Split-ring Resonator Defected Ground Structure Research Articles

UWB bandpass filter with notched band using DSRR

A topology of a compact planar microstrip filter with a notched band is introduced, which employs a split-ring resonator defected ground structure (DSRR). Folded short-circuited stubs are used to realise the bandpass filter with good selectivity and out-of-band characteristics. By employing a split-ring resonator defected ground structure, a narrow notched band was introduced to reject the undesired wireless local-area network (WLAN) radio signals. The measured insertion loss is less than 1.6 dB, the return loss is more than 13 dB, and the variation of group delay is less than 0.5 ns throughout most of the two passbands. The width of the narrow notched band is about 1 GHz and the attenuation is more than 25 dB at the centre frequency of 5.4 GHz.

A COMPACT LOW-PASS FILTER WITH SHARP CUTOFF AND LOW INSERTION LOSS CHARACTERISTIC USING NOVEL DEFECTED GROUND STRUCTURE

In this paper, a compact stepped-impedance hairpin resonator (SIHR) low-pass fllter (LPF) with an improved split-ring resonator defected ground structure (ISRR DGS) and two elliptical DGSs is presented. The proposed LPF exhibits the advantages of low insertion loss, sharp cutofi characteristic, wide stopband over the ordinary LPFs. The introduced DGSs are presented to improve the in- band and out-band characteristic. An equivalent RLC circuit model of the two kinds of DGSs is presented and analyzed. Combining with these two structures, a new SIHR LPF having 3dB cutofi frequency of 2.5GHz is fabricated and measured. Measured results show that the selectivity of the proposed LPF is more than 100dB/GHz and the insertion loss is less than 0.5dB in the passband. A wide stop-band bandwidth with 20dB attenuation from 2.58 up to 7.5GHz is achieved. Moreover, the occupied area is only 20 £ 25mm 2 .

Wideband Cross Coupled Filter Using Split-Ring Resonator Defected Ground Structure

A wideband cross coupled bandpass filter making use of square split-ring resonator (SRR) defected ground structure (DGS) and parallel microstrip feed line is presented in this paper. The coupling between a pair of SRR DGS is much larger than that of the conventional SRR, which is fully investigated and applied to the design of wideband cross coupled filter. By extracting the coupling coefficient of various coupling structures and external quality factors of various feed structures, a SRR DGS four-pole filter with center frequency of 2.2 GHz and bandwidth of 20% is designed and fabricated.

Equivalent Circuit Analyzed of Complementary Split Ring Resonator DGS for Low Pass Filter

This paper presents a novel complementary split-ring resonator (CSRR) defected ground structure (DGS) for low pass filter (LPF) design. The equivalent circuit (EC) model of the CSRR was extracted and discussed in details. Based on the advantages of the CSRR, a compact LPF was designed without open stubs. The 3-dB cut-off frequency of 4.89 GHz has presented good measured characteristics, including sharp selectivity, very low insertion loss of 0.695 dB and wide stopband from 5.02 GHz to 10 GHz below −32 dB. The LPF with low return loss and high out-band suppression is designed and fabricated effectively.

Study on Transmission Characteristic of Split-ring Resonator Defected Ground Structure

A square split-ring resonator (SRR) defected ground structure (DGS) is studied in this paper. This DGS structure has a ∞at low-pass characteristic and a sharp band-gap property compared to the conventional dumbbell DGS. A detailed analysis of the relationship between the transmission characteristic and the split-ring dimension is made. In order to enhance the out-band suppression, an improved SRR DGS cell with open stubs loaded on the conductor line is then presented and fabricated.

Equivalent-Circuit Analysis and Lowpass Filter Design of Split-ring Resonator DGS

The equivalent-circuit of a split-ring resonator (SRR) defected ground structure (DGS) is investigated in this paper. The dependence of the transmission characteristic on the dimension of a split ring, such as side-length and split-gap, is analyzed in detail. In addition, an improved SRR DGS cell model with open stubs loaded on the conductor line is then presented to improve the out-band suppression. By using the equivalent-circuit analytical method, an S-band microstrip low-pass filter with perfect low-pass characteristic and high out-band suppression is designed and fabricated.