Defected Ground Structure Research Articles

Design and application of D‐band bandpass filter based on 0.18 μm complementary metal oxide semiconductor process

AbstractThis paper designs a bandpass filter for D‐band and 0.18 μm complementary metal oxide semiconductor (CMOS) process. The bandpass filter is composed of an inverted L‐shaped coupling microstrip line and a cross‐coupled resonator, and is coupled to produce two controlled transmission zeros. A defected ground structure is used to make a good impedance match. The designed filter has a 3 dB impedance bandwidth of 52 GHz (149–201 GHz) with a center frequency of 175 GHz and an insertion loss of 3.23 dB. The design of this paper is a CMOS 0.18 μm process capable of applying the D‐band bandpass filter with the advantages of lower insertion loss, broadband, and compact size.

A novel dual-band defected ground structure wearable microstrip patch antenna for breast tumor detection in biomedical applications

This paper presents a dual-band, low-profile wearable antenna for detecting breast tumors in biomedical applications. The antenna is designed on the FR4 substrate with an optimized dimension of 32 × 27.5 × 0.61 mm3. The compact rectangular patch is miniaturized by cutting the rectangular slots on the front side. The partial ground structure is used for moving the resonance frequency in the ISM band region and for giving the tripping result of the return loss. A breast phantom is created between the transmitter and receiver for detecting the tumor in the phantom model. The different sizes and positions of the tumor in the breast phantom provide different values of the return loss. The final optimized design of the antenna is operated at 2.43 GHz and 3.32 GHz with −35 and −24 return losses respectively. It has been observed from the simulated and measured results that the antenna has a negligible difference between the reflected coefficient, radiation pattern and gain. Afterward, the antenna is also checked for biocompatibility, which represents its good performance. The on-body analysis of the antenna represents a minor variation in the results. The Specific Absorption Ratio (SAR) value of the antenna is in the acceptable range as defined for the wearable device. It is a promising compact wearable antenna that can be used in biomedical applications.

A Defected Ground Structure for TE and TM Coupling Reduction of Dual-Polarized Antenna Array

A Defected Ground Structure for TE and TM Coupling Reduction of Dual-Polarized Antenna Array

A defected ground structure based ultra-compact wider bandwidth terahertz multiple-input multiple-output antenna for emerging communication systems

This work presents a quad-port Multiple Input Multiple Output (MIMO) wideband antenna that operates in the terahertz (THz) frequency range is designed and analyzed. To improve MIMO performance, a defective ground structure (DGS) is used. A rectangular metallic patch was altered by adding parasitic elements to the radiator with the lowered ground plane on a polyamide substrate in order to achieve the wideband THz operating frequency. The THz antenna was turned into a MIMO antenna by replicating horizontally and vertically with a spacing of 0.05 λ and 0.002 λ, respectively (λ calculated at 1.7 THz). The designed THz MIMO antenna, comprising 40 μm × 46 μm × 2 μm, operates across the 1.7–10.4 THz frequency region. The THz MIMO antenna provides isolation of more than 20 dB in the frequency range of 2.8–10.4 THz and more than 10 dB for the frequency of 1.7–2.7 THz. Isolation augmentation is accomplished by establishing different local current channels using the antenna's DGS. The MIMO diversity properties of the proposed THz MIMO antenna are analyzed and found to be ECC<0.004, DG ~ 10 dB, TARC < −10 dB, MEG < −3 dB, and CCL<0.23 bps/Hz over the antenna's operating frequency.

Design of a Compact Multiband Monopole Antenna with MIMO Mutual Coupling Reduction.

In this article, the authors present the design of a compact multiband monopole antenna measuring 30 × 10 × 1.6 mm3, which is aimed at optimizing performance across various communication bands, with a particular focus on Wi-Fi and sub-6G bands. These bands include the 2.4 GHz band, the 3.5 GHz band, and the 5-6 GHz band, ensuring versatility in practical applications. Another important point is that this paper demonstrates effective methods for reducing mutual coupling through two meander slits on the common ground, resembling a defected ground structure (DGS) between two antenna elements. This approach achieves mutual coupling suppression from -6.5 dB and -9 dB to -26 dB and -13 dB at 2.46 GHz and 3.47 GHz, respectively. Simulated and measured results are in good agreement, demonstrating significant improvements in isolation and overall multiple-input multiple-output (MIMO) antenna system performance. This research proposes a compact multiband monopole antenna and demonstrates a method to suppress coupling in multiband antennas, making them suitable for internet of things (IoT) sensor devices and Wi-Fi infrastructure systems.

A Novel 4-port MIMO Antenna with Chamfered Edge for 5G NR n77/n78/n79 Bands and WLAN Applications

Abstract A novel, compact and low-cost four-element multiple-input multiple-output (MIMO) antenna with a high gain is proposed in this work. The suggested antenna structure uses easily accessible substrate material and has been designed and simulated using Ansys HFSS 3D electromagnetic simulation software. The radiating elements are placed orthogonally, and each of them consists of two circular rings. To improve the impedance matching and reduce mutual coupling, the corners are chamfered and partial ground structure is applied. For further enhancement in isolation, Defected Ground Structure (DGS) method is applied which makes the isolation as high as -55 dB. The measured gain of the proposed antenna is more than 12 dB over the considered frequency range. The antenna covers a frequency range from 3.3-6 GHz. The value of diversity gain is found to be more than 9.99 dB and envelope correlation coefficient is less than 0.006 respectively. Also, the mean effective gain, channel capacity loss, and total active reflection coefficient results are within the optimal range. These make the designed antenna suitable for the sub-6 GHz, 5G new radio (NR) n77/n78/n79 where n77 (3.3-4.2 GHz), n78 (3.3-3.8 GHz), and n79 (4.4-5 GHz) bands along with WLAN (5.1-5.8 GHz) applications.&amp;#xD;

Analysis, design, and optimization based on genetic algorithms of a highly efficient dual-band rectenna system for radiofrequency energy-harvesting applications

This paper gives an enhanced Rectenna design that operates at dual-band [2.45 and 5.8] GHz in the ISM (Industrial, Scientific, and Medical) band and is printed on an FR4-Epoxy substrate. This Rectenna design includes two proposed sub-designs for the receiving antenna and rectifier circuit based on the microstrip technology. The first sub-design concerns the microstrip patch antenna (MPA) described by its radiating element as a pentagonal, its ground being affected by a defective ground structure technique, and its polarization manner as circular polarization. This MPA design is analyzed, designed, optimized using genetic algorithms (GAs), simulated under CST MWS (i.e., computer simulation technology microwave studio), and confirmed by another software named HFSS (high-frequency structure simulator). The second sub-design concerns the microstrip rectifier circuit (MRC) that contains an input matching network based on a coupled-line impedance transformer strategy to achieve good adaptation between MPA and MRC, voltage doubler converter using an SMS7630 Schottky diode thanks to its high sensitivity, microstrip interdigital capacitor to mitigate the intrinsic losses due to the lumped elements, harmonic rejection filter based on a stepped-impedance low-pass filter to reject the unwanted harmonics generated by the non-linear behavior of SMS7630, and the resistive load that models the consumption of the system to be fed. This MRC is analyzed, designed, optimized using GAs, and simulated under ADS (Advanced Design System). The effectiveness of the proposed MPA is proven in terms of gain equals 3.06 dBi and 4.683 dBi at 2.45 GHz and 5.8 GHz respectively, and efficiency equals 95.13 % and 96.552 % at 2.45 GHz and 5.8 GHz respectively. The proposed MRC is effective in terms of efficiency at a lower input power value of about 97.18 % and 67.93 % at 2.45 GHz and 5.8 GHz respectively.

Mutual Coupling Reduction of Super Wide Band MIMO Antenna Using Metamaterial Periodic Defected Ground Structures for THz Applications

Mutual Coupling Reduction of Super Wide Band MIMO Antenna Using Metamaterial Periodic Defected Ground Structures for THz Applications

A compact wideband low‐profile all textile on/off body antenna for Satcom and defense applications

SummaryA compact, flexible, low‐profile end‐fire broadband wearable antenna operating in Ku‐band /X‐band is proposed in this manuscript for defense and satellite communications (Satcom) applications. The main objective of this work is cross‐polarization reduction by the defected ground structure (DGS), which offers a wider bandwidth. Due to its flexibility and ability to absolutely conform to the curved‐shaped human body, denim fabric is used as a substrate, whereas copper tape is used as a conductor, which allows for the integration of the antenna into garments and makes it appropriate for a wide range of wearable applications in various bands. The prototype has been developed with a size of mm3 for experimental validation. The measured results from a fabricated prototype are well matched with the simulated ones of the proposed design, which indicate a wide bandwidth of 57.35% (7.76–14 GHz) appropriate for use in applications such as defense operating from 8 to 12 GHz, satellite TV (11.7–12.2 GHz), Ku‐band downlink (10.95–11.7 GHz), Ku‐band uplink (11.7–14.5 GHz), and a high gain of 5.1 dBi. The specific absorption rate (SAR) is much below the permissible limit of 1.6 W/kg, with better radiation characteristics. Thus, the proposed antenna is more compact, and it clearly achieves a smaller footprint, larger impedance bandwidths, and a low SAR with potential prospect for Satcom and defense purposes.

Miniaturized planar defected ground structure antenna enabled with Yagi directors for enhanced gain performance in mm-wave 5G applications

The compact and miniaturized high gain antenna for millimetre wave 5G applications is proposed in this paper. The antenna is designed on RT Duriod 5880 substrate with dielectric constant, tangential loss, and specific heat of 2.2, 0.0009, and 0.23 Cal/g/C respectively. The peak gain of 9.5 dBi in E-Plane is achieved for high gain characteristics by applying Microstrip circular Yagi Directors. The antenna operates over the frequency range of 26.5–28.5 GHz with a good reflection coefficient of −25.60 dB at a resonance frequency of 27.56 GHz. Moreover, Defected Ground Structures (DGS) are adopted in the structure to optimize the characteristics by widening the path of surface current. The proposed antenna structure is fabricated and the measured results are found in good agreement with the simulated results. The better performance of the proposed antenna makes it a viable candidate for 5G millimetre-wave communications.

A quad port dual band notch UWB MIMO antenna using hybrid decoupling structure

A four-port dual-band notch ultrawideband (UWB) multiple input and multiple output (MIMO) antenna for automotive applications is presented. Initially, a circular patch monopole antenna is designed and optimized by embedding a rectangular stub onto the radiator and lowering the ground plane to realize the UWB frequency spectrum. The dual-band frequency notch, from 4.6 to 5.9 and 6.8–8.8 GHz, is achieved using a half wavelength slot onto the feedline and a pair of H-shaped stubs across the feedline, respectively, to cover WLAN and complete x-band satellite communication. Further, the designed dual-band notch UWB antenna is transformed to a four-port MIMO antenna with interelement spacing much smaller than λ/4 (λ at 3.1 GHz) and a size of 0.46 × 0.41 × 0.01 λ3. Isolation improvement is achieved by a hybrid decoupling technique comprising a distinctive neutralization line (NL) and defected ground structure (DGS). The average isolation of the proposed design is better than 22 dB. Characteristic mode analysis of the proposed antenna is performed to analyze the specific significant mode and their contribution to the antenna radiation. The antenna design's diversity and time-domain properties are analyzed and found suitable for automotive applications. The antenna's electromagnetic interaction with the electrically large structure is studied by mounting the antenna onto an open-source automobile model, and the gain is determined to be more than 6.1 dB at the antenna's resonant frequencies.

Design and performance analysis of L‐slotted MIMO antenna with improved isolation using defected ground structure for S‐band satellite application

SummaryThe increasing prevalence of MIMO technology in wireless communication networks is attributed to its ability to augment system capacity and dependability. Consequently, there is a notable enthusiasm for the advancement and implementation of S‐band applications. Nevertheless, the mutual coupling between numerous antennas presents a crucial obstacle to MIMO system performance. This paper presents a novel technique that utilizes a defective ground structure with parasitic components to increase antenna isolation and gain. Additionally, an L‐shaped slot is incorporated into the patch element to enhance the antennas impedance bandwidth. Antennas are intentionally placed in a perpendicular arrangement to minimize the impact of the coupling effects. The antenna exhibits an impedance bandwidth in the frequency range of 2.62–2.79 GHz. Furthermore, the utilization of a four‐element MIMO antenna setup with a defective ground structure yields outstanding isolation properties, with values notably lower than −25 dB. To achieve an optimal MIMO performance, we assessed various diversity parameters, including diversity gain, channel capacity loss, total active reflection coefficient, and envelope correlation coefficient. The parameter values were within acceptable limits (ECC &lt; 0.04, DG = 10 dB, TARC &lt; 0 dB, and CCL &lt; 0.1 bits/s/Hz). This research paper therefore offers essential insights into the design and optimization of MIMO antennas specifically for 2.7 GHz applications.

Super compact and ultra-wideband bandpass filter with three band notches using triple-mode stepped impedance resonator and defected ground structure

A super-compact ultra-wideband (UWB) microstrip band-pass filter (BPF) with triple-notched bands and wide stopband is proposed in this paper. The super-compactness of the proposed filter is achieved by integrating the modified SCRLH-TL UWB-BPF and backbone-shaped defected ground structure (DGS). The equivalent LC circuit models of the DGS and the modified SCRLH-TL UWB-BPF with the DGS are analyzed to validate their numerical simulation results. To introduce the triple notched-bands to mitigate the interference the two triple-mode SIRs are designed and loaded on the modified UWB-BPF without increasing the circuit size. The proposed filter was fabricated by using a conventional PCB process with the substrate of FR4. The measured 3-dB passband ranges from 2.8 through 10.2 GHz with the fractional bandwidth (FBW) of about 114%. The triple-notched bands with attenuation of more than 15 dB are measured at 4.4, 5.3 and 8.2 GHz, respectively. The filter exhibits a high selectivity with steep skirt property and has a wide upper stopband with an out-of-band rejection of −10 dB at 11.8−20 GHz. Its total dimension, including the rectangular substrate with feed lines, occupies only 16mm × 8 mm.

Design of an enhanced dual-band microstrip patch antenna with defected ground structures for WLAN and WiMax

This research presents an innovative dual-band microstrip patch antenna design enhanced with defected ground structures (DGS) and barium strontium titanate (BST) thin film, tailored for wireless local area network (WLAN) and WiMax applications. The first design phase involved the development of an microstrip patch antenna (MPA) using an flame retardant (FR4) substrate with a permittivity (εr1) of 4.3 and a thickness of 1.524 mm, enhanced with DGS. This configuration achieved a single-band resonance at 4.1 GHz, with a bandwidth of 0.82 GHz and a return loss (S11) of -32 dB. The second phase involved the integration of a BST thin film, with a high permittivity(εr2) of 250 and a thickoness of 0.1 mm, into the DGS-enhanced microstrip patch antenna (MPA). This mdification led to a transformation in the antenna's performance, enabling dual-band operation at resonance frequencies of 2.8 GHz and 5.8 GHz. Further, there was a corresponding substantial increase in bandwidth to 1.34 GHz and 1.25 GHz, respectively, an improvement in S11 values to -16.3 dB and -21.4 dB. Moreover, and antenna’s size of 14×10×1.524 mm&lt;sup&gt;3&lt;/sup&gt; . The study underscores the critical role of innovative material use and design optimization in advancing antenna technology, offering significant enhancements in bandwidth, and miniaturization, for wireless communication systems.

Improvement in Depth–of–Return-Loss and Augmentation of Gain-bandwidth with Defected Ground Structure For Low Cost Single Element mm–Wave Antenna

Improvement in Depth–of–Return-Loss and Augmentation of Gain-bandwidth with Defected Ground Structure For Low Cost Single Element mm–Wave Antenna

A high-isolated wideband two-port MIMO antenna for 5G millimeter-wave applications

Fifth-generation (5G) technology is extremely important in the current context since it seeks to fix the shortcomings of its predecessors, the 4G generation. To achieve this goal, this project entails constructing a small ultra-wideband (UWB) MIMO antenna featuring an anti-parallel layout, designed for operation within the millimeter-wave spectrum. Moreover, the investigation scrutinizes and fine-tunes the mutual coupling interaction between the two elements in detail. The presented MIMO antenna occupies a small footprint of 6 × 17.37 mm2. Despite its compact dimensions, this MIMO antenna provides an impressive isolation of 65 dB, attributed to the adequate inter-element spacing and the anti-parallel arrangement. Additionally, the integration of a defected ground structure (DGS) enhances isolation by approximately 20 dB. Furthermore, the proposed MIMO antenna demonstrates a satisfactory gain of approximately 6 dBi, boasting high efficiency surpassing 96 %, and lying between 34.1 and 39.7 GHz. The proposed antenna has undergone simulation and analysis utilizing both the High-Frequency Structure Simulator (HFSS) and Computer Simulation Technology (CST) in order to confirm its utility. Based on these findings, the suggested MIMO antenna appears to be well-suited for compatibility with 5G communication systems, specifically covering the n260 band (37–40 GHz) and the Ka-band.

2 × 2 MIMO dual spiral octagonal prism liquid DRA with snake-shaped DGS for OAM multiplexing.

In this paper, we proposed a 2 × 2 multiple-input multiple-output (MIMO) dual spiral octagonal prism liquid dielectric resonator antenna (DRA) with snake-shaped defective ground structure (DGS) for space multiplexing of orbital angular momentum (OAM). The DRA element adopts an inner and outer nested dual spiral structure filled with 0.035 g/ml of brine outside and a cylinder filled with distilled water inside. The proposed MIMO antenna can generate resonance at 1.78-3.02 GHz and 4.01-7.73 GHz (S11≤-10 dB). The isolation among ports is below -20 dB at 2.6 GHz and below -40 dB at 5.1 GHz, which can effectively isolate the l = ±1 and l = ±3 modes' OAM waves through the snake-shaped DGS. The proposed MIMO antenna improves spectral efficiency by OAM spatial multiplexing with l = ±1 and l = ±3 modes' OAM, which improves the data transmission efficiency. The proposed MIMO antenna provides a novel, to the best of our knowledge, solution for wireless communications to improve spectral efficiency.

A four-port self-multiplexing tunable graphene based dielectric resonator antenna with defective ground structure for high isolation and MIMO capabilities

Objectives and designA novel self-multiplexing terahertz antenna with four tunable ports is proposed in this work. The configuration comprises four rectangular dielectric resonators (DRs) affixed to a substrate, which are excited through L-shaped microstrip-fed slots positioned beneath them. To guarantee efficient isolation among the tunable antenna components, periodic unit cells are introduced into the ground plane, forming a defective ground structure (DGS). Each L-shaped slot element is equipped with a graphene strip to regulate the tunability of each DR element. Results and applicationsThis antenna can operate in various modes with resonant frequencies at 4.01, 4.23, 4.37, and 4.57 THz. It holds potential for future terahertz wireless applications that require the utilization of adjacent channels with distinct communication frequencies. Furthermore, a four-port antenna design is implemented, offering tunable MIMO capabilities with self-quadruplexing ability. The MIMO parameters, specifically the envelope correlation coefficient (ECC) and diversity gain (DG), have been assessed and found to fall within acceptable limits across the operating frequency bands. Additionally, an equivalent circuit model (ECM) is analysed to shed light on the antenna's working principle and verify the obtained results.

A compact highly flexible two-element wideband MIMO antenna based on modal analysis for 5G wireless applications

The ever-evolving world of wearable technology demands compact, highly efficient, and flexible antennas to meet a seamless communication. To keep pace, a compact, flexible two element antenna with a low profile of 20 × 30 × 0.1 mm3 is presented in this article for 5G wireless applications. A lotus shaped radiator with stub integrated defective ground structure provides the desired band of interest with a measured impedance bandwidth of 4.56–5.65 GHz and isolation of 21 dB throughout the bandwidth. Characteristic mode analysis is exclusively utilized in this study to investigate and design the decoupling mechanism to improve the isolation. SAR analysis is performed using the Specific Anthropomorphic Mannequin (SAM) head model and a low SAR profile of 1.088/0.276 W/kg for 1 g/10 g is achieved. MIMO diversity performance of the antenna also shows favourable results with ECC < 0.5, DG ∼10, TARC < −10dB, MEG < −3 dB, CCL < 0.4 bps Hz−1 and ME < −0.5 that favours its applicability for real time MIMO applications.

Drone Shaped Fractal Antenna with Defected Ground Structure for RF Energy Harvesting Applications

A proposed multiband drone shaped fractal antenna (Antenna-1) is introduced in this paper that targets the most required frequencies used for radio frequency energy harvesting applications, including WLAN-2.4G, WLAN-5G, WLAN-6G, Mobile DCS1700, Mobile LTE and WIMAX services. A novel fractal shape is designed and combined with a standard square geometrical shape in order to implement the front patch of the antenna. The antenna is simulated with CST Studio Suite software and fabricated on FR-4 substrate. Different antenna stages with parametric study and optimization were implemented to get the best performance from the drone shape fractal antenna. The multiband (Antenna-1) supports six resonate frequencies (1.7155 GHz, 2.424 GHz, 3.36 GHz, 3.789 GHz, 5.843 GHz, 6.886 GHz) with peak gain of (2.83 dBi) at the frequency 2.45 GHz and a maximum bandwidth of (0.4281 GHz) at the frequency 5.8 GHz that make it a suitable antenna for radio frequency energy harvesting applications.