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Background: Acute myeloid leukemia is one of the deadliest hematologic malignancies that is marked by genetic alterations, abnormal cellular functions, and proliferation. Mutations in isocitrate dehydrogenase genes, particularly isocitrate dehydrogenase gene 1 and isocitrate dehydrogenase gene 2, have emerged as recurrent genetic abnormalities in acute myeloid leukemia. These mutations lead to abnormal enzymatic activity, accumulating 2-hydroxyglutarate, which disrupts normal cellular processes including DNA methylation. Objectives: This review article explores recent findings related to the implication of isocitrate dehydrogenase gene mutations on the acute myeloid leukemia epimethylome and provides evidence of the relationship between these mutations and the pathogenesis, prognosis, and treatment of acute myeloid leukemia. Methods: A comprehensive literature search was conducted to identify relevant studies investigating the impact of isocitrate dehydrogenase mutations on altered DNA methylation patterns of acute myeloid leukemia-related genes. The selected studies were reviewed and analyzed to highlight the significance of their findings. Results: The review highlights that isocitrate dehydrogenase gene mutations in acute myeloid leukemia are associated with widespread changes in DNA methylation patterns. These alterations primarily affect DNA methylation of acute myeloid leukemia-associated genes, including DNA methyltransferases and ten-eleven translocation proteins. Such epigenetic dysregulation in the DNA methylation modifying genes contributes to global DNA hypermethylation and specific gene hypomethylation leading to abnormal cellular functions and the development of acute myeloid leukemia. Conclusion: The findings of this review support the significant impact of isocitrate dehydrogenase gene mutations on DNA methylation of acute myeloid leukemia-related genes. Understanding the interplay between isocitrate dehydrogenase gene mutations and DNA methylation dysregulation provides insights into acute myeloid leukemia pathogenicity and may have implications for prognostication and targeted therapies.

This article presents accurate, efficient and reliable small-signal model parameter extraction approaches applied to Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT). Firstly, a scanning-based systematic model parameter extraction methodology is developed. Then, newly reported Optimization Algorithms (OAs) namely Marine Predators Algorithm (MPA), Pelican Optimization Algorithm (POA) and Tunicate Swarm Algorithm (TSA) in combination with direct extraction method are utilized to develop hybrid model parameter extraction methodologies. Lastly, both the scanning-based systematic and OA-based hybrid modelling procedures are thoroughly validated and demonstrated on a GaN HEMT grown on diamond substrate to identify their pros and cons in distinct application settings. Moreover, reliability, accuracy, convergence behavior, complexity and execution time of MPA-, POA- and TSA-based hybrid extraction procedures are also discussed. We found that both classes of the approaches are able to produce an excellent agreement between the measured and modelled S-parameters for a wide frequency range up to 40 GHz. However, OA-based hybrid modelling procedures are more physically relevant.

A number of machine learning (ML) algorithm based small signal modeling of Gallium Nitride (GaN) High Electron Mobility Transistors (HEMTs) have been reported in literature. However, these techniques rarely provide any inkling about their suitability in modeling GaN HEMTs under varied operating conditions. In this context, this paper thoroughly investigates various ML based techniques and identifies their suitability for specific application scenarios. At first, an array of commonly employed modeling techniques based around Artificial Neural Network, RANdom SAmple Consensus, Support Vector Regression, Gaussian Process Regression, Decision Tree, and Genetic algorithm assisted Artificial Neural Network are used for development of modeling framework to exploit the bias, frequency and geometry dependence on S-parameter based outputs. Subsequently, the ensemble techniques namely Bootstrap aggregating, Random Forests, Extremely Randomized Trees, AdaBoost, Gradient Tree Boosting, Histogram-based Gradient Boosting, and Extreme Gradient Boosting are also explored to understand the capability of these algorithms in the development of GaN HEMT small signal models. Thereafter, an exhaustive analysis of bias and variance is carried out to figure out the most appropriate algorithms for specific applications. The discrepancies during model development are removed by tuning the hyperparameters of the respective models using Random search optimization with 5-fold cross validation technique. Post tuning, the models are evaluated in terms of generalization capability, Advanced Design System compatibility, computational efficiency, training and simulation time, models’ capacity and parameters’tuning time.

In this paper, a novel X-band TM01–TE01 mode converter for high-power microwave (HPM) system is proposed. To realize the compact design, a helical corrugated waveguide with large deformation is employed to convert the TM01 mode into TE01 mode. By optimizing the structure parameters, the simulation results demonstrate that the maximum conversion efficiency of the proposed TM01–TE01 mode converter reaches 98.8% at 9.2 GHz. Moreover, this mode converter exhibits a conversion efficiency of over 95% in the operation band from 8.7 to 9.42 GHz, and the power capacity of the mode converter reaches GW-level in theory. More importantly, the overall longitudinal and transverse dimensions of the mode converter are less than three wavelengths. The results show the compact structure and high conversion efficiency of this mode converter, which has great potential application value in the HPM system.

This article presents an extensive study and demonstration of efficient electrothermal large-signal GaN HEMT modeling approaches based on combined techniques of Genetic Algorithm (GA) with Artificial Neural Networks (ANN), and Particle Swarm optimization (PSO) with Support Vector Regression (SVR). Another promising Gaussian Process Regression (GPR) based large-signal modeling approach is also explored and presented. The GA-ANN addresses the typical problem of local minima associated with the backpropagation (BP) based ANN. The GA successfully aids in the determination of optimal initial values for BP-ANN and enables it to find a unique optimal solution after subsequent of iterations with higher rate of convergence. This is also achieved using PSO-SVR with lower optimization variables. The developed modeling techniques are demonstrated and used to simulate the gate and drain currents of a 2-mm GaN device. All the models are relatively simple, practical, and easy to implement. The gate and drain currents models are embedded in an equivalent large-signal circuit’s model and built in Advanced Design System (ADS) software. The implemented model is validated by large-signal measurements and very good fitting results have been obtained. The model also showed an accurate simulation for a nonlinear power amplifier with very good computational speed and convergence.

This paper presents a new design methodology for broadband Doherty architecture using the three-port input and output networks technique. The proposed topology was developed to overcome the Doherty power amplifier (DPA) bandwidth limitations. The output three-port network performs the impedance matching from any load impedance to the optimum loads for both main and peaking transistors and also combines the power delivered from the two devices at any power ratio. On the other hand, the input-splitting network is proposed for matching the input impedances of the two transistors to the source impedance. The freedom in choosing the power division ratio of the input network enables us to achieve a tradeoff between efficiency and linearity. Also, it provides a way to accomplish the phase compensation using an arbitrary phase difference between the two branches of the Doherty power amplifier and thus, helps obviate the need of the highly bandwidth limiting offset lines found in the Doherty design. A two-stage broadband Doherty power amplifier is implemented using 0.25-um GaN HEMT MMIC process to validate the proposed topology. The fabricated DPA was measured under both continuous wave (CW) and modulated signal at different operating frequencies. Across 3.3-3.7 GHz, the implemented DPA delivers a maximum output power exceeding 42 dBm, power added efficiency (PAE) over 52 % at the peak power and over 38 % in the back-off state over the operating 400 MHz bandwidth. The fully integrated circuit has a chip-size of 4.4 mm × 3.5 mm.

In this work, the properties of a two-tone signal driven concurrent power amplifier (CPA) are analyzed extensively. Firstly, the characteristics of two-tone signals are discussed to explain the nonlinearity and efficiency of two-tone signal driven CPA. Secondly, a method of how to solve the efficiency of a two-tone signal driven CPA is proposed in this paper with a detailed calculation procedure and complete theory. Finally, a general empirical expression to calculate the drain efficiency (DE) of CPA versus the frequency ratio and the amplitude ratio of the two carriers is proposed. Simulation results and experimental verifications are given to validate the proposed analytical formulation to predict the efficiency of CPAs when driven with balanced or imbalanced two-tone signals.

The present study focuses on the examination of the propagation of plane surface waves on a coated half-space, which is accompanied by the magnetic field force, and the normal mechanical loading, due to Winkler’s elastic foundation. The study is based upon the application of the analytical and asymptotic integration procedures to acquire and further analyze the aspiring secular equation. Asymptotically, the influence of the coating layer is suppressed by deploying apposite effective boundary conditions that are ingrained on a long-wave approximation condition, to obtain the resulting pseudo-differential operator of the reduced equation of surface motion. In fact, the comparison between the two approaches yielded considerable agreement through the dependency plots, featuring the scaled velocity v/vR versus the dimensionless wavenumber K. Moreover, certain well-known results in the literature are obtained as liming circumstances of the present examination. Additionally, an insightful finding about the vanishing possibility of the coating layer is illustratively highlighted.

We demonstrate experimentally, for the first time, a distributed digital predistortion model for radio-over-fiber (RoF) downlink suitable for broadband 5G signals. The model reduces the analog-to-digital converter sampling frequency up to 1/3 of the required sampling in the example of the conventional memory polynomial DPD model, hence reducing demodulator costs and hardware complexity. This model also provides better intercarrier interference by reducing the adjacent channel leakage ratio (ACLR). This leads to reduced crosstalk, which impacts the multi-core and multimode RoF links. Long-term evolution advanced signals of a 256-quadratic-amplitude modulation of different bandwidths are used to validate the model. We achieved an average reduction of 2.5 dB in ACLR for signal bandwidths in the range 100–300 MHz while maintaining minimum error vector magnitude (EVM). The RoF downlink can deliver a peak bit rate of 2.016 Gb/s with a spectral efficiency of 6.72 b/Hz and EVM less than 4%.

This paper presents a broadband gallium-arsenide pseudomorphic high-electron-mobilitytransistor (GaAs pHEMT) power amplifier integrated circuit (PAIC) based on a dual-frequency selective impedance matching technique for warfare applications. For a broadband PA design, lower and upper-frequency corners where serious performance degradation is likely to occur should be carefully considered. Feedback and resistive biasing circuits were adopted for driver and main stages to making their frequency responses as flat as possible. Optimum impedances of not only extended lower and upper-frequency corners but also center frequency, were then extracted. Such dual-frequency selective impedance matching technique was applied for extended lower and upper-frequency corners while checking the mismatch level for the center frequency. The proposed broadband PAIC for frequency band from 6 to 18 GHz was designed using a 0.15 μm GaAs enhanced-mode pHEMT (E-pHEMT) process. The implemented broadband PAIC with a simple two-stage structure had a very small chip size of 1.19×0.82 mm2. It exhibited a power gain of more than 16.4 dB and output power of 19.2 dBm. Very flat characteristics in power gain and an output power within ±1.0 dB through the whole band were achieved.

In this paper, an analytical design space of power amplifiers (PAs) including the Class-A/B/J continuum for dynamic load modulation (DLM) at the current generator plane (CGP) is proposed based on the theory of load modulated (LM) continuous Class-B/J PAs. By introducing a biasing operation factor ρ, the theory of DLM PAs provides an analytical design space for all the operation modes from Class-B/J mode to Class-A mode. The analytical design space of DLM PAs shows that high efficiency is maintained at a large dynamic range of output power back-off (OPBO) with a purely resistive load modulation at the CGP when Class-B/J mode is performed. For deep Class-AB mode, the analytical design space of the DLM PAs shows that a combination of resistive and reactive load modulation at the CGP is used to maintain the high efficiency at the OPBO. The effectiveness of the proposed analytical design space is validated by load-pull measurements of a bare-chip gallium nitride (GaN) device.

This paper presents a fully integrated C-band Doherty power amplifier (DPA) based on a 0.25-μm GaN-HEMT process for the 5G massive MIMO application. The performance degradation caused by nonlinear output capacitance is analyzed, and a novel compensation technique is proposed. A low-Q output network is employed to broaden the bandwidth, and its insertion loss in the back-off region is demonstrated to be mainly decided by the Q-factor of the drain bias inductor of the main PA. Hence, by adopting on-chip transmission lines with high Q-factors for drain biasing, a full integration, and a low loss can be achieved simultaneously. Reversed uneven power splitting and back-off input matching are proposed for gain enhancement. The fabricated DPA demonstrates a small-signal gain of 8.6-11.6 dB, an output power of 40.4-41.2 dBm, a 6-dB back-off drain efficiency (DE) of 47% - 50%, and a saturation DE of 55%-63% across a wide bandwidth from 4.5 to 5.2 GHz, with an ultra-compact size of 2.2 mm × 2.1 mm. Using a 40-MHz LTE signal with a 7.7-dB peak-to-average power ratio at the carrier frequency of 4.9 GHz, the measured average output power and efficiency are 33 dBm and 43%, respectively. The raw adjacent channel power ratio is -29 dBc and is improved to -46 dBc by applying digital predistortion.

This paper demonstrates a Ku-band medium and long distance microwave wireless energy transmission system based on the rectifier diode. The transmitting compact Cassegrain antenna with an aperture of 1.5m forms a more centralized and uniform 2m x 2m field zone, which has more than 80% transmission efficiency. According to the distribution of receiving field, the multiple ways synthesizers connected to rectangular patch arrays are designed. And the results predict that the receiving efficiency of the antenna is directly related to the performance of the system, which reaches 50%, not including the possible insert loss. Besides, the Ku-band rectifying circuit is optimized and measured, and the comparing results show that the practical rectifier diode can obtain more than 40% conversion efficiency at the operating frequency of 12.75GHz. Finally, the microwave wireless energy transmission system is designed, and it finally obtains 4% DC-DC conversion efficiency at a distance of 60m, which is likely to be used in unmanned aerial vehicle hovering charging system, robot charging while working, isolated island wireless power supplying and wireless charging of various sensors.

The paper presents a design of a broadband high-efficiency class-E power amplifier (PA) for the advanced efficiency enhancement architectures applications. A sequential load pull methodology to design broadband class-E power amplifiers using a packaged gallium nitride power transistor is presented. Two different broadband matching synthesis techniques have been proposed using lumped elements have been presented and implemented in the manuscript. A fourth-order low-pass impedance transformation topology is designed as the output matching network to provide the optimum load reflection coefficients in the targeted bandwidth (1.8-2.7 GHz). A combination of input and output matching network has been proposed in the manuscript to satisfy the given fractional bandwidth requirements. For practical validation, a Wolfspeed (Cree) CGH40025 package transistor has been used. Under continuous wave test condition the fabricated PA showed more than 50% power added efficiency (PAE) with up to 29 W output power for 40% fractional bandwidth from 1.8-2.7 GHz. Furthermore, the proposed broadband Class E PA is deployed in efficiency enhancement architecture like delta-sigma modulation based transmitters. The PA shows more than 48% PAE all over the frequency band when driven with a delta-sigma modulated LTE downlink signal while maintaining high signal quality and PA reliability.

This paper presents a comprehensive study of the impact of resistive harmonic loading on the design of integrated Class-F power amplifiers (PAs). The proposed time-domain waveform-based analysis allows for an evaluation of the performance of Class-F PAs while controlling both second and third harmonics simultaneously. The voltage mapping is presented to include the impact of the resistive second harmonic impedance in the design of Class-F PAs. Besides, drain current formulations as a function of conduction angle are used to evaluate the harmonic coefficients under the impact of resistive third harmonic impedance. As such, the combination of resistive second and third harmonics is modeled to study its impact on efficiency and optimum impedance in the Class-F PAs. For practical validation, the derived knowledge is applied to propose a novel integrated Class-F PA that absorbs the output capacitance into the match while maintaining a purely resistive load at the fundamental frequency. The output match is fabricated on a highly integrated NXP Laterally Diffused MOSFET (LDMOS) process. At 1.8 GHz, using NXP 5-mm LDMOS die, the integrated Class-F achieves a drain efficiency ranging from 52% to 61% at 5-W output power based on two different design topologies. Both prototypes demonstrate excellent isolation at the second and third harmonics. Measurement results confirm the theoretical framework reported in this paper.

A concurrent dual-band six-port receiver based on real-valued time-delay neural network (RVTDNN) is proposed in this paper to retrieve two baseband signals from a dual-band radio frequency signal, concurrently. Different from the traditional six-port correlator, the new passive circuit correlator, which is composed of one power divider and three quadrature couplers, has three inputs and three outputs, resulting in the decreased hardware complexity as well as circuit size, and a reduced power consumption for the system. The new six-port correlator, its output power as well as the baseband signal recovery theory are described and analyzed in detail. The calibration algorithm based on the RVTDNN is adopted to verify the feasibility of the concurrent dual-band receiver based on the proposed correlator circuit. Finally, a practical wideband six-port receiver test bench, which operates from 2 to 3 GHz, is built and tested using the common modulated signals. The calculated error vector magnitudes are all less than 2% verifying the correctness of this novel system implementation approach.

In this paper, a dual-branch topology driven by a Delta-Sigma Modulator (DSM) with a complex quantizer, also known as the Complex Delta Sigma Modulator (CxDSM), with a 3-level quantized output signal is proposed. By de-multiplexing the 3-level Delta-Sigma-quantized signal into two bi-level streams, an efficiency enhancement over the operational frequency range is achieved. The de-multiplexed signals drive a dual-branch amplification block composed of two switch-mode back-to-back power amplifiers working at peak power. A signal processing technique known as quantization noise reduction with In-band Filtering (QNRIF) is applied to each of the de-multiplexed streams to boost the overall performances; particularly the Adjacent Channel Leakage Ratio (ACLR). After amplification, the two branches are combined using a non-isolated combiner, preserving the efficiency of the transmitter. A comprehensive study on the operation of this topology and signal characteristics used to drive the dual-branch Switch-Mode Power Amplifiers (SMPAs) was established. Moreover, this work proposes a highly efficient design of the amplification block based on a back-to-back power topology performing a dynamic load modulation exploiting the non-overlapping properties of the de-multiplexed Complex DSM signal. For experimental validation, the proposed de-multiplexed 3-level Delta-Sigma topology was implemented on the BEEcube™ platform followed by the back-to-back Class-E switch-mode power amplification block. The full transceiver is assessed using a 4th-Generation mobile communications standard LTE (Long Term Evolution) standard 1.4 MHz signal with a peak to average power ratio (PAPR) of 8 dB. The dual-branch topology exhibited a good linearity and a coding efficiency of the transmitter chain higher than 72% across the band of frequency from 1.8 GHz to 2.7 GHz.

The majority of techniques that deal with the mitigation of in-phase and quadrature-phase (I/Q) imbalance at the transmitter (pre-compensation) require long training sequences, reducing the throughput of the system. These techniques also require a feedback path, which adds more complexity and cost to the transmitter architecture. Blind estimation techniques are attractive for avoiding the use of long training sequences. In this paper, we propose a blind frequency-independent I/Q imbalance compensation method based on the maximum likelihood (ML) estimation of the imbalance parameters of a transceiver. A closed-form joint probability density function (PDF) for the imbalanced I and Q signals is derived and validated. ML estimation is then used to estimate the imbalance parameters using the derived joint PDF of the output I and Q signals. Various figures of merit have been used to evaluate the efficacy of the proposed approach using extensive computer simulations and measurements. Additionally, the bit error rate curves show the effectiveness of the proposed method in the presence of the wireless channel and Additive White Gaussian Noise. Real-world experimental results show an image rejection of greater than 30 dB as compared to the uncompensated system. This method has also been found to be robust in the presence of practical system impairments, such as time and phase delay mismatches.

The present study was carried out to evaluate the hematological and cytogenetic effects of water pipe smoke (WPS) in albino male mice. The investigated parameters were total count of leukocytes (TCL), mitotic index (MI), micronucleus (MN) formation and chromosomal aberrations. The results of our study showed that, mice were exposed to WPS using a special inhalation glass chamber (whole body exposure). Mice exposed daily to 100 puffs of WPS on the bases of (1h exposure per day). The exposure experiment continued daily for the periods of 3, 5, 7 weeks consequently. The results revealed that the TCL significantly decreased in the second and third treatment (5930, 4120 cell/ cu. mm. blood) respectively, in comparison to control (6200 cell/ cu. mm. blood), while the MI decreased in all 3 treatment after 3, 5, 7 weeks. Nevertheless, both the MN cells and chromosomal aberration remain the same percentage as the control in the first treatment and then began to be higher than the control in the second and third treatment. The results indicated that the WPS has cytotoxic and mutagenic effects, according to the obtained results of MN cells and chromosomal aberration assays in the three types of treatment.

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