Defected Microstrip Structure Research Articles

Design of Low Pass Filters Using a Symmetrical T-Shaped Defected Microstrip Structure

Design of Low Pass Filters Using a Symmetrical T-Shaped Defected Microstrip Structure

On the Design of a Stepped Mixed Signal Transmission Line with Defected Microstrip Structure for High-Frequency PCB Traces

The paper addresses the challenge of crosstalk in neighboring paths on PCBs, emphasizing its growing importance with the advancement of electronic circuits in terms of speed and frequency. The proposed solution involves the introduction of a novel W-shaped Defected Microstrip Structure (DMS) on a step-shaped coupled transmission lines to mitigate near-end crosstalk (NEXT) and far-end crosstalk (FEXT) using mixed signal input. A novel W-shaped defective microstrip structure (DMS) that is etched on step-shaped coupled transmission lines. The proposed technique focuses on minimizing the electromagnetic coupling strength with a minimum spacing of one time the width of the trace. It optimizes the ratio of capacitive coupling and inductive coupling between the coupled microstrip transmission lines to improve crosstalk. The frequency domain simulation, conducted using Computer Simulation Technology (CST), indicates promising results. The insertion loss (|S21|), near-end crosstalk (|S31|), and far-end crosstalk (|S41|) of the suggested structure are reported as 1.425dB, <25dB, and <25dB, respectively, over the frequency range of 0 to 10 GHz. Eye diagram characterizations are done and measured in terms of eye height, eye width, jitter and data rate are reported as 0.942V, 695.5ps, 6.69ps and 1.4Gbps respectively.

A systematic approach for the development of wide band band pass filters using resonators

In this paper, for the first time a novel and systematic approach is presented to construct a wideband Band Pass Filters (BPFs) with high selectivity and stopband response. Two BPFs (Filter I and Filter II) were built on a Taconic (TLX-9) substrate using semi-circular tapered coupled lines, Defected Microstrip Structures (DMSs), Defected Ground Structures (DGS), and Stepped Impedance Resonators (SIRs). The precision of the design procedure is confirmed through 3-D full wave Electro-Magnetic (EM) simulation software where two wideband filters were designed for L, S, and C-bands. Additionally, parametric analysis has been done to evaluate the performance of both wideband filters with key features such as return loss, insertion loss, Band Width (BW), selectivity, and stopband response. Even-odd mode analysis has been implemented using the ABCD matrix that acts as a source for mathematical analysis of Filter I. Eventually, two wideband filters have been fabricated and tested for their effectiveness, and the measured results of two wideband filters are in line with the simulated ones with slight deviations due to fabrication tolerances and connector losses. The prototyped Filter I functions as a bandpass in the frequency range of 2.4 GHz to 4.8 GHz with a maximum insertion loss of 0.85 dB and return loss of 19.5 dB thereby providing 64% Fractional Band Width (FBW). Near 19 dB rejection is observed in the lower and upper stopband regions with BW (stopbands) greater than 2 GHz. Moreover, Filter II is also fabricated and tested. The experimental return loss of 20 dB and insertion loss (maximum) of 0.73 dB over the passband (1.9 GHz to 3.4 GHz) were found with 0.7 Selectivity Factor (SF). More than 20 dB attenuation of stopbands (lower and upper) was achieved. Thus, the fabricated wideband BPFs operate in L, S, and C-bands for radars, satellite and long-distance radio communications, and military telemetry applications.

Compact Absorptive Dual-Beam Patch Antenna by Fusing Resistor-Terminated Defected Microstrip Structure

Compact Absorptive Dual-Beam Patch Antenna by Fusing Resistor-Terminated Defected Microstrip Structure

Design of half circular wideband antenna for ship radar

The research aims to design a wideband antenna for the ship's radar. The ship's radar works on the S-Band range whose wavelengths range from 8 to 15 cm with a frequency of 2-4 GHz, This antenna design uses a new approach involving the use of Defected Ground Structure (DGS) and Defected Microstrip Structure (DMS), which builds on the initial theory. The results of the study obtained a bandwidth value of 1.6 GHz, an impedance antenna value of 49.7 ohms, with a total efficiency of -0.3356 a working frequency range ranging from 1.74 GHz to 3.3 GHz. The radiation pattern obtained the main lobe magnitude value of 3.85 dBi, Main lobe direction of 162.0 deg, angular width (3dB) of 76.7 deg, and side lobe level of -1.1 dB. From the results of working frequency, it is found that the antenna can be used for airborne warning & control (AWACS), remote sensing, WiFi, Bluetooth, mobile communication, XM radio, airport surveillance radar (ASR), radioastronomy, wireless LAN, ZigBee, missile guidance.

Reduction of electromagnetic coupling between parallel high speed interconnects using defected Microstrip structure

In the context of designing printed circuit boards (PCBs) for the upcoming fifth generation double data rate (DDR5) technology, the issue of electromagnetic coupling emerges as a significant challenge. To address this concern, a comprehensive approach to mitigating both forward and backward coupling is proposed in this paper. The presented research introduces an innovative solution by incorporating a Defect Microstrip Structure (DMS) with a meticulously designed mitered meander shape. This unique structure is strategically imposed within the victim microstrip lines, aiming to effectively curtail coupling effects between interconnected microstrip lines. By embedding the mitered meander DMS onto the microstrip line, the electromagnetic (EM) coupling strength is substantially reduced. The reduction in coupling is primarily attributed to the achievement of an optimized ratio between capacitive and inductive coupling among the interconnected microstrip lines. The effectiveness of the proposed method is rigorously evaluated through a series of full-wave electromagnetic simulations. These simulations encompass microstrip lines etched both with and without the integration of the mitered meander-shaped DMS. The analytical framework leverages the ANSYS Structure Simulator (HFSS), a powerful tool for evaluating electromagnetic behaviour.

Cloverleaf filtenna with reconfigurable quintuple rejection bands using defected microstrip structure

This paper presents a quintuple-notched Filtenna based on a cloverleaf ultra-wideband (UWB) antenna and an inverted L-shaped bandstop filter (BSF). This filtenna rejects frequencies of Bluetooth (2.4 GHz), Wi-Max (3.5 GHz), Wi-Fi (5.2 GHz), ISM (5.8 GHz), and satellite communications (7.8 GHz). Using the defected microstrip structure (DMS) technique, all notches are obtained. The UWB antenna resonates over a frequency range from 2.1 to 13.6 GHz with double notches at 2.4 and 5.8 GHz, generated by etching two C-shaped DMSs on the patch. Two switches are connected to these two C- shaped slits. Controlling the ON/OFF states of these switches enables notch reconfiguration. The inverted L-shaped BSF suppresses triple notch rejections at 3.5, 5.2, and 7.8 GHz using three DMSs. Similarly, by controlling the ON/OFF states of three switches, frequency reconfiguration is observed. Simulation and measurement confirm that the UWB antenna, the BSF and the filtenna can operate in four states, eight states, and 20 states, respectively. The filtenna has good efficiency (79–95 %) and presents low radiation efficiency at rejection bands. It obtains stable gain (2–5.5 dBi) except at notches where the gain registers negative values. Additionally, this filtenna can freely switch between ultra-wideband mode and any notch-band mode.

Reduction of Near-End and Far - End Crosstalk in Microwave and Millimetre Wave Band of Parallel Transmission Lines using Meander Shaped DMS

This research proposes a unique design that makes use of a defective microstrip topology to decrease electromagnetic coupling between parallel high speed interconnects. The performance of this new microstrip construction with defects is evaluated using near-end crosstalk and far-end crosstalk. Serpentine shaped defected microstrip is introduced in one parallel of high speed interconnects and its performance is also compared the existing structure. In this research, the proposed defected microstrip structure (DMS) is simulated and compared with a conventional microstrip structure using Ansoft HFSS software which employs the Finite Element Method (FEM). Simulation results indicate that the DMS design effectively reduces crosstalk in comparison to the previous structure. It reduces more than 5dB near end crosstalk and more than 3dB far end crosstalk compared to conventional model.

A Compact Passive Quad‐Band Negative Group Delay Circuit With Stepped Impedance Resonator and Defected Microstrip Structure

AbstractBased on two‐stage stepped impedance resonator (SIR) and defected microstrip structure (DMS) with an E‐shaped slot, a novel compact passive quad‐band negative group delay circuit (NGDC) is proposed whose resonation frequencies and group delay performance are mainly determined by the SIR and the DMS. In order to help reveal the working mechanism of the quad‐band NGDC, an equivalent circuit of the NGDC is developed. It is composed of the transmission lines and serial‐parallel LC networks, and its S‐parameters are derived by using the theory of transmission matrix. The theoretical and simulated results for the transmission characteristics of the NGDC agree well with each other. To validate the design concept, a prototype of the proposed quad‐band NGDC was fabricated and measured. The measured results show that at the frequencies of 2.64, 7.88, 13.08, and 18.18 GHz, the negative group delay values achieve −5.4, −3.1, −1.18, and −1.14 ns, with |S21| values of −17.2, −20.5, −12.8, and −18.1 dB, respectively. Compared with the recently reported works, the proposed NGDC exhibits the largest number of operation frequency bands. Furthermore, it does not use lumped resistors and has miniaturized dimension.

Defected microstrip structure-based near-end and far-end crosstalk mitigation in high-speed PCBs for mixed signals

PurposeThe design, fabrication and experimental validation of defected microstrip structure (DMS) are proposed to address the problem of near-end crosstalk (NEXT) and far-end crosstalk (FEXT) between the microstrip transmission lines in a printed circuit board.Design/methodology/approachThe proposed DMS evolved with the combination of spur line (L-shaped DMS) and U-shaped DMS topologies. This technique reduces the strength of electromagnetic coupling and suppresses crosstalk by optimizing the capacitive and inductive coupling ratio between the linked microstrip lines. The practical inductance value is much more significant in DMS than in defected ground structures (DGS), but the capacitance value remains the same.FindingsA DMS unit is etched on the aggressor microstrip line instead of the DGS circuit. Because there is no leakage via the ground plane and the circuit size is far smaller than with DGS, the enclosure issue is disregarded. DMS structures have a larger effective inductance and are resistant to electromagnetic interference. A tightly coupled transmission line structure with minimal separation between the coupled microstrip line is designed using DMS. Further research must be conducted to improve the NEXT, FEXT and spacing between the transmission lines.Originality/valueSimulation and actual measurement results show that the proposed DMS structure can effectively suppress crosstalk by analysing the S-parameters, namely, S_12, S_13 and S_14, with measured values of 1.48 dB, 20.65 dB and 21.099 dB, respectively. The data rate is measured to be 1.34 Gbps as per the eye diagram characterization. The results show that the NEXT and FEXT are reduced by approximately 20 dB in the frequency range of 1–11 GHz for mixed signals. The substantial measured results in the vector network analyser coincide with the computer simulation technology microwave studio suite simulation results.

A Parasitic Hat for Microstrip Antenna Design Based on Defected Structures for Multiband Applications

In this article, a novel design of a quad-band parasitic hat microstrip antenna is proposed for multiband applications. The proposed antenna consists of a rectangular patch of dimensions 30 mm×11 mm cut with four L-shaped slots connected with a rectangular slot in the middle of the front side of the antenna to form a parasitic hat based upon defected microstrip structure. On the other side of the antenna, a defected ground structure is integrated as five rectangular slots embedded in the ground plane with the same width but with various lengths. The suggested antenna is designed and fabricated on a substrate material with an area of 45 × 40 mm2 with a thickness of 1.52 mm to generate four frequency bands. The proposed antenna is fed by a microstrip transmission line. The simulated radiation patterns, return losses, maximum gains, and efficiencies of the antenna are carried out by using electromagnetic simulation software based on the finite element method. The measured return loss results validate that the suggested antenna can be designed to cover the frequency ranges from (3.8464 to 4.1456) GHz for sub-7GHz 5G applications, (6.7 to 7.162) GHz for ultra-wideband applications, (9.1616 to 9.5187) GHz for maritime radio-navigation positioning systems, and (11.5421 to 16.4085) GHz for radio-navigation satellite standards. The suggested antenna is based upon defected ground structure and defected microstrip structure techniques to improve the antennaperformance.

A novel compact quad-band planar antenna using meander-line, multi-stubs, and slots for WiMAX, WLAN, LTE/5G sub-6 GHz applications

AbstractThis article concerns the design of a new quad-band monopole antenna with a specific configuration and reduced size. The antenna design is based on a single step meander-line parasitic structure, parasitic stubs, and double inverted L-shaped defected microstrip structure units on the top side of the substrate, and double rectangular-shaped defected ground structure units along with partial ground plane on the bottom side. This design procedure allows to achieve quad-band characteristics and improve the impedance matching. The fabricated antenna prototype with overall dimensions of (0.24λ0 × 0.17λ0 × 0.013λ0) is operating at 2.55, 3.65, 4.65, and 5.8 GHz with fractional bandwidth about 7.7, 12.84, 9.23, and 12.8%, respectively. The antenna exhibits an omnidirectional and a monopole like radiation patterns in the H- and E-planes, respectively, with suitable gains between 2.1 and 3.75 dBi. The measurement results are in good agreement with simulation values, which indicates that the proposed antenna design is suitable for WiMAX, LTE B7 (2.52–2.75 GHz), Sub-6 GHz 5G (n77) (3.39 – 3.87 GHz), Sub-6 GHz 5G (n78) (4.4–4.86 GHz), and WLAN, LTE B46 (5.1–5.82 GHz) wireless applications.

Crosstalk reduction between microstrip lines using TL‐shaped defected microstrip structure

AbstractAiming at the problem of far‐end crosstalk between microstrip lines, a method to improve crosstalk by using the TL‐shaped defective microstrip structure (DMS) is proposed. This method optimizes the ratio of the capacitive coupling and the inductive coupling between coupled microstrip lines by etching TL‐shaped DMSs on the microstrip lines, reducing the strength of electromagnetic coupling, thereby achieving an improvement in crosstalk. The quantitative equivalent model, S‐parameters, and full‐wave EM simulations are used to analyze the frequency response of the TL‐shaped DMS and crosstalk between the microstrip lines. The results of High Frequency Structure Simulator software simulation and sample texts show that the TL‐shaped DMS can effectively improve the far‐end crosstalk while ensuring the transmission of signals on the microstrip line. In the frequency range of 0–8 GHz, the far‐end crosstalk can be improved by about 11 dB, and the maximum can be improved by 42 dB. Compared with other DMSs, the TL‐shaped DMS has better crosstalk improvement effect and practical application potential.

Analysis of Septuple-Band NGD Circuit Using an E-Shaped Defected Microstrip Structure and Two T-Shaped Open Stubs

In this article, a compact distributed septuple-band negative group delay circuit (NGDC) is proposed and analyzed. It is mainly composed of a high–low–high step-impedance microstrip line with an E-shaped groove and two T-shaped open stubs. This NGDC was first simulated and then fabricated by using a conventional printed circuit board (PCB) process with the substrate of RO4350. To investigate the operational mechanism of the NGDC, an equivalent circuit, consisting of nine transmission lines, four series–parallel <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> resonant circuits, and two T-type series <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">LC</i> resonant circuits, has been developed and analyzed. It is found that the theoretical group delay characteristic calculated from the equivalent circuit agrees well both with the simulated data by using ADS as well as HFSS and with the experimental results. The measured seven NGD resonant frequencies occur at 2.03, 2.84, 8.14, 8.74, 13.0, 16.02, and 18.46 GHz, and the corresponding NGD values read −3.65, −3.04, −1.73, −3.23, −1.16, −1.20, and −1.47 ns. The dimensions of the presented passive NGDC are only 25 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times22$ </tex-math></inline-formula> mm without using any lumped components.

Design and fabrication of a novel multilayer bandpass filter with high‐order harmonics suppression using parallel coupled microstrip filter

This study presents a novel multilayer structure of parallel coupled-line bandpass filtercentered at 2.42 GHz with a fractional bandwidth value of approximately 19.4%. The designed filter can suppress harmonics with an appropriate frequency response by incorporating different techniques based on the multilayer technique. A combination of different techniques such as radial microstrip stubs and defected ground structure (DGS) and defected microstrip structure techniques are employed to suppress harmonics up to 5f0. These techniques are used in two layers to suppress up to 5f0. In addition, in this study, the effects of different parameters, such as the width of slot-line DGS, the angle of diagonal line slots in the upper layer, and the air gap between the two layers on the filter performance, are investigated. To verify the correct circuit operation, the designed filter is implemented and tested. The measurement results of the proposed filter are compared with the simulation results.

A quad‐band defected microstrip structure loaded bandpass filter for standard GPS , WiFi , WLAN , and WiMAX applications

A quad-band bandpass filter is proposed using a defected microstrip structure (DMS) for GPS, WiFi, WLAN, and WiMAX applications. This filter uses a stub-loaded stepped-impedance resonator (SL-SIR). The proposed filter is fabricated on an RT/Duroid5880 substrate (εr = 2.2, h = 0.787 mm, tanδ = 0.0009). Then, the LC equivalent circuit of the proposed filter is presented. A 28th-order transfer function is obtained and approximated by 8th-order transfer functions. The results of simulation, measurements and the LC equivalent circuit are in good agreement. The proposed filter operates at 1.6, 2.48, 3.76, and 5.44 GHz. The measured insertion losses are 0.32, 027, 0.51, and 0.41 dB in the four bands, while the return losses are better than 10 dB in all frequency bands. Finally, the proposed filter is compared with other bandpass filters.

Frequency Switchable and Tunable Negative Group Delay Circuits based on Defected Microstrip Structures

Frequency Switchable and Tunable Negative Group Delay Circuits based on Defected Microstrip Structures

A Compact Bandstop Filter Design Using DMS-DGS Technique for Radar Applications

In this study, a novel compact bandstop filter (BSF) by utilizing the defected ground structure (DGS) and defected microstrip structure (DMS) techniques are presented. DGS, DMS, and compensated capacitors are used on both bottom and top layers to obtain sharp transition and wider stopband. The operating frequency bandwidth of the filter can be comfortably regulated by tuning the dimensions of the etched structures. In addition to parametric studies, an equivalent circuit model of the proposed filter is extracted. The BSF has an insertion and return losses better than –1.6 and –17 dB in the passband, respectively. Moreover, the developed filter covers X-band frequency range and has stop bandwidth of 10.8–11.8 GHz with the rejection of better than 20 dB. Furthermore, the measurement and simulation results are in compliance with the suggested method. The proposed BSF has a very small size of 14.28 mm ×× 4 mm ×× 0.508 mm and has the potential to be used for radar applications with its high compactness, low cost, and high harmonic rejection performance.

A Band-Notched Antenna With Two Radiation Zeros Using Grounded Coplanar Waveguide Filter for 2.4/5 GHz WLAN Applications

In this article, a band-notched dual-polarized crossed dipole antenna is proposed for 2.4/5 GHz WLAN applications. The proposed antenna works on the WLAN 2.4-GHz (2.4–2.48 GHz) and 5-GHz (5.15–5.85 GHz) bands for a VSWR &amp;lt;2 with two radiation zeros within 3.4–3.6 GHz. First, an ultra-wideband crossed dipole antenna with an operating frequency of 2.4–5.8 GHz is designed using the grounded coplanar waveguide (GCPW) feeding structure. Second, a miniaturized defected microstrip structure (DMS) is embedded in the GCPW feeding strip to form a stopband behavior with a radiation zero. Finally, combining with the design of a C-shaped split ring resonator (SRR) on the arms of the dipole antenna, a band notch (3.4–3.6 GHz) with two radiation zeros can be realized. These two radiation zeros can be adjusted independently to achieve a wide stopband performance. As a result, compared with the original ultra-wideband dipole antenna, the realized gains of the proposed antenna in the 3.4–3.6 GHz range are all suppressed from 8 dBi to less than −8 dBi. The proposed antenna can realize the stable unidirectional radiation pattern and a high gain of around 7 dBi in the lower band and 8.5 dBi in the higher band of WLAN. As a demonstration, the proposed antenna is fabricated and measured, and the measurement results are in good agreement with the simulation results.

Design of a compact reconfigurable bandpass filter using interdigital capacitor, DMS slots and varactor diode for wireless RF systems

This paper proposes a new design of a reconfigurable bandpass filter based on an interdigital capacitor and varactor diode for wireless and mobile applications. The designed reconfigurable bandpass filter has been implemented on an RT 6010 substrate with a relative dielectric constant of 10.2, thickness of 1.27 mm, and loss tangent of 0.0023. In order to reduce the filter size, the defected microstrip structure (DMS) is used due to its easy design, high compactness, high quality factor and easy integration with other RF devices. The suggested reconfigurable filter has a simple structure with a very attractive compact size of 4.7 × 8.4 mm2, low insertion loss than -1 dB, and tuning range (2–2.6 GHz).