Multi-layer radial power divider/combiner

Abstract

An N-way multi-layer radial power combiner/divider comprises an RF layer including N planar RF transmission lines radiating from a common port to N ports. An isolation layer substantially parallel to the RF layer comprises a star resistor having N resistive arms radiating from a common junction and N planar isolation transmission lines coupled in series to respective resistive arms. Each series pair of a resistive arm and an isolation transmission line is ideally a half-wavelength in electrical length. N vertical interconnects between the RF layer and the isolation layer connect the ends of the N isolation transmission lines to the ends of the N RF transmission lines at the N individual ports, respectively. Any path from one individual port through the common junction of the star resistor to another individual port is approximately a full wavelength λc or multiple thereof so that the phase angle through the isolation network is approximately zero degrees. This approach can achieve better isolation and power handling than the Wilkinson design while employing the benefits of planar metallization technology.