US 12298428 B2 / May 13, 2025

Antenna subsystem with analog beam-steering transmit array and sparse hybrid analog and digital beam-steering receive array

In an embodiment, an antenna subsystem includes a sparse receive antenna and an electronically steerable transmit antenna. The sparse receive antenna includes an array of electronically steerable receive elements each configured to receive a respective signal having a wavelength and each spaced apart from each adjacent one of the receive elements by a respective first distance that is more than one half of the wavelength, has an aperture, and is configured to generate a receive beam pattern. And the electronically steerable transmit antenna includes an array of transmit elements each configured to radiate a respective signal having the wavelength and each spaced apart from each adjacent one of the transmit elements by a respective second distance that is less than one half of the wavelength, has an aperture that is significantly smaller than the aperture of the sparse receive antenna, and is configured to filter, spatially, the receive beam pattern.