V. O. Skripachev1, V. O. Osipova2, E. V. Samokhina3
1–3 MIREA – Russian Technological University (Moscow, Russia)

1 skripachev@mirea.ru, 2 osipova@mirea.ru, 3 samohina@mirea.ru

This article presents the development of an angular tracking error signal generator for spacecraft, focusing on the reception of broadband signals using advanced digital signal processing techniques. The study addresses the limitations of traditional analog systems, such as large size, susceptibility to noise, and high costs for electromagnetic compatibility, by proposing a digital solution based on programmable logic integrated circuits (PLICs) and modern microcircuits.

Current analog-based systems for spacecraft angular tracking suffer from significant drawbacks, including bulkiness and sensitivity to interference. The transition to digital signal processing offers enhanced flexibility, reduced dimensions, and improved reliability. The article highlights the need for a modernized approach to meet the demands of high-precision spacecraft tracking.

The investigated system employs the amplitude sum-difference monopulse method for direction finding, which is less sensitive to channel characteristics compared to phase-based systems. Key features include: four-channel reception (two azimuthal and two elevation planes; amplitude and phase comparison to determine angular deviation; sum and difference signal processing to derive error signals proportional to the spacecraft's deviation from the equisignal direction (ESD).

The error signal generator comprises three functional groups: 1) signal amplification tract uses low-noise amplifiers with adjustable gain (–12 to 0 dB); 2) frequency conversion tract implements direct digital synthesis (DDS) and phase-locked loops (PLLs) to downconvert signals to intermediate frequencies (6.5 MHz and 6.501 MHz); 3) error signal formation tract combines sum and difference signals, applies automatic gain control (AGC), and uses correlation detection to extract error signals (±6 V range).

A prototype has been developed using cost-effective alternatives (e.g., Altera Cyclone IV PLIC and 1508PL9T microcircuits with integrated VCO). Testing confirmed the system's functionality under various conditions: maximum deviation – ±6 V error signal; half deviation – ±3 V error signal; zero deviation – 0 V error signal (ESD alignment).

The digital error signal generator demonstrated high accuracy in tracking spacecraft angular deviations, noise resistance and scalability due to digital processing, cost efficiency through modern component integration.

The study successfully validates the feasibility of a digital angular tracking error signal generator, offering a robust alternative to analog systems. The prototype's performance confirms the advantages of digital processing in terms of precision, reliability, and adaptability for aerospace applications.

Skripachev V.O., Osipova V.O., Samokhina E.V. Angular tracking error signal generator. Antennas. 2025. № 3. P. 70–78. DOI: https://doi.org/10.18127/j03209601-202503-07 (in Russian)

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