Samsung patents phone case that powers itself via NFC

1. An accessory device for use with an electronic device, the accessory device comprising: a receptacle including a bottom wall and side walls extending from the bottom wall, wherein the bottom wall and the side walls define an internal volume having a size and a shape that receive the electronic device; an antenna for near field communication (NFC), embedded in the bottom wall; power supply circuitry usable for obtaining power for components of the accessory device through the antenna from the electronic device positioned in the receptacle; a first linear regulator, comprising circuitry, connected to the power supply circuitry; a second linear regulator, comprising circuitry, connected to the power supply circuitry; integrated circuitry that is connected to the antenna, is connected through the first linear regulator to the power supply circuitry, and includes wireless communication circuitry for NFC and memory, wherein one or more nodes connecting the power supply circuitry to the antenna are also connected to the integrated circuitry; and a circuit, connected through the second linear regulator to the power supply circuitry, usable for providing information; wherein the memory stores instruction to cause the integrated circuitry to support communication with the electronic device performed through the antenna, to authenticate the accessory device in the electronic device positioned in the receptacle.