In a method of manufacturing a semiconductor device for use in such applications as a flash memory device, a field insulating pattern defines an opening that exposes an active region of a semiconductor substrate. The parasitic power circuit derives a supply voltage from an external AC or other signal suitable for use as a communications signal. 11 h standard defines mechanisms for dynamic frequency selection and transmit power control that may be used to satisfy regulatory requirements for operation in the 5 GHz band in Europe.