This paper describes a new low-profile X antenna array separated 0.1-0.15 wavelengths from a flat or rimmed square reflector of 0.6 wavelengths in size. The array consists of two closely spaced elements: an active two-port folded-wire X antenna, which radiates two cross-polarized fields and a passive X element. This very compact double X reflector antenna has around 8-9 dBi peak directive gain, 12.5% bandwidth on average around the design frequency of 1800 MHz, a high interport isolation (about 25-30 dB) and low cross-polarization in the whole input-match frequency range. The practical applications of the properly designed and tuned double X reflector antenna may include among others, base station antennas with polarization diversity for GSM PCS or DCS bands, or for the whole UMTS band. (C) 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2833-2837, 2010: View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25616