The invention relates to a liquid-
crystal microwave modulation device and a modulation method thereof. The device comprises n
liquid crystal boxes of the same structure and n paths of driving
voltage signal sources A, n ranges from 2 to 10, each
liquid crystal box structurally comprises a first glass substrate, a first ITO
electrode, a first orientation layer, a
liquid crystal layer, a second orientation layer, a second ITO
electrode and a second glass substrate from top to bottom successively, the liquid
crystal layer is provided with spherical resin separators, the n liquid
crystal boxes of the same structure are stacked from top to bottom successively, the n paths of driving
voltage signal sources A form n waveform
signal generators independent from one another, and each waveform
signal generator is connected with one liquid crystal box correspondingly. According to the invention, the liquid crystal
dielectric constant of each layer in the
microwave spreading direction can be changed according to multipath driving
voltage signals set by users, and interference and
diffraction results of emission microwaves can be adjusted.