According to ambipolar diffusion equation of the non-equilibrium carriers in a semiconductor, a one-dementional continuity equation of carrier concentration in the intrinsic area of suface PIN diode (SPIN) at steady state under an applied electric field was derived and the conductivity of solid-state plasma in this area with high current injected was caculated out. Based on this conductivity, a reconfigurable patch monopole antenna structure was built and simulated in Advanced Design System (ADS), the result showed that SPIN has similar electromagnetic radiation characteristics to metals under high current injection , which means SPIN can be used as basic radiating element，instead of metals, to build reconfigurable antenna array.
