The touch screen is composed of transparent electrodes separated by the transparent screen, and the electrodes are capacitively coupled. As a finger approaches, the capacitance changes since a finger looks like a grounded conductor at the transmit frequency. This causes the phase of the received signal to shift, which is used as the detection signal. In the example, when the sense voltage (a measure of the phase shift) exceeds 0.2 V, the pixel is activated which is indicated in the animation by a green square.