An antenna structure has a substrate, having a first-side surface and a second-side surface. The supporting frame includes a supporting stem and a parasol frame, which is supported by the supporting stem, comprising a plurality of elongated awning ribs radially extended in a pivotally movable manner and a shading awning substantially supported by the awning ribs to define a shadowing area thereunder. The remote unit includes multiple remote basic units. This can ensure a necessary and sufficient voltage to the gate of the IGBT device. An air dam is in the disc cavity upstream of the actuator arm. At least one embodiment of a method includes receiving a plurality of video frames that comprise at least one segment of a video, the plurality of video frames being captured by a capture device and determining a maximum undesired movement of the capture device for the plurality of video frames during the at least one segment.