Scanning antenna, scanning antenna drive method, and liquid crystal device

A scanning antenna including a transmission and/or reception region including a plurality of antenna units and a non-transmission and/or reception region located in a region other than the transmission and/or reception region, the scanning antenna comprising:

• a TFT substrate including
• a first dielectric substrate,
• a plurality of TFTs supported by the first dielectric substrate,
• a plurality of gate bus lines,
• a plurality of source bus lines, and
• a plurality of patch electrodes;
• a slot substrate including
• a second dielectric substrate, and
• a slot electrode formed on a first main surface of the second dielectric substrate;
• a liquid crystal layer provided between the TFT substrate and the slot substrate;
• and
• a reflective conductive plate disposed opposing a second main surface of the second dielectric substrate opposite to the first main surface with a dielectric layer interposed between the reflective conductive plate and the second dielectric substrate,
• wherein the slot electrode includes
• a plurality of slots disposed corresponding to the plurality of patch electrodes,
• at least one monitoring capacitance section formed in the non-transmission and/or reception region and including the liquid crystal layer and a monitoring capacitance including a first measurement electrode and a second measurement electrode opposing each other with the liquid crystal layer interposed between the first measurement electrode and the second measurement electrode, and
• a voltage monitor connectable to the first measurement electrode of the monitoring capacitance.