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This paper is dedicated to the investigation of the influence of different waveforms on the efficiency of radio frequency (RF) to direct current (DC) conversion in wireless power transfer (WPT) systems. Single-tone, multi-tone, random and chaotic signals are used and compared as waveforms for wireless power transfer. The influence of peak-to-average power ratio (PAPR) and average input power of the...
According to the prior knowledge used in the algorithms, NMF-based speech enhancement can be categorized into supervised (NMF) one and semi-supervised (SNMF) one. In the supervised version, speech is estimated with the prior knowledge of both speech and noise. For the semi-supervised version, speech bases are learned on clean speech data in advance and adapted to different noise conditions. With the...
The ever increasing number of people who need continuous medical attention coupled with the rising costs of healthcare have triggered the concept of remote patient monitoring. This can be achieved using wireless sensor nodes attached to the human body. Such technology is mainly limited by the amount of available energy. Thus efficient power consumption estimation in the early stage of the design is...
The concept of Radio Frequency (RF) fingerprinting is that electronic devices can be identified and authenticated through their radio frequency emissions, which contain intrinsic features of the device itself. RF fingerprinting can be used to enhance the security of wireless networks because the fingerprints provide a form of authentication. In previous research papers, the RF fingerprints have typically...
The development of mobile internet and semiconductor technology making the people getting strong demand for the home life of the network, intelligence and energy saving. Now a days, energy saving is becoming more vital role as the energy conservation and environmental protection are taking more and more attentions. We can detect environmental condition through intelligent control using Wireless Sensor...
A significant cause of low production in agriculture is the absence of water in soil. The measurement of moisture level of plants is a basic parameter and in order to calculate it, we can quantify the difference between the leaf temperature and the air temperature. In this work, we introduce a novel leaf temperature sensor for agricultural monitoring. The sensor communicates remotely with a reader...
This paper presents an RF rectifier circuit for electromagnetic energy harvesting system. The double voltage rectifier together with the super capacitor are employed to harvest the electromagnetic energy. The proposed circuit is designed to operate at 5.8 GHz Wi-Fi frequency band. The Schottky diode SMS7630-061 is used to implement the proposed rectifier circuit. The super capacitor 5 V with capacity...
This paper presents a fully passive front-end operating at 461 MHz, as a building block for implementation of wakeup receivers in sensor networks. We use an Aluminum Nitride (AlN) microelectromechanical system (MEMS) resonator for impedance transformation in order to achieve passive voltage boost at the input of a quadratic envelope detector, fabricated in a 130nm CMOS process. Each individual block...
This article presents the design and experimental results of a continuous-time (CT) sigma-delta (ΣΔ) flexible modulator and low noise amplifier (LNA) with data-weighted average (DWA) technology. An image-reject low noise amplifier is designed for wireless tracheostomy tube and bio-signal acquisitions. An inter-stage T-structure filter is used in the low noise amplifier design to bending antenna. The...
Climate change and resultant scarcity of water are becoming major challenges for countries around the world. With the advent of Wireless Sensor Networks (WSN) in the last decade and a relatively new concept of Internet of Things (IoT), embedded systems developers are now working on designing control and automation systems that are lower in cost and more sustainable than the existing telemetry systems...
Accurate localization of Wireless video capsule endoscope (VCE) is a crucial requirement for proper diagnosis of intestinal abnormalities. A major challenge in RF based localization is the shadow fading and multi-path propagation effects of non-homogeneous medium of human body which causes high random deviations in the measured path loss resulting in high localization error. To address the randomness...
This paper focuses on the implementation of a modified lightweight version of the MODBUS protocol optimized for wireless sensor networks. Here, the master and slave arrangement is made wireless using low cost and multi-featured RF modules (nRF24L01P). The modified MODBUS Packet Data Unit is sent in the data frame of the nRF24L01P. As part of the implementation in this paper the nRF24L01P's feature...
This paper proposes a highly sensitive RF-to-DC power converter with an extended dynamic range that is designed to operate at the medical band 433 MHz and simulated using 0.18 μm CMOS technology. Compared to the conventional fully cross-coupled rectifier, the proposed design offers 3.2× the dynamic range. It is also highly sensitive and requires −18 dBm of input power to produce a 1 V-output voltage...
Far field radio frequency (RF) harvesting technique have become popular method to power wireless sensor network (WSN) recently. However, due to the low efficiency of RF energy harvester, RF powered WSN is unable to perform dynamic network allocation. Accordingly, the functionality of WSN is limited. This paper presents a practical RF powered wireless sensor node design that could dynamic join the...
Monitoring of partial discharge (PD) activity within high voltage electrical environments is frequently used for the assessment of insulation condition. Traditional measurement techniques employ technologies that require either offline installation or high power consumption and cost. A wireless sensor network is proposed that utilizes only received signal strength to locate partial discharge within...
In this work we propose and study via numerical simulation a new metamaterial-inspired device for MRI. The proposed device is a one-dimensional periodic structure formed by multiple inductively-coupled split-loop resonators (SLRs). The whole structure at the resonance of its fundamental eigenmode has a homogeneous magnetic field in a hollow surrounded by the split-loops. It has been shown that the...
An underground wireless attendance system is designed based on radio frequency identification and wireless sensor network technology. The advantages of wireless sensor network have been applied in the attendance system, mainly solving the problems of wiring complexity and error-prone information collection, among other issues in the current attendance system. This system consists of radio frequency...
This article reports the findings of a radio received signal strength (RSS) based biometric sensing approach for lightweight walker recognition. A vertically deployed radio sensing network is designed to obtain the movement of walker at seven different heights. The sequential RSS at each height contributes weak distinguished feature to walker's identify. The human subjects are recognized by vector...
The ever-increasing demand for the radio frequency spectrum is transforming current radio regulations at national and international levels. Data collected with earth exploration satellites can easily become unusable due to RF interference whether it is from out-of-band or spurious emissions towards the bands used by the sensors. In 2006, the FCC auctioned 90MHz of the spectrum for 3G cellular communications...
Several thousand sensors hard-wired to data acquisition units may be used to instrument a gas turbine engine during its development phase. This process of hard-wiring is time-consuming, expensive, and inflexible. A wireless sensor network (WSN) is proposed as a solution for selectively replacing wired sensors with wireless sensors and for adding new sensors. The WSN shall operate between the engine...
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