A liquid-crystal antenna device includes a signal source, a driving module, a correction module, and a plurality of radiation units. The signal source provides an input electromagnetic wave. The driving module outputs a plurality of initial voltage signals according to a radiation address. The correction module receives the initial voltage signals and outputs a plurality of corrected voltage signals according to a lookup table. The radiation units respectively receive the corrected voltage signals and are coupled to the input electromagnetic wave to generate an output electromagnetic wave.