Design and Implementation of Active Phased Array Antennas Applicable to Space Surveillance Radar

Abstract

Human space activities can be threatened by the recent increase in space waste. Therefore, a space surveillance radar must be developed to continuously monitor them. In this study, an 8×8 modular active phased array antenna applicable to an L-band space surveillance radar was designed/produced through module-level expansion. Considering the actual wide beam steering range (off-axis ±45°) of the space surveillance radar, the active reflection coefficient of single elements within the steering range was minimized by setting to less than −7 dB. Additionally, the calibration path was applied to the radiation element to check and rectify the real-time state of the transmission/reception path after system-level integration. Furthermore, the design prevented gain reduction that might occur during beam steering and satisfied the 6 dB beam width of more than 120°. Simulations and measurements confirmed that the performance of the designed/produced antenna met the target performance.