance in the region of interest and the ease of fabrication. Fabrication stage is facilitated by large in-plane geometric dimensions of the metamaterial pattern and small thickness of the full absorber geometry.
VANET and cognitive radio network (CRN) are both new emerging technologies in wireless networking. The application of CR concept in wireless communication systems for intelligent vehicles has been envisioned as a promising idea towards solving the problem of scarce spectrum. This paper discusses CR technologies for VANETs aimed at opportunistic spectrum access (OSA) for improved vehicular communication...
The advances in wireless low-power sensors and the increasing demand for portable healthcare monitoring systems have inspired the realization of Wireless Body Sensor Networks (WBSNs). IEEE Std. 802.15.6 defines the communication protocol for WBSN applications in terms of physical and medium access layers. The high generality and flexibility of standard requirements poses the question of how WBSN parameters,...
This work presents the design of a high-bandwidth and high slew rate class-AB amplifier in a linear assisted hybrid converter for envelope tracking (ET) applications. ET has become prevalent for improving the efficiency of RF power amplifiers (PA) in portable devices when transmitting LTE signals. The class-AB amplifier in the hybrid converter provides the AC power to the PA, whereas the DC power...
A low-noise and low-power signal conditioning circuit with narrow bandwidth is presented. The circuit cascades three stages. A high current and low supply voltage amplifier as the first stage decreases the thermal noise and power consumption. A differentiator and an integrator are used as the second and third stages to reach the amplification with a narrow bandwidth suitable for microelectromechanical...
As the Internet of Things (IoT) continues to expand to include applications including home automation, fitness, video, and tracking as well as traditional embedded electronics use cases the needs for testing and optimizing these designs become clearer. Even as IoT expands, the test requirements have begun to crystallize into a set of capabilities that can assist a design team in achieving their goals...
The cognitive radio (CR) have been proposed to improve spectral efficiency and to meet growing demands for higher data rates in mobile communications and satellite communications. In this paper, we propose a blind estimation algorithm for a secondary user to estimate transmission parameters of the primary signal in an OFDM overlay system, using only the available fast Fourier transform (FFT) component...
Channel assignment is a key problem in Cognitive Radio Networks. The channels are leased to the secondary users when the licensed or primary users are OFF, provided that the secondary users will leave those channels as soon as the primary users are reactivated. Therefore, to achieve a high performance of the network, we should lease a channel to a secondary user while both of them achieve the best...
The Manet or Mobile Ad-Hoc Networks are capable of forming wireless networks with different topologies. The radios which form the network uses a specific band, data rate and frequency. The paper focuses on the implementation of intelligent Mobile Ad-hoc NETwork (iMANET) in which wireless networks are established using reconfigurable radios so that intelligent networks can be formed. The nodes involved...
The steadily growing use of license-free frequency bands requires reliable coexistence management for deterministic medium utilization. For interference avoidance, proper wireless interference identification (WII) is essential. In this work we propose the first WII approach based upon deep convolutional neural networks (CNNs). The CNN naively learns its features through self-optimization during an...
Radio Frequency Interference (RFI) continues to be an annoyance to passive microwave remote sensing as spectrum demands escalate. For microwave imagers such as GMI and WindSat, the X-band and Ku allocated passive bands exhibit RFI from terrestrial based sources and from space-based geostationary satellites reflecting from the ocean, lakes, frozen ground, and other reflective surfaces. The GMI bands...
The paper presents an exhaustive visualization of different problems encountered in efficient utilization of spectrum for advanced wireless communication. It is a well known fact that there is a crisis for available radio spectrum due to incredible expansion and advancement of the communication systems and technologies. But in reality, there is no shortage of available spectrum but only lack of advance...
In this paper, measurements of the spectral occupancy in some high frequency (HF) bands in the Western part of Romania are presented. Signals have been acquisitioned by means of an Universal Software Radio Peripheral (USRP) equipment and spectrum occupancy values have been calculated off-line for a set of frequency bands that present interest for establishing of a system for emergency communications...
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