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Novel Nano Structure for Green Energy Harvesting at 10μm Thermal Radiation

Journal of Electronic Science and Technology 2016年第3期14卷 242-248页

作者： mohd Khairul Hisham Ismail Mazlina Esa mohd fairus mohd yusoff Noor Asniza Murad National Space Agency Banting 42700Malaysia the Faculty of Electrical engeering Universiti Teknologi MalaysiaJohor Bahru 81310Malaysia

In recent years, the potential of renewable green energy sources has been extensively studied. The proven technology which is photovoltaic solar cells strictly depends on daylight and produces low-efficiently. To overcome the restrictions, one technology studied is through harvesting the thermal radiation energy which can provide a 24-hour energy source. The continuity of energy sources promises very good energy conversion especially for military applications. This article presents a new structure that can harvest the abundant thermal radiation energy into usable energy at the wavelength of l0 lum. A rectangular structure with a perturbation slit was designed to integrate with a rectifier circuit for green energy conversion. The slit tunnel junction guided the electromagnetic field into a junction where the energy could be collected and converted. An enhancement factor of approximately 110.6 can be achieved by a perturbation slit length of 1.0 μm. The results extracted from the proposed design promise a better candidate to overcome the disadvantages of photovoltaic solar cells for energy harvesting devices.

关键词： Enhancement factor green energy harvesting renewable thermal radiation.

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维普期刊数据库

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Real-Time Frequency Estimation of Complex GMSK Signal of Green Communications Devices

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Journal of Electronic Science and Technology 2016年第2期14卷 126-132页

作者： Umar Suleiman Dauda NikNoordini NikAbdMalik Mazlina Esa Kamaludin mohd Yusof mohd fairus mohd yusoff Mohamed Rijal Hamid Department ofCommunication Faculty of Electrical EngineeringUniversiti TeknologiMalaysia81310 Johor BahruMalaysia

Parameter estimation of signals of universal software radio peripheral （USRP） devices is crucial to solve the problem of phase offsets of received signals in distributed beamforming. For systems that will utilize the closed loop feedback algorithm where the receiver needs to send the received signal strength （RSS） values periodically to the beamforming node so as to take advantage of energy conservation, the frequency and phase of these signals should be estimated before smoothening by nonlinear filters. This article presents the estimation of the frequency offsets of a Gaussian minimum shift keying （GMSK） signal from N210 USRP devices in real time by using the Radix-2 fast Fourier transform （FFT） algorithm in GNURadio. For these green communications devices, most of the needed hardware parts have been software defined, thereby reducing the supposed energy consumption. The frequency offsets from reference carrier frequencies of 900 MHz and 2.4 GHz are less than 3 kHz each before the estimation, but the average offsets are 45 Hz and 100 Hz after the estimation, respectively. The high offset value experienced with the 2.4 GHz carrier was due to consistent interference from devices on that same frequency.

关键词： Cramer-Rao lower bound Gaussianminimum shift keying maximum likelihood estimation,universal software radio peripheral.

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维普期刊数据库

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Process Noise Parameters of Beamforming Green Nodes

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Journal of Electronic Science and Technology 2016年第2期14卷 111-117页

作者： Umar Suleiman Dauda NikNoordini NikAbdMalil Mazlina Esa Kamaludin mohd Yusof mohd fairus mohd yusoff Mohamed Rijal Hamid Department of Communication Faculty of Electrical EngineeringUniversiti Teknologi Malaysia81310 Johor BahruMalaysia

Signals arrive out of phase at the intended receiver from collaborative beamforming （CB） nodes due to the instability in the output frequency signals of the universal software radio peripheral＇s （USRP） local oscillator （LO）. These nodes including the target must synchronize their oscillator frequencies for coherent signal reception. In order to do this, frequencies and phases of the signals should be estimated in software defined radio （SDR） and smoothen with nonlinear filters such as the extended Kalman filter （EKF）. The process noise parameters of the NI USRP-2920 nodes will have to be calculated and used with the EKF process noise covariance matrix. These nodes are green communication hardware devices where most of the hardware units are now software defined. This article uses the direct spectrum method to obtain the phase noise values at various frequency offsets of the NI USRP-2920 in order to calculate the power spectral density of fractional frequency fluctuation. By applying the power-law noise model to this obtained value, the generated white frequency noise and random walk frequency noise values are q_1=1.93x10^-21 and q_2=5.86x10^-18, respectively.

关键词： Collaborative beamforming phasenoise process noise parameters universal software radioperipheral.

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维普期刊数据库

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