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.

/pdf/an-overview-on-defected-ground-structure-3dt7yj00ew.pdf

An Overview on Defected Ground Structure

A novel dual-band bandpass filter with meander-loop resonator and complement split-ring resonator (CSRR) defected ground structure (DGS) is proposed in this letter. Microstrip meanderloop resonator and CSRR DGS are operated for respective passbands. Several finite attenuation poles in stopbands are realized to improve the selectivity of the proposed bandpass filter and isolation between the two passbands. Compact size, dual band and high selectivity characteristics are realized by this type of filter structure. The filter is evaluated by experiment and simulation with very good agreement.

/pdf/design-of-novel-dual-band-bandpass-filter-with-microstrip-wa0stmr4cw.pdf

Design of Novel Dual-Band Bandpass Filter with Microstrip Meander-Loop Resonator and CSRR DGS

A compact dual-band bandpass filter using equal-length split-ring resonators (SRRs) is proposed in this paper. The two- resonance frequency response of equal-length split-ring resonator is described in detail. A cross-coupled dual-band filter with four equal- length split-ring resonators is designed. Several finite out-of-band attenuation poles are realized to improve the selectivity of the proposed filter. The measurement of the filter is in good agreement with the simulation.

/pdf/design-of-cross-coupled-dual-band-filter-with-equal-length-wlowsadrce.pdf

Design of Cross-Coupled Dual-Band Filter with Equal-Length Split-Ring Resonators

In this paper, miniature planar UWB filters with circular slots in ground is presented and we are using a new technique by etching a wideband circular-shape slot resonator in the ground plane of the filters. The proposed filters have compact size of 15 × 12.4 mm2. Two filters are introduced and the final design achieves flat insertion loss and linear phase of S12 throughout the passband (3.14–8.28 GHz) but occasional slight ripple occurs. Two different results are shown and the minimum insertion loss is less than 0.13 dB for both of presented filters.

/pdf/miniature-planar-uwb-bandpass-filters-with-circular-slots-in-1pnnt4xbis.pdf

Miniature Planar UWB Bandpass Filters with Circular Slots in Ground

A new dual-mode microstrip bandpass filter with wide stop-band is presented using the square loop resonator with treeshaped patches attached to the four inner corners of the loop. The mode splitting is realized by introducing a small cut locating at a 45◦ offset from its two orthogonal modes. It is shown that the dual-mode filter has a wide stop-band including the first spurious resonance frequency. The center frequency can be tuned. Moreover, the proposed filter has a smaller size compared with conventional dualmode bandpass filters at the same central frequency.

/pdf/a-compact-square-loop-dual-mode-bandpass-filter-with-wide-20e2suu5jx.pdf

A Compact Square Loop Dual-Mode Bandpass Filter with Wide Stop-Band

Three types of novel microstrip bandpass filters, a square split ring stepped-impedance bandpass filter, a square ring stepped-impedance bandpass filter, and a dual-mode square ring bandpass filter, which operate from L to S waveband are proposed, their filter performances are calculated. In these novel structures, ring stepped-impedance resonator, DGS and dual-mode technique are applied to not only reduce the volume but also improve the frequency responses of filters. The optimized results show that microstrip bandpass filter with DGS has nicer performances such as low insertion losses, wide stopband responses etc., while with dual-mode technique, a pair of transmission zeros can be implemented and the filter performances are effectively improved. The filters proposed in this paper have outstanding advantages such as compact and novel structures, small volumes, high selectivity, wide stopband responses, low insertion losses and so on, and can be applied in wearable systems.

Y. Li

Papers

Novel compact microstrip square ring bandpass filters