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This paper introduces an anti‐aliasing image reconstruction method in the optical coordinate domain for point‐to‐point transmission in AR/VR headset displays, employing variable downsampling ratios across different image areas to reduce transmission bandwidth and corresponding upscaling ratios at the receiver. Filter parameters for anti‐aliasing calculations at each pixel position are determined based on optical coordinates distorted by the lens, enhancing detail in areas with significant image deformation. Image quality is evaluated using MSSSIM and supported by experimental evidence. [ABSTRACT FROM AUTHOR]

This paper proposes a 6Gbps receiver for 8K 240Hz OLED display. In the proposed receiver, video image compression is presented to double the effective data bandwidth. In addition, it proposes dual path CTLE offset voltage calibration and CTLE adaptation with eye margin tester to implement 6Gbps receiver. The prototype IC is implemented in a 0.18μm HVCMOS process and is evaluated as an 8K 65‐inch panel. [ABSTRACT FROM AUTHOR]

This paper proposes a 6Gb/s receiver for 8K displays and beyond. In the proposed receiver, a novel channel coding with 1.96% overhead is presented to guarantee minimum run‐length in the clock embedded interface. It can also reduce bandwidth for effective data transmission compared to 9b/10b coding that requires 11.11% overhead. Furthermore, we present an on‐chip eye margin tester that can measure the internal timing margin of receiver with only 1% area overhead. The prototype ICs are implemented using 0.18‐μm HVCMOS process and evaluated in an 8K 65‐inch panel. [ABSTRACT FROM AUTHOR]

In this study, a novel anti‐aliasing image reconstruction approach for foveated transmission in VR/AR headset microdisplays is presented. It efficiently reduces transmission bandwidth by varying downsampling ratios across different image zones at the transmitter, and uses corresponding upscaling ratios at the receiver. Unique scaling‐ratios and slope parameters per position dynamically adjust the bilateral filter and bicubic interpolation in the optical coordinate system for enhancing detail preservation and minimizing aliasing artifacts. Image quality is assessed using MSSSIM, backed by experimental results. [ABSTRACT FROM AUTHOR]

A compact 2-element antenna for MIMO applications with performance across the WLAN frequency bands is designed and fabricated on paper with a FUJI Film Dimatix 2800 material printer and conductive ink. This antenna is ∼1.1 cm × 3.5 cm and utilizes co-planar feeding techniques and ground design to allow for resonance in the 2.4 and 5 GHz frequency bands with a minimum 800-MHz bandwidth. The design is established using commercially available products for minimal processing. Factors such as ink handling, printing conditions, and paper selection are discussed qualitatively as they relate to antenna fabrication and performance. Successful simulation and fabrication is reported with low correlation, high isolation, and low reflection. [ABSTRACT FROM AUTHOR]

To achieve high refresh rate 8K+ resolution display for virtual reality, we developed the sub‐area control scanning technology with the human eye visual perception characteristic, which can reduce the bandwidth by 80% while ensuring the clarity of the viewing area. [ABSTRACT FROM AUTHOR]

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Wideband radio frequency (RF) channelization is essential for the reception and detection of cross-band RF signals in various applications, including communications, radar, and spectrum sensing. However, digital channelizers are inefficient at performing RF channelization over a working bandwidth above 10 GHz. Meanwhile, current photonic RF channelizers face challenges in simultaneously considering a wideband, multi-channel, and a high crosstalk suppression ratio. In this work, we proposed and demonstrated a wideband image-reject RF channelization scheme based on integrated dual-soliton microcombs. The dual-soliton microcombs are used for RF spectral copies and heterodyne detection, respectively. Supported by image-reject mixers, the RF channelization is verified with an 8–37 GHz working bandwidth, a 1.2 GHz channel bandwidth, and 25 channels. The image suppression ratio is higher than 34 dB for single-tone signals and 20 dB for wideband signals. Our approach provides an innovative architecture of integrated photonic RF channelizers with high performance, which can benefit a wide range of RF applications by miniaturizing the systems. [ABSTRACT FROM AUTHOR]

Background and Objectives: In this paper, a novel structure as a Folded-Mirror (FM) Trans-impedance Amplifier (TIA) is designed and introduced for the first time based on the combination of the current-mirror and the folded-cascade topologies. The trans-impedance amplifier stage is the most critical building block in a receiver system. This novel proposed topology is based on the combination of the current mirror topology and the folded-cascade topology, which is designed using active elements. The idea is to use a current mirror topology at the input node. In the proposed circuit, unlike many other reported designs, the signal current (and not the voltage) is being amplified till it reaches the output node. The proposed TIA benefits from a low input resistance, due to the use of a diode-connected transistor, as part of the current mirror topology, which helps to isolate the dominant input capacitance. So, as a result, the data rate of 5Gbps is obtained by consuming considerably low power. Also, the designed circuit employs only six active elements, which yields a small occupied chip area, while providing 40.6dBΩ of trans-impedance gain, 3.55GHz frequency bandwidth, and 664nArms input-referred noise by consuming only 315µW power using a 1V supply. Results justify the proper performance of the proposed circuit structure as a low-power TIA stage. Methods: The proposed topology is based on the combination of the current mirror topology and the folded-cascade topology. The circuit performance of the proposed folded-mirror TIA is simulated using 90nm CMOS technology parameters in the Hspice software. Furthermore, the Monte-Carlo analysis over the size of widths and lengths of the transistors is performed for 200runs, to analyze the fabrication process. Results: The proposed FM TIA circuit provides 40.6dBΩ trans-impedance gain and 3.55GHz frequency bandwidth, while, consuming only 315µW power using a 1V supply. Besides, as analyzing the quality of the output signal in the receiver circuits for communication applications is vital, the eye-diagram of the proposed FM TIA for a 50µA input signal is opened about 5mV, while, for a 100µA input signal the eye is opened vertically about 10mV. So, the vertical and horizontal opening of the eye is clearly shown. Furthermore, Monte-Carlo analysis over the trans-impedance gain represents a normal distribution with the mean value of 40.6dBΩ and standard deviation of 0.4dBΩ. Also, the value of the input resistance of the FM TIA is equal to 84.4Ω at low frequencies and reaches the value of 75Ω at -3dB frequency. The analysis of the effect of the feedback network on the value of the input resistance demonstrates the input resistance in the absence of the feedback network reaches up to 1.4MΩ, which yields the importance of the existence of the feedback network to obtain a broadband system. Conclusion: In this paper, a trans-impedance amplifier based on a combination of the current-mirror topology and the folded-cascade topology is presented, which amplifies the current signal and converts it to the voltage at the output node. Due to the existence of a diode-connected transistor at the input node, the input resistance of the TIA is comparatively small. Furthermore, four out of six transistors are PMOS transistors, which represent less thermal noise in comparison with NMOS transistors. Also, the proposed Folded-Mirror topology occupies a relatively small area on-chip, due to the fact that no passive element is used in the feedforward network. Results using 90nm CMOS technology parameters show 40.6dBΩ trans-impedance gain, 3.55GHz frequency bandwidth, 664nArms input-referred noise, and only 315µW power dissipation using a 1volt supply, [ABSTRACT FROM AUTHOR]

Resource discovery is a key challenge in dynamic environment such as Peer-to-Peer (P2P) MANETs. To leverage the lookup costs and efficiently discover the resources, the peers in a P2P network communicate with each other forming one-or-more overlay structure. And, thus the peer's connections in such overlay networks plays a crucial role. To harness this, we propose a model that focuses on the underlying network topology as each virtual link of the overlay network is supported by a path in the underlying physical network. Also, we design a new resource discovery algorithm that uses the famous Rock-Paper-Scissors (RPS) game ideology. In this work, we present a Rock-Paper-Scissors-Game-Based (RPSGB) algorithm for content discovery in mobile peer-to-peer network. The proposed work focuses on providing efficient resource discovery scheme in such a dynamic network, using the game theory concepts. Our scheme is a light-weight model aimed to suit the unstructured architecture better. The major goal of this work, is to reduce the consumption of power, minimize the lookup cost, lower the bandwidth consumption, and increase the hit ratio. We compare our scheme with the traditional well-known benchmarked schemes. After evaluation, the simulation results justify the effectiveness of the proposed protocol. The obtained results show that the proposed scheme substantially decreases the network traffic, lowers the battery power and bandwidth consumption, while having good search efficiency. Also, the search latency is minimized. The result justifies that RPSGB algorithm proposes to make resource searching much more efficient, and improves the statistics against the posed challenges. [ABSTRACT FROM AUTHOR]

This paper presents a 14‐Gb/s dual mode receiver with MIPI D‐PHY and C‐PHY interfaces for mobile display drivers. To reduce size overhead from the dual mode interfaces, we propose the termination circuit that can share 50‐Ω terminations and common‐mode capacitors while maintaining a perfectly matched load balance. The proposed dual mode receiver supports up to 14 Gb/s total bandwidth in each interface mode, resulting in broad compatibility with application processors. A mobile display driver using the proposed dual mode receiver is fabricated in a 28‐nm high‐voltage CMOS process and verified up to 3.5 Gb/s per lane in the D‐PHY mode and 2.2‐Gs/s per lane in the C‐PHY. [ABSTRACT FROM AUTHOR]

In this paper, the method for the design automation of a narrow band-pass amplifier, and hence the amplifier tuned oscillator is discussed. A fixator approach is utilized in this method to design the narrow band-pass amplifiers and a reference circuit is required for this process. The fixator–norator pair helps to generate an extra sub-circuit, generally the feedback network; the addition of this sub-circuit in the actual amplifier circuit will modify the frequency response of the amplifier. The amplifier now behaves like an active narrow band-pass filter, which exactly follows the frequency response of the model circuit. This can be turned into an oscillator by providing positive feedback. Such a circuit possesses independent frequency and amplitude control. Hence, the re-designed circuit can be employed as an active filter or an oscillator at the selected center frequency. In addition to the technical merits, the proposed method has pedagogical importance. Few case studies are worked out in this paper to demonstrate the method. [ABSTRACT FROM AUTHOR]

In modern companies, the functions of divisions, departments and staff are provided by telecommunication transmitting analog and digital unit information via SCS. Such cable system refers to the use of copper or optical cable networks, passive and active switching devices. Structured cabling system or abbreviated SCS is a complex set of cable trunks and switching equipment that provide the transfer of various types of media data (audio, video, computer data) and is the basis for the operation and integration of telephone, local computer networks, security systems and other services. Many modern systems of security or communications today integrate a wide variety of interfaces into their arsenal, greatly expanding their capabilities and performance. In this paper a smart model based on high-speed communication network with the help of structured cabling system (SCS). Here the speed and bandwidth play the major role. The proposed system focused the highspeed communication between sender and receiver with some higher bandwidth optimization. [ABSTRACT FROM AUTHOR]

An optical approach to double the pixel density by using a Pancharatnam‐Berry deflector (PBD), which generates two virtual shifted‐pixel grids based on polarization‐multiplexing, is present. A three‐layer multi‐twist PBD is fabricated, which can achieve high diffraction efficiency, broad bandwidth, and large incident angle in the visible spectral region. [ABSTRACT FROM AUTHOR]

In this paper, we propose a paper-based very thin ultra-wideband(UWB) frequency selective structure to block UWB radar or broadband interfering signals. The proposed structure combines a square loop structure with low frequency blocking characteristics and a fan-wing structure with high frequency blocking characteristics to realize wideband rejection. Resistive elements were added to compensate for polarization and incident angle stability. Based on the simulation results, we fabricated conductive patterns and resistive elements on a thin paper using the screen printing technique. We measured the transmission characteristics of the fabricated frequency selective structure using the free space measurement method and found that it has a wide bandwidth of 6.9 GHz and stable performance despite the variation in polarization and incident angle [ABSTRACT FROM AUTHOR]

The article offers information on research papers that are published in technical journals and conference proceedings. Topics include maximizing lifetime of multiple data aggregation trees in wireless sensor networks; shallow quantum circuits with uninitialized ancillary qubits; and multiperiod Internet Protocol (IP)-over-elastic network reconfiguration with adaptive bandwidth resizing and modulation.

This paper elucidates the design of an S-band conformal loop filter. A combination of loop filter loaded with split ring resonator loading is proposed for the Band Pass Filter (BPF) in the proposed design. The reduced insertion loss and improved fractional bandwidth are achieved using the symmetrical tuning stubs in the loop filter. The operating range of the proposed filter in the S-band is between 2.12 GHz to 2.24 GHz, with a fractional bandwidth of 5.5% and a reduced insertion loss of 1.1 dB. The conformal geometry has been simulated on an EM solver, and the simulation results are analyzed. The simulation results of conformal geometry show an excellent match with the planar structure. The proposed filter is further fabricated, and the S-parameters are measured. The Sparameter results of the realized filter from simulations match closely with those from measurements of prototypes but with a small shift in frequency. The measured filter operates at 2.21 GHz to 2.41 GHz with a Fractional Band-Width (FBW) of 8.6% and a minimum insertion loss of 1.4 dB. [ABSTRACT FROM AUTHOR]

This paper follows a detection-theoretic approach for using synthetic-aperture measurements, made at multiple moving passive receivers, in order to form an image showing the locations of stationary sources that are radiating unknown electromagnetic or acoustic waves. The paper starts with a physics-based model for the propagating fields, and, following the general approach of McWhorter et al (2023 arXiv:2302.06816, IEEE Open J. Signal Process. 4 437–51), derives a detection statistic that is used for the image formation. This detection statistic is a quadratic function of the data. Each point in the scene is tested as a possible hypothesized location for a source, and the detection statistic is plotted as a function of location. Because this image formation process is nonlinear, the standard linear methods for determining resolution cannot be applied. This paper shows how to analyze the detection image by first writing the noiseless image as a coherent sum of shifted complex ambiguity functions of the source waveform. The paper then develops a technique for calculating image resolution; resolution is found to depend on the sensor-source geometry and also on the properties (bandwidth and temporal duration) of the source waveform. Optimal filtering of the image is given, but a simple example suggests that optimal filtering may have little effect. Analysis is also given for the case in which multiple sources are present. [ABSTRACT FROM AUTHOR]

Radio over fiber (ROF) is a very attractive technology for the increasing demand for flexibility and transmission capacity and due to its high bandwidth and low attenuation, it offers an economic advantage. The wavelength division multiplexing (WDM) is used to multiplex the different wavelengths signals within a single optical fiber. In this paper, WDM-ROF system is analysed with different filters using an optisystem. Results were compared using max Q factor, min BER, and eye height parameters. [ABSTRACT FROM AUTHOR]

In the paper, a wideband four-way filtering power divider with arbitrary power division ratio and input absorptive feature is proposed. Two sets of coupled lines (CLs) are used to achieve the wideband performance. To obtain absorptive properties, a set of T-type absorption structure consisting of two isolation resistors and a λ/4 short-circuit stub is connected between the two CLs. Meanwhile, high frequency selectivity and good out-of-band rejection are realized by introducing two stepped-impedance resonators. Besides, output impedance matching, isolation, and unequal power distribution are achieved by the power division section in the second stage. In the analysis, the equations are derived by using the method of even-odd mode decomposition and voltage-current method. For demonstration, a prototype is designed, fabricated, and measured with the power distribution ratio of 2 : 1 : 1 : 2. Measurements show that an allfrequency band absorption of 200% is obtained with the 3-dB passband bandwidth of 78.1% and out-of-band rejection of 14 dB. Besides, it also shows 15-dB isolations within more than 60% FBW and has the feature of small size. [ABSTRACT FROM AUTHOR]

This paper describes a 2-stage tactic for achieving an odd-order variable-bandwidth (OO-VBW) filter with absolutely guaranteed stability. The design methodology aims to minimize the p-norm amplitude-response error while maintaining the OO-VBW-filter's stability. In order to tune OO-VBW filter's amplitude response, we utilize a kind of functions of the bandwidth (BW)-tuning parameter to express the filter's coefficients. Because those functions have changeable function values, the designed OO-VBW-filter's amplitude response possesses variability. Another important concern in this paper is the stability issue. When the filter coefficient values expressed as function values are changed, the OO-VBW filter that has feedback structures may become unstable. This necessitates that the OO-VBW-filter's stability must always be preserved during real-time tuning. In order to stabilize such an OO-VBW filter that has feedback structures, a coefficient-conversion (CC) algorithm is adopted, and it is incorporated into the 2-stage methodology for obtaining the OO-VBW filter. To illustrate both the stability and high approximation accuracy, the design of an OO-VBW bandpass filter is simulated. The simulation details verify that both stability and high accuracy can be successfully achieved. [ABSTRACT FROM AUTHOR]

A 360° video offers a more immersive experience, gaining increasing popularity among users. However, enhancing the transmission efficiency of 360° videos under limited bandwidth conditions remains a significant challenge. This paper segments the video into three areas: the attention area, the edge area, and the viewpoint-switching transition area. Based on the segmentation of these three distinct video areas, a novel non-uniform coding transmission method for 360° videos is presented, along with mathematical modeling to define the optimization problem. A heuristic algorithm is subsequently introduced, which adaptively determines the optimal number of tiles and allocates the bitrate for each tile in real time to enhance the user's quality of experience (QoE). Finally, a simulation platform has been developed to validate the efficacy of the proposed algorithm by conducting comparative analyses with existing algorithms. [ABSTRACT FROM AUTHOR]

This paper explores the potential of an Integrated Sensing and Communication (ISAC) system to enhance search-and-rescue operations. While prior research has explored ISAC capabilities in Unmanned Aerial Vehicles (UAVs), our study focuses on addressing the specific challenges posed by modern communication standards (e.g., power, frequency, and bandwidth limitations) in the context of search-and-rescue missions. The paper details effective methods for processing echoed signals generated by downlink transmissions and evaluates key performance indicators, including Noise Equivalent Sigma Zero (NESZ) and channel capacity. Additionally, we utilize synchronization uplink signals transmitted by User Equipment (UE) to improve target detection and classification of possible victims by fusing SAR imagery with triangulation results from uplink signals. An experimental campaign validates the proposed setup by integrating SAR images of the environment with active localization results, both produced by a UAV equipped with a Software Defined Radio (SDR) payload. Our results demonstrate the system's capability to detect and localize buried targets in avalanche scenarios, with localization errors ranging from centimeters to 10 m depending on environmental conditions. This successful integration highlights the practical applicability of our approach in challenging search-and-rescue missions. [ABSTRACT FROM AUTHOR]

In order to solve the requirements of multi-channel communication applications, this paper proposes a miniaturized dualpassband substrate integrated waveguide filter with asymmetric passband response. The design uses a half-mode substrate integrated waveguide (HMSIW) cavity, which is loaded with a back-to-back complementary open resonant ring (CSRR) according to the vanishing mode propagation theory to generate a passband response lower than the HMSIW basic mode TE101, further reducing the cavity size. In addition, the band-resistive characteristics of the single-ring structure of the CSRR resonator are analyzed, and a C-slot is added at the feeder to improve the out-of-band characteristics of the second passband. Through simulation optimization and testing, the center frequency of the dual-passband filter is 4.05 GHz/8.64 GHz; the relative bandwidth is 16%/44%, the insertion loss of both passbands is better than 0.8 dB; the physical test results are consistent with the simulation ones; and the size of the filter is only 0.42λg × 0.14λg. It shows that the proposed filter has the characteristics of small size and low loss, and can be widely used in multi-channel RF front-end systems in the field of wireless communication. [ABSTRACT FROM AUTHOR]

The atmospheric Unified Model (UM) developed at the UK Met Office is used for weather and climate prediction by forecast teams at a number of international meteorological centres and research institutes on a wide variety of hardware and software environments. Over its 25 year history the UM sources have been optimised for a better application performance on a number of HPC systems including NEC SX vector architecture systems and recently the IBM Power6/Power7 platforms. Understanding the influence of the compiler flags, MPI libraries and run configurations is crucial to achieving the shortest elapsed times for a UM application on any particular HPC system. These aspects are very important for applications that must run within operational time frames. Driving the current study is the HPC industry trend since 1980 for processor arithmetic performance to increase at a faster rate than memory bandwidth. This gap has been growing especially fast for multicore processors in the past 10years and it can have significant implication for the performance and performance scaling of memory bandwidth intensive applications, such as the UM. Analysis of partially used nodes on Intel Xeon clusters is provided in this paper for short and medium range weather forecasting systems using global and limited-area configurations. It is shown that on the Intel Xeon based clusters the fastest elapsed times and the most efficient system usage can be achieved using partially committed nodes. [ABSTRACT FROM AUTHOR]

The paper proposes an ultra-wideband frequency selective rasorber (FSR) with low infrared emissivity for the composite detection threat of both radars and infrared sensors. Firstly, the equivalent circuit (EC) method based on transmission line (TL) theory is utilized to analyze the absorption/transmission conditions. Then, based on the analysis above, sinusoidal microstrip lines with non-frequency-varying characteristics are adopted in the design, which significantly enhances the transmission bandwidth of FSR. The FSR demonstrates an absorption band ranging from 2.65 GHz to 8.80 GHz and a transmission band ranging from 9.15 GHz to 17.71 GHz. Furthermore, an infrared shielding layer (IRSL) exhibiting low emissivity in the infrared band and high transmittance in the microwave band is applied to the FSR. The simulation and experiment results verify that the IRSL-FSR demonstrates an ultra-wide transmission band ranging from 9.16 GHz to 17.94 GHz and an ultra-wide absorption band ranging from 2.66 GHz to 8.01 GHz. Additionally, it exhibits a low emissivity value (0.23) in 8–14 μm, providing a viable solution to the formidable challenge of radar-infrared bistealth for satellites and other communication-enabled flying platforms. [ABSTRACT FROM AUTHOR]

GPUs are commonly used to accelerate the execution of applications in domains such as deep learning. Deep learning applications are applied to an increasing variety of scenarios, with edge computing being one of them. However, edge devices present severe computing power and energy limitations. In this context, the use of remote GPU virtualization solutions is an efficient way to address these concerns. Nevertheless, the limited network bandwidth might be an issue. This limitation can be alleviated by leveraging on-the-fly compression within the communication layer of remote GPU virtualization solutions. In this way, data exchanged with the remote GPU is transparently compressed before being transmitted, thus increasing network bandwidth in practice. In this paper, we present the implementation of a parallel compression pipeline designed to be used within remote GPU virtualization solutions. A thorough performance analysis shows that network bandwidth can be increased by a factor of up to 2×. [ABSTRACT FROM AUTHOR]

This paper first determines the generalized optical orthogonal code (GOOC) parameters to minimize the bit error probability in fiber-optic code division multiple access systems. The systems use on-off keying as the modulator and the optical AND logic gate as the receiver. In situations where the problem of finding the lowest bit error probability has more than one answer, we introduce and examine four approaches to choose the optimal answer. Finally, by employing a complete search of code parameters, we determine GOOC parameters (if there are any) to achieve the maximum bandwidth efficiency considering the design constraints, i.e., the number of network users and the maximum acceptable probability of error. [ABSTRACT FROM AUTHOR]

In this paper, we investigate a scenario in which protected and unprotected services coexist in an elastic optical network under dynamic traffic. In the investigated scenario, unprotected services can reuse the reserved idle bandwidth to provide protection to the protected services. Under this scenario, we propose a new heuristic algorithm that enables such reuse as well as define and introduce a new assignment problem in elastic optical networks, named a Transmission Spectrum Assignment (T-SA) problem. In this paper, we consider a scenario in which services may be routed using the multipath routing approach. Additionally, protection using bandwidth squeezing is also considered. We assess our proposal through simulations on three different network topologies and compare our proposal against the classical protection approach, in which bandwidth reuse is not allowed. For the simulated range of network loads, the maximum (minimum) blocking probability reduction obtained by our proposal is approximately 48% (10%) in the European topology, 46% (7%) in the NSFNET topology, and 32% (6%) in the German topology. [ABSTRACT FROM AUTHOR]

This paper proposes a core and spectrum allocation algorithm for elastic optical networks based on multi-core fibers. In this context, the fragmentation and crosstalk mitigation algorithm (FraCA) is proposed. FraCA implements mechanisms to reduce spectral fragmentation and inter-core crosstalk in the network, proving efficient when compared with six other algorithms reported in the literature. The numerical results show that when compared with the most competitive of the six algorithms, FraCA achieves a gain of request blocking probability of at least 16.87%, a gain of bandwidth blocking probability of at least 43.95%, and a mean increase in spectral utilization of at least 4.36%. [ABSTRACT FROM AUTHOR]

This paper presents the design of a frequency-tunable substrate-integrated waveguide (SIW) band-reject filter, specifically for spectrum underlay cognitive radio operation. The proposed filter has a simple tuning circuit but provides a wide frequency tuning range from 2.9 to 4.4 GHz (41%). The second resonant mode has been suppressed using a simple quadrature coupling; hence, the fundamental mode bandwidth of the filter has been increased from 2.08 GHz to 3.36 GHz. Due to its wide tuning range, simple tuning circuit, and increased fundamental mode bandwidth, the proposed filter is greatly important in underlay cognitive radio construction. The second-order filter has also been developed, and its performance is analyzed with both simulation and measurement. It gives a tunable bandwidth of 41%, an insertion loss of more than 10 dB, and a fundamental mode bandwidth of 3.36 GHz. The filter performance is also analyzed after connecting it to the standard horn antenna. Finally, from the total efficiency plots, it has been concluded that the proposed filter achieves all the above advantages with a low-lossy nature. [ABSTRACT FROM AUTHOR]

In this paper, a 3-bit circularly polarized reconfigurable reflectarray is proposed. The array consists of 64 units in an 8 × 8 configuration, with each unit containing a circular metal patch loaded with phase-delay lines and eight PIN diodes. To independently control each unit, a corresponding DC control circuit was designed and tested with the array. In the bandwidth of 3.43–3.71 GHz, the circularly polarized reconfigurable reflectarray achieved a gain of 16 dB, an aperture efficiency of 27%, an axial ratio of ≤3 dB, an operating bandwidth of 8%, and a beam scanning range of ±60°. The circularly polarized reconfigurable reflectarray can also achieve a good dual-beam radiation performance after testing. The 3-bit circularly polarized reconfigurable reflectarray proposed in this paper offers several advantages, including low loss, high aperture efficiency, a wide beam scanning range, and excellent stability in wide-angle oblique incidence. It has potential applications in low-cost phased array, satellite communications, and deep space exploration. [ABSTRACT FROM AUTHOR]

Optical packet switching has gained lot of popularity in last a few years due to its advantages like, large speed, more bandwidth and very less crosstalk. But due to immature optical fabrication and designing technology OPS is still beyond reality. However, many of the optical components are commercialized and some of them are still in laboratory. Thus, for optical switches which are considered as future generation routers, many switch architectures are proposed by using different sets of optical components. This paper presents a detailed review of notable switch designs in past 20 years, and also presents a comprehensive literature survey of the notable papers related to optical packet switch designs. [ABSTRACT FROM AUTHOR]

We have developed a fast, spatially direct scanning tunable diode laser absorption spectrometer (dTDLAS) that combines four polygon-mirror based scanning units with low-cost retro-reflective foils. With this instrument, tomographic measurements of absolute 2-D water vapour concentration profiles are possible without any calibration using a reference gas. A spatial area of 0.8m×0.8m was covered, which allows for application in soil physics, where greenhouse gas emission from certain soil structures shall be monitored. The whole concentration field was measured with up to 2.5 Hz. In this paper, we present the setup and spectroscopic performance of the instrument regarding the influence of the polygon rotation speed and mode on the absorption signal. Homogeneous H2O distributions were measured and compared to a single channel, bi-static reference TDLAS spectrometer for validation of the instrument. Good accuracy and precision with errors of less than 6% of the absolute concentration and length and bandwidth normalized detection limits of up to 1.1 ppmv .m. √Hz-1 were achieved. The spectrometer is a robust and easy to set up instrument for tomographic reconstructions of 2-D-concentration fields that can be considered a good basis for future field measurements in environmental research. [ABSTRACT FROM AUTHOR]

In this paper, we present the design and performance evaluation of a prototype device based on gain-driven polariton, which can function as an amplifier. This device can outperform a single microwave cavity in terms of phase noise and stability. Employed as a standalone amplifier, it demonstrates consistency between input and output phase noise, achieving a gain of up to 35 dB with a typical output of 5 dBm at 4.26 GHz. Despite its limited bandwidth, the device provides an effective solution for small signal amplification, ensuring minimal noise introduction. [ABSTRACT FROM AUTHOR]

This paper presents a flexible and wearable textile array antenna designed to generate Orbital Angular Momentum (OAM) waves with Mode +2 at 3.5 GHz (3.4 to 3.6 GHz) of the sub-6 GHz fifth-generation (5G) New Radio (NR) band. The proposed antenna is based on a uniform circular array of eight microstrip patch antennas on a felt textile substrate. In contrast to previous works involving the use of rigid substrates to generate OAM waves, this work explored the use of flexible substrates to generate OAM waves for the first time. Other than that, the proposed antenna was simulated, analyzed, fabricated, and tested to confirm the generation of OAMMode +2. With the same design, OAM Mode -2 can be generated readily simply by mirror imaging the feed network. Note that the proposed antenna operated at the desired frequency of 3.5 GHz with an overall bandwidth of 400 MHz in free space. Moreover, mode purity analysis is carried out to verify the generation of OAM Mode +2, and the purity obtained was 41.78% at free space flat condition. Furthermore, the effect of antenna bending on the purity of the generated OAM mode is also investigated. Lastly, the influence of textile properties on OAM modes is examined to assist future researchers in choosing suitable fabrics to design flexible OAM-based antennas. After a comprehensive analysis considering different factors related to wearable applications, this paper demonstrates the feasibility of generating OAMwaves using textile antennas. Furthermore, as per the obtained Specific Absorption Rate (SAR), it is found that the proposed antenna is safe to be deployed. The findings of this work have a significant implication for body-centric communications. [ABSTRACT FROM AUTHOR]

Low-order feedforward controllers have attracted much attention in engineering applications due to their simple structure and easy implementation. This paper focuses on low-order feedforward controllers with closed-loop-injection architectures. Currently, the gain of this type of feedforward controller is tuned with the goal of accurately fitting the following error. However, due to the limited control bandwidth, the compensation signal generated by the feedforward controller cannot be fully responded to by the feed axis. This paper proposes a new gain-tuning method. It enhances the feedforward controller's performance by considering the axis dynamics. The effectiveness of the proposed method is verified by experiments implemented on a two-axis bench. The results show that, compared with the method that does not consider the axis dynamics, the proposed method further reduces the following error and the trajectory error during trajectory tracking. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of robust output feedback control tracking for a class of nonlinear dual-rate sample-data systems subject to time-varying disturbances. These dual-rate systems, known as slow measurement fast control (SMFC) systems, are characterised by a slow sampling rate of the sensor and a fast updating rate of the controller. To facilitate high-frequency signal tracking, this paper introduces an alternating predictive generalised proportional integral observer (APGPIO). The proposed control method not only effectively restores the system state and captures disturbance changes between samples but also enhances the control bandwidth and anti-disturbance ability, enabling effective tracking of high-frequency reference outputs. By combining it with a fast updating sample-data feedback controller, APGPIO utilises predictive methods to increase the sampling rate of the system's sensors, matching the update frequency of the controller. Stability analysis demonstrates that the tracking error of this hybrid nonlinear system converges to a bounded region centred at the origin. Finally, the designed method's high control bandwidth and anti-disturbance ability are demonstrated through multiple sets of simulations using a real system. [ABSTRACT FROM AUTHOR]

Microwave hyperspectral instruments represent one of the main atmospheric sounders of China's next-generation Fengyun meteorological satellites. In order to better apply microwave hyperspectral observations in the fields of atmospheric parameter retrieval and data assimilation, this paper analyzes the sensitivity of trace gases to five selected bandwidth channels using a radiative transfer model based on the simulated data of microwave hyperspectral radiances at 50–60 GHz. This method uses information entropy and a weighting function to select channels and analyze the impact of this on the retrieval accuracy of atmospheric profiles before and after channel selection. The experimental results show that channel selection can reduce the number of channels by approximately 74.05% while maintaining a large amount of information content, and this retrieval effect is significantly better than that of MWTS-III. After channel selection, the 10 MHz, 30 MHz, and 50 MHz bandwidths have the best retrieval results in the stratosphere, whole atmosphere, and troposphere, respectively. When considering the number of channels, computational scale, and retrieval results comprehensively, the channel selection method is effective. [ABSTRACT FROM AUTHOR]

Path hopping serves as an active defense mechanism in network security, yet it encounters challenges like a restricted path switching space, the recurrent use of similar paths and vital nodes, a singular triggering mechanism for path switching, and fixed hopping intervals. This paper introduces an active defense method employing multiple constraints and strategies for path hopping. A depth-first search (DFS) traversal is utilized to compute all possible paths between nodes, thereby broadening the path switching space while simplifying path generation complexity. Subsequently, constraints are imposed on residual bandwidth, selection periods, path similitude, and critical nodes to reduce the likelihood of reusing similar paths and crucial nodes. Moreover, two path switching strategies are formulated based on the weights of residual bandwidth and critical nodes, along with the calculation of path switching periods. This facilitates adaptive switching of path hopping paths and intervals, contingent on the network's residual bandwidth threshold, in response to diverse attack scenarios. Simulation outcomes illustrate that this method, while maintaining normal communication performance, expands the path switching space effectively, safeguards against eavesdropping and link-flooding attacks, enhances path switching diversity and unpredictability, and fortifies the network's resilience against malicious attacks. [ABSTRACT FROM AUTHOR]

The use of metamaterial enhances the performance of a specific class of antennas known as metamaterial antennas. The radiation cost and quality factor of the antenna are influenced by the size of the antenna. Metamaterial antennas allow for the circumvention of the bandwidth restriction for small antennas. Antenna parameters have recently been predicted using machine learning algorithms in existing literature. Machine learning can take the place of the manual process of experimenting to find the ideal simulated antenna parameters. The accuracy of the prediction will be primarily dependent on the model that is used. In this paper, a novel method for forecasting the bandwidth of the metamaterial antenna is proposed, based on using the Pearson Kernel as a standard kernel. Along with these new approaches, this paper suggests a unique hypersphere-based normalization to normalize the values of the dataset attributes and a dimensionality reduction method based on the Pearson kernel to reduce the dimension. A novel algorithm for optimizing the parameters of Convolutional Neural Network (CNN) based on improved Bat Algorithm-based Optimization with Pearson Mutation (BAO-PM) is also presented in this work. The prediction results of the proposed work are better when compared to the existing models in the literature. [ABSTRACT FROM AUTHOR]

A novel Fabry-Perot cavity (FPC) antenna with metasurface is presented, which can achieve broad bandwidth and low profile. Traditional FPC antennas, with rectangular microstrip antennas as feeds, have limited impedance bandwidth and struggle to make a compromise in the gain bandwidth and maximum gain value. To obtain wide bandwidth, the FPC antenna proposed in this paper utilizes a feed antenna loaded with parasitic patches. To widen impedance bandwidth and gain bandwidth and reduce the profile, a positive phase gradient partially reflective surface (PRS) and an artificial magnetic conductor (AMC) are located above and below the feed antenna, respectively. The phase property of the PRS and AMC also brings in a more smooth gain value curve. To further increase gain values, four metal reflector plates are located around the proposed antenna. The overall dimension of the antenna is 2.5λ0×2.5λ0×0.25λ0 (λ0 is the free space wavelength at 7.5 GHz). Simulated results show that the resonant cavity antenna proposed in this letter exhibits an impedance bandwidth of 13.3% (7-8 GHz) and a 3 dB gain bandwidth of 14.3% (7.02-8.10 GHz). The maximum gain in the whole operating band is 14.5 dBi. The measured results are in good agreement with the simulated ones. [ABSTRACT FROM AUTHOR]

This paper presents a computer-simulation-based design of an in-line, coaxial-to-circular waveguide adapter for converting the coaxial transverse electromagnetic (TEM) mode to the circular waveguide TE11 mode over more than a one-octave bandwidth. The proposed adapter consists of a coaxial-to-rectangular waveguide transformer employing a stepped-ridge converter and a rectangular-to-circular waveguide transformer employing a curved transition. The proposed adapter has been optimized using a commercial simulation tool. The dimensions of the designed adapter are given so that it can be verified by anyone who is interested. The designed adapter operates from 8.00 GHz to 22.95 GHz (2.87:1 bandwidth) with a reflection coefficient of less than −20 dB and a higher-order mode level of less than −25.0 dB. [ABSTRACT FROM AUTHOR]

In order to reduce the sampling delay and improve bandwidth, sability margin, and the robustness of the active damping in LCL-filtered grid-connected inverters, real-time sampling provides a convenient method. However, aliasing is easily introduced in the control loop because of high-frequency switching harmonics, resulting in a rise in low-order harmonics. To address the challenge of aliasing under real-time sampling, a new method based on multisampling and mean filtering is proposed by combining the proposed harmonic detection and control methods in this paper. This method works by sampling and controlling the fundamental current and selective subharmonic currents separately. The fundamental current control loop without any additional filters maintains real-time sampling, while multisampling and mean filters are applied to the harmonic current control loop. The proposed control method can not only improve the dynamic response performance and control stability of the system but also effectively suppress the selective low-order current harmonics and the aliasing of sampling. Finally, the correctness of the proposed sampling scheme and control strategy is verified by the simulation based on R2018b, MathWorks, Natick, MA, USA and an experimental prototype of a three-phase grid-connected photovoltaic inverter rated at 230 V/50 Hz/40 kW. [ABSTRACT FROM AUTHOR]

Super-computing or HPC clusters are built to provide services to execute computationally complex applications. Generally, these HPC applications involve large scale IO (input/output) processing over the networked parallel file system disks. They are commonly developed on top of the C/C++ based MPI standard library. The HPC clusters MPI–IO performance significantly depends on the particular parameter value configurations, not generally considered when writing the algorithms or programs. Therefore, this leads to poor IO and overall program performance degradation. The IO is mostly left to individual practitioners to be optimised at code level. This usually leads to unexpected consequences due to IO bandwidth degradation which becomes inevitable as the file data scales in size to petabytes. To overcome the poor IO performance, this research paper presents an approach for auto-tuning of the configuration parameters by forecasting the MPI–IO bandwidth via artificial neural networks (ANNs), a machine learning (ML) technique. These parameters are related to MPI–IO library and lustre (parallel) file system. In addition to this, we have identified a number of common configurations out of numerous possibilities, selected in the auto-tuning process of READ/WRITE operations. These configurations caused an overall READ bandwidth improvement of 65.7% with almost 83% test cases improved. In addition, the overall WRITE bandwidth improved by 83% with number of test cases improved by almost 93%. This paper demonstrates that by using auto-tuning parameters via ANNs predictions, this can significantly impact overall IO bandwidth performance. [ABSTRACT FROM AUTHOR]

Coplanar monopole antennas printed using copper oxide nanoparticles on flexible substrates are characterized in order to study the effect of the ink drop spacing on the antenna parameters. Polyethylene Terephthalate and Epson paper were the chosen flexible substrates, and the antennas were designed to operate at 20GHz. A maximum conductivity of 2.8 × 107 Ω-1m-1 was obtained for the films printed on Polyethylene Terephthalate using a drop spacing of 20 μm. The corresponding antenna achieved a gain and an efficiency of 1.82 dB and 97.6%, respectively. Experiments showed that smaller drop spacings lead to bulging of the printed lines while the antenna performance worsens for longer ones. At the same drop spacing, antennas printed on Epson paper substrate showed a -10 dB return loss bandwidth which extended from 17.9GHz to 23.3GHz, leading to a fractional bandwidth of 26.0%. [ABSTRACT FROM AUTHOR]

This paper introduces a 4-port antenna tailored for 5G, operating in the 4.4 to 7.25 GHz (Fractional Bandwidth is 48.9%) range with a 10 dB impedance bandwidth. The operating bandwidth includes the n79 band (4.4–5 GHz), 5G WLAN band (5.125–5.825 GHz), and Wi-Fi 6E band (5.925 to 7.125 GHz). Constructed on a compact FR4 substrate (0.057λ × 0.057λ × 0.0018λ (where λ is the wavelength at 4.4 GHz), it exhibits robust performance in fabrication and measurements. The single antenna covers a total area as small as 20×17.6 mm², which enables the compactness of the MIMO antenna with a gain of up to 6 dBi and 85% radiation efficiency; it supports MIMO with a low correlation coefficient (< 0.02), high diversity gain (up to 9.98 dB), and minimal channel capacity loss (0.25 bps/Hz). The Total Active Reflective Coefficient (TARC) is computed to validate MIMO performance over the operating bandwidth. Featuring bidirectional radiation patterns in both E-plane and H-plane, the antenna is well suited for 5G applications, demonstrating potential for future wireless systems. [ABSTRACT FROM AUTHOR]

A novel bandpass-to-all-stop switchable absorptive filter with an ultra-wideband reflectionless range is proposed in this paper. The bandpass section of the filter consists of a dual-mode resonator and two L-shaped feeding lines. The dual-port reflectionless characteristic is achieved by loading absorption networks at the end of the open stubs of the feeding lines, which are composed of two parallel coupled lines and absorption resistors. The switching of the reflectionless bandpass filter (RBPF) to the all-stop filter (ASF) is realized by controlling the on/off behavior of the PIN diode through the bias voltage. Measurements show that the filter prototype at the center frequency of 2.43 GHz with the 3-dB fractional bandwidth (FBW) is 8.23%. For the RBPF state, the filter has an ultra-wideband reflectionless FBW of 214% and upper stopband rejection better than 33 dB up to 6 GHz. Besides, the rejection is better than 30 dB from 0 to 5.32 GHz in the ASF state. [ABSTRACT FROM AUTHOR]

In this paper, a wideband wide-beam circularly polarized (CP) antenna excited by sequential rotation feeding technology is proposed. The antenna is primarily constituted of a loop radiating element and a reactive impedance structure (RIS) cavity. The loop radiator is stimulated by a curved feeding line through six slots etched on the ground, thereby enabling the antenna to achieve broadband performance. In order to achieve a wide 3-dB axial-ratio beamwidth (ARBW), as well as exhibit less effect on the half-power beamwidth (HPBW), a RIS cavity is introduced beneath the loop radiator. To validate the proposed structure, a prototype was constructed and subjected to a series of tests. The results indicate that the bandwidth of the antenna is 187.5% (0.11 ∼ 3.41 GHz) under a 10-dB return loss. In the frequency band spanning from 1.07 GHz to 2.1 GHz, the AR is less than 3 dB, yielding a bandwidth of 64.98%. Furthermore, at the frequencies of 1.2 GHz, 1.5 GHz, and 1.8 GHz, the proposed antenna demonstrates wide beam characteristics, with the HPBW exceeding 90◦, and the 3-dB ARBW within 162◦ 224◦ . In addition, since no extra feeding network is utilized, the antenna is compact in size. [ABSTRACT FROM AUTHOR]

In this paper, a transmissive linear-to-circular polarization conversion (LCPC) multibeam metasurface is presented which shows promise for point-to-multipoint transmission in satellite communications under interference conditions. The unit cell consists of four identical metal layers and three dielectric substrates, where each metal layer includes a square ring and a cross-shaped structure. By altering the arm length of the cross-shaped structure, independent control of the phase of x- and y-polarized waves can be achieved. Thus, by keeping the amplitude of the x- and y-polarized waves equal and the phase difference at 90◦ , LCPC is realized. Based on the multibeam superposition theorem, the metasurface array is arranged using four discrete elements with a phase gradient of 90◦ . It can convert linearly polarized (LP) waves into right-handed circularly polarized (RHCP) waves and generate transmitted multibeam at predetermined angles and gain ratios. Three-beam LCPC metasurfaces with equal and unequal gain in the Ka-band (26 to 40 GHz) were demonstrated to validate the proposed unit cell and methods. The equal gain metasurface has an approximate 6% bandwidth for the 3 dB axial ratio (AR) and a 6% bandwidth for the 1 dB realized gain. Furthermore, at the center frequency of 30 GHz, the unequal gain metasurface achieves gains of 22.9 dBi, 19.7 dBi, and 17.3 dBi, respectively, with an AR of less than 2 dB for all three beams. [ABSTRACT FROM AUTHOR]