Shakhawat Parvez

Investigation on EBG structures: A critical analysis to optimize the performance of asymmetric couple-line bandpass filter

EBGSs, Electromagnetic Band Gap Structures, have been developed into the most prominent framework by virtue of their superior efficacy, less intricacy in fabrication, and unified integration with the monolithic microwave integrated circuits (MMICs). In this letter, a certain number of advanced designs of EBGS are introduced and characterized with some rigorous parametric studies. This epistle regards the planar-EBG frameworks in the fashion of conventional uniform circular, square, and annular ring patterns. By the same token, optimum Filling Factor has been investigated by exclusively analysing the traditional frequency response of band pass filter from three imperative aspects such as: initial stop band analysis, pass band analysis, and conclusive stop band analysis. In like manner, the parametric comparison has been demonstrated in view of the initial frequency response, selectivity, 3dB cut-off frequency, 3dB pass bandwidth, insertion loss at 2nd harmonics, and the insertion loss at 3rd harmonics to figure out the optimum filling factor for certain planar-EBG patterns.

Dumbbell annular ring with circular patterned microstrip low-pass filter with higher selectivity, wider stopband and lower insertion loss

Electromagnetic Band Gap Structures (EBGs) have been developed to improve the efficiency of microwave and millimeter-wave devices, grown into most prominent framework by virtue of their unique electromagnetic and electrical properties. This article inspects the relationship between the operating performances of the low pass filter with the different EBG pattern. In this article, two high selectivity, wide stopband low pass filters (LPF) etched on ground plane with Tschebycheff polynomial distribution are proposed. A number of methods, method of moments (MOM) for numerical analysis and Tschebycheff polynomial distribution for designing the circuit are used. Moreover, to increase the stopband bandwidth of the new filters, a hybrid structure is used. The filter using ten dumbbell annular ring (DAR) patterns has improved selectivity of 47.19%, great matching upto 80 dB, negligible insertion loss less than 0.2 dB and two rejections in the stopband within 6.25 GHz, 12.97 GHz. In brief, this high selectivity, compact, wide stopband low pass filters were designed to alleviate the problem of low selectivity and small stopband bandwidth in microwave communication.

The 1×1 annular ring: Bandwidth enhancement of microstrip asymmetric couple-line bandpass filter with superior matching and lower insertion loss

Electromagnetic Band Gap (EBG) structures which is an exclusive innovation in modern microwave design arena by reason of their high potential and less intricacy of designing in the microwave and millimeter-wave integrated circuits. This paper examines the relationship between the filling factor (FF) of the annular ring structure on couple-line and capacitive coupling for improving the performance. A number of methods, method of moments (MOM) for numerical analysis and uniform distribution with constant aspect ratio (AR) for designing the circuit are used. In like manner, the parametric comparison has been demonstrated considering selectivity, 3-dB bandwidth (3-dB BW), insertion loss and return loss in the passband. Consequently, not only a very wide passband upto 49% increment but also a return loss upto 65 dB which illustrates great matching are achieved. Although, the insertion loss is less than 0.2 dB in the passband, but the selectivity shrinks with expanding bandwidth. In short, remodeling of the selectivity can be done by appropriately choosing the filling factor for annular ring pattern on the couple-line as well as on the transmission line.

Demonstration on performance characteristics of microstrip low-pass filter for various substrates employing Tschebycheff distribution

In modern microwave design sector, Electromagnetic Band Gap (EBG) structures which is a unique innovation by virtue of their high potency and low complexity in designing with integrated circuits. This article examines the relationship between operating performance of different substrates and Tschebycheff polynomial distribution. A number of methods, method of moments (MOM) for numerical analysis and Tschebycheff polynomial distribution for designing the traditional circular pattern on ground plane are used. In like manner, the parametric comparison has been demonstrated in view of the selectivity, 20-dB insertion loss bandwidth (20-dB IL BW) and 10-dB return loss bandwidth (10-dB RL BW). The consequence of that is, two substrates FR4 and RT/Duroid 5870 prevail with good matching upto 70 dB, negligible ripple less than 0.7 dB in the passband and wider, deeper stopband performance upto 6-7.5 GHz. Improving compactness of the circuit with high efficiency, this complication is solved by Tschebycheff polynomial distribution.

Uniform high-Q factored 3:9 annular ring resonator in coupled-line bandpass filter: Design and applications

To enhance the efficacy of antennas, filters and microwave circuits, EBG structures have been developed into most notable framework considering their unique electromagnetic and sophisticated properties. This article investigates the relationship between the aspect ratio of annular ring and performance of the coupled-line filter. A number of methods, uniform distribution of ring patterns with constant filling factor 0.35 and lumped circuit model, method of moments for numerical analysis are used. Originally, the parametric comparison has been demonstrated reviewing the selectivity, 3-dB cut-off frequency and Q factor. Consequently, not only a very sharp selectivity of 56.67 dB/GHz with narrow bandwidth, low insertion loss in the passband but also wide stopband up to 13GHz with Q factor of 118 with 0.69% deviation are achieved. This structure should ease the task of designers of designing a compact matching network for the microwave receiver with high Q factor and sharp selectivity.

Chebyshev type-I low pass filter using annular ring resonator: A comparative performance analysis for different substrates

In this letter, compact microstrip Chebyshev function low pass filters (LPFs) with sharp roll-off based on annular ring resonators (ARRs) on various substrates and its design theory are demonstrated. To fabricate ARRs, Chebyshev type - I function with fixed side lobe level (SLL) and method of moments (MOM) for numerical analysis are applied. The ARRs inscribed on the ground plane, behave as shunt connected capacitances with low radiation, nevertheless the 50 Ω transmission line on the upper plane provide the total transmission to realize the Chebyshev function response. Consequently, RT/Duroid 5880 prevails with low insertion loss (<0.6 dB), wide stopband, very sharp roll-off (>90 dB/GHz) and isolation up to 70 dB in the stopband. The frequency responses of the device from the two different softwares are in good agreement with the known theoretical data.

A quasi-elliptic low pass filter based on complementary split ring resonator with sharp selectivity and wide stopband

This Paper illustrates the low pass filter (LPF) topology based on complementary split ring resonator (CSRR) with added slot. The introduction of a slot structure in the CSRR can not only reduce the group velocity of the transmission but also decrease the inductive reactance which results in compactness of the device by providing the transmission zero after resonance. Therefore, quasi-elliptic function and extension of the rejection band has been established. In other words, this LPF exhibits significant improvement on rejection bandwidth, selectivity and return loss (RL) in the passband. Besides, with electrical length for the ring is o.11Xg (single cell), the device characterizes by pointing out the capability of the approach with rejection levels of 13-dB over 50% of the stopband and selectivity of about 142 dB/GHz. The group delay is within 0.20 ns over 75% of frequency of interest. Well agreement between theoretical and simulated data are accomplished.

Chebyshev quarter wavelength wideband bandstop filter based on dumbbell annular ring resonator

In this letter, a novel seventh order equal ripple wideband bandstop filter (BSF) is proposed and demonstrated. This device is based on dumbbell annular ring (DAR) resonators which introduces additional magnetic coupling with quarter wavelength open circuited stubs in the conventional 50-Ω transmission line. However, introducing this DAR resonators (DARRs) generate multiple transmission zeros which is responsible for wider stop band and can be determined from the S-plane. Moreover, the proposed BSF has selectivity up to 170 dB/GHz, rejection level is better than 50-dB, suppress reflection up to 12-dB in the pass band and fractional bandwidth 113.1%. Besides, the group delay is within 3 ns over the 80% of the stop band. The simulated frequency performances of the device from two different softwares are in well agreement with the theoretical data.

A novel quasi-lumped UWB high pass filter with multiple transmission zeros

In this letter, a compact sixth order microstrip Chebyshev short circuited stubs high pass filter (HPF) via hole grounding is proposed. It is fundamentally based on quasi-lumped short circuited stubs of an optimum commensurate line band pass filter, which widen the bandwidth of the device. Furthermore, the resonant frequency and return loss performance can be improved by multiple transmission zeros, generated because of via hole grounding. Moreover, the proposed high pass filter (HPF) has wide bandwidth up to 10 GHz which satisfies the UWB spectrum, rejection level is better than 18-dB with multiple deep transmission zeros. Besides, the group delay is 1.5 ns over the 97% of the passband. Moreover, the simulated frequency responses under different via hole dimension from two softwares are in good agreement with the theoretical response.