Dual-Band Transmitarray With Low Scan Loss for Satcom Applications

Abstract

This communication presents the experimental validation of independent and wide beam scanning with a dual-band transmitarray antenna (TA) in Satcom upand down-links at Ka-band. The TA consists of two subarrays: one operates in the down-link with central frequency at 19.5 GHz, while the other one operates in the up-link centered at 29 GHz. Both subarrays share a common radiating aperture to obtain the compact configuration. The TA layout is made of 1 bit unit-cells and its design relies on the bifocal technique to extend the beam-scanning capability. The proposed bifocal prototype includes 1500 up-link unitcells in a 30 × 50 matrix and 1581 down-link unit-cells arranged in a 31 × 51 rectangular lattice. The 1-D scanning is validated by displacing the feed horn along one direction. We show that the TA beam can be scanned in a ±40° and ±30° independently in each band while keeping a very low scan loss (.2 dB).