A conventional target detection technique for FMCW millimeter-wave radar applies a two-dimensional (2D) cell-averaging constant false alarm rate (CA-CFAR) detector to all range-Doppler cells in order to suppress noise and clutter. However, this 2D CA-CFAR method has significant drawbacks, particularly its high computational cost due to the large number of additions required, resulting in a time complexity of O(n^{4}). To decrease the computational complexity while ensuring the detection accuracy, a novelty CA-CFAR technique based on the prefix sum algorithm with the complexity O(n^{2}) is proposed in this article. Simulations prove the feasibility of the proposed method. Compared to both conventional and state-of-the-art optimized CA-CFAR techniques, the proposed method reduces the number of addition operations by 95%, lowers CFAR loss by approximately 0.5 dB, and improves the figure of merit (FoM) by about 20% at a fixed false alarm rate of 10^{-6}. This advanced technique offers significant computational efficiency for radar applications.

In remote sensing image segmentation, recognizing buildings is challenging when the visual evidence from pixels is weak or when buildings belong to small, spatially structured objects. To address this issue, we propose a structure-prior guided adaptive context selection network (SGACS-Net) for remote sensing semantic segmentation. The core is to use structure-prior knowledge to dynamically capture prior contextual information and higher-order object structural features, thereby improving the accuracy of remote sensing building segmentation. First, an adaptive context selection module is designed. By dynamically adjusting the spatial sensing field, this module effectively models the global long-range context information dependencies. It captures varying context information of buildings at different scales, thereby enhancing the network’s ability to extract building feature representations. Second, a structure-prior guided variable loss function is proposed. It utilizes the structural features of building points, lines, and surface to identify key regions. By leveraging advanced structure-prior knowledge, it enhances the network’s ability to express structural features. Experimental results on two datasets show that the proposed SGACS-Net outperforms other typical and state-of-the-art methods in terms of remote sensing semantic segmentation performance.

This letter presents a low-distortion bootstrapped switch for improving sampling network linearity. The dynamically driven gate approach and the dynamically driven DNW (Deep N-well) technique are proposed to reduce the parasitic capacitance at crucial nodes. Simulated in a 180nm CMOS process, the proposed switch achieves a total harmonic distortion (THD) of -102.1dB at an 80MHz sampling frequency. This is an 21.4dB increase in THD, over the conventional switch.

Attention-based Transformer model has achieved remarkable performance in various artificial intelligence fields, while the attention computation, being a combination of matrix multiplication and softmax function, is still sub-optimized in terms of hardware implementation. Normally, it needs 3 pass of input memory access to compute attention, and the on-chip storage requirement is coupled with the input length, both of which pose significant memory issues. Further, the computation burden is heavy for long inputs. This paper proposes an algorithm-hardware co-design for attention. On algorithm side, it uses a linear-softmax fused kernel to fuse the matrix multiplication and non-linear functions, which enables high on-chip memory source utilization. On hardware side, it shows an accelerator named BLADE with identical partial product removing, which eliminates unnecessary computation by exploiting math feature of softmax. Experiment on ViT, Swin Transformer, GPT-2 and LLaMA2 show that the proposed design achieves 10.6% - 18.7% of energy efficiency improvement compared to state-of-the-art Flash Attention implementations.

White blood cell image segmentation plays a vital role in the accurate analysis and diagnosis of blood-related diseases, facilitating the identification and quantification of white blood cells in microscopic images. This process is essential for early disease detection, treatment monitoring, and immune response studies, ultimately supporting clinical decision-making. In this paper, we propose an enhanced approach based on the Segment Anything Model. First, Contrast Limited Adaptive Histogram Equalization is applied for pre-processing to enhance the features of white blood cells. Then, Segment Anything Model is utilized for segmentation. Experimental results demonstrate that our method achieves state-of-the-art performance on cross-domain datasets, providing accurate and reliable segmentation of white blood cells.

We propose a novel batch gradient descent algorithm for parameterized quantum circuits that significantly reduces the time complexity in terms of batch size for training quantum neural networks. Batch data constructed to quantum random access memory (qRAM) structure is mapped to one circuit that estimates average loss. As the number of circuits decreases, the range to which quantum amplitude estimation can be applied increases, speeding up with a quadratic scale in batch size.

The time step functions as a crucial temporal unit for simulating neuronal dynamics within spiking neural networks, which play a significant role in neuromorphic computing systems. Efficient management of these time steps is vital to ensure model accuracy while optimizing overall system performance. As system scale increases, variations in hardware across subsystems and their asynchronous operations create challenges in achieving effective time step control. To address this issue, this paper proposes an innovative framework for managing time steps in large-scale neuromorphic systems. This framework allows subsystems to dynamically adjust their time step lengths according to computational loads and to perform look-ahead computations. Such a strategy effectively reduces the overhead related to time step synchronization, enhancing system efficiency. Additionally, the paper introduces a safeguard mechanism to ensure the system’s reliability. Experimental results indicate that the proposed framework sustains the correct long-term operation of the system and improves model execution performance by 8.88% to 27.15% when compared to existing methods.

A low-cost high-responsivity design of Si/SiGe Heterojunction Bipolar Phototransistor (HPT) built in an industrial 55nm-BiCMOS technology is integrated in a cascode configuration with a bipolar bipolar transistor (HBT) to be used for microwave-photonic communication receivers. Performances of both the cascode pair and the single Heterojunction Bipolar Phototransistor are compared. At high-frequency, the cascode circuit has better performances than the single HPT stage. At 850-nm wavelength, the pair can reach a low-frequency responsivity a low-frequency responsivity of 3.24 A/W and a bandwidth of 0.69 GHz when coupling losses are corrected.

Inverse Synthetic Aperture Radar (ISAR) is a crucial radar imaging technique that relies on the relative motion between the radar and the target to produce high-resolution images. However, traditional ISAR methods are highly sensitive to inaccuracies in estimating rotational parameters, such as roll, pitch, and yaw. Errors in these estimates can result in significant image degradation. In this paper, we present a novel approach for imaging dynamically rotating scenes using a multistatic ISAR setup, where we estimate motion parameters through a Differential Semblance Optimisation (DSO) criterion. This is done by minimising discrepancies between images formed from multiple transmitter-receiver pairs, our method delivers focused images with improved estimates of the yaw rotation parameter of the targets. We demonstrate the effectiveness of this approach through a series of numerical experiments, highlighting its robustness in both noise-free and noisy environments, and discuss its potential for enhancing ISAR imaging in complex scenarios.

Fluid antenna multiple access (FAMA) is a concept capable of massive connectivity on the same physical channel without the need of precoding or interference cancellation, by exploiting a super-high dimensional received signal in the spatial domain from fluid antenna system (FAS). This letter investigates the use of 5G New Radio (NR) Modulation Coding Scheme (MCS) for FAMA systems to improve its connectivity over block fading channels. In particular, we propose an iterative decoding receiver with iterative interference covariance estimation for the coded FAMA system. Extrinsic information transfer (EXIT) chart is used to analyze the performance of the proposed iterative receiver. Both EXIT chart analysis and numerical results show that the proposed receiver outperforms the one that uses fixed covariance in the block fading channel. Also, the results indicate that coded FAMA can serve 100 user terminals (UTs) at the rate of 0.5 bit/s/Hz under rich scattering.

In this letter, we propose a novel algorithm for sparse L-shaped array that addresses gain/phase uncertainties and off-grid direction of arrival estimation using compressed sensing theory. Firstly, the receiving signal of the sparse array is structured into an Errors in Variables model. Then, a novel algorithm termed IOMP-TLS is proposed for off-grid signal reconstruction and gain/phase uncertainties estimation based on an enhanced greedy algorithm. Finally, the simulations show that our proposed algorithm is superior to many other methods in estimation performance.

Phased array antennas, with high directivity and low sidelobe levels, are extensively employed in radar and communication systems. As the array scale increases, the complexity and cost of controlling each element individually are increased significantly. To overcome this challenge and improve the efficiency, one of the effective engineering solutions is subarray partitioning. Traditional clustering algorithms, such as K-means, require a predefined number of subarrays, and limits the flexibility, especially in scenarios with complex geometries or irregular distributions. A subarray partitioning approach is presented in this paper using the Iterative Self-Organizing Data Analysis (ISODATA) algorithm, and the proposed scheme dynamically adjusts the number of subarrays based on the geometric characteristics of the array. According to numerical experiments results, good performance of sidelobe suppression, beamforming and partitioning flexibility have been achieved, and shows better characteristic compared with the K-means. This algorithm has potential application in large-scale phased arrays.

In this letter, a beam downtilt reconfigurable linear antenna array is presented for the demand of the electrical downtilt of 5G/6G macro base station antennas. The antenna is capable of fine-angle beam direction reconfiguration, allowing for improved adaptability in various environmental conditions. A hierarchical network design is employed, which incorporates essential elements such as phase shifter modules, power dividers, and couplers. These fundamental components are used to construct a five-element reconfigurable feeding network for the antenna array. The designed network ensures stable phase shifts and excellent impedance matching performance. By integrating the feeding network with the antenna elements, the system achieves electronic beam tilt adjustment across four states, enabling the linear array to tilt downward within a range of 6 - 12° around 3.5 GHz. This design provides enhanced beam control, making it suitable for next-generation macro base station applications in 5G and 6G networks.

In this paper, a Packaged Tapered Balun (PTB) with enclosed metal shield is proposed to achieve multi-octave bandwidth operation for power combining applications such as push-pull power amplifiers and harmonics suppressed combiners. By establishing a parasitic transmission line equivalent circuit model of double-sided Shielded Tapered Lines, a suspended balance compensating branch and a common mode suppressed Balanced-to-Balanced transformer is introduced to improve the balance of PTB. Based on the proposed technique, a 0.6-6.5GHz PTB is demonstrated. According to the measured results, the designed balun exhibits better than -10dB return loss, -0.5dB insertion loss, ±0.15dB amplitude balance and ±0.4° phase balance.

A novel approach is proposed in this paper to reconstruct the far-field radiation pattern from the phaseless electric field of an antenna scanned on a single near-field sphere. It adopts the dipole equivalence approach to project the near-field electric field into a spherically distributed array of electric dipoles. We introduce a term representing the residue from the linearly correlated portion in the least-square problem associated with the dipole equivalence, namely the linear correlation residue (LCR). It is demonstrated that by iterative search to minimize the LCR using the Covariance Matrix Adaptation Evolution Strategy (CMA-ES), near-field phase distributions can be found efficiently from the magnitude-only near-field, and the far-field radiation pattern can be computed. Two representative case studies are given here to validate the proposed method. Results demonstrate good agreements between computations and simulations.

High Resolution Range Profiles (HRRP) have become a key area of focus in the domain of Radar Automatic Target Recognition (RATR). Despite the success of deep learning based HRRP recognition, these methods needs a large amount of training samples to generate good performance, which could be a severe challenge under non-cooperative circumstances. Currently, deep learning based models treat HRRP as sequences, which may lead to ignorance of the internal relationship of range cells. This letter introduces HRRPGraphNet, whose pivotal innovation is the transformation of HRRP data into a novel graph structure, utilizing a range cell amplitude-based node vector and a range-relative adjacency matrix. This graph-based approach facilitates both local feature extraction via one-dimensional convolution layers, global feature extraction through a graph convolution layer and a attention module. Experiments on the aircraft electromagnetic simulation dataset confirmed HRRPGraphNet’s superior accuracy and robustness, particularly in limited training sample environments, underscoring the potential of graph-driven innovations in HRRP-based RATR. Codes are available at: https://github.com/MountainChenCad/HRRPGraphNet.

This brief investigates the multi-point fault repair problem in active distribution networks, establishing resilience assessment metrics and constructing a fault repair mathematical model with road network coupling. An improved genetic algorithm is proposed, utilizing a comparison crossover operator and population information entropy. Compared to traditional algorithms, the comparison crossover operator preserves high-quality genes, while population information entropy maintains diversity, preventing the algorithm from converging on local optima. Simulation analysis demonstrates that the proposed fault repair method can restore normal power supply to distribution network lines within a short period and offers significant advantages in fault repair tasks.

Fault injection attacks can compromise cryptographic operations with out the necessity of physical alteration, thereby potentially disclosing private keys, which poses a grave threat to the security of elliptic curve digital signature algorithms. This letter presents an efficient and prac tical lattice-based fault injection attack on the SM2 digital signature algorithm (SM2-DSA), along with the corresponding defense strategy. The proposed attack method significantly reduces the moment precision requirements compared to existing lattice-based fault attacks, while also demonstrating computational advantages over other fault attacks. From the defensive perspective, the proposed strategy effectively defend against the lattice-based fault injection attacks while minimizing both time and spatial overheads. Specifically, our countermeasure incurs only a 0.8% time overhead and the area overhead for secure design does not exceed 1%. Our research provides valuable insights for evaluating the security of hardware implementations of SM2-DSA.