Small Shielded Bluetooth Module Equipped with Slot Antenna on the Surface

In this paper, a land grid array-type ultra-small shielded module that has a 2.4 GHz slot antenna is presented. Slots are patterned on both an interposer and a shield layer. The slots are connected at the side of the interposer and compose the slot antenna. A large part of the slot antenna is formed on the shield deposited on the surface of the module. The slot on the interposer is short and occupy a small area, therefore the slot antenna allows the area of the interposer to be reduced. In addition to that the slot antenna reduces the keep-out zone in which no wires can be laid out on the board. It is because the area of the slot on the interposer is small. A prototype of the module with a Bluetooth Low Energy chip was fabricated. The volume of the prototype is 5.25 x 9.0 x 1.0 mm3. The keep-out zone of the module is 9.0 mm2. The module has received Japanese modular approval certification because it contains all the elements for wireless communication except for a power supply.