{'fraction_non_alphanumeric': 0.016260162601626018, 'fraction_numerical': 0.011382113821138212, 'mean_word_length': 5.124378109452737, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Structure Design and Thermal Deformation Simulation of Spaceborne SAR Antenna

Spaceborne synthetic aperture radar (SAR) is an active microwave imaging equipment and has play a key role in many fields such as target dynamic monitoring and 3D mapping, due to its unique advantage of observing in all time and all-weather. In this paper, a structure design and thermal deformation analysis of a large spaceborne millimeter wave phased array SAR antenna is prescribed. The total heat per unit time generated by the antenna, whose size is about 590λ0×56λ0 (λ0 is the wavelength in free space), is as high as 19000W. In order to alleviate the thermal deformation of antenna array, which may deteriorates seriously the flatness of the antenna, a study is conducted first to analysis the thermal deformation under high and low temperature conditions, based on which, a partial constraint released method was then adopted for the structure design of the antenna array. The simulation shows that the thermal deformation of the antenna array using partial constraint released method is effectively reduced compared with the one without using it, which is of significance for the electrical performance of the antenna array working on orbit.