Design and analysis of a band-notched UWB 1 to 4 Wilkinson power divider using symmetric defected ground structure

In this paper, design and simulation of a band-notched UWB 1 to 4 Wilkinson power divider (WPD) using symmetric spiral DGS is proposed. The method of additional sections is used to provide a large increase in bandwidth. The paper presents the design of two-section and three-section WPD by analysis of even/odd modes by which the characteristic impedances and isolation resistors are obtained as the required parameters. In the ground plane of the microstrip structure, the defected ground structure (DGS) is used to suppress the desired band-notched frequency. DGS also enables band rejection of two different frequencies or periodic rejection in the frequency band. Desired results with good matching and isolation over the UWB frequency band are achieved even by using two-section WPD. To validate the design approach, the two-section 1 to 4 WPD with band rejection using symmetric spiral DGS is fabricated. The results show a good agreement between the simulation and experimental results.