MULTI-OBJECTIVE OPTIMIZATION AND PERFORMANCE ANALYSIS OF BIMORPH MAGNETO-ELECTRO-ELASTIC ENERGY HARVESTERS

This study thoroughly investigates the multi-objective optimization of a magneto-electro-elastic (MEE) harvester in bimorph configurations and by the new method of Harris Hawk’s optimization (HHO). The harvesters are configured in both series and parallel connections and under harmonic excitation to explore the effects of various parameters on the performance of the harvesting system. The primary objective is to maximize the total harvested power. Optimization involves various parameters, including dimensions, relative displacement changes, voltage, and current values. The Pareto fronts from the HHO method reveal optimal points in different configurations and scenarios. Notably, the optimal points are selected based on the criterion of maximum total power. The results reveal distinct optimal points for each objective function, demonstrating trade-offs between performance metrics. These findings provide valuable insights into the design and operation of efficient energy harvesters in MEE systems. The parallel configuration outperforms the series connection in terms of the current generation. Moreover, the evaluation of the overall performance of the energy harvesters in terms of total harvested power indicated that both series and parallel connections could lead to promising outcomes. However, the series connection exhibited a more dominant effect on maximizing the total harvested power, proving its relevance in pursuing the highest possible power output

Indoor broadcasting using visible free space optic over broadband powerline communication

Visible Free Space Optic (VFSO) is a new and attractive technology, which employs visible light generated by white light emitting diode (LED) for optical wireless communications. In addition, it is possible to use ubiquitous powerline cables as a communication medium among other fixed network equipments which is powerline communication (PLC) technology. An integrated system of VFSO and PLC uses existing powerline cables and white LEDs as a communication channel hence it has the advantage of low operating cost and provides easy data transmission. The current integrated system encounters some problems due to PLC multipath, noise, and no practical modeling for white LEDs, which degrades significantly the performance of the whole system. Therefore, this study presents the optimum orthogonal frequency division multiplexing (OFDM) modulating signal power, proper DC biasing point, and LED dynamic range to solve system degradation. Moreover, a practical LED model is also presented, and the performance of the integrated system in terms of OFDM signal power versus bit error rate in the presence of broadband PLC impulsive noise, multipath issue, and additive white Gaussian noise optical channel is studied. Based on indoor applications, the primary purpose for VFSO link is the general lighting designation with the standard brightness level and the secondary purpose is for data transmission. Therefore, to have a high quality VFSO link besides ensuring sufficient horizontal brightness of the place, high data rate of optical communication links with low bit error rate are also achieved. The radiometric parameters of white LEDs using simulation and experiment are reported. Optimum 15dBm OFDM signal power, (3.2V, 350mA) biasing point, and 1Vp-p dynamic range for white LED has the data rate more than 28Mbits/second with the bit error rates lower than 610? . Moreover, at least 400lx of indoor lighting was also fulfilled. So, the new integrated system is considered as a good alternative for other indoor wireless system counterparts

INVESTIGATION OF ELASTIC FOUNDANTIONS ON PULL-IN PHENOMENON OF DOUBLE CANTILEVER NANOSWITCHES IN PRESENCE OF CASIMIR FORCES

ABSTRACT In this paper, we study the instability of double cantilever type nanoelectromechanical systems (NEMS) supported on nonlinear elastic foundations in presence of casimir forces. Modified Adomian decomposition (MAD) is introduced to investigate the pull in parameters. pull in parameters are investigated for difference stiffness parameter of nonlinear elastic foundations and it is found that the nonlinear elastic foundations increases the pull-in voltage but the effect of nonlinear elastic foundations on the pull in deflection of double cantilevernanoswitches is weak. In modeling of the electrostatic force, the fringing field effect is taken into account. The results of analytical MAD solutions are in good agreement with the numerical one

Radio frequency signal generation and wireless transmission using PANDA and add/drop systems

The radio frequency (RF) signal generation and its modulation is the basic building block of wireless communication system. High frequency RF signals are desired in high speed systems but traditional methods to generate high frequency RF signals suffered from electronic devices data processing rate. On the other hand, spectral efficient modulation is also played vital rule in the high speed wireless communication where orthogonal frequency-division multiplexing (OFDM) transmission is mostly preferred. Due to the challenges regarding to electronic devices, optically generation and processing of RF OFDM signals has gained considerable attention. In this work microring resonator (MRR) system is used to implement all optically generation and modulation of RF OFDM signal. The MRRs can be used as filter devices where generation of high frequency (GHz) soliton signals as single and multi-carrier can be performed using suitable system parameters. The results show the generation of 64 multi-carriers evenly spaced in the range from 54.09 GHz to 55.01 GHz to generate OFDM signal all optically, where the RF modulation was achieved by two optical carriers with free spectral range (FSR) = by 5 GHz

Several mode-locked pulses generation and transmission over soliton based optical transmission link

A soliton-based optical communication system is presented to generate and transmits several mode locked laser pulses (generated by fiber laser setup) over 50 km fiber and 120 m wireless link. The passive mode-locking feature of the laser system proposed in this paper is based on nonlinear polarization rotation evolution

High-capacity soliton transmission for indoor and outdoor communications using integrated ring resonators

A system consisting of a series of microring resonators, incorporating an add/drop system, is presented in order to create ultra-short spatial and temporal single and multisoliton pulses, which can be used for indoor and outdoor optical communications. Chaotic noise can be generated by a bright soliton pulse propagating inside a nonlinear microring resonator system. The results obtained show that a single temporal and spatial soliton pulse, with full width at half maximums of 75 fs, 80 fs, 700 fs, 4.4 ps, and 0.30 nm, can be generated. The add/drop system can be used to generate a high number of ultra-short soliton pulses in the ranges of nanometer/second and picometer/second. The simulated multisolitons have full width at half maximums of 16 ps, 20 pm, 130 ps, and 35 pm and free spectrum ranges of 500 ps, 0.57 nm, 3.5 ns, and 1.4 nm, respectively. The multisolitons generated at the drop port can be used in indoor optical communications, where the ultra-short pulses with a variety of central wavelengths (from λ = 1550 to λ = 1560) from the through port can be multiplexed-demultiplexed along an optical fiber with a length of 50 km. The filtered signals can be obtained at the end of the transmission link used for optical outdoor communication

Analytical treatment of the ring resonator passive systems and bandwidth characterization using directional coupling coefficients

We have shown that an add/drop system connected to a single microring resonator could be constructed using the fiber optics, where it can be used to generate a single soliton carrier, in which the tuning and manipulation of the bandwidth is performed to control the output signals. The chaos filtering via the add/drop device is implemented by using suitable parameters of the system. The coupling coefficient of the system is considered to be an effective parameter to determine the output intensity power of the system. In order to optimize the system, the smaller coupling coefficient is required. The bandwidth of the generated pulse changes respects to variation of the coupling coefficient. Here the chaotic signals which are used widely in communication, for variation of coupling coefficients is analyzed. To recover the pulses from the chaotic noises in the fiber ring resonator, we use the add/drop filter system with the appropriate parameters, where the insertion loss and gain of the system is measured. As a result, the increase of the coupling coefficients leads to increase of the bandwidth of the soliton pulse. In order to use ultra-short soliton pulses applied in optical communication, lower coupling coefficient is admired where, the power control can be performed within the system

IEEE 802.15.3C WPAN standard using millimeter optical soliton pulse generated by a panda ring resonator

A system of microring resonators (MRRs) connected to an optical modified add/ drop filter system known as a Panda ring resonator is presented. The optical soliton pulse of 60 GHz frequency band can be generated and used for Wireless Personal Area Network (WPAN) applications such as IEEE 802.15.3c. The system uses chaotic signals generated by a Gaussian laser pulse propagating within a nonlinear MRRs system. The chaotic signals can be generated via a series of microring resonators, where the filtering process is performed via the Panda ring resonator system wherein ultrashort single and multiple optical soliton pulses of 60 GHz are generated and seen at the through and drop ports, respectively. The IEEE 802.15.3c standard operates at the 60 GHz frequency band, and it is applicable for a short distance optical communication such as indoor systems, where the higher transmission data rate can be performed using a high frequency band of the output optical soliton pulses. The single and multi-soliton pulses could be generated and converted to logic codes, where the bandwidths of these pulses are 5 and 20 MHz, respectively. Thus, these types of signals can be used in optical indoor systems and transmission link using appropriate components such as transmitter, fiber optics, amplifier, and receiver

Adaptive control for laser transmitter feedforward linearization system

In this paper, an adaptive control system is employed in a novel implementation technique of the feed forward linearization system for optical analog communication systems' laser transmitter. The adaptive control system applies the Newton trust-region dogleg algorithm, which is a numerical optimization algorithm, to automatically tune the adjustment parameters in the feed forward loops to optimize the feed forward system performance and adapt to process variations. At the end of this paper, significant reductions of over 20 dBm in the third-order inter modulation distortion products have been achieved for operating frequencies from 5.0 to 5.8 GHz