摘要 |
A reflectarray antenna with a scanned radiated beam has an antenna feed for radiating a wave. A reflecting surface excited by the wave is reflected from a reflecting surface located on a tunable substrate in accordance with a variable surface impedance of the tunable substrate modulated to scan the radiated beam. The tunable substrate surface impedance is varied by modulating the dielectric constant or the permeability. The tunable substrate may be an electromagnetic band gap (EBG) material electromagnetic crystal (EXMT) structure to vary the surface impedance. The reflecting surface may be located on short-circuited waveguides with a variable surface impedance modulated to scan the radiated beam by adjusting phase shifts of the waveguides with tunable substrate phase shifter located in the waveguides or by adjusting the position of a piezoelectric movable short.
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