A novel SIW power divider with good out-of-band rejection and isolation

Abstract

A novel substrate integrated waveguide (SIW) power divider with good out-of-band rejection and isolation is first presented in this paper, which is implemented by the combination of three different electromagnetic structures, saying, substrate integrated waveguide (SIW), defected ground structure (DGS) and resistive coupling slot. Since the SIW has high-pass performance and the DGS has band-stop characteristics, four periodic butterfly-shaped DGS are etched on the ground plane of the SIW power divider to realize the band-pass filtering response. Moreover, a resistive coupling slot is utilized to improve the isolation of power divider. To verify the design, a prototype of the SIW power divider is fabricated and measured. Measured results show that a very wide out-of-band rejection ranging from 13.5 to 22 GHz at −20 dB is realized. The isolation, input return loss, output return loss, amplitude imbalance, and phase imbalance of the in-phase SIW power divider are better than 15.3, 14.1, 9.2, 0.5 dB, and 5.1°, respectively, within the frequency range from 8.25 to 12.25 GHz. The measurement results show good agreements with the simulation ones.