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The in-body operation of implantable medical devices (IMDs) bring the challenge of delivering power conveniently and safely from outside of the body-contact distance through obstacles, including skin and tissue. Magnetic resonance-based wireless power transfer (WPT) provides a promising solution for IMDs, featured by its high-power transfer efficiency at midrange distances. However, to our knowledge, very few works have investigated the performance of the resonance-based method for transferring power to sensors in vivo. Therefore, in this paper, we design an IMD powered by a WPT system and carry out an in-vivo experiment on the device. This IMD is a Bluetooth module integrated with a temperature sensor and its power is provided by a 3-coil magnetic resonance-based WPT system without batteries. Through the in-vivo experiment on a pig, we successfully apply the WPT system to power the implanted sensor for wireless in-body temperature monitoring. The results demonstrate that the examined 3-coil coupled magnetic resonance WPT method can meet the power requirement and ensure the functional operations of the implanted temperature sensor. Consequently, the capability and feasibility of the magnetic resonance approach for powering in-vivo IMDs are verified, paving the way for the future design and applications of implantable sensors.

The new generation of 5G mobile and inter-satellite communication systems are using mmWave active phased array (APA) which have up to hundreds of individual analog transmitter and receiver chains and antennas. When moving to high integration scenarios, the isolation between the array and the power amplifiers(PAs) is often removed. Since the array elements are electromagnetically coupled, the waves fed to the antennas are also driving the output ports of the PAs. This effect creates a possible variable load at the output of each PA, depending on steering angle and radiated power at each element in the array. In this system, the behavior of each PA cannot be fully described solely as a function of its input, as it will change according to the coupled signal. In this paper the inter-element coupling of a 4x4 planar patch antenna array and the resulting variation in output impedance of the PA connected to each patch is simulated by using computer simulation tool (CST).The impact of the interelement coupling has been verified on linearization procedure of the active array.

In this paper, we demonstrate how a deep neural network (DNN) can be used to compensate for nonlinearities and distortion effects introduced by the latest technology of 5G transmitters. A linearization approach based on neural networks can successfully cope with the challenges introduced not only by the high nonlinearity, wide bandwidth, and high frequency but also with challenges due to inter-PA crosstalk and load modulation. The device-under-test used in this experiment, is a state-of-the-art 5G 4x4 active phased array (APA) operating in very highly nonlinear regions at 28 GHz with a 100 MHz wide 3GPPbasestationsignalandwithOTAmeasuredsignalsusedfor training. Using the proposed DNN based linearization technique, an improvement of 11 % in error vector magnitude (EVM) and 10 dB adjacent channel leakage ratio (ACLR) are achieved which demonstrates the promising potential of this technique for emerging broadband communication systems such as 5G/6G and low earth orbit (LEO) satellite networks

Electronic biomedical implants rely on wireless power transfer (WPT) systems to remove their dependency on chemical batteries to avoid potential safety issues. As traditional systems based on the inductive link are limited by their transmission distance, the magnetic resonance coupling (MRC) method for WPT has been proposed to increase the delivered power for mid-range applications. In this paper, we design a 3-coil magnetic resonant WPT system with a small power receiver for micro biomedical implants and evaluate its power transfer capability with a pork steak to mimic the attenuation caused by biological tissues. Operating at 180 kHz, the output of the proposed system can supply 56 mW at 3.3 V for an implanted receiver at a distance of 80 mm, which is 1.5 times more efficient than the traditional 2- coil system under the same conditions. Such a result demonstrates the applicability and improvement of the MRC-WPT system for powering up in-body biomedical devices.

This paper proposes a deep neural network (DNN)based digital signal recovery (DSR) technique for low Earth orbit (LEO) satellite communications. Different from existing work, which only investigates impacts of the satellite-to-ground communication channel, this work focuses on handling the nonlinearity variations caused by input power level perturbations in the transmitter. The system is validated using a high gain radio frequency power amplifier(RF-PA) operating at 28.5 GHz, where perturbations are introduced by varying the power level of the input signal, from −39 dBm to −31 dBm, to the RFPA. Experimental results show that the DNN trained at an input power level of−35 dBm achieved an improvement of 7.52 dB in the adjacent channel leakage ratio (ACLR), and an improvement of 4.2% in error vector magnitude (EVM). Applying the DDN trained at −35 dBm to other cases demonstrates that a 1 dB power level perturbation only leads to ≈ 1 dB degradation of the ACLR and ≈ 1.6% degradation of the EVM, respectively, which indicates the potential of the proposed approach. This paper proposes a deep neural network (DNN)-based digital signal recovery (DSR) technique for low Earth orbit (LEO) satellite communications. Different from existing work, which only investigates impacts of the satellite-to-ground communication channel, this work focuses on handling the nonlinearity variations caused by input power level perturbations in the transmitter. The system is validated using a high gain radio frequency power amplifier (RF-PA) operating at 28.5 GHz, where perturbations are introduced by varying the power level of the input signal, from -39 dBm to -31 dBm, to the RF-PA. Experimental results show that the DNN trained at an input power level of -35 dBm achieved an improvement of 7.52 dB in the adjacent channel leakage ratio (ACLR), and an improvement of 4.2% in error vector magnitude (EVM). Applying the DDN trained at -35 dBm to other cases demonstrates that a 1 dB power level perturbation only leads to ≈ 1 dB degradation of the ACLR and ≈ 1.6% degradation of the EVM, respectively, which indicates the potential of the proposed approach.

This paper discusses the training of deep neutralnetworks (DNNs) for electromagnetic problems. The main concernsinclude how to modify EM problems to take the advantageof the deep learning techniques and how to tailor conventionaldeep learning concepts with electromagnetic domain knowledge,which has been overlooked by most existing DNN based EMresearch. A 1 8 patch antenna array has been adopted as thetest vehicle for investigation, with the aim to use deep learningfor radiation pattern synthesis. It is analyzed via electromagneticsimulation first to collect sufficient training data sets containingdifferent combinations of excitation signals and correspondingradiation patterns. These data are then pre-processed and passedto DNNs for training to imitate the mapping between excitationsignals and radiation patterns. With careful feature selection andDNN architecture optimizations, two DNN models are obtainedeventually. One of them aims at forward radiation synthesisin any certain excitation condition, and the other seeks outbackward excitation signals needed for a given radiation pattern,and both achieved an accuracy over 80%. This paper mayprovide enlightenment and reference in applying deep learningto electromagnetic problems in terms of feature selection andarchitecture modification.

Rapid and accurate detection of partial discharge (PD) of metal enclosed AC switchgear (HV switch cabinet for short) is of great significance for safe operation of the power grid and high reliability of power supply. The existing methods such as transient earth voltage (TEV), ultra-high frequency (UHF) and acoustic emission (AE) methods still have shortcomings, and the optical pulse method has not been applied yet. Additionally, due to mutual independence, heavy workload, low efficiency and measurement limitations of testing equipment, as well as the single criterion of signal source, technicians have great doubts about whether there are insulation defects in the interior of switchgear cabinets. Therefore, in this paper, an integrated composite sensor for HV switchgear cabinet is designed and its installation method is given. The preliminary experimental study in the laboratory shows that the designed sensor can measure ultrasonic, optical pulse, transient ground voltage and UHF signals at the same time, which provides a new research direction for the effective detection of partial discharge signals of high voltage switchgear cabinets.

Domain knowledge assisted training dataset generation for deep learning aided metasurface designs is investigated. By combining the domain knowledge of metasurface from the designer and the advanced machine learning (ML) technique, an efficient training dataset generation approach has been successfully achieved. Unlike most existing metasurface generative designs that allow for arbitrary target pattern generation, which results in a time-consuming or even nonconvergence model training process, the proposed method takes the full advantages of the prior knowledge from designer to reduce the target solution space greatly, leading to reduced design cycles and higher ex-plainabilities of the designs. The proposed ML model combines generative adversarial network (GAN) and variational autoen-coder (VAE) as an encoder to transfer the original data into the latent space, which greatly improves the design efficiency as demonstrated in the validation results.

A radiation-beam switchable phased array antenna is proposed for 5G mobile terminals. The design consists of eight discrete-fed slot radiators placed at the top edge of the mobile phone PCB. The configuration of the antenna element is composed of an I-shaped slot radiator with a single director. By implementing and biasing RF switches (D$_{1} \& {D}_{2}$) across the I-shaped slot radiators of the main design, the radiation beams of the phased array can be switched from end-fire to broad-side radiation modes. The proposed design can provide a 2 GHz impedance-bandwidth with S$_{11}\le$-10 dB at 28 GHz (5G candidate band) and generates high-gain radiation beams in both end-fire and broad-side modes. Fundamental characteristics of the design in terms of S-parameters, radiation patterns, efficiency, and antenna gain are investigated. The obtained results showed promising performance of the array under different states of the switches.

Today, huge amount of data can be searched through the Internet. To divide the big data into several and different information groups is difficult. In this paper, the proposed Automatic Correlation Keyword Grouping and Combination Based Deep Information Search could find the further grouping information according to the specific language. By the proposed procedure, the deep searching via using simple keywords can be automatically done through the data source grouping step, Correlation Keywords Combination method, and convergence step. The implementation and verification shows that the proposed system could find the deep grouped information corresponding to different language.

In this study, a new dipole-slot antenna array with beam-steering characteristic and end-fire radiation beams is proposed for 28 GHz smartphone applications. Eight elements of compact dipole-slot antennas have been placed on the top region of PCB (60×120 mm2). Another set of the 8-element linear phased array with the same performance could be used at the bottom portion. A low-cost FR-4 dielectric is used as the substrate. The antenna elements provide a broad bandwidth with more than 10 GHz while impedance matching is better than -10 dB. The proposed 5G array antenna offers good fundamental characteristics including directivity and wide-scan beam-steering function which makes it fit the need of 5G mobile terminals. Simulation validations were conducted and satisfactory results were obtained.

A frequency-switchable patch antenna for millimeter-wave (mm-Wave) 5G communications is presented in this paper. The antenna is designed on a Rogers RT5880 substrate with 0.8 mm thickness, 2.2 dielectric constant, and 0.0009 loss tangent. The antenna design consists of a conventional patch antenna surrounded by a rectangular-ring parasitic load structure. By implementing and biasing an active element (diode switch) the antenna response can be switched to operate at either 22.25 GHz or 28 GHz which are two of the candidate frequency bands for the future 5G networks. Performances of the antenna in forms of single element, linear array (1×8), and planar array (4×4) have been investigated. Furthermore, the radiation performance of the planar array in the presence of the human hand is studied. The simulated results of the proposed design show good characteristics of the arrays.

It can be extremely mission-critical to identify the source of an error in satellite communication systems and in this initial work an approach based on neural networks is proposed for diagnosing the faulty antenna elements remotely from the receiver side. A simple active antenna array which consists of four power amplifiers and a four-by-one linear antenna array has been considered in this work for proof of concept. Signals captured from various fault scenarios are used to train a 4layered feed-forward neural network using amplitude and phase data. The validation results show that the trained neural network can correctly identify the fault power amplifier with an accuracy higher than 96 %, which indicates the promising potential of the proposed approach.

This paper presents an electrical impedance characterization and measurement method for monitoring bone fracture healing progress after osteosynthesis, for cases applying an intramedullary nail. While existing solutions fail due to the presence of the nail, the proposed method makes active use of the nail to achieve accurate healing progress monitoring. The proposed method captures variations in the electrical impedance at the fracture site as body tissues transform from the blood (hematoma) to fully recovered intact bone during healing. The proposed method, therefore, has the potential to be used for data acquisition of bone healing and pave the way for digitized diagnosis and treatment of bone fractures.

In this paper, a radiation-beam switchable antenna phased array is proposed for 28 GHz 5G mobile terminals. Its configuration contains eight elements of discrete-fed T-shaped slot radiators with pairs of directors placed at the top edge of the mobile phone PCB. By implementing and biasing RF switches across the first director of the antenna elements, the radiation beams of the array can be switched from end-fire to broadside radiation modes. The proposed design provides a 2 GHz impedance-bandwidth at 28 GHz. The simulated results show good characteristics of the array for different states of the switches.

In this paper, we propose a coplanar-waveguide (CPW)-fed ultra-wideband (UWB) monopole antenna with improved gain characteristic. The antenna configuration consists of a circular monopole radiator with a rectangular strip. It is designed on an FR-4 substrate with a compact size of 25 × 25 mm2. By employing a new single-layer frequency selective surface (FSS), formed by 10 × 10 unit-cells, the gain characteristic of the antenna is enhanced from 1 ~ 3 dBi to 6.5 ~ 9 dBi. The FSS layer reflector is placed below the UWB monopole antenna. The unit cell of the proposed FSS consists of a square-ring patch with a protruded diamond-ring strip in it. The design concept has been discussed with simulations and good results are achieved.

In this manuscript, the design of a dualport/dual-polarized slot antenna with improved gaincharacteristic is proposed for ultra-wideband (UWB)applications. The antenna design contains a diamond-ring slotradiator fed by two independently arrow-shaped microstripfeeding lines which can exhibit a polarization diversitycharacteristic. A low-cost FR-4 dielectric (= 4.4, = 0.02) isused as the substrate. In order to increase the gaincharacteristic of the antenna a 10×10 single-layer frequencyselective surface (FSS) is employed below the dual-polarizedslot antenna. The unit cell of the proposed FSS contains asquare-ring radiator with a protruded circular-ring strip. Amaximum gain of 9 dBi with less than 3 dB variation isobtained over the UWB frequency band. The characteristicsof the dual-polarized UWB slot antenna with and without theFSS were examined using simulations and good simulationresults have been obtained.

This paper investigates the linearization of active antenna arrays with non-uniform power distributions, which is challenging for conventional linearization methods. A technique based on the nonlinearity consistencies existing among the PAs is proposed and the technique allows linearizing the whole array using a single pre-distortion signal. Simulation results with a four-element array using GaN PAs show that the proposed technique can improve the ACPRs of the PAs in the array by up to 16 dB.

This paper proposes the design of a new reconfigurable dipole antenna array for cognitive 5G cellular networks. The single-element of the design contains a dipole radiator along with a pair of spiral resonators (SRs) at both sides of the substrate. The reconfigurability characteristic of the antenna is achieved by employing two active elements (PIN diodes) connecting the tips of the dipole arms and the spiral resonators. In the simulations, the rectangular copper sheets are excluded to approximate the cases with a turned on and off switch. The frequency response of the antenna can be switched to operate at 18 and 32.5 GHz while maintaining the main resonance at 25 GHz. In addition, the radiated beam directions can be reconfigured to broadside and end-fire modes. Using the proposed design, radiation properties of a smartphone antenna with a $1\times 8$ linear dipole array have been investigated and satisfactory results have been achieved. The obtained results show that the proposed reconfigurable dipole antenna array fulfills the general requirements in cognitive cellular networks.

In this paper, a high-performance phased array antenna design with Yagi-Uda antenna elements is proposed for 5G cellular communications. The design configuration contains eight antenna elements arranged on the top portion of smartphone mainboard with a thin Alron-350 substrate. The configuring of the antenna element is composed of a driven dipole radiator with multiple directors. The proposed array is working in the frequency range of 26 GHz- 30 GHz. By increasing the number of employed directors, the fundamental properties of the elements can be improved. Good beam-steering function, high radiation beams, and efficiencies are achieved for the proposed design. In addition, the antenna exhibits sufficient performances in the presence of the user-hand.

Fe 2 O 3 nanopowders were prepared by solid phase reaction method. The phase structure, microstructure, magnetic properties and gas sensor properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), vibration sample magnetometer (VSM) and gas sensor measuring system. It was found that the precursor sintered at 300 °C was spinel structure and transformed into α-Fe 2 O 3 above 400 °C. The results of the room temperature hysteresis loops showed that the results obtained from the magnetic hystersis loop at room temperature were in agreement with those from the XRD spectra. Moreover, it was shown that γ-Fe 2 O 3 can be used as gas sensor of the alcohol. he α-Fe 2 O 3 nanopowders can be obtained at a lower sintering temperature. In addition, the gas sensor of γ-Fe 2 O 3 was more sensitive to the alcohol.

Pulse Diagnosis (PD) is a well-established diagnostic technique used in Traditional Chinese Medicine (TCM). The positions for PD are the radial arteries in the left and right wrists, and the pulse assessment is done by placing index, middle, and ring fingers on each wrist. The pulse of patients is then measured in the superficial, middle, and deep levels by TCM doctors to obtain more information regarding energy or Qi imbalance of the patients. For modern medical researches, PD is also used for indicating some status of patients. However, it is a challenging issue for all medical staff to properly assess the pulse of various patients. Therefore, this work proposes a systematic scheme to measure patient pulse by Photoplethysmography (PPG) sensors. An evaluation framework of some treatments, e.g., acupuncture therapy, is then built on top of the PPG sensing system with machine learning solutions. In our implementation, sensor data will be collected and transferred from Arduino platforms to our server for the PD assessment. The effect of the evaluated treatments will be estimated by the analysis of the PD results with machine learning supports. The major performance index is on the accuracy of the assessment for the treatments.

In this research, Finite Element Method (FEM) is used to simulate transient thermal conduction in the monolithic three-dimensional integrated circuit (3DIC) with a novel location-controlled-grain (LCG) technique. Through this method, the impact of laser flux, amorphous Si thickness and interlayer dielectric (ILD) thickness on that model can be investigated. Furthermore, with the assistance of thermal damage simulation, we can utilize the optimal process parameters in this state-of-the-art technique to accelerate the development of advanced semiconductor technologies.

In this paper a novel outphasing amplification architecture, Transmitted Linear Amplification with Nonlinear Components (T-LINC), is proposed and evaluated. Different from conventional LINC techniques that combine the outphased signals before transmission, the proposed architecture transmits both outphased signals and implements the signal combination in the base-band domain at the receiver side. By digitally combining the signals in the receiver, it is easier to correct gain or phase mismatch existing between the two outphased signals, without adding any extra complexity in the transmitter. Additionally, a power combiner is no longer required in the transmitter. Simulations show that the proposed technique is able to correct transmitter gain and phase imbalance and achieve an ACPR level of -42 dBc and EVM below 2.5 % for 16-QAM signals. Index Terms—Digital combination, digital mismatch correction, linear amplification with nonlinear components (LINC), outphasing amplification, Transmitted LINC (T-LINC). With the recent popularization of nanosatellite technologies, the industry is putting a notable effort into increasing the performance of the systems integrated in these small spacecrafts. In this paper, a novel outphasing amplification architecture to enhance the power efficiency of a satellite downlink is presented and evaluated. Based on a conventional LINC (LInear amplification with Nonlinear Components) architecture, the proposed architecture transmits both outphased signals, and carry out the signal combination in the receiver in the base-band domain. The resulted architecture takes advantage of an efficient signal amplification given by the nonlinear power amplifiers, while the elimination of the signal power combiner from the transmitter, increases the overall power efficiency. We outline and analyze those elements that restrict the performance of this novel approach. The simulations and laboratory experimentation probes the proposed architecture is feasible, and able to improve a ?? % the power efficiency, compared to a classic transmitter front-end architecture.

—By the increased number of antennas and power amplifiers connected to each in 5G system, the linearization methods like Digital Pre-Distortion (DPD) of each power amplifier is inefficient due to antenna imperfections such as crosstalk. Furthermore due to limited area the distance between antennas in array can vary, which leads to unwanted coupling between antennas. A solution to this problem can be treating the amplifiers and antennas as one system and linearizing the main beam signal at receiver rather than on each single power amplifier. In the work described in this paper the whole system including amplifiers, antennas and receiver is treated as a 2-ports system and the impacts of above mentioned constraints are investigated. By increasing the number of antennas and power amplifiers connected to each in 5G system, the linearization methods like digital pre-distortion (DPD) of each power amplifier is inefficient due to antenna imperfections such as crosstalk. As a result of limited area the distance between antennas in array can vary which leads to unwanted coupling between antennas. A solution to this problem could be treating the amplifiers and antennas as one system and linearizing the main beam signal at the receiver rather than on each single power amplifier. In the work described in this paper, the whole system including amplifiers, antennas and the receiver is treated as a 2-ports system and the impacts of the above mentioned constraints are investigated.

Due to the battery capability of drone or unmanned aerial vehicle, the ability of services and flying distance provided by drone are limited. Considering the frequent monitoring of the agricultural disease, the power recharging station for unmanned aerial vehicle without manual operation is important issue. Based on the proposed Environment and Location Aware Drone Services Corresponding to Green Energy Charging Station, the drone services can be started at one green energy charging station and ended at another. According to the complete-coverage path planning algorithm, the drone service such as environment monitoring or pesticide spraying can fully cover the farm. In addition, the implementation shows that suitable green energy power source can be dynamically embedded into power recharging station. The feasibility of the proposed system is verified.

Recently, in order to reduce the consummation of energy, the automation for personal services in a family become popular. Since, every members within one family have their own behaviors, for each family member, the provided services should be also different. Hence, in this paper, we use the adaptive cloud IoT devices, named Intelligent Tetris Switch (ITS), combining with the Bigdata analytics and deep learning technique for providing smart home personalizing services. First, the usual energy consummation for all family members are collected. And then, we using the Bigdata analytics to find the hidden pattern in the collected data. Those patterns are used for distinguish the usages of different family members and learned by the Deep learning technique. In the experimental results, we can see the analyzing results of the collected data. At final, the learned patterns are used to predict the usages of the family members.

This paper presents a Non-Line-Of-Sight (NLOS) identification approach based on machine learning algorithms for ultra wide band positioning systems. The identification of NLOS conditions is crucial for positioning using trilateration as NLOS introduces positive biases in the calculated distances. The proposed method is based on the classification of the Channel Impulse Responses using Fisher's Linear Discriminant and Support Vector Machines (SVM). The proposed approach has been validated by measurements in both an anechoic chamber where known reflections and obstacles are introduced and in a basement corridor as real environment scenario with more than 500 and 700 measured data sets for training, respectively. Results show an average identification accuracy of 92% for the case using SVM in the anechoic chamber and almost 100% for Fisher's discriminant combined with SVM for the corridor scenario.

Since the Internet Of Things (IOT) are generally used, the data or information transferred between IOT devices and servers should be secured. In this research, hybrid cryptosystem based on the shared-key and asymmetric cryptography (or called Public-key cryptography) is proposed. According to the network communication, MAC address information of the IOT device is used for public-key querying and exchanging. Via asymmetric cryptography, the shared key can be automatically exchanged between IOT device and server. The implementation shows the feasibility of the proposed hybrid cryptosystem which could secure the data.

This paper presents a new auditing system scheme based on radio frequency identification technologies for cryopreservation applications using liquid nitrogen at temperature of -196°C. Conventional approaches such as hand written labels or printed barcodes suffer from the significant manual labor work and freeze-thaw-damaging risk of the sample. The proposed scheme integrates miniaturized RFID electronic devices and antennas in the thin cryogenic straws without significantly changing their dimensions. In addition, 900 MHz frequency band is chosen for long reading range, which eliminates the need to take the preserved biological samples out of liquid nitrogen and minimizes the damaging risk. Four most important technical aspects for the system have been identified and investigated: 1. The link budget is evaluated by FDTD numerical simulations to make sure the RF signal strength meets the requirement for the reading range. 2. The total efficiency of small and tightly coupled RFID dipole antennas is studied and obtained by simulations. 3. The current-voltage behaviors of two types of transistors in typical RFID electronics have been characterized by measurements to identify the suitable transistor type for reliable circuit designs at -196°C. 4. The easy-to-access and anti-collision reading system for fast data collection is analyzed. The obtained results indicate that the proposed scheme is feasible, which can be beneficial for the relevant scientific fields.

In this work, a filtering mm-wave antenna array is proposed for the future 5G mobile devices. The filtering antenna design is based on the fourth-order coupled line planar filter with a metal lid added in order to increase the filter sharpness and decrease loss. In this paper, the metal lid is modified so the slot antenna is formed at the end of the filter. Finally, the proposed antenna element is combined into a linear phased array on the short edge of the typical mobile ground plane.