A Self-Packaged Power Divider With Compact Size and Low Loss

Abstract

This brief presents a self-packaged spiral shape power divider (SSPD) using substrate integrated suspended line (SISL). The two output paths are designed to form mutually coupled spiral shape, and the isolation resistor is placed at the center of the spiral to reduce the circuit area. By properly increasing the coupling, short total electrical length can be obtained. SISL is adopted for low loss and self-packaging. The suspended substrate is patterned to further reduce the dielectric loss. The even-/odd- mode method is used to analyze this circuit, and the design equations are derived. A SISL SSPD with patterned substrate works at 2.5 GHz is implemented for verification. In a wide fractional bandwidth (FBW) of 55%, the measured return loss and two output ports isolation are both better than 15 dB, while the SSPD with patterned substrate achieves 0.06 dB insertion loss at the center frequency.