A novel multiband planar antenna for GSM/UMTS/LTE/Zigbee/RFID mobile devices

A new multiband planar antenna with a compact size is designed and developed for mobile devices. The proposed antenna consists of a two-strip monopole and a meandered strip antenna which occupy a compact area of only 15 mm × 42 mm. This planar antenna has a bandwidth of ∼ 42% at the 900 MHz band and ∼ 53% at the 1900-MHz band. The wide bandwidth at the low frequency is attributed to the mutual coupling of an S-shaped strip and an inverted-F strip which are separately printed on the two sides of a thin substrate, forming a two-strip monopole configuration. The bandwidth at the high frequency is enhanced by inserting a meandered strip which improves the impedance matching for the high-frequency band. The experimental results verify the simulations. The featured broad bandwidths over two frequency bands and the miniaturized size of the proposed antenna make it very promising for applications in wireless communication and wireless sensing devices.