An electrostatic discharge, ESD, protection structure (200) formed within a semiconductor substrate of an integrated circuit device (600). The integrated circuit device (600) comprising: a radio frequency domain (632); a digital domain (610). The ESD protection structure (200) further includes an intermediate domain located between the radio frequency domain (632) and the digital domain (610) that comprises at least one radio frequency, RF, passive or active device that exhibits an impedance characteristic that increases as a frequency of operation increases.