Liquid crystal cell and scanning antenna

A liquid crystal cell in which a plurality of antenna units are arranged, comprising:

• a TFT substrate including a first dielectric substrate, a plurality of TFTs supported by the first dielectric substrate and a plurality of patch electrodes electrically connected to the TFTs, and a first alignment film formed to cover a groove part between the patch electrodes adjacent to each other;
• a slot substrate including a second dielectric substrate, a slot electrode including a plurality of slots and supported by the second dielectric substrate, and a second alignment film formed to cover the slot electrode;
• and
• a liquid crystal layer sandwiched between the TFT substrate and the slot substrate in which the patch electrodes and the slot electrode are arranged to face each other,
• wherein the liquid crystal layer is constituted of liquid crystal material having a lower limit temperature T1 of a nematic phase of the liquid crystal material in a range from −43° C. to −32° C., and an upper limit temperature T2 of the nematic phase of the liquid crystal material in a range from 110° C. to 143° C.,
• the liquid crystal layer includes the first region located between each of the patch electrodes and the slot electrode and having small thickness, and the second region located between the groove part and the slot electrode and having large thickness, and
• the first alignment film has a thickness at a portion in contact with the liquid crystal layer in the second region in a range from twice to 10 times greater than a thickness at a portion in contact with the liquid crystal layer in the first region.