Compact Wilkinson Power Dividers Based on Narrow Slits Loaded Transmission Lines

In this paper, a new approach based on the utilization of narrow slits to improve the return loss and isolation levels of the Wilkinson power dividers is proposed. 2-, 4- and 8-way power dividers are designed by using narrow slits on the quarter wavelength transmission lines. The proposed circuits are designed at the center frequencies of 2, 2.1 and 2.05 GHz. The fractional bandwidths (FBWs) for the return loss of better than 15 dB and isolation levels of better than 20 dB are 19.7%, 28%, 28.2 % for 2-, 4-, and 8-way power dividers, respectively. The proposed method can also reduce the circuit size about 25 % and more in the 2-way and 4-way (8-way) circuits, respectively. Three circuits have been fabricated and measured in a very good agreement with the simulated results.