摘要:
Second ground plane (18), substantially rectangular in shape, is connected to first ground plane (17) mounted with a data processing circuit, and radio communication circuit (12) makes radio communications at communication wavelength λ. A portion of second ground plane (18) from ground connecting means (14) to ground connecting means (33) along continuous edges of second ground plane (18) acts as an antenna. However, since the longest distance a between a plurality of ground connecting means (14, 33) along the continuous edges of second ground plane (18) satisfies “a