A Substrate-Integrated Waveguide Filtering Power Divider with Broadside-Coupled Inner-Meander-Slot Complementary Split-Ring Resonator

TL;DR

This paper introduces a compact microwave component that combines filtering and power division functions using a modified resonator design.

Contribution

The novel inner-meander-slot complementary split-ring resonator enables size reduction and improved performance in microwave systems.

Findings

The proposed design reduces the circuit size by over 30% compared to traditional designs.

The filtering power divider achieves a center frequency of 3.53 GHz with good isolation and low insertion loss.

The design shows good magnitude and phase variations, suitable for microwave system integration.

Abstract

In this work, a substrate-integrated waveguide (SIW) filtering power divider with a modified complementary split-ring resonator (CSRR) is reported. Firstly, by integrating the meander-shaped slots with the conventional CSRR, the proposed inner-meander-slot CSRR (IMSCSRR) can enlarge the total length of the defected slot and increase the width of the split, thus enhancing the equivalent capacitance and inductance. In this way, the fundamental resonant frequency of the IMSCSRR can be effectively decreased without enlarging the circuit size, which can generally help to reduce the physical size by over 35%. Subsequently, to further reduce the circuit size, two IMSCSRRs are separately loaded on the top and bottom metal covers to constitute a broadside-coupled IMSCSRR, which is combined with the SIW. To verify the efficacy of the proposed SIW-IMSCSRR unit cell, a two-way filtering power divider is implemented. It combines the band-selection function of a filter and the power-distribution property of a power divider, thereby enhancing system integration and realizing size compactness. Experimental results show that the proposed filtering power divider achieves a center frequency of 3.53 GHz, a bandwidth of about 320 MHz, an in-band insertion loss of (3 + 1.3) dB, an in-band isolation of over 21 dB, and a size reduction of about 30% compared with the design without broadside-coupling, as well as good magnitude and phase variations. All the results indicate that the proposed filtering power divider achieves a good balance between low loss, high isolation, and compact size, which is suitable for system integration applications in microwave scenarios.

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