Abstract: A novel single-ended-to-balanced power divider(SETBP) with broadband common mode rejection performance is proposed. The power divider is realized by a pair of coupling lines and two isolation resistors. The differential output port is realized by two ideal 180°phase inverters, which greatly reduces the size of the circuit to 0. 0624λg×λg and realizes the miniaturization of the circuit structure. Under the conditions of differential mode and common mode excitation, the two balanced ports are highly isolated and well matched. Common mode noise can be effectively suppressed in the range of 0. 6-1. 4 GHz. With the help of scattering matrix and transmission line theory, the odd mode and even mode equivalent circuit of the proposed power splitter structure are analyzed, and the key parameters are obtained. The feasibility of the design scheme is verified by simulation and test results.