Latest ArticlesA millimeter power synthesizer based on a novel suspended microstrip transition structure has been proposed. The terahertz power combiner combines/distributes power through a traditional waveguide power splitter with one to eight channels, and connects the eight channels of power splitters with a new suspended microstrip transition structure. The proposed new microstrip transition structure is easy to process, and by optimizing the length of the suspended microstrip substrate, the two sides of the substrate are mounted in the protruding waveguide sidewalls, which can suspend and fix the entire microstrip inside the waveguide without affecting transmission performance. The average insertion loss test values of the processed samples remained stable below 0.5 dB. Finally, the overall optimization analysis was conducted on the power combiner. Simulation results showed that within the operating frequency range of 180~220 GHz, the S11 parameter of the power combiner remained stable below -15 dB, and the loss from the input port to the output port of the power combiner was approximately 0.25 dB.
Substrate Integrated Waveguide (SIW) has been widely used in the design of microwave circuits and systems due to its low insertion loss and high-quality factor. However, compared to traditional microstrip lines, SIW has larger transverse dimensions, which limits its application in miniaturized and compact microwave circuits and systems. This paper proposes a SIW-SSPP hybrid circuit by integrating a three-dimensional SSPP structure composed of metallized blind vias and metal patches. Theoretical analysis of dispersion characteristics and full-wave electromagnetic simulations demonstrate that this SIW-SSPP integrated hybrid circuit can achieve a 30% reduction in transverse length and a 50% reduction in longitudinal length of the transmission line. Furthermore, by etching an orthogonal radiation structure on top of the SIW-SSPP hybrid circuit, a compact ultra-wideband circularly polarized leaky-wave antenna was designed. The results indicate that the antenna exhibits a return loss below -10 dB and an S21 below -6 dB within the operating frequency band of 11.2 to 17 GHz. It achieves an axial ratio of less than 3 dB between 11.2 and 16.2 GHz. The antenna's gain ranges from 10 to 15 dBic. It also features continuous scanning performance from backward space (-27°) to forward space (+30°). This design method provides a new approach for the development and design of high-performance, compact microwave, millimeter-wave, and terahertz systems.
With the aim of enhancing the space-air-ground integrated telemetry and telecontrol capabilities of the shooting range and meeting the comprehensive measurement demands for high-altitude high-speed targets and low-altitude multiple targets, we propose an air-based multi-target integrated telemetry and telecontrol system scheme leveraging phased array antenna technology. The system employs a space-air-ground integrated three-dimensional architecture. It constructs a large-capacity information relay transmission node via the air-based platform, the onboard telemetry and telecontrol subsystem, and the data relay subsystem. This system possesses the functions of receiving and forwarding multi-target omnidirectional telemetry data and relaying high-bit-rate measurement information. It accommodates the requirements of rapid mobility in stationing within complex terrains such as plateaus and seas. Moreover, key technologies including conformal array antenna design, unit-level all-digital beamforming, and wideband data relay communication have been conquered, thus providing crucial support for the telemetry and telecontrol operations in the aero-weapon range.
The diversity of space missions presents enormous challenges to the development of satellite ground TT&C station. The modular construction of equipment can bring about many improvements to space equipment construction. First, this paper analyzes the demands of space missions to find out the key points and connotations of satellite ground TT&C station. Second, the basic development elements of modular connotations, the capacity requirements of satellite ground TT&C station and the current status of equipment construction are analyzed, and the modular construction of satellite ground TT&C station is proposed. Finally, combined with the positive role of modular construction and development, suggestions for the modular construction of satellite ground TT&C station are presented, which can effectively support the modular construction and development of satellite ground TT&C station.
Radar communication integration is an effective solution to spectrum competition and electromagnetic interference. The integrated waveform determines the architecture and performance of the integrated system. This paper proposes a radar communication integrated waveform based on multi-frequency-band Chirp-BOK to solve the low communication rate issue in Chirp Binary Orthogonal Keying (Chirp-BOK). Furthermore, it designs modulation and demodulation methods based on Inverse Fast Fourier Transform(IFFT) and Fast Fourier Transform(FFT) to reduce system complexity. To tackle the high Bit Error Rate(BER) issue, an optimization method using a double-window approach to reduce the judgment frequency is proposed. The ambiguity function and Doppler performance of the multi-frequency-band Chirp-BOK are analyzed. Simulation results demonstrate that the multi-frequency-band Chirp-BOK not only enhances the communication rate but also reduces the BER, ensuring detection resolution and excellent Doppler tolerance.
This paper presents the design and implementation of a multi-bus interface data recording device with high overload resistance, specifically developed to meet the data recording demands of aircraft operating in high-impact and high-overload environments. The device is centered around a Field-Programmable Gate Array (FPGA) and integrates three communication interfaces:1553B bus, Ethernet, and RS422, ensuring accurate and reliable signal acquisition across various data transmission rates. The application of key technologies such as multi-layer energy absorption structure design, encapsulation protection technology, miniaturized circuit design, and efficient storage modules significantly enhances the system's overload resistance and overall stability. Testing and verification have demonstrated that this device can operate stably in extreme overload environments, ensuring data integrity and system reliability.
With the rapid development of network real-time system, in order to achieve more efficient communication, the problem of network resource scheduling has been widely concerned by experts and scholars. The static scheduling table is an effective solution for configuring network resources, which is the focus of research in related fields at home and abroad. Since the advent of TTE (Time-Triggered Ethernet) in 2002, the solution method of TTE network static scheduling table has been improved and innovated because of different application fields and specific use scenarios. With the continuous optimization of various algorithms, the generating effect of static scheduling table is more and more ideal, but the scheme still can not be applied to engineering practice. This paper proposes to select Sparrow Search Algorithm (SSA) and add disturbance to the individual optimal position, which can significantly improve the convergence efficiency of fitness function, avoid falling into local optimal, and achieve the purpose of solving TTE static scheduling table.
To address challenges such as fast frequency changes and highly dynamic signal environments in frequency-hopping systems, this paper proposes an improved diagonally loaded SMI (Sample Matrix Inversion) algorithm suitable for FPGA (Field-Programmable Gate Array) implementation to enhance the system's anti-interference capability in complex environments. Compared with the traditional SMI algorithm, the improved diagonally loaded SMI algorithm is more effective in handling signal processing demands under low snapshot numbers and complex interference environments, with a lower computational complexity for the diagonal loading factor. This paper briefly introduces the basic principles of the improved diagonally loaded SMI algorithm and the calculation method of the diagonal loading factor, while providing a detailed explanation of its FPGA implementation and performance analysis. Firstly, low-complexity estimation of the diagonal loading factor is achieved using high-level synthesis (Vivado HLS)technology, enabling the optimal weight vector calculation and simplifying the design process. Subsequently, the IP core generated by HLS is packaged and integrated into the project to implement beamforming. Simulation results show that the diagonally loaded SMI algorithm can achieve an interference-to-signal ratio (SIR) improvement of over 70 dB on the FPGA platform, demonstrating significant interference suppression effects. Additionally, the algorithm completes anti-interference weight calculation, and beamforming update within 4734 clock cycles, ensuring fast performance and meeting the real-time processing requirements for frequency-hopping signals with over 10 000 hops per second.
With the continuous development of telemetry technology, there higher higher requirements for phased array beamfor-ming capabilities and anti-interference capabilities. Based on the iterative Fourier algorithm, this paper proposes a new twostage optimization algorithm to solve the spaceborne phased array beamforming problem. In the first stage, the iterative Fourier algorithm is improved by adding virtual array elements with zero excitation to supplement the array and increasing dynamic range constraints of the array element excitation, so that it can be used to achieve beamforming and low sidelobe requirements. In the second stage, the excitation with low sidelobe characteristics obtained in the previous stage is used as the constraint vector of the new beamforming algorithm, so as to improve the anti-interference performance of the phased array without changing the original response as much as possible. The experimental results show that the proposed two-stage optimization method can reduce the sidelobe level while beamforming, enhance the anti-interference performance of the array, and has high computational efficiency.
As the existing ray tracing algorithms exhibit low efficiency in indoor scenarios, this paper presents a novel ray tracing approach for computing the electromagnetic field within a building. Firstly, a matrix is incorporated to denote the visibility of all surfaces. Among all candidate rays between a pair of source and field points, the least likely ones are eliminated by the visibility matrix. The remaining rays are then analyzed using the conjugate gradient method to precisely determine the ray path. Subsequently, ray-object intersection tests are carried out, which are also expedited by the visibility matrix. Eventually, if the ray is present, the electromagnetic field is calculated via the uniform theory of diffraction (UTD). This new ray tracing algorithm can handle all types of rays, such as the reflected, diffracted, and refracted ones. Hence, it is more flexible compared to the image method. An example of a house demonstrates that it is more accurate and faster than WinProp in indoor scenarios.