A RADIO COMMUNICATIONS MEDIUM PROCESSING UNIT

摘要

Providing a radio communications medium processing unit which suppresses variations in potential at the grounding end and variations in ground potential used for signal processing, thereby performing accurate signal processing The invention comprises an antenna, a read/write section for reading or writing data, or reading and writing data from/to a radio communications medium via the antenna, a conductive line having an electric distance below the quarter wavelength of a frequency in use, the conductive line connected to the extremity of at least one grounding end present on the read/write section and the antenna, and a variable lumped constant unit for changing the lumped constant of the impedance connected at some midpoint in the conductive line, characterized in that the extremity of the conductive line is an open end.