In one embodiment, a radio frequency power meter operates according to a variable loop bandwidth according to the nature of the RF signal to be measured. The weight of the ramp portion biases the ramp portion toward the deployed position when the ramp portion is between the deployed position and the neutral position, and toward the stowed position when the ramp portion is between the stowed position and the neutral position. According to the above structure, because the protective film is adhered onto the AlOx layer of the thin film encapsulation structure, which has a relatively weak adhesive force, the adhering and releasing processes may be performed smoothly, and thus, the thin film encapsulation structure may be prevented from being damaged in the adhering and releasing processes.