Micromachines MDPI’s Post

Wireless power transfer (WPT) systems based on the inductive link which is used in a wide variety of applications such as handle mobile devices (HMDs), charging electric vehicles (EVs), RFID applications and biomedical devices (IMDs) have received more attention in recent years. Basically, a WPT system is constructed by the transmitter coil (TX) and the receiver coil (RX). The power transfer efficiency (PTE) of the WPT system is significantly affected by the distance between the TX and RX coils (coil coupling distance), increasing the coupling distance causes reduction in the PTE of the WPT system. To compensate this effect, some relay resonators (repeaters) are inserted between TX and RX coils in the proposed wireless power relay transfer (WPRT) system. Actually, the repeaters can unload the coils and play an important role in improving the PTE in long coupling distance. That is why, WPRT systems have drawn much attention in the recent years. There are two major techniques used to calculate PTE in WPRTs; Coupled mode theory (CMT) and equivalent lumped circuit theory (ELCT). However, another technique, based on the filter theory, has been recently proposed, which deals with problems such as the complexity of selecting and designing the proper type of filters. In practice, extracting the mathematical model of the WPRT systems with N-2 repeaters based on CMT or ELCT is more difficult specially when N is large. In this paper, despite the complexity, we extended the mathematical analysis for WPRT system with N-2 repeaters based on the ELCT model and the equation of the PTE was extracted. The obtained model is simple and N can be extended to any value. In addition, to achieve the highest possible PTE, we used genetic algorithm (GA) to optimize the proposed model. In order to validate the accuracy of the extracted model and verify the proposed algorithm, WPRT systems with different numbers of repeaters were designed and simulated. The simulation results are in agreement with calculation results. #AnahitaBagheri #AbbasErfanian #Implantable #IMDs #Wireless #Inductive #wirelesspower #wirelesscharging #circuitdesign #implantabledevices #rfidtechnology

New device precisely controls photon emission for more efficient portable screens https://lnkd.in/e5cNnNvP

Today's featured paper in our May issue deals with bandwidth and frequency-dependent digital predistortion This article describes a computational efficient approach to bandwidth and frequency-dependent digital predistortion to significantly improve performance of simpler, less costly non-flat PA designs for 5G and beyond user equipment.    Device: Scalable bandwidth and frequency-dependent digital predistortion (DPD) linearizer based on an incremental bandwidth frequency dependent (IBWFD) generalized memory polynomial (GMP) behavioral model. Spectrum: 5G sub-6 GHz spectrum (approach is not intrinsically frequency specific). Novelty: The behavioral model applies the doubly orthogonal matching pursuit (DOMP) greedy algorithm and resource economy strategies such as a regretting process to be used to configure the linearizer with simpler algorithms and a smaller number of algorithm coefficients to compute. Performance: Adjacent channel power ratio (ACPR) improved about 6 dB;      Normalized mean square error (NMSE) improved more than 20 dB. Application: Significantly improves performance of simpler, less costly non-flat PA designs for modern for 5G and beyond user equipment. Read More Here:      https://lnkd.in/eQzbyC_a #ieee #ieeemtt #ieeetmtt #microwaves #rf #powergeneration #frequency #linearity #tablelookup #fpga

Amorphous Silicon/IGZO/CMOS flat panel detectors belong to indirect imaging. The principle is to convert X-rays into visible light, and by sensing the intensity of X-rays passing through the object, the images are given different grayscale levels, so the image be seen. The basic structure of the indirect conversion detector includes: scintillator, sensor and readout circuit and peripheral control circuit. Scintillator and sensor are the core parts, which determine the main performance indicators of the flat panel detector. In contrast, Direct Conversion does not require scintillators. After the photoconductive semiconductor material collects X-rays, it directly converts X-rays into electrical signals. The basic structure of the direct conversion detector includes: sensor and readout circuit, peripheral control circuit, and the sensor (photoconductive semiconductor) is the core part. At present, Amorphous Silicon, CMOS and new IGZO are the absolute mainstream of the market, occupying more than 90% of the market share of flat panel detectors. #cmos #scintillator #detector #sensor #readout_circuit #IGZO

New hard drive technology utilizing three-dimensional magnetic recording could significantly increase storage capacities and reduce the number of HDDs required. Research collaboration between NIMS, Seagate Technology, and Tohoku University has demonstrated the feasibility of multi-level recording, potentially achieving areal densities exceeding 10 Tbit/in². By stacking recording layers vertically and adjusting laser power during writing, this innovation promises more efficient and cost-effective data storage solutions. Future developments aim to further enhance magnetic properties and reduce grain size to optimize high-density HDDs. #HardDrive #Magnetic #3D #technology

modulation in optical Transmission - modulation is used in wireless communication and with optical Transmission - modulation help increasing the system capacity , distance and spectrul efficiency - modulation depends on carrier signal , we can control carrier paramters based on the baseband signal - traffic coming from client devices to be modulated called baseband signal - paramters can be controlled in the carrier can be : amplitude ( intensity of light wave ) frequency phase polarization - in optical illusion , we are focusing on ASK , PSK , QAM - ASK : amplitude shift key , in this type of modulation we are encoding the traffic by turning the laser on and off - laser on , means bit 1 , laser off means bit 0 , it's very simple - OOK ( on - off keying ) can be considered as the simple type of ASK - OOK can be return to zero or non return to zero encoding - PSK : phase shift key , in this type of modulation we change the carrier phase accordingly to represent the informations variation - PSK has many types : B-PSK D-PSK DQ-PSK DP-QPSK - third type is QAM ( quadrature amplitude modulation ) - most common type , support high spectrul efficiency , use amplitude and phase paramters to represent the informations - we have many types of QAM: 4 QAM 16 QAM 64 QAM - the differences is in baud rate , number of symbols and bits / symbol - demodulation in optical called detection , we have 2 main types of detection : direct detection coherent detection - direct detection is used in case we using direct intensity modulation ( OOK ) , it's simple and widely used with 2.5 , 10 Gbps systems 0 direct detection use PIN & APD to detect and demodulate the signal - coherent detection much complex & used with 40 , 100 , 200 Gbps systems - coherent detection used to mix the received modulated signal with local oscillator optical carrier to recover the phase and amplitude of the signal - types of modulators : direct electro absorber mach zehnder - differences between them are in dispersion tolerance , cost & wavelength stability #WDM #OTN #Optical #Modulation

In this study, researchers demonstrated a high-intensity spatial-mode steerable frequency up-converter in both temperature and wavelength manipulating methods. Stable TM 01, TM 10, and TM 00 modes at the sum–frequency generation (SFG) wavelength could be prepared automatically within a few-mode periodically poled LN waveguide without prefabricating the spatial modes of the incident signal and pump lights by adjusting the incident combined lights or using a spatial light modulator. This result is appealing for on-chip integration with the microlasers such as distributed feedback laser (DFB) or semiconductor optical amplifier. Full-length paper available at https://lnkd.in/gNS82M5y High-intensity spatial-mode steerable frequency up-converter toward on-chip integration