In-sheet transceiver testing

A method of testing the RF communication operation of a plurality of RF transponders, comprising the steps of:

• providing a sheet characterized by first and second opposite faces and a thickness;
• mounting on the sheet a plurality of RF transponders, wherein each transponder includes a transponder RF antenna;
• positioning a first test fixture section having a first RF shield so that the first RF shield abuts the first face of the sheet;
• positioning a second test fixture section so as to abut the second face of the sheet, wherein:
• the second test fixture section includes a plurality of RF shields,
• each RF shield in the second test fixture section is in the shape of a cup having a mouth abutting said second face of the sheet,
• the first and second test fixture sections so that each RF shield in the second test fixture section encircles a corresponding one of the transponder RF antennas so as to form, in combination with the first RF shield, a closed cavity that completely surrounds and encloses said corresponding transponder RF antenna except where the thickness of the sheet separates the first RF shield from the mouth of said RF shield in the second test fixture section, and
• said thickness is sufficiently small so that the first and second RF shields prevent any RF signals within the cavity from radiating outside the cavity;
• positioning within each cavity a corresponding test fixture RF antenna;
• transmitting an RF signal from each test fixture antenna;
• detecting a response by each transponder to the RF signal transmitted by its corresponding test fixture antenna;
• and
• subsequently removing each transponder from proximity to the first and second test fixture sections and the test fixture RF antennas, so that no shielding obstructs each transponder RF antenna from sending and receiving RF radiation at any angle.

A test fixture for testing the RF communication operation of an RF transponder which is mounted on a sheet which extends beyond the perimeter of the transponder, the RF transponder having an antenna for receiving RF signals, comprising:

• first and second RF shields, the second RF shield being in the shape of a cup having a mouth;
• an alignment mechanism for positioning the first and second RF shields to abut opposite sides of the sheet so that the mouth encircles the transponder antenna and so that the combination of the first and second RF shields forms a closed cavity completely surrounding and enclosing the transponder antenna except where the sheet separates the two RF shields, wherein the distance by which the sheet separates the two RF shields is small enough to prevent any RF signals within the cavity from radiating outside the cavity;
• and
• a test fixture RF antenna mounted within the cavity.

A test fixture for testing the RF communication operation of a plurality of RF transponders mounted on a sheet, each RF transponder having an RF antenna, comprising:

• a first test fixture section including a first RF shield;
• a second test fixture section including a plurality of RF shields each of which is in the shape of a cup having a mouth;
• an alignment mechanism for positioning the first and second test fixture sections to abut opposite sides of the sheet so that each RF shield in the second test fixture section encircles a corresponding one of the transponder antennas so as to form, in combination with the first RF shield, a closed cavity that completely surrounds and encloses said corresponding transponder RF antenna except where the sheet separates the first RF shield from the mouth of said RF shield in the second test fixture section, wherein the distance by which the sheet separates the first RF shield from each RF shield of the second test fixture section is small enough to prevent any RF signals within each cavity from radiating outside that cavity;
• and
• a test fixture RF antenna mounted within each cavity.