Wireless tag communication device and sheet processing apparatus

A sheet processing apparatus, comprising:

• a sheet conveyance path along which a sheet having a wireless tag is conveyed in a conveyance direction;
• and
• a wireless tag communication device configured to communicate with the wireless tag and including:
• an antenna with a plurality of radiation regions from which a polarized radio wave is emitted, the plurality of radiation regions including:
• a first radiation region extending along a first direction crossing the conveyance direction and having a first length in the first direction, and
• a second radiation region extending parallel to the first radiation region and having a second length that is different from the first length in the first direction, and
• a controller configured to cause at least one of the first and second radiation regions to emit a polarized wave towards the wireless tag.