| 摘要 |
<P>PROBLEM TO BE SOLVED: To appropriately control gain and directivity without increasing costs, upsizing a casing and decreasing reliability. <P>SOLUTION: A portable RFID reader/writer 1 is composed so that a parasitic element 31 can be attached or detached at a position for forming a director of Yagi antenna to an element 21 of a dipole antenna 20 and at a position for forming a reflector of Yagi antenna to the element 21 of the dipole antenna 20 while a parasitic element 30 can be attached or detached. By fitting the parasitic elements 30, 31, the Yagi antenna can be formed with the element 21 of the dipole antenna 20 and the parasitic elements 30, 31, thus appropriately controlling gain and directivity. <P>COPYRIGHT: (C)2010,JPO&INPIT |
