We propose a frequency reconfigurable slot dipole antenna mounted with surface PIN (S-PIN) diodes. Instead of using conventional chip-packaged PIN diodes, a plasma channels induced on the S-PIN diodes with high carrier concentrations are used to electrically change effective lengths of the slots. Thus, by turning on and off the S-PIN diodes, we can make our antenna operate in three different frequency bands. Reasonably high realized gain near at each resonant frequency confirms that the plasma channel well mimics a desired metallic property rather than absorbing RF signals. In addition, we can also estimate appropriate conductivity of the proposed S-PIN diodes by parametric study of simulations, which was not clear in conventional researches.