This PDF file contains the front matter associated with SPIE Proceedings Volume 12752, including the Title Page, Copyright information, Table of Contents and Conference Committee lists.

An active millimeter wave (mmWave) antenna with tunable zero-mode[1] resonances is proposed in this paper. Based on the zero-mode theory, shorting pins are employed to the patch antenna so as to produce TM10 and the zero modes. Particularly, PIN diodes is utilized as the switch for tuning these resonances upwardly or downwardly, thereby obtaining a wide bandwidth from 24.3-28.8 GHz on the 0.508 mm thick substrate. This proposed antenna can be applied to B5G/6G scenarios wherever mmWave bands are needed.

In the field of optical fiber distributed acoustic sensing, the combination of pulse compression and frequency division multiplexing will occupy a large bandwidth. In this paper, a novel distributed optical fiber acoustic sensor system is proposed, which can reduce the spectrum resources occupied by the combination of the above two technologies. The system continuously injects nonlinear frequency modulation detection pulses of different frequency ranges. The frequency response range of vibration is improved by frequency division multiplexing, and the spatial resolution is enhanced by nonlinear frequency modulation. Nonlinear frequency modulation also improves the sidelobe rejection ratio without loss of signal-to-noise ratio. In the experiment, eight frequencies were multiplexed using a 120MHz bandwidth. We achieved a spatial resolution of about 5m and a frequency response range of 1~20kHz on a 16.3km fiber.

In response to the influence of parameter setting on the extraction of fault feature frequency of mechanical trouble signal by variational mode decomposition (VMD), a study on trouble signal feature extraction based on Quantum Genetic Algorithm (QGA) optimized variational mode decomposition was constructed. First, take the envelope entropy as a fitness feature, and use the quantum genetic algorithm to calculate the two parameters [K, α] of VMD are selected adaptively. Secondly, the VMD with the optimized parameter [K, α] is used to decompose the fault vibration signal, and multiple intrinsic mode components (IMF) are obtained. Finally, Hilbert envelope spectrum analysis was carried out for the modal component with the lowest envelope entropy, and can effectively determine the fault type through the fault characteristic frequency. It is proved that this method is useful and can solve the effect of parameter setting on VMD.

Clothing pressure is an important index to evaluate clothing comfort. Inappropriate clothing pressure will make the wearer feel uncomfortable, affecting the work efficiency and health of the human body. Therefore, the measurement and distribution of clothing pressure play an important role in the comfort of clothing pressure. Starting from the concept and generation of clothing pressure, the theoretical research of clothing pressure is summarized, including the impact of contact mechanics mechanism, human body shape and different clothing on human body pressure. From the direct measurement method and indirect measurement method, the measurement method and principle of clothing pressure are analyzed respectively. The research status of measurement of clothing pressure by sensor method and soft mannequin method is introduced. The problems of garment pressure measurement are pointed out, and the future direction of garment pressure research is forecasted. the pressure is verified experimentally by using fiber Bragg grating sensor. The sensor has the advantages of simple structure and good measurement accuracy. The results show that the sensor has good sensitivity and linearity, which is suitable for garment pressure testing environment and has a good development prospect.

A microelectromechanical system (MEMS) gyroscope mounting error calibration platform composed of autocollimator and manual turntable were proposed. In order to achieve the dynamic angular range reflected in the mounting error of MEMS gyroscope, the range of the NIKON-6D autocollimator has been extended from ±15' to ±9°by exploiting the relationship between the angular range and the structure of the reflector. In addition, in the software design, a common data acquisition serial port between CMOS camera and MEMS gyroscope was built. By integrating the angular rate measurements of the MEMS gyroscope with the sampling time, a uniformity of magnitude was obtained between the angular readings of the autocollimator and the angular rate readings of the MEMS gyroscope. Experimental verification shows that compared with precision three-axis angular rate output turntable, the relative calibration deviation of the MEMS gyroscope mounting error coefficient is less than 0.6%, and the platform benefits from the traceable reference of the autocollimator, which has the advantages of low maintenance evaluation rate and high stability, and can serve the long-cycle and high-efficiency MEMS gyroscope mounting error calibration and calibration process.

The process of combining features from two images of different sources to generate a new image is called image fusion. In order to adapt to different application scenarios, deep learning was widely used. However, existing fusion networks focued on the extraction of local information, neglected the long-term dependencies. In order to improve the defect, a fusion network based on Transformer was proposed. To accommodate our experimental equipment, we made some modifications to Transformer. A dual-branch autoencoder network was designed with detail and semantic branches, the fusion layer consists of CNN and Transformer, and the decoder reconstructs the features to get the fused image. A new loss function was proposed to train the network. Based on the results, an infrared feature compensation network was designed to enhance the fusion effect. In several metrics that we focus on, we compared with several other algorithms. As the experiments on some datasets, our method had improvement on SCD, SSIM and MS-SSIM metrics, and was basically equal to other algorithms on saliency-based structural similarity, weighted quality assessment, and dge-based structural similarity. From the experimental results, we can see that our method was feasible.

In recent years, Siamese network algorithms based on deep learning classes have achieved better tracking accuracy and speed and become one of the research hotspots in the field of target tracking. However, the traditional Siamese network algorithm lacks a holistic view of the target and extracts shallow features, making it easy to lose track of the target in complex environments. The paper proposes a Contextual transformer network for visual recognition (CotNet) target tracking algorithm based on attentional mechanisms and contextual awareness to address this. The paper innovatively uses the CotNet50 network as the backbone network and adopts a residual network variant design scheme with a self-attention mechanism, which can enhance the feature representation capability of the network model and improve the performance of the algorithm. In addition, to handle changes in appearance during target tracking, an efficient channel attention module, and a global contextual feature module are embedded in the backbone network branch to enhance the network's overall perception of the target and improve the algorithm's tracking accuracy. The experimental results of this paper's algorithm on the VOT2018 data show that the accuracy, robustness, and EAO (Expected Average Overlap) are improved by 7.3%, 13.95%, and 11.9% respectively compared to SiamFC. It has good tracking results when dealing with complex scenes on the OTB100 dataset.

The inductance measurement scheme designed in this paper adopts a steady-state RL series circuit with sinusoidal current and voltage signals, and utilizes phasor analysis to convert the measurement of inductance into corresponding voltage values. The converted signal is sent to the MCU CPU for data calculation and processing after AD conversion, and the measurement results are directly displayed in digital form on the LCD. This paper provides a detailed introduction to the measurement principle and hardware-software design of this measurement scheme. From simulation test data, it can be found that the measurement range of the inductance measurement circuit is 5mH~990mH, and the accuracy is relatively high. The overall structure of the measurement circuit is simple, and the peripheral components have low precision requirements, which is easy to implement and can be extended to capacitance measurement.

Binary weighted beamforming aims to achieve the optimal radiation pattern with only part of the array elements. The corresponding applications include sparse synthesis, management of aperture resources and targets allocation. However, due to the discrete weighting values as well as the corresponding non-deterministic polynomial computational complexity, most existing adaptive beamforming approaches are not suitable. Here, an algorithm based on simulated annealing optimization is proposed and the performances of binary weighted beamforming with one-dimensional and two-dimensional random arrays are numerically evaluated. According to the results with number of array elements ranging from 17 to 151, the side lobes can be reduced by 4.43 dB in average utilizing only around 66.7% of the total array elements while the width of the main lobe has increased by about 30%. For adaptive beamforming circumstances, an extra depth of up to 20 dB is achieved in presence of a preset jammer. Furthermore, a proof-of-principle optical experiment employing the spatial light modulator device is designed and studied through Huygens-Fresnel simulation.

We propose and demonstrate a figure-nine polarization-maintaining fiber laser with a nonlinear amplifying optical loop mirror (NALM) as a fast saturable absorber. The oscillator includes a non reciprocal phase shifter, which can achieve low mode locking threshold and excellent self starting performance. The repetition frequency of the laser reaches 101.8 MHz. The signal-to-noise ratio of a single frequency is approximately 70 dB. The pulse duration of the laser is 80 fs. By employing cut-back techniques to accurately compensate for intracavity dispersion, we are able to achieve a flat and broad spectral output with a full width at half maximum (FWHM) of better than 62.5 nm at the center wavelength of 1584.4 nm. Thisrepresentsthe broad FWHM spectrum observed in all polarization-maintaining fiber NALM lasers.

With the development of large-scale wear debris, the demand for condition monitoring of mechanical devices increases accordingly. The fast detection device of lube oil wear debris is intended for the mechanical equipment lubricated with grease, collecting information on the abrasive particles in the equipment lubricating grease, and consequently monitor the status of the equipment. The rapid detection device needs a fitting lighting environment to collect the abrasive particle information; therefore, it is necessary to research into the lighting system of the fast detection device.

In the bistatic arc array synthetic aperture radar (AA-BiSAR) with a moving transmitter, the moving transmitter is helpful to improve the flexibility of the imaging system and expand the imaging scene, which has important significance in the field of helicopter assisted landing, emergency rescue and so on. The motion state of the transmitter is closely related to the bistatic arc array SAR echo model and imaging quality. This article establishes the echo signal model under accelerated motion, analyzes the impact of acceleration on echo phase and imaging quality, studies the effect of different accelerations on the approximate expansion phase error of slant range, and provides relevant analysis results through point target simulation experiments. The analysis results have a certain guiding significance for the follow-up moving transmitter bistatic arc array SAR high-precision and accurate imaging and motion error compensation.

The spaceborne squint sliding spotlight mode provides the capacity to observe the Earth in high resolution with different angles. However, with the increased squint angle, the imaged swath is obviously reduced due to the large range cell migration. To extend the reduced swath, a new spaceborne wide swath sliding spotlight mode with a high squint angle is proposed in this paper. Besides azimuth beam steering to improve the azimuth resolution, antenna beam is also steered in elevation to improve the swath width. The imaging principle of the proposed imaging mode is described in detail, while its corresponding flowcharts of SAR system design and imaging processing are given. Furthermore, the beam steering law of the designed system example with azimuth resolution of 0.5m and swath width of 20km is given, while the imaging result of the designed scene with three targets is given. Both simulation results validate the proposed imaging mode in the high squint case.

As the resolution of images processed in real-time continues to increase, it is necessary to compress the transmitted image data, and then transmit it to the terminal to decompress and restore the image. JPEG-LS is an algorithm that supports lossless and near-lossless compression. However, the decompression of JPEG-LS images is mostly implemented in a software environment. When decompressing multiple high-resolution images, the problems of decoding speed and resource consumption are more prominent. Therefore, the implementation of the JPEG-LS image decompression algorithm on FPGA is proposed in this paper, which divides the image into blocks and adopts a parallel processing structure. After the experiment on the hardware decoder, for the 1024*2048 test image, the designed hardware decoder can improve the original software decoding time by approximately 55%.

In the cabin area communication scenario based on quasi-static electric field coupling, signal leakage will occur when a single channel or negative plate is grounded. This paper analyzes the cause of this problem through modeling and simulation, and proposes to use differential transmission in cabin area communication to solve the problem of signal leakage. Finally, a test prototype is made using FPGA and a test device is designed to verify the feasibility of this method.

With the rapid development of earth observation by optical remote sensing satellites, there is an urgent requirement of remote sensing data with high-resolution in environmental monitoring, urban planning and other applications. The resolution of remote sensing images (RSIs) significantly depends on the aperture size of space imaging system. However, limited by manufacturing level and carrying capacity, the traditional optical materials and reflection/refraction imaging principle have encountered a bottleneck in the manufacturing of space imaging system with ultra-large aperture and lightweight. Consequently, it is necessary to develop brand new space optical imaging systems. In this paper, we summarize the imaging mechanism and development history of three ultra-large aperture imaging technologies, including synthetic aperture imaging technology, diffractive membrane imaging technology and rotating synthetic aperture imaging technology, and analyze the challenges existing in their application.

The 1.7 μm modulated digital signals transmission through water fog based on a homemade pump-modulated fiber laser is proposed and experimentally demonstrated. The 1.7 μm modulated fiber laser could improve transmission performance through water fog.

We design a simultaneous measurement of the thickness and speed to monitor mechanical cylindrical parts during external grinding based on a laser self-mixing interference in a single-channel system. If the wavelength is modulated via the laser-injecting-current to generate a frequency shifting corresponding to the rising- and falling- edge of the triangular modulated function. The Doppler frequency caused by the cylindrical part is split into rising- and falling- edge frequencies by the frequency shifting due to wavelength variations. The expressions of the measurement are derived via the derivative of the phase’s polynomial based on the emission-intensity expressions. The frequency shifting is related to the modulation function and the thickness of the cylindrical part. The rising- and falling- edge frequencies of the laser self-mixing interference obtained from the spectrum are used for calculating the Doppler frequency and the frequency shifting for estimating the thickness and the rotation speed of a cylindrical part during external grinding and the results show a good standard derivation less than 10⁻³ .

The beam scanning range of frequency diversity arc array (FDAA) has all-round advantages. When it is equivalent to a linear array, it exhibits the characteristics of "The middle spacing is large, and the spacing between the two sides is gradually reduced", and there is an inverse density weighting phenomenon, which will lead to a high sidelobe of the FDAA beam. In order to further reduce the influence of sidelobe level and inverse density weighting, the amplitude weighting is carried out on the basis of the nonlinear frequency offset of the array element, but the amplitude weighting is realized by the attenuator in each channel, which will lead to the decrease of the antenna gain, which is generally used when the radar receives the signal. For the transmitter of antenna radar, this paper proposes a phase weighting method for nonlinear frequency offset. The effectiveness of this method for sidelobe suppression is proved by simulation.

This paper studies the collaborative unmanned aerial vehicle (UAV) sensing in integrated sensing and communication (ISAC) networks. By equipping sensing and communication units on UAVs, they can execute sensing tasks and transmit the sensing information to the base station (BS) for environment sensing. Due to the mobility and dense deployment of UAVs, they can sense the environment with much lower cost compared to the BS sensing. We aim to minimize the network sensing cost by optimizing the UAV deployment and task assignment collaboratively. For this joint optimization problem, we propose an iterative mechanism to optimize the UAV deployment and task assignment iteratively. UAV deployment problem is modeled as a cluster problem and we utilize a K-means cluster algorithm to solve it efficiently. For task assignment problem, we propose a greedy algorithm to solve it with low complexity. Simulation results validate the effectiveness of our proposed method in different scenarios.

Researching the effect of complex ground on the echo characteristics is important for impulse-radio ultra-wideband (IR-UWB) proximity fuze. In this paper, the mathematical model of mixed medium ground is established by Monte Carlo method to represent complex ground, and the time-domain signal scattering model is established based on the unit decomposition method. The correlation between echo signals of complex ground and single medium ground is studied by using this model, and the complex ground echo signal is analyzed by wavelet time-frequency transform. The simulation results show that, compared with the single medium ground, the complex ground mainly affects the peak amplitude of the echo signal, and has little influence on the peak position. The simulation and analysis provide a 1 theoretical basis for the ranging control of the IR-UWB fuze on the complex ground.

In the actual design of the sampling integral differential circuit of the IR-UWB proximity fuze receiver, it is impossible to guarantee the complete symmetry of the circuit due to the deviation of the component parameters, which leads to the inability of the receiver to filter out the noise completely. In order to study the effect of the scattering of component parameters in the circuit on the output of noise, this paper investigates the effect of noise in the circuit on the output signal waveform of the circuit under two cases of complete symmetry and asymmetry of the circuit, based on the model of ultra-wideband fuze receiver, respectively, to provide a theoretical basis for the selection and design of ultra-wideband fuze detector devices in the future.

The spectral response of passive optical devices reveals the important characteristics of their materials and functions and is an essential evaluation index in the development, production and application of optical devices. In this paper, a broadband and high-resolution spectral response measurement method is proposed based on single sideband modulation technology. The optical carrier emitted by the tunable light source is incident on the dual parallel Mach Zehnder modulator (DPMZM), and the Microwave signal emitted by the frequency source is loaded on the modulator. Combined with the bias voltage and the hybrid couple, carrier suppression single sideband (CS-SSB) modulation is realized. The modulated signal is received by the photodetector after passing through the passive optical device under test, and frequency of the single sideband modulated optical signal can be swept through the frequency source. This signal passes through the optical beam splitter, and the spectral response of the passive optical device is measured by the balance detection of two signals. A broadband high-resolution spectral response measurement system is constructed in the experiment. The experimental results show that the spectral measurement resolution of the system reaches at least 5 MHz, and the measurement range is 1528-1568 nm. This measurement method combines a tunable light source with a single sideband microwave photon scanning frequency. The system structure is simple, the measurement accuracy is high, and the measurement range is large. It can realize the spectrum response measurement of passive optical devices such as narrow linewidth filters and wavelength division multiplexers.

A method for generating reconfigurable photonic arbitrary phase-coded microwave signal with fundamental/double/triple carrier frequencies is proposed and demonstrated. A dual-parallel dual-polarization Mach‒Zehnder modulator (DP-DPMZM) and an optical bandpass filter (OBPF) are cascaded to generate orthogonally polarized optical carrier signals and 1st/2nd/3rd -order sideband signals, which are sent into a polarization-dependent phase modulator (PD-PM), which can realize phase modulation with different polarization state optical signals. The phase modulated signal after PD-PM will be projected into the polarization direction with a polarizer (Pol) and the phase shifting microwave signal will be obtained with a photodetector (PD). This method enables the frequency multiplication factor to be changed by tuning the bias voltage of the modulator alone, which makes the system can work in a wide bandwidth, and it also reduces the frequency requirements of the local oscillator (LO) signal. In the simulation, binary phase-coded signals with center frequencies of 6 GHz, 12 GHz, and 18 GHz are generated, and their performance is verified.