Tri-band concentric slot-ring antenna with ultra-wide frequency tunability for cognitive radio applications

Abstract

This paper presents a compact, triband, rectangular slot-ring frequency reconfigurable antenna designed on FR-4 board having dimension 43 x 48 x 1.56 mm3. Two concentric slot-rings are placed such that their mutual interaction leads to triband operation of the antenna. Frequency reconfigurability is achieved by reactive loading of each slot-ring with varactor diode. The proposed antenna could be continually tuned over ultra-wide frequency range from 1.91-5.9 GHz. The antenna covers major wireless standard bands such as Bluetooth (2.38-2.49), Wi-Max (3.3-3.6), WLAN (5.15-5.725), LTE 2300/2600 and Wi-Fi (2.4–2.5). Hence, the designed antenna is appropriate for handheld mobile terminals for cognitive radio based applications.