A digital-correlation full-polarized microwave radiometer is an important passive remote sensor, as it can obtain the amplitude and phase information of an electromagnetic wave at the same time. It is widely used in the measurement of sea surface wind speed and direction. Its configuration is complicated, so the error analysis of the instrument is often difficult. This paper presents a full-polarized radiometer system model that can be used to analyze various errors, which include input signal models and a full-polarized radiometer (receiver) model. The input signal models are generated by WGN (white Gaussian noise), and the full-polarized radiometer model consists of an RF front-end model and digital back-end model. The calibration matrix is obtained by solving the overdetermined equations, and the output voltage is converted into Stokes brightness temperature through the calibration matrix. Then, we use the four Stokes parameters to analyze the sensitivity, linearity, and calibration residuals, from which the simulation model is validated. Finally, two examples of error analysis, including gain imbalance and quantization error, are given through a simulation model. In general, the simulation model proposed in this paper has good accuracy and can play an important role in the error analysis and pre-development of the fully polarized radiometer.

The design and application of broadband phased array RF links is a complex and highly precise endeavor. To achieve optimal performance, it is essential to compare and validate multiple schemes during the system design phase. Utilizing simulation models to simulate system structures and validate parameters can effectively reduce research and development time and costs. This article takes the broadband phased array RF system (RFS04) currently being developed by Nanhu Laboratory as a reference and constructs a behavioral-level signal simulation model. Through this model, the antenna pattern of RFS04 was generated, and the relationship between beam pointing accuracy and delay quantization bit number was analyzed. The 3 dB beam coverage range of the 18 GHz antenna array was calculated, and the synthesis scheme of multi-phased arrays was explored. Additionally, the correspondence between the angle measurement accuracy and signal-to-noise ratio of the RFS04 system was analyzed. This article also measured the delay module parameters of the RF system and developed a correction strategy for the delay control scheme. Through simulation calculations and laboratory testing, it has been proven that this strategy can effectively improve delay accuracy. After applying the modified delay control scheme to the RFS04 simulation model, the beam pointing accuracy during phased array antenna scanning was significantly enhanced. The model research and integrated simulation software construction of the broadband phased array RF system provide an efficient and accurate simulation tool for system design and optimization.

The rapid advancement of unmanned aerial vehicle (UAV) technology has introduced increasingly severe airspace security challenges. As a critical component of counter-UAV systems, the direction-finding (DF) accuracy of airborne warning systems directly affects threat assessment and response efficiency. This paper addresses the problem of limited DF accuracy in airborne environments by proposing a direction-finding method that integrates attitude self-calibration with real-time signal-to-noise ratio (SNR) estimation. Based on the monopulse amplitude–phase comparison angle-measurement principle, the proposed method dynamically corrects the angle-discrimination curve using real-time SNR information and adaptively calibrates azimuth information by incorporating UAV attitude data. Simulation and experimental results demonstrate that the proposed method significantly reduces angle-measurement errors under low-SNR conditions, and attitude calibration further improves DF accuracy across the full angular range. Field experiments indicate that, after attitude calibration, the angle-measurement error is less than $2^{\circ }$ in over $77\%$ of the test points.