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In recent years, to meet the increasing demandsfor vehicular communications, cognitive radio(CR) technology have been used to make the communication more effectively. In this paper, we propose a spectrum sensing channel model based on cooperative interference and interleaved channel which consists of two stages transceiver in vehicular network. This model makes use of CR technology with switching...
Digital isolators are widely used in isolated power converters for transmitting high-frequency gating pulses. Opto-isolators generally suffer from low reliability, while emerging RF based isolators are expensive and power-hungry. In this work, two Phase-Locked-Loop (PLL) based synchronization schemes are introduced and demonstrated to operate a bidirectional Dual-Active-Bridge (DAB) dc-dc converter...
With a stringent input-to-output conversion ratio (CR) of 20 (24V input and 1.2V output) for a DC-DC converter, two stage cascaded architectures are easy to implement, but suffer from poor efficiency and doubled number of power components. This paper presents a single-stage solution with a proposed Adaptive ON-OFF Time (AO2T) control. In steady state, the control works as an adaptive ON-time valley...
A reduced switch converter for active magnetic bearing system is analyzed and its performance is experimentally validated at 24,000 rpm on a 4-axis magnetic bearing test-rig. Based on the coupled coil arrangement and unidirectional current operation, the reduced switch converter is derived and its modes of operation are elaborated. In comparison to conventional topologies, this converter reduces the...
Unobtrusive in-home monitoring systems are gaining acceptability and are being deployed to enable relatives and caregivers to remotely monitor and provide timely care to their elderly loved ones or senior clients, respectively, who are living independently. Such systems can provide information about non-movement or inactivity of the elderly resident. As prolonged inactivity could mean potential danger,...
Spin Torque Transfer RAM (STT-RAM), a assuring possible choice of Static RAM for diminishing leakage power utilization. STT-RAM has the resistance of the MTJ (Magnetic Tunnel Junction) that changes based on stored data. By using differential sensing with reconfigurable cache cell, the STT-RAM performance can be improved. This scheme largely reduces the read disturbance error and average power dissipation...
Cognitive radio network (CRN) is a recent paradigm of techniques for enhancing the quality of radio communication systems through the efficient utilization of frequency spectrum. It is characterized by overlay and underlay CR. Antennas designed for overlay CR must possess the capability to sense the channel and communicate over a portion of it. CR overlay antennas can be implemented as two-port, where...
A conventional Flyback converter's synchronous rectification switch is controlled from the primary side via opto-isolators; introducing propagation delay. A new control concept is presented here that eliminates the need for opto-isolators, communicating instead through the coupled inductor to assist more precise soft-switching control at much higher frequencies. As a precursor to a 1-MHz GaN demonstrator,...
This paper presents a high accuracy and high bandwidth current sense circuit for digitally controlled DC-DC buck converters. The circuit uses lossless inductor DCR current sensing and a sigma delta modulator ADC to sense the average current in the inductor to high accuracy. These accurate but low bandwidth measurements are unsuitable for use in feedback control loops as their acquisition delay would...
This paper describes the implementation of a second order sliding mode (SOSM) controller for a practical point-of-load (POL) power supply with realistic values of output capacitor equivalent series resistance (ESR) and equivalent series inductance (ESL). The SOSM control presented in this paper results in fast transient responses, has a current limiting feature, supports light load operation, and...
Traditionally, DCM/CCM Boundary Boost PFC Converters with current-mode control require line voltage sensing (via a resistor divider) to define the sinusoidal shape of the reference for the inner current loop and a multiplier to adjust the amplitude of this reference to regulate the output voltage. In contrast, using voltage-mode control neither line voltage sensing nor a multiplier is needed. Lower...
A new dual-port antenna suitable for cognitive radio system is proposed. The antenna structure consists of a sensing(UWB) antenna and a frequency reconfigurable antenna for communication. It has a capability to operate in wide band (3.1–12GHz) and three narrow bands (band1∶3.7–4.2GHz, band2∶5.0–5.8GHZ, band3∶7.4–8. GHz). Three switches are used to control the antenna working at different narrow bands.
Interleaved DC-DC boost converters are interesting choices in applications like fuel cells and photovoltaic systems. Although this converter offers low current ripple, but an open-circuit switch fault can lead to unacceptable current ripples. In this paper, a very fast and simple method is proposed to detect an open-circuit switch fault and its location. This method doesn't need any additional sensors,...
An overview of solar energy technology is discussed briefly. To increase the energy efficiency of a solar array, maximum power output is desired. There are three major approaches for maximizing power extraction from a solar array. They are sun tracking, maximum power point (MPP) tracking or a combination of both. The sun-tracking design can increase energy yield up to 50% over the year compared to...
In this project, a quadcopter-based auto cameraman system is designed and implemented. The quadcopter equips with an ordinary camera for both video recording and target tracking. Via tracking the position and orientation of the markers on the reporter’s microphone, the quadcopter can move to the corresponding position relative to the microphone such that the onboard camera can always have a good view...
The emergence of Internet of Things (IoT) has brought forth new opportunities by seamlessly integrating the physical world using computing, sensing, and wireless networks, transforming it into a cyber-physical system. An essential building block enabling an IoT is a sensing system. The use of “near-field communication (NFC)” has gained attention in recent years, as it enables low-power short-range...
STT-MRAM has been considered as one of the most promising nonvolatile memory candidates in the next-generation of computer architecture. However, the read reliability and dynamic write power concerns greatly hinder its practical application. In this paper, we propose a synergistic solution, namely pseudo-differential sensing (PDS), to jointly address these two concerns. Three techniques, including...
Novel, simple and accurate Direct Digital Converters suitable for variable reluctance sensors are presented in this paper. These sensors have two inductors that vary in a push-pull manner with-respect-to the measurand. It is known that a small linear range can be obtained by taking the difference between the values of the sensor inductances. The proposed digital readout circuits accept the sensor...
Within this work, an analytical approach for robust recognition of four different head gestures in a continuous data stream is presented. Analytical solutions are more robust against signal variations than pure signal-oriented approaches. Furthermore, they enable user-independent gesture recognition. The proposed model integrates information about sensor placement and ideal shape of gestures. Furthermore,...
Cognitive Radio (CR) networks is well-known for its expertness in solving the problem of spectrum scarcity that reside with wireless resources where unlicensed users can opportunistically perform transmission without impacting the operations of licensed users. Channel switching is inherently necessary to make unlicensed and licensed users to appropriate propagation in the channel. All through the...
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