Abstract
This letter presents a new design of a compact multi-frequency band antenna, which is composed of two concentric annular ring slots and a circular patch. The antenna resonates at around 1.48, 2.1, 2.3, 3.85 and 4.6 GHz while its bandwidths cover from 1.41-1.50 GHz, 1.88-2.65 GHz and 3.30-4.85 GHz at S-11<-10 dB (VSWR 2:1). It has a compact overall dimension of 0.14 lambda x 0.186 lambda and a small partial ground of 0.03 lambda x 0.14 lambda, where lambda considered at the lowest resonance. With a very simple configuration, the antenna operating range supports multiple wireless applications, covering the PCS/GSM1900 (1850-1990 MHz), UMTS (1850-1990/ 1920-2170 MHz), ISM/Bluetooth/ZigBee/RFID/WLAN/ Wi-Fi (2400-2485 MHz), WiMAX (3300-3600 MHz), and LTE (1427-1500/ 1850-1990/ 1910-1930/ 1920-2170/ 1900-2620/ 2010-2600/ 2300-2400/ 2500-2690/ 2570-2620/ 3400-3600/ 3600-3800 MHz) frequency bands. Moreover, the antenna obtained good polarization purity, radiation efficiency and an average peak gain of 4.5 dBi over the bands. For practical validation, the proposed antenna has been prototyped and tested; the measured results agreed very well to the simulations.