Dual-band 3-way power divider and combiner based on CRLH-TLs

In this paper, by using composite right and left handed transmission lines and non-radiating CRLH-TLs, a dual-band 3-way series power divider (SPD) is presented. The proposed dual-band divider is designed and fabricated on an inexpensive FR4 substrate of thickness h = 0.79 mm and a relative dielectric constant of εr = 4.4 to work at 0.915 and 2.440 GHz. Also, in order to improve the isolation characteristics of this divider, three isolation resistors are implemented among output ports. Derived formulas are presented in details. The dual-band nature of the designed SPD, good input return loss, as well as equal power split among the three output ports, flexibility of spacing the output ports arbitrarily apart, and easy integration with planar devices make the proposed divider well suited for feeding many dual-band microwave circuits, such as multipliers, mixers, and planar array antennas. In addition, due to its excellent return-loss at the output ports and its high isolation, the proposed divider in this paper can be used as a power combiner.