Ahmed Boutejdar

Bio: Ahmed Boutejdar is an academic researcher from Otto-von-Guericke University Magdeburg. The author has contributed to research in topics: Microstrip & Low-pass filter. The author has an hindex of 18, co-authored 112 publications receiving 1361 citations. Previous affiliations of Ahmed Boutejdar include Cairo University.

Control of bandstop response of Hi-Lo microstrip low-pass filter using slot in ground plane

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.

Compact stub type microstrip bandpass filter using defected ground plane

Abstract: Usually a defected ground plane structure (DGS) provides only a band-reject response. However, in this work we introduce a simple band-accept circuit element in the DGS and developed a microstrip stub type compact 3-pole bandpass filter (BPF) at 4.2 GHz. The BPF has bandwidth and insertion loss 38% and 0.6 dB respectively. It has better than 25 dB rejection in the stopband up to 12 GHz.

A novel compact UWB monopole antenna with enhanced bandwidth using triangular defected microstrip structure and stepped cut technique

Abstract: In this paper, a compact monopole wideband antenna is designed and manufactured for ultra-wide band (UWB) applications. In order to extend the impedance bandwidth of the proposed antenna, rectangular and triangular slots are etched from the partial ground and from the center of the rectangular patch respectively. Also, by cutting the lower corners of the radiating patch using stepped technique, additional resonances are regenerated and lead to further improvement in the covered bandwidth. The proposed patch antenna has advantageous of compactness its overall size equals 40 × 40 mm2.Simulated and measured results show that the proposed antenna design exhibits a bandwidth from 2.9 – 19.2 GHz for VSWR< 2. The antenna structure provides a wide usable fractional bandwidth of 148%. These inherent characteristics of the proposed antenna make it suitable for efficient transmission and reception in UWB systems. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1514–1519, 2016

Resonator switching techniques for notched ultra-wideband antenna in wireless applications

Abstract: This study presents the design of switching techniques for dual-notched ultra-wideband antenna. The dual band-notched frequencies are achieved by using switched defected microstrip structure band stop filter inserted in the microstrip feed line and a switched meandered slot etched in the radiation patch. The switching reconfiguration is accomplished by combining the two ideal switches to introduce a notch filter response to prevent the interference to the primary users operating in the middle and upper WiMAX wireless local area network bands. The proposed structure has four modes by controlling the two switches on and off. The proposed antenna has good matched impedance from 2.5 to 12 GHz with two notched bands from 3.3 to 3.8 GHz (middle WiMAX applications) and from 5.1 to 5.9 GHz (upper WiMAX applications). The antenna is fabricated and tested. Good agreement is achieved between the simulated and measured results.

Control of bandstop response of cascaded microstrip low-pass-bandstop filters using arrowhead slots in backside metallic ground plane

Abstract: In this paper, a new equivalent circuit and modeling method for a uniform arrowhead-defected-ground-structure slot are proposed for the design of a DGS-cascade lowpass or bandstop filter. The effect of the geometry of a defected ground structure (DGS) on the performance of the cascaded-LPF or BSF and the effect of the cascaded-method is also examined. The proposed LPF or BSF based on pi-arrowhead DGS slot is 70% shorter than a conventional LPF. Only three cells of the proposed structure are necessary for a 15-dB stopband at 6 GHz. The validity of the proposed equivalent circuit model is established by comparing their response to the full-wave EM simulation of several structures. Measured results show that the new designs exhibit better performance by suppressing ripples and enlarging stopband bandwidth

An Overview on Defected Ground Structure

Abstract: 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.

Mutual Coupling Reduction Between Microstrip Patch Antennas Using Slotted-Complementary Split-Ring Resonators

Abstract: A novel structure based on complementary split-ring resonators (SRRs) is introduced to reduce the mutual coupling between two coplanar microstrip antennas that radiate in the same frequency band. The new unit cell consists of two complementary SRR inclusions connected by an additional slot. This modification improves the rejection response in terms of bandwidth and suppression. The filtering characteristics of the band-gap structure are investigated using dispersion analysis. Using the new structure, it was possible to achieve a 10-dB reduction in the mutual coupling between two patch antennas with a separation of only 1/4 free-space wavelength between them. Since the proposed structures are broadband, they can be used to minimize coupling and co-channel interference in multiband antennas.

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

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.

A novel defected ground structure for planar circuits

Abstract: A new compact defected ground structure (DGS) is proposed for the microstrip line. The structure is compact in microstrip line direction. Here, this DGS is used to design a compact low pass filter (LPF) that is at least 26.3% more compact lengthwise than other reported compact structures and has sharper transition knee.

Miniaturized microstrip lowpass filter with wide stopband using double equilateral U-shaped defected ground structure

Abstract: A compact double equilateral U-shaped defected ground structure (DGS) unit is proposed. In contrast to a single finite attenuation pole characteristic offered by the conventional dumbbell DGS, the proposed DGS unit provides dual finite attenuation poles that can be independently controlled by the DGS lengths. A 2.4-GHz microstrip lowpass filter using five cascaded double U-shaped DGS units is designed and compared with conventional DGS lowpass filters. This low pass filter achieves a wide stopband with overall 30-dB attenuation up-to10 GHz and more than 42% size diminution.