Compact power divider with improved isolation and bandpass response

This article presents a compact power divider with bandpass response and improved isolation by using substrate integrated waveguide (SIW) and defected ground structure (DGS) techniques. The band-pass response is realized by combining the high-pass characteristic of SIW and low-pass feature of DGS. In order to achieve improved isolation performance, a slot which is terminated by four resistors is etched on the top plane of the SIW to balance the three input/output ports. The size of the proposed power divider is relatively small because of the slow-wave characteristic of DGS. To verify the proposed concept, a prototype power divider with equal power division is fabricated and measured. Measured results show that it has a 3-dB pass-band from 8 GHz to 10 GHz and the isolation is higher than 20 dB within the pass-band.