A new defected ground structure (DGS) for the microstrip line is proposed in this paper. The proposed DGS unit structure can provide the bandgap characteristic in some frequency bands with only one or more unit lattices. The equivalent circuit for the proposed defected ground unit structure is derived by means of three-dimensional field analysis methods. The equivalent-circuit parameters are extracted by using a simple circuit analysis method. By employing the extracted parameters and circuit analysis theory, the bandgap effect for the provided defected ground unit structure can be explained. By using the derived and extracted equivalent circuit and parameters, the low-pass filters are designed and implemented. The experimental results show excellent agreement with theoretical results and the validity of the modeling method for the proposed defected ground unit structure.

A design of the low-pass filter using the novel microstrip defected ground structure

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 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 circuits were fabricated with identical periodic and different dimensions. Measurements on the fabricated DGS circuits show that the cutoff and stopband center frequency characteristics depend on the physical dimension of the proposed DGS unit lattice,.

A novel 1-D periodic defected ground structure for planar circuits

A new one-dimensional (1-D) defected ground unit lattice is proposed in order to improve the effective inductance. In- creasing 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 char- acteristics. In order to show the improved the effective inductance, three DGS circuits were fabricated with identical periodic and dif- ferent dimensions. Measurements on the fabricated DGS circuits show that the cutoff and stopband center frequency characteris- tics depend on the physical dimension of the proposed DGS unit lattice.

A Novel 1-D Periodic Defected Ground Structure for

Slots or defects integrated on the ground plane of microwave planar circuits are referred to as Defected Ground Structure. DGS is adopted as an emerging technique for improving the various parameters of microwave circuits, that is, narrow bandwidth, cross-polarization, low gain, and so forth. This paper presents an introduction and evolution of DGS and how DGS is different from former technologies: PBG and EBG. A basic concept behind the DGS technology and several theoretical techniques for analysing the Defected Ground Structure are discussed. Several applications of DGS in the field of filters, planar waveguides, amplifiers, and antennas are presented.

/pdf/defected-ground-structure-fundamentals-analysis-and-27vyawjqvf.pdf

Defected Ground Structure: Fundamentals, Analysis, and Applications in Modern Wireless Trends

A new photonic bandgap unit structure for microstrip line is proposed. The equivalent circuit for the proposed photonic bandgap unit structure is derived by means of three dimensional field analysis methods. The equivalent circuit parameters are extracted by using the circuit analysis method. By employing the extracted parameters, the wide-band harmonic rejection low-pass filter is designed. The experimental results show the excellent agreements with theoretical results.

Modeling of a photonic bandgap and its application for the low-pass filter design

In this paper, a new design technique called the direct frequency conversion method is proposed, for wideband pass filters, which can be applied to the UWB (ultra wide band) system. Using the proposed method, a wide band-pass filter is designed as an equivalent circuit, composed of parallel and serial L-C resonators. In the equivalent circuit, a microstrip line and a suspended stripline (SS) are adopted to implement short-and open-stubs of the parallel L-C resonator. Distributed models for the inductor and the capacitor are used to implement the series L-C resonator. The proposed filter is designed so that the attenuation characteristic is better than -30 dB in the range of DC~1.4 GHz and 6.6-20 GHz, and lower than -60 dB in the range of 7.2-20 GHz. The low-pass filter is connected to the wide band-pass filter, in order to obtain a flat band stop characteristic that is lower than -60 dB at 20 GHz and above. The very low insertion loss and excellent attenuation rejection characteristics are remarkable aspects of the proposed design. The measured data agree well with predictions.

New Design Technique for Wide Band Pass Filters using Direct Frequency Conversion Design Method

A novel equivalent circuit modeling method for a Dumbbell Type Defected Ground Structure(DBT-DGS) unit section is proposed The proposed equivalent circuit consists of a short stub, additional series transmission lines and a resistor All things consider is transmission zero, to compensate a phase difference, and to show losses such as conductor, dielectric, and radiation loss for the DBT-DGS, respectively The circuit parameters are extracted from a simple circuit analysis method EM simulation results show good agreements with circuit simulation results in wide band and the validity of our circuit modeling for the DBT-DGS

http://www.wseas.us/e-library/conferences/2005salzburg/papers/492-140.pdf

Jong-Im Park

Papers

Modeling of a photonic bandgap and its application for the low-pass filter design

New Design Technique for Wide Band Pass Filters using Direct Frequency Conversion Design Method

A new equivalent transmission line modeling of dumbbell type defected ground structure