In this paper, the advantages of the gold ribbon welding connection technology over solder connection technology are described, and the effects of different sizes and positions of gold ribbon welding on electrical transmission performance were analyzed by simulation technology. Through a series of orthogonal tests, the paper shows how the three parameters of spot welding voltage, spot welding time and electrode pressure affected the welding effect during the spot welding process between gold strip and substrate and adapter. The formation mechanism of different fracture modes and the mechanism of smoke generation were analyzed, and the relationship between single parameter and welding breaking force is revealed. Finally, the optimized process parameters are obtained. The optimized process parameters were used to produce the gold ribbon according to the specified process steps, and the excellent performance of the ribbon was verified by the high and low temperature cycle test and the electrical property test.

This paper mainly focuses on the thermal deformation of microwave components during reflow soldering. Firstly, the"birth-death setting" of the contact pairs was utilized to accurately simulate the dynamic constraint relationship between the shell and PCB(the Printed Circuit Board), a thermal-mechanical sequential coupling simulation method was adopted to conduct a simulation analysis of the thermal deformation of microwave components during the reflow soldering process. Then, through the comparative analysis of the simulation and actual test results, it is found that the error between the simulation results and the measured results is within 10%, thus verifying the effectiveness and accuracy of this simulation method. Finally, analyses and studies were conducted on the influencing factors such as structural stiffness, solder thickness, soldering temperature, and material combinations. Through the research in this paper, the thermal deformation of microwave components during reflow soldering can be accurately predicted at the initial stage of design. Meanwhile, the analysis and study of several typical influencing factors can provide clear guidance for subsequent design optimization, offering references and examples for improving the reliability of reflow soldering of microwave components.

Based on the requirements of multi-application function fusion, integration, and reconfigurability of integrated electronic equipment, this paper designs a comprehensive RF(Radio Frequency) microsystem for communication, navigation, reconnaissance, and other applications to achieve multiple functions such as telemetry, safety control, and data link. Based on the RF digital integration design method, we aim to achieve high-density integration of 8 heterogeneous chips across 5 process nodes, addressing issues such as wiring difficulties, limited isolation space resources, and difficulties in integrating heterogeneous chips. Adopting BGA1369 packaging, the packaging size is 37.5 mm × 37.5 mm × 3.97 mm. To meet the high reliability requirements of universal applications, establish a reliability assessment system for electricity, heat, and power, and achieve batch unmanned aging and life testing. Developing an operating system based on IP software-defined application method to meet the demand for multifunctional communication, navigation and reconnaissance. This system can achieve reconfigurable applications in different RF digital integration scenarios such as handheld telemetry terminals and flight communication systems, and meet the application requirements for convenient development.

The current wireless SAW (Surface Acoustic Wave) sensor based on langasite (LGS) can work at temperatures as high as 600 °C. Nevertheless, the propagation loss of LGS increases significantly as frequency and temperature increase, which limits the operating frequency of the SAW sensor based on LGS to 1 GHz. However, SAW resonator based on AlN/sapphire structure exhibits gigantic potential for high-temperature sensing applications due to its resistance to high temperatures, high Q-factor, and low propagation loss. In this work, an efficient model for SAW resonator based on AlN/sapphire is developed using the coupled mode (COM) theory combined with the finite element method (FEM). The influence of different numbers of interdigital transducers(IDT), reflective gratings, and different aperture lengths on device performance are investigated. Furthermore, the relationship between resonant frequency and temperature at various temperatures is simulated, which compares well with that of the experimental results. The investigation results show that the resonator works reliably in the temperature range of up to 500 °C and the operating frequency of up to 2.45 GHz. The frequency-temperature characteristics exhibit good linearity, with a temperature coefficient of-67×10^-6 °C^-1. This work provides an important reference for designing high-performance SAW high-temperature sensors.

Solid rocket motors are widely used in space launch vehicles, missile weapon propulsion, and spacecraft attitude and orbit control. Its tail flame temperature is a key parameter in evaluating propellant combustion performance and the engine efficiency. Due to the high temperature, high pressure and strong washout characteristics of the solid rocket motor exhaust flame, the test site environment is often accompanied by strong vibration, strong stray radiation, dust pollution and high noise, it's a challenge to temperature measurement techniques. In this paper, the development of contact and contactless temperature measurement techniques for solid rocket motor exhaust flame is summarized, and the advantages and disadvantages of the current techniques are analyzed. It is also pointed out that multispectral radiometric imaging thermometry and its temperature inversion algorithm are the current and future research frontiers.

The operating temperature of common acrylic-coated optical fibers is usually -65 °C to 80° C, and the working temperature of common high-temperature polyimide-coated optical fibers is up to 300 °C. At higher temperatures, metal-coated special optical fibers, such as aluminum-coated, copper-coated, and gold-coated fibers, are usually used for signal transmission. In this paper, the transmission loss of gold-coated fibers is tested at different ambient temperatures, and it is found that the transmission loss of gold-coated fibers varies greatly when the ambient temperature changes. For fiber optic temperature sensors based on the blackbody radiation principle, the error introduced by the variation in transmission loss can exceed 60 °C. On this basis, based on the transmission characteristics of light in different bands in gold-coated fibers, a dual-band correction method is proposed, which can correct the transmission loss of optical fibers caused by ambient temperature. After the correction, the error caused by the transmission loss is less than 15 °C.

Spaceborne synthetic aperture radar is one of the important means of detecting ocean internal waves, and sea surface wind speed has a significant impact on the ability of synthetic aperture radar to detect ocean internal waves. Based on the theory of the influence of sea surface wind speed on the ability of synthetic aperture radar to detect ocean internal waves, combining the insitu measured parameters of ocean internal waves, additional with the corresponding ocean environment and synthetic aperture radar data, this paper analyzes the imaging mechanism of ocean internal waves on synthetic aperture radar images, discusses the different manifestations of upward and downward ocean internal waves, and elaborates on the ability of synthetic aperture radar to detect ocean internal waves under the combined influence of internal wave amplitude, thermocline depth, and thermocline intensity under different wind speed conditions. Simulation analysis shows that the smaller the sea surface wind speed, the larger the internal wave amplitude, the shallower the thermocline depth, and the stronger the thermocline intensity, the stronger the ability of synthetic aperture radar to detect internal waves in the ocean. The results can provide technical support for the planning of satellite observation tasks in the early stage of detecting ocean internal waves using spaceborne synthetic aperture radar.

Fiber Optic Gyroscope (FOG) is the core component of the fiber optic strapdown inertial navigation system, which has been widely used in aviation, aerospace, navigation and other fields. The scale factor is the main factor affecting the dynamic performance of FOG. Because the photoelectric devices inside FOG are highly sensitive to temperature vaviations, the scale factor error will be produced under the influence of temperature, which will affect the precision of FOG. In the variable temperature environment, each photoelectric device is heated unevenly, which leads to the hysteresis of the scale factor error. In this paper, the scale factor hysteresis error of FOG is studied, and a multi-temperature sensor measuring system is built. The source and characteristics of the scale factor hysteresis error are determined by the experimental results. Based on the above analysis, an error compensation algorithm based on gravitational search algorithm (GSA) and long short-term memory (LSTM) network is proposed. The parameters of LSTM network are optimized by GSA, and the LSTM model is used to compensate the scale factor hysteresis error. The experimental results show that the peak-to-peak value of scale factor error in the whole temperature range is reduced from 835.1×10^-6 to 38.02×10^-6 by the proposed algorithm. By comparing with the compensation results of multilayer perceptron (MLP) and traditional LSTM algorithm, the effectiveness of the proposed algorithm in scale factor hysteresis error compensation is further verified.

Polymer Derived Ceramics (PDCs) thin-film thermocouples have the advantages of a simple preparation process and a stable high-temperature performance. They are very suitable for temperature measurement of hot-end components such as aircraft engine turbine blades. However, as the operating temperature of advanced engines increases, the upper limit of their temperature resistance needs to be improved. This article develops a precursor ceramic encapsulated PDCs: ITO/In₂O₃ thin film thermocouple. The encapsulation layer uses SiCN as the precursor solution and nano-Al₂O₃ powder as the filling material, and is prepared by the screen printing process. High-temperature test results show that the prepared sensor can survive at 1 500 °C in the short term and have stable output within 1 400 °C. The calibration test at 1 100 °C shows a linearity better than 0.999, with a multiple-cycle error of less than 1%.

In the field of ultra-high sound pressure noise environment of rocket engines, fiber laser microphones without diaphragm packaging have prominent pressure-resistant advantages. However, the phase noise problem introduced by unbalanced interferometer in engineering applications limits their performance. This paper focuses on the phase noise of the fiber laser microphone array introduced by the unbalanced interferometer in the modulation system. Firstly, the working principle of the modulation system and the source of the phase noise of the unbalanced interferometer are discussed, and a stable laser light source is incident on the unbalanced interferometer shared by the microphone system, to construct fiber laser microphone array system with suppressed optical phase noise. Then, the suppression principle is theoretically analyzed using the differential cross multiplying (DCM) demodulation. The noise information of the optical reference is used to cancel out the system noise introduced by the interferometer, thereby achieving the dynamic noise suppression. Finally, numerical simulation and experimental verification are conducted on the microphone array system. As a result, the phase noise measured in the non-equilibrium interferometer is reduced from approximately ± 0.34 rad to within ± 0.15 rad compared with the system without optical reference under field experimental conditions. The noise peak is sup-pressed by more than 7 dB, and the noise power spectral density is reduced from -25.02 dB/ to below -32.93 dB/. The suppression effect of phase noise is significant.