300-900 MHz Midband Array Design for the Lunar Farside Technosignatures and Transients Telescope

Brigham Young University Engineering Building, Provo, UT

The Lunar Farside Technosignature & Transients Telescope (LFT3), planned as an ultra-high frequency (UHF) phased array near the lunar antipode, is introduced as a pioneering mission capitalizing on recent advancements in analog beamforming. LFT3's midband array specifically leverages a described analog beamformer to achieve critical baseline measurements, enabling observations of astrophysical phenomena free from terrestrial interference. The authors describe the development of a wideband, low-power analog beamformer suitable for lunar-based radio astronomy, evaluating the primary architectures: a combiner tree, Rotman lens, Butler matrix, Nolen matrix, and Blass matrix. Each approach is analyzed in terms of performance, complexity, reliability, and suitability for implementation on a space-secured lunar lander. Measurements and comparative analysis highlight distinct trade-offs, revealing that a Blass matrix incorporating true time delays offers the highest reliability, lowest complexity, and minimal component count, making it optimal for low-power lunar operations.