A Compact Filtering Power Divider With Quasi-Elliptic Bandpass Response

In this paper, a new filtering power divider (FPD) was proposed. The proposed third-order FPD mainly comprises only a tri-mode stub-loaded resonator (SLR) and a isolation resistor, which leading to a small circuit area. Due to the inherent characteristic of the SLR, two extra transmission zeros (TZs) were created at the lower and upper passband and, thus, a high-selectivity quasi-elliptic bandpass response can be achieved. The resistor loaded between the output feeding lines was introduced to improve the impedance matching of the output ports and the isolation between the output ports. For a demonstration, a FPD with third-order quasi-elliptic bandpass response was designed and fabricated using microstrip technology. The EM simulation results were consistent with the experiment results.