Ultracompact two‐way and four‐way SIW/HMSIW power dividers loaded by complementary split‐ring resonators

Abstract

In this paper, two ultracompact power dividers based on the substrate integrated waveguide (SIW) and half-mode SIW (HMSIW) technologies loaded by complementary split-ring resonators (CSRRs) are presented. The presented structures are designed based on the theory of evanescent mode propagation. To obtain a size reduction, the CSRR unit cells are etched on the metallic surface of the SIW and HMSIW structures. First, a two-way HMSIW power divider is reported. In this circuit, the concept of HMSIW is utilized aiming at a further size reduction in addition to the size reduction by the CSRR unit cells. Then, a four-way SIW power divider is designed so that the direct coaxial feed is used for the input port and microstrip transmission lines are used for the output ports. Both two-way and four-way SIW/HMSIW power dividers at 5.8 GHz covering WLAN are designed, fabricated, and measured. They respectively have 0.18 × 0.21 λg2 and 0.38 × 0.21 λg2 total size. A fair agreement between simulated and measured results is achieved. The measured insertion losses are 0.5 ± 0.5 and 0.6 ± 0.5 dB for the two-way and four-way SIW/HMSIW power dividers, respectively, in the operating band of interest.