A shielded antenna system is provided for reading from and/or writing to an RFID transponder wherein the RF energy radiated from the antenna system has a narrow beam width so that only one RFID transponder in a record member along a web of record members is read from and/or written to without affecting or being affected by any other RFID transponder along the web. It is preferred to provide shielding that enables more energy to be radiated in the upstream direction from the antenna than in the downstream direction from the antenna to provide for earlier reading and/or writing to the transponder in the moving web. The shielding is selectively configured and/or positionable to narrow or broaden the RF energy field of the antenna.