In this letter, a novel reconfigurable microstrip antenna with polarization diversity is proposed. The proposed antenna has a simple structure, consisting of a corner-truncated square radiating patch, two small triangular conductors, and a microstrip line feed. The proposed antenna can produce left hand circular polarization or right hand circular polarization according to the on- or off-state of PIN diode, which is between radiating patch and parasitic triangular conductor. Comparing with a conventional antenna, the proposed antenna may obtain a size reduction of the antenna system and a low-consumption current because the required PIN diode is reduced by half Measured results show that symmetrical radiation patterns with good CP characteristics are obtained at the resonant frequency. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2053-2056, 2010; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/mop.2539