An expandable implant device for implantation at a surgical site is provided. The digital radio receiver includes an internal memory configured to store the information on the piece of music; an operation unit configured to set a timing at which a flag is attached to the information on the piece of music recorded in the internal memory; and a controller configured to perform a process for storing the information on the piece of music in the internal memory. A shielding structure is disposed at the bottom and insulated from the trenched gate to provide shielding effect for both the trenched gate and the Schottky diode. The drain of the enhancement-mode HFET serves as the input drain node, the source of the enhancement-mode HFET serves as the input source node and a second terminal of the voltage shifter serves as the input gate node.