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Journal ArticleDOI

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

TL;DR: In this article, a new defected ground unit structure (DGS) for the microstrip line is proposed, which can provide the bandgap characteristic in some frequency bands with only one or more unit lattices.
Abstract: 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.
Citations
More filters
Journal ArticleDOI
TL;DR: In this article, a simple ground plane structure that can reduce mutual coupling between closely packed antenna elements is proposed and studied, which consists of a slitted pattern, without via's, etched onto a single ground plane and it is therefore low cost and straightforward to fabricate.
Abstract: A simple ground plane structure that can reduce mutual coupling between closely-packed antenna elements is proposed and studied. The structure consists of a slitted pattern, without via's, etched onto a single ground plane and it is therefore low cost and straightforward to fabricate. It is found that isolations of more than -20 dB can be achieved between two parallel individual planar inverted-F antennas (PIFAs) sharing a common ground plane, with inter-antenna spacing (center to center) of 0.116 lambdao and ground plane size 0.331lambdao 2. At 2.31 GHz it is demonstrated that this translates into an edge to edge separation between antennas of just 10 mm. Similarly the structure can be applied to reduce mutual coupling between three or four radiating elements. In addition the mutual coupling between half wavelength patches and monopoles can also be reduced with the aid of the proposed ground plane structure. Results of parametric studies are also given in this paper. Both simulation and measurement results are used to confirm the suppression of mutual coupling between closely-packed antenna elements with our slitted ground plane.

586 citations


Cites background from "A design of the low-pass filter usi..."

  • ...Additionally researchers have found that the defected ground structure (DGS) is also able to provide a bandstop effect due to the combination of inductance and capacitance [8], [9]....

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Journal ArticleDOI
TL;DR: In this paper, a USB dongle MIMO antenna for the 2.4 GHz WLAN band is presented, which consists of two antenna elements and a coupling element which artificially creates an additional coupling path between the antenna elements.
Abstract: This paper introduces a coupling element to enhance the isolation between two closely packed antennas operating at the same frequency band. The proposed structure consists of two antenna elements and a coupling element which is located in between the two antenna elements. The idea is to use field cancellation to enhance isolation by putting a coupling element which artificially creates an additional coupling path between the antenna elements. To validate the idea, a design for a USB dongle MIMO antenna for the 2.4 GHz WLAN band is presented. In this design, the antenna elements are etched on a compact low-cost FR4 PCB board with dimensions of 20times40times1.6 mm3. According to our measurement results, we can achieve more than 30 dB isolation between the antenna elements even though the two parallel individual planar inverted F antenna (PIFA) in the design share a solid ground plane with inter-antenna spacing (Center to Center) of less than 0.095 lambdao or edge to edge separations of just 3.6 mm (0.0294 lambdao). Both simulation and measurement results are used to confirm the antenna isolation and performance. The method can also be applied to different types of antennas such as non-planar antennas. Parametric studies and current distribution for the design are also included to show how to tune the structure and control the isolation.

413 citations


Cites background from "A design of the low-pass filter usi..."

  • ...Also, the defected ground structure (DGS) [10], [11] or a simple ground plane modification [12] has also been shown to provide a band-stop effect by suppressing the ground current flowing between antenna elements....

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Journal ArticleDOI
TL;DR: In this paper, the effect of the geometrical shapes of a defected groundplane structure (DGS) slot on performance of the Hi-Lo microstrip low-pass filter (LPF) was examined.
Abstract: This paper examines the effect of the geometrical shapes of a defected ground-plane structure (DGS) slot on performance of the Hi-Lo microstrip low-pass filter (LPF). A three-pole LPF based on an arrowhead DGS slot has 67% less length as compared to a conventional three-pole LPF. It has insertion loss of 0.5 dB and 15-dB rejection in the stopband up to three times the cutoff frequency.

292 citations


Cites background from "A design of the low-pass filter usi..."

  • ...The increase in brings and closer, thereby improving sharpness of the transition....

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  • ...I. INTRODUCTION THE quasi-lumped element based on the photonic-bandgap(PBG) ground plane and the defected ground-plane structures (DGSs) have been proposed to improve rejection in the stopband of a low-pass filter (LPF) [1]–[8]....

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  • ...4, Computer Simulation Technology (CST), Darmstadt, Germany....

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  • ...Moreover, we will also see in Section II-D that the shape of a slot head has an influence on the design of a broad-band bandstop filter....

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Journal ArticleDOI
TL;DR: In this paper, the authors present an introduction and evolution of DGS and how DGS is different from former technologies: PBG and EBG, and several theoretical techniques for analysing the Defected Ground Structure are discussed.
Abstract: 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.

273 citations


Cites background or methods from "A design of the low-pass filter usi..."

  • ...Figure 5: RLC equivalent circuit for unit DGS [12]....

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  • ...1 2 3 4 5 6 7 8 Frequency (GHz) (b) Figure 11: Low pass filter with cascaded dumbbell shaped DGS integrated with microstrip transmission line along with T-junction stub: (a) schematic diagram; (b) simulated S-parameters [12]....

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  • ...number Shape Reference Advantage Disadvantage Applications 1 Dumbbell [12] Simple structure, easy to design and analyse Single stop band Band-stop filter...

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  • ...The first DGS model has been reported as a dumbbell shaped defect embedded on the ground plane underneath the microstrip as shown in Figure 1 [12]....

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  • ...Dumbbell shaped DGS was initially used to realize a filter [12], and other shapes were reported subsequently to realize different microwave circuits such as filters [13–20], amplifiers [21], rat race couplers [22], branch line couplers, and Wilkinson power dividers [23, 24]....

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Journal ArticleDOI
TL;DR: In this article, a compact elliptic-function low-pass filter using microstrip stepped-impendance hairpin resonators and their equivalent-circuit models is developed.
Abstract: A compact elliptic-function low-pass filter using microstrip stepped-impendance hairpin resonators and their equivalent-circuit models are developed. The prototype filters are synthesized from the equivalent-circuit model using available element-value tables. To optimize the performance of the filters, electromagnetic simulation is used to tune the dimensions of the prototype filters. The filter using multiple cascaded hairpin resonators provides a very sharp cutoff frequency response with low insertion loss. Furthermore, to increase the rejection-band bandwidth, additional attenuation poles are added in the filter. The filters are evaluated by experiment and simulation with good agreement. This simple equivalent-circuit model provides a useful method to design and understand this type of filters and other relative circuits.

252 citations


Cites background from "A design of the low-pass filter usi..."

  • ...Recently, the low-pass filter using photonic-bandgap and defect ground structures [8], [ 9 ] illustrated a similar performance as those of the conventional ones....

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References
More filters
Book
01 Apr 1990

10,459 citations

Book
01 Feb 1980

3,929 citations


"A design of the low-pass filter usi..." refers background in this paper

  • ...[ 14 ], [15] The parallel capacitance value for the given DGS unit dimension can be extracted from the attenuation pole location, which is parallel LC resonance frequency, and prototype low-pass filter characteristics by using the following procedures....

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Journal ArticleDOI
TL;DR: In this article, the photonic band gap structures, those three-dimensional periodic dielectric structures that are to photon waves as semiconductor crystals are to electron waves, are discussed.
Abstract: The analogy between electromagnetic wave propagation in multidimensionally periodic structures and electron-wave propagation in real crystals has proven to be a fruitful one. Initial efforts were motivated by the prospect of a photonic band gap. a frequency band in three-dimensional dielectric structures in which electromagnetic waves are forbidden irrespective of the propagation direction in space. Today many new ideas and applications are being pursued in two and three dimensions and in metallic, dielectric, and acoustic structures. We review the early motivations for this research, which were derived from the need for a photonic band gap in quantum optics. This need led to a series of experimental and theoretical searches for the elusive photonic band-gap structures, those three-dimensionally periodic dielectric structures that are to photon waves as semiconductor crystals are to electron waves. We describe how the photonic semiconductor can be doped, producing tiny electromagnetic cavities. Finally, we summarize some of the anticipated implications of photonic band structure for quantum electronics and for other areas of physics and electrical engineering.

1,352 citations

Journal ArticleDOI
TL;DR: In this paper, a 2D photonic bandgap (PBG) structure for microstrip lines is proposed, in which a periodic 2D pattern consisting of circles is etched in the ground plane of microstrip line.
Abstract: A new two-dimensional (2-D) photonic bandgap (PBG) structure for microstrip lines is proposed, in which a periodic 2-D pattern consisting of circles is etched in the ground plane of microstrip line. No drilling through the substrate is required. Three PBG circuits were fabricated with different circle radii to determine the optimum dimensions, as well as a PBG circuit with the compensated right-angle microstrip bend. Measurements show that deep and wide stopbands can be achieved using this method.

706 citations


"A design of the low-pass filter usi..." refers background in this paper

  • ...[ 4 ]‐[8] Many passive and active microwave and millimeter devices have been developed to suppress the harmonics and realize the compact physical dimensions of circuits....

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Journal ArticleDOI
TL;DR: In this article, a photonic bandgap (PBG) structure is proposed to realize a magnetic surface in the stopband and is used in the waveguide walls to provide magnetic boundary conditions.
Abstract: A novel waveguide using a photonic bandgap (PBG) structure is presented. The PBG structure is a two-dimensional square lattice with each cell consisting of metal pads and four connecting lines, which are etched on a conductor-backed Duroid substrate. This uniplanar compact PBG structure realizes a magnetic surface in the stopband and is used in the waveguide walls to provide magnetic boundary conditions. A relatively uniform field distribution along the cross section has been measured at frequencies from 9.4 to 10.4 GHz. Phase velocities close to the speed of light have also been observed in the stopband, indicating that TEM mode has been established. A recently developed quasi-Yagi antenna has been employed as a broad-band and efficient waveguide transition. Meanwhile, full-wave simulations using the finite-difference time-domain method provide accurate predictions for the characteristics of both the perfect magnetic conductor impedance surface and the waveguide structure. This novel waveguide structure should find a wide range of applications in different areas, including quasi-optical power combining and the electromagnetic compatibility testing.

383 citations


"A design of the low-pass filter usi..." refers background in this paper

  • ...Several efforts have been made to realize such devices on a various PBG circuits—e.g., a power amplifier with PBG circuits [9], [10], the PBG structure for slow-wave circuits [11], and realization of a magnetic wall in waveguide [12], [ 13 ]; their experimental results are sufficient to show the validity of PBG circuit applications....

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