Compact tri-band Wilkinson power divider based on metamaterial structure for Bluetooth, WiMAX, and WLAN applications

A novel Wilkinson power divider is presented in this paper for triple band operation. It comprises a -shaped transmission-line coupled to a rectangular split ring resonator metamaterial structure. The -negative feature of the rectangular split ring resonator metamaterial structure is investigated by retrieving its constitutive parameters from the S-parameter response. To demonstrate the versatility of the proposed Wilkinson power divider it was designed to cover Bluetooth (2.4GHz), WiMAX (3.5GHz), and WLAN (5.2GHz). The tri-band Wilkinson power divider was fabricated and its performance measured to verify the design. Good agreement between the measured and simulated data is obtained. Measured results show that the tri-band Wilkinson power divider has fractional bandwidth of 3.86%, 5.82%, and 3.89% at 2.4, 3.5, and 5.2GHz, respectively. In addition, the rectangular split ring resonator metamaterial Wilkinson power divider has a small physical footprint (14x17.9mm(2) or 0.15(g)x0.19(g)), which is 60% smaller than conventional designs.