ABSTRACTThis article describes the design of a compact penta band triangular patch antenna backed by a hexagonal complementary split ring resonator operating in the GPS (1.57 GHz), GSM (1.80 GHz), WLAN (2.4/5 GHz), and WiMAX (3.5 GHz) bands. The antenna has a very compact dimension of 20 × 20 × 1.6 mm3. Three concentric hexagonal split ring slots in the ground plane yield the uppermost triple bonds (2.45, 3.5, 5.2 GHz) and the two parameterized radiating branches attached to the triangular patch accounts for the two lowermost operating bands (1.57, 1.8 GHz). A prototype of the proposed antenna is fabricated and tested. Simulated and measured results are in good agreement. It has a uniform radiation pattern over all the operating frequencies and a peak gain of 6.3 dBi at 3.5 GHz. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1538–1542, 2015