A Fully Integrated Arbitrary Power Divider on Printed Circuit Board by a Novel SMD-Resistor-Free Isolation Network

Abstract

An arbitrary power divider (PD), which can be fully integrated on a multilayered printed circuit board (PCB), is presented without using the surface-mounted device (SMD) resistors. In the proposed SMD-resistor-free isolation network, a new multiple microstrip gap-coupled resonators (MM-GCRs) is designed in an FR4 substrate based on an optimization algorithm to achieve an equivalent grounded resistor in the desired frequency band. Consequently, the acquired output matching and isolation bandwidths are designable and much wider than that of other existing SMD-resistor-free PDs with both output matching and isolation characteristics. To verify it, the design of PCB-based SMD-resistor-free PDs with the power division ratio being 1–3 is given. For all fabricated PDs, the measured input return loss and extra insertion loss are, respectively, better than 20 dB and less than 0.52 dB, respectively, at the operating frequency. In addition, the measured output return loss and isolation loss are better than 15 dB from 2.4 to 2.5 GHz. Moreover, the measured output matching and isolation bandwidths are, respectively, 8 and 3.5 times wider than that of other existing SMD-resistor-free PD with both output matching and isolation characteristics. Since the proposed PD is synthesized based on distributed elements without using any SMD resistor, the proposed PD thus possesses the advantages of being suitable for system-on-package (SoP), cost-efficient, suitable for millimeter-wave (mm-Wave) application, and capable to be fully integrated on a multilayered PCB.