A novel bandpass filter (BPF) based on half-wave-length (λ/2) stepped-impedance resonators (SIRs) is proposed in this paper. By properly designing the impedance ratios of the SIRs, the spurious harmonics of the filter can be pushed to upper frequency. With several bandstop structures such as open stubs and defected ground structures (DGSs) applied to the BPF, a good stopband performance is obta...

─ A novel quarter-circle defected ground structure shape is introduced in this paper to design and implement an ultra-wide reject band low-pass filter (LPF). Moreover, an equivalent circuit model (ECM) is presented. The proposed LPF has small size and, a low insertion loss and a return loss less than -20 dB. Also, a round -20 dB suppression level ranging from 4 GHz to more than 20 GHz is achiev...

A new one-dimensional (1-D) defected ground unit lattice is proposed in order to improve the effective inductance. Increasing the effective inductance makes it easy to control the cutoff frequency characteristics. The proposed periodic defected ground structure (DGS) provides the excellent cutoff and stopband characteristics. In order to show the improved the effective inductance, three DGS cir...

This paper focuses on a tutorial overview of defected ground structure (DGS). The basic conceptions and transmission characteristics of DGS are introduced and the equivalent circuit models of varieties of DGS units are also presented. Finally, the main applications of DGS in microwave technology field are summarized and the evolution trend of DGS is given.

This paper proposes a two way L and S band Gysel power divider/combiner that uses line to ground resistors. Step by step methods to obtain a wide isolation and transmission bandwidth are presented. A design that uses five resistors is selected and optimized based on Quasi Newton method. Then the Defected Microstrip Structure (DMS) and Defected Ground Structure (DGS) is used to obtain better tra...