“…However, narrow-bandwidth characteristic of individual mode is one of the limitations for PIFA, and its 3D structure may be a fabrication challenge [4]. Numerous techniques for multiband planar monopole antenna design have been presented in literature, e.g., Land U-shaped slots [5], an additional strip [6], multiresonator-loaded structures including a pair of symmetrical edge resonators and a T-shaped stub resonator [7], U-shaped slot with paper substrate [8], dual inverted L-shaped strips [9], two spiral ring strips [10], a modified fork-shaped strip [11], a chopped circular radiator appended with a meander line and an L-strip coupled element [12], a slot-ring antenna with single-and dual-capacitive coupled patch [13], a rhombic patch with modified minkowski fractal geometry [14], and a two-strip monopole loaded with a chip capacitor and an L-shape high-pass filter [15]. However, design of a compact multiband monopole antenna with sufficient bandwidth at three frequency bands remains a challenge.…”