A novel reconfigurable broadside-endfire microstrip antenna is proposed. The beam steering is achieved by reconfiguring the ground plane. The ground plane can be reconfigured either into a high-impedance surface for broadside radiation or into a surface waveguide for endfire radiation. A DC bias line, not connected to the folded dipole feed in any way, is used to switch the PIN diodes. PIN diodes are soldered on the back of the antenna and have no possibility of interfering with the feed. The proposed antenna is designed to work at the ISM 2.45 GHz band with a combined 2:1 VSWR bandwidth of 110 MHz and a combined radiation coverage of 133° on the Hplane. A 5 V power supply or a 9 V battery can be used to operate the active antenna.