Proposed Patch Antenna Research Articles

Design of a UWB patch antenna and performance evaluation in detecting brain tumors

In this study, a patch antenna is designed for easy fabrication and effective operation across a wide frequency range, making it particularly valuable for detecting brain tumors within a human head phantom using the monostatic technique. The study presents the proposed antenna's modeling in four stages, analyzing all essential parameters where a substrate material consisting of FR 4 is used. The antenna has a patch area of 0.27 λ × 0.21 λ and operates at 7.5 (free space), 7.48, and 7.47 GHz with a wide bandwidth of 3.188 GHz (free space), whereas in measurement, it operates in free space at 6.79 GHz with a bandwidth of 3.24 GHz, which is also categorized as an ultra-wide band. A comparative analysis is carried out between the proposed patch antenna and previous studies utilizing FR4 and similar substrate materials to enhance understanding. In this research, the analysis includes a human head phantom model, assessing key performance criteria such as SAR, return loss, and VSWR. The time-dependent analysis provides in this study insights into the dynamic behavior of the system in detecting brain tumor. The proposed antenna has been evaluated and yielded a maximum specific absorption rate (SAR) of 0.420985 W/kg for 1 gram of tissue in the head phantom. The performance of the patch antenna is evaluated using CST software, while the fabricated PCB antenna is tested in real-world conditions to ensure dependable operation in practical applications. The main challenge addressed in this work is achieving accurate brain tumor detection within a human head phantom model in a CST environment and using a UWB patch antenna fabricated via PCB technology.

RCS-reduced patch antenna with wide frequency tuning range based on absorbing metasurface

A frequency-tunable patch antenna with reduced radar cross section (RCS) based on absorbing metamaterial is proposed. By controlling the external voltage of the varactor diodes, the working frequency of the patch can be adjusted. Through an investigation of the composite structure of the patch and absorbing metamaterial, RCS reduction is achieved over the entire wide tunable frequency range of the antenna. Measured results illustrate that the proposed patch antenna can dynamically operate in the range from 2.28 to 3.6 GHz with a gain variation of 7.1–8.7 dBi. Meanwhile, the RCS can be reduced by at least 7 dB and up to 20 dB in a fractional bandwidth of 44.9% of the antenna under a normal incidence. In comparison to conventional RCS-reduced antennas, the proposed one features a broader frequency tuning range and has potential value in wideband radar systems under complex electromagnetic interference environments.

Design, analysis and validation of a microstrip patch antenna with enhanced coupling for leaf moisture sensing: an IoT approach

An innovative IoT-based system utilizing a modified slotted microstrip patch antenna with enhanced coupling is presented for precise measurement of leaf moisture content. The antenna employs a rectangular slot above the feed point with an advanced coupling technique to enhance sensitivity. The antenna, fabricated on a 0.8 mm F4B substrate, is designed to resonate within the 2.40 to 3.0 GHz range under unloaded conditions. A parametric analysis focusing on leaf permittivity ranging from 20 to 30 is conducted to determine the antennas’ sensitivity. Experimental measurements of the reflection coefficient (S11) with respect to resonant frequency shift are performed with leaf samples as the samples under test (SUT). Experimental results reveal that the proposed patch antenna’s sensitivity is significantly enhanced, ranging from 0.57 to 1.67 times greater than that of traditional patch antennas for the five leaf samples tested. The antenna exhibits a sensitivity of 0.06 GHz and 0.02 GHz for the modified and enhanced coupling designs, respectively. The mean relative error between predicted and measured moisture content values is low at 0.038. The findings highlight the antenna’s increased sensitivity in detecting leaf moisture content and illustrate the potential of the proposed IoT-based system for real-time agricultural monitoring, marking an advancement in precision farming practices. The study validates the microstrip patch antenna’s capability as a moisture sensor through detailed sensitivity analysis, frequency shift measurements, and regression modeling.

Design and simulation of a novel THz patch antenna for early detection of malignant neoplasms

This research presents a novel patch antenna prototype that operates in the THz range for early detection of malignant cancerous cells. The antenna has dimensions of 100 µm × 100 µm and achieves −27.3 dB return loss at an operating frequency of 2.34 THz. The proposed sensor is optimized for a polyimide substrate with a dielectric constant of 3.5 and thickness of 15.7 µm. The prototype’s sensitivity and performance are evaluated by simulating different malignant neoplasms using High-Frequency Simulation Software (HFSS) for five types of breast cancer cells. The results indicate that the variation in resonant frequency and the S21 parameter between malignant cells and healthy breast cells are the primary factors that determine the sensitivity of the prototype. The proposed patch antenna’s high sensitivity and low profile make it a promising solution for the early detection and prognosis of cancerous cells.

Meta-atom loaded circularly polarized triple band patch antenna for Wi-Fi, ISM and X-band communications

Microstrip antennas usually suffer from high losses, gain, and efficiency degradation. It is a challenging task to miniaturize the patch antenna without degrading the performance parameters. To mitigate the above problems, a microstrip patch antenna loaded with stubs and printed on the ground plane loaded with dumbbell meta-atom is presented in this paper. The proposed double dumbbell meta-atom consists of two complementary split ring resonator (CSRR) cells loaded with rectangular rings. This exhibits the Double Negative (DNG) characteristic at 2.45 GHz. The devised meta-atom possesses dimensions of 0.05λ x 0.03λ at lower giga-hertz range. The meta-atom is further analyzed in CST-Microwave Studio and the corresponding S-parameters are extracted in MATLAB using the Nicolson Ross Weir (NRW) method. The electrical model of the meta-atom is also analyzed using Agilent ADS simulator. Further, two models of the proposed antenna with FR-4 and RT/Duroid-5880 are designed and compared. The proposed patch antenna resonates at three different frequency bands i.e. 2.445 GHz with a 3-dB bandwidth of 110 MHz (2.4 GHz–2.51 GHz), at 5.85 GHz with a 3-dB bandwidth of 730 MHz (5.13 GHz–5.86 GHz), and at 8.83 GHz with a 3-dB bandwidth of 1.83 GHz (7.7 GHz–9.53 GHz). This exhibit peak gains of 2.75dBi, 3.53dBc and 4.36dBi with low cross polarization levels at the said frequencies of operation. Further, the antenna possesses circular polarization in the frequency band (5.15 GHz–5.63 GHz). This antenna is used for Wi-Fi, ISM and X-band communications. The designed prototype is fabricated and tested and bears resemblance to the simulated results.

Frequency reconfigurable circular microstrip G-slotted antenna with DGS for various wireless applications

Frequency reconfigurable circular microstrip G-slotted antenna with DGS for various wireless applications

A miniaturized passive wireless patch antenna sensor for structural crack sensing

This paper presents a miniaturized patch antenna sensor for structural crack sensing, and the patch antenna sensor can be interrogated wirelessly. The proposed patch antenna sensor can detect the expansion of structural crack through relative movement between antenna components, and the relationships between the antenna resonant frequency and the crack width were studied. By using Rogers RO3010 laminate with high dielectric constant as the dielectric substrate of the antenna, the size of the proposed antenna sensor is significantly reduced, and higher sensing sensitivity is achieved. Furthermore, the wireless interrogation methods of the patch antenna sensor were also studied. The resonant frequency of the patch antenna sensor was wirelessly interrogated using linearly polarized wide-band antennas. Compared with the previous patch antenna sensor, the overall area of the proposed antenna sensor has been reduced to 33.4%, and the miniaturized patch antenna sensor shows a sensing sensitivity of 116.1 MHz/mm, which is 2.6 times higher than the previous patch antenna sensor. A series of simulations and experiments have demonstrated the feasibility of the proposed patch antenna sensor for structural crack sensing and the effectiveness of wireless interrogation methods.

A 9.73 GHz wide-band off-body patch antenna for biomedical applications

<span>The primary goal of this study is to design a simple antenna that has a wide bandwidth and low return loss for biomedical applications. The paper shows the recommended antenna’s three-stage modeling, with the goal of assessing every important parameter while a Teflon or polytetrafluoroethylene (PTFE) polymer substrate is used. In order to better comprehend, a comparison with prior studies employing teflon and similar substrate materials is conducted for the proposed patch antenna. The analysis includes the phantom model, evaluating performance criteria such as specific absorption rate (SAR), return loss, bandwidth, and gain values relevant to biomedical applications. The antenna works at two different frequencies: 9.73 and 9.39 GHz, one in free space and another in a skin-cotton layer. The bandwidth of the antenna is 4.067 GHz in free space at the resonance frequency of 9.73 GHz, where the return loss is -62.18 dB. The performance of the proposed antenna in the field of biomedical applications, its underlying reasons, and its impacts are discussed in detail in this study.</span>

A Lattice-Hinge-Design-Based Stretchable Textile Microstrip Patch Antenna for Wireless Strain Sensing at 2.45 GHz.

The manuscript presents a novel approach to designing and fabricating a stretchable patch antenna designed for strain sensing and the wireless communication of sensing data at the same time. The challenge lies in combining flexible and stretchable textile materials with different physical morphologies, which can hinder the adhesion among multiple layers when stacked up, resisting the overall stretchability of the antenna. The proposed antenna design overcomes this challenge by incorporating a lattice hinge pattern into the non-stretchable conductive e-textile, transforming it into a stretchable structure. The innovative design includes longitudinal cuts inserted in both the patch and the ground plane of the antenna, allowing it to stretch along in the perpendicular direction. Implementing the lattice hinge pattern over the conductive layers of the proposed patch antenna, in combination with a 2 mm thick Polydimethylsiloxane (PDMS) substrate, achieves a maximum of 25% stretchability compared to its counterpart antenna without a lattice hinge design. The stretchable textile antenna resonates around a frequency of 2.45 GHz and exhibits a linear resonant frequency shift when strained up to 25%. This characteristic makes it suitable for use as a strain sensor. Additionally, the lattice hinge design enhances the conformability and flexibility of the antenna compared to that of a solid patch antenna. The realized antenna gains in the E and H-plane are measured as 2.21 dBi and 2.34 dBi, respectively. Overall, the presented design offers a simple and effective solution for fabricating a stretchable textile patch antenna for normal use or as a sensing element, opening up possibilities for applications in the communication and sensing fields.

High gain compact wearable antenna for IoT applications

In this paper, the design of a Defected Ground Structure (DGS)-based microstrip patch antenna tailored for sub-6 GHz 5G applications is reported. The proposed patch antenna is crafted using Jeans textile material. By integrating DGS into the traditional patch antenna design, we achieve a significant reduction in size while simultaneously enhancing the antenna’s performance. The antenna features a rectangular patch shape and is powered through a 50-ohm microstrip feed line. Boasting a compact size of 35.6 × 42.6 × 1.6 mm³, the antenna’s performance is further improved by incorporating DGS and etching slots on the patch. The expertly designed antenna yields a 34.87 dB return loss and a gain of 10.9 dB at a frequency of 3.5 GHz. The fabricated antenna demonstrates a robust impedance bandwidth within the range of 3.41–3.606 GHz. Consequently, the proposed antenna is well-suited for applications in WiMAX and IoT technologies.

Design and Modeling of Ultra-Compact Wideband Implantable Antenna for Wireless ISM Band

This paper proposes a wideband ultra-compact implantable antenna for a wireless body area network (WBAN). The proposed patch antenna works in the industrial, scientific, and medical (ISM) bands. The proposed patch antenna with an ultra-compact size (5 × 5 × 0.26 mm3) was designed with 29% wide bandwidth (about 670 MHz). This wide bandwidth makes the antenna unaffected by implantation in different human body parts. The miniaturization process passed many steps by adding many slots with different shapes in the radiating element as well as in the ground plane. A 50 Ω coaxial feeding excites the antenna to maintain matching and low power loss. The specific absorption rate (SAR) was calculated for health considerations. The result was within the standard limits of IEEE organizations and the International Commission on Non-Ionizing Radiation Protection (ICNRP). The antenna was tested in tissues with multiple layers (up to seven layers) and at various depths (up to 29 mm). The link margin was calculated, and the proposed antenna enables 100 Kbps of data to be transferred over a distance of 20 m and approximately 1 Mbps over a distance of 7 m. The proposed antenna was fabricated and tested. The measured S11 parameters and the simulated results using the Computer Simulation Technology (CST Studio) simulator were in good agreement.

Continuous Beam Steering Realized by Tunable Ground in a Patch Antenna

A continuously steerable patch antenna employing liquid metal is presented. The proposed antenna employs a novel tunable ground plane together with parasitic steering to steer the direction of the main beam. The tunable ground plane consists of a permanent region, made from copper, and two tunable regions formed from liquid metal. The liquid metal channels were fabricated using 3D printing technology. By continuously injecting liquid metal into channels, the proposed patch antenna can provide continuous beam steering from −30° to +30° in the elevation plane, while achieving low side lobe level performance combined with low scan loss performance. Such an approach has never been tried before and it is only possible due to the unique properties of liquid metal. To the best of the authors’ knowledge, this is the first time that tunable ground plane has been used for a patch antenna to achieve continuous beam steering. The proposed antenna operates at 5.3 GHz. The antenna is fabricated and measured. Measurement results agree well with the simulation results and validate the effectiveness of the proposed beam steering technique. The proposed antenna has a measured gain of 8.1 dBi at 5.3 GHz and wide bandwidth performance. The tunable ground technique proposed in this work will find numerous applications within future wireless communications systems.

Compact Dual-band (28/38 GHz) Patch for MIMO Antenna System of Polarization Diversity

In this work a novel design of a compact-size patch antenna is introduced for dual-band operation at 28/38 GHz. The antenna is constructed as a perforated resonant patch on a defected ground structure (DGS). The development stages of the design are described in detail. The patch is inset-fed through a microstrip line. A four-port MIMO antenna system is constructed using the proposed patch antenna. The antennas are arranged at the corners of a mobile handset in orthogonal orientations which results in polarizations and spatial diversities as well as low mutual coupling. The single antenna as well as the MIMO antenna system performance is assessed through numerical simulations and experimental measurements. The scattering parameters including the reflection and coupling coefficients are calculated using the commercially available CST® package and measured experimentally showing good agreement. The proposed antenna has a bandwidth of 0.6 GHz at 28 GHz and 1.17 GHz at 38 GHz. To evaluate the performance of the proposed MIMO antenna system, key performance parameters such as the radiation efficiency, envelope correlation coefficient (ECC), and diversity gain (DG) are investigated. The proposed four-port MIMO antenna system configuration is shown to be suitable for polarization and spatial diversity schemes as illustrated from the resulting radiation patterns. The proposed antenna has high radiation efficiency and the MIMO system has very good values for the ECC and DG over the operating frequency bands. The MIMO system possesses good polarization and spatial diversities with good isolation between the antennas without the use of any isolation enhancement techniques.

Characterization of metamaterial based patch antenna for worldwide interoperability for microwave access application

Electromagnetic metamaterial is an artificial material that is made up of different types of structural designs on dielectric substrates. In this paper a broad and elite investigation is being carried out by designing and simulating a metamaterial cell comprising a square split ring resonator with a copper wire strip etched on the ground plane to discover its some unusual parameters such as double negativity of cell which are naturally not found in other materials of nature. A course of action of these unit cells in a grouping shapes metamaterial. These metamaterial cells show exceptionally great applications in the design of microstrip patch antennas by improving their characteristics such as bandwidth, return loss, and gain. The proposed microstrip line feed patch antenna is designed at a 3.5 GHz resonance frequency useful for various worldwide interoperability for microwave access (WiMAX) applications. The ground plane of a substrate of a patch antenna is loaded with a square split-ring resonator, the proposed antenna is fabricated to obtain experimental parameters. A conventional and proposed patch antenna is simulated, fabricated tested analysed, and reported for performance comparison of its parameters.

A compact triple band circular polarized slotted microstrip patch antenna with low frequency ratio

A pentagon shaped triple band circular polarized (CP) slotted microstrip patch antenna with asymmetric single microstrip feed line is designed. The proposed patch antenna is loaded with a pair of asymmetric slits, a pair of symmetric slots and a triangle shape truncation at the right side of the antenna. The antenna is drafted within the size of 0.43λ × 0.43λ and resonates at 2.17, 3.08, and 3.48 GHz with impedance bandwidth (IBW; IS11I < −10 dB) 2.14–2.20, 3.06–3.10, and 3.45–3.51 GHz, respectively. The Axial Ratio Bandwidth (ARBW; AR < 3 dB) is obtained as 2.17–2.40, 3.07–3.10, and 3.48–3.54 GHz at the three resonances which almost cover the IBW. An additional feature of the design is that the CP bands are very closely spaced with frequency ratio of 1.36 between first and second CP resonances and 1.13 between second and third CP resonances. The obtained gain at three resonances is 3.9, 3.79, and 4.81, respectively. The CP radiation patterns are found to be stable with good right hand CP (RHCP) to left hand CP (LHCP) isolation at the boresight direction. This antenna is suitable for S-band applications. The advantage of the proposed design has been highlighted with respect to multiband CP, CP frequency ratio, compactness and RHCP to LHCP isolation. A prototype of the proposed design is fabricated and the measured results are in accord with the simulated results.

High-Isolated Coupling-Grounded Patch Antenna Pair With Shared Radiator for the Application of 5G Mobile Terminals

We propose a coupling-grounded patch (CGP) antenna pair for sharing the same radiator with the high isolation performance, where the two feeding ports are connected through such shared radiator with very close distance of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.1 \lambda _{0}$ </tex-math></inline-formula> . More specifically, two coupling pins (C-pins) grounded on the symmetry plane of the radiator are shown to be capable of tuning the common mode (CM) impedance to be the same as the differential mode (DM) impedance, thus a very high isolation of such patch antenna pair is obtained. Both simulation and measurement results demonstrate that the isolation of the patch antenna pair could be greatly improved from the original 3 dB to approximately 25–50 dB in the N79 band (4.8–4.9 GHz). Furthermore, the extension to four-port antennas is also investigated. The proposed patch antenna pair with less occupied area provides significant promising application values for the multiple-input multiple-output (MIMO) systems, especially for the sophisticated fifth-generation (5G) mobile terminals.

Modeling and Performance Optimization of a Compact Three-Petalled Flower-Like Microstrip Patch Antenna for IoT Applications

The article is aimed at proposing the design and investigating the performance of a three-petalled flower-shaped wideband microstrip patch antenna for IoT and next-generation wireless applications. The proposed printed monopole antenna is provided with a microstrip feed line for excitation with a defected ground plane. The antenna is designed and analyzed using a finite-element-based simulator HFSS (version 15.0). The Optimetrics feature in the simulator is used for the performance optimization of the designed antenna that results in wide impedance bandwidth between 2.5 and 5.5 GHz, with add-on benefits such as less human efforts along with fast optimum results. The designed antenna holds an advantage of being low profile and reduced in size as overall diminutive dimensions of the proposed patch antenna are 0.54 λ o × 0.43 λ o × 0.021 λ o m m 3 , making it suitable for use in Wi-Max- and WLAN-enabled IoT applications. The paper is aimed at proposing an innovative optimal design aiming at the concerns about the risks in the growth of IoT and mobile computing, particularly in wireless and mobile networks. The anticipated antenna, owing to its simple and compact design, can be easily integrated into portable mobile devices, and thus, it is considered suitable for 4G and 5G and other next-generation communication applications of IoT devices.

Wideband Patch Antenna with Shorting Vias

A novel patch antenna with three resonant modes is proposed for wideband applications. By introducing the ring slot on the circular patch, the TM02 mode of the smaller circular patch and the TM02 mode of the annular ring can be excited. Also, compared with the traditional circular patch with shorting vias, four components of shorting vias are distributed nonuniformly on the edge of the proposed patch antenna, which can generate another new resonance mode. By merging the three resonant modes, the impedance bandwidth of the antenna is expanded. Meanwhile, the gain of the antenna is enhanced in the wide operating band. The results illustrate that the antenna can operate in the 5.8 GHz ISM band. Its −10 dB impedance bandwidth is from 5.06 to 6.99 GHz, and the relative bandwidth reaches 32%. In addition, the maximum gain of 5.3 dBi is obtained at 6.7 GHz.

A Jug-Shaped CPW-Fed Ultra-Wideband Printed Monopole Antenna for Wireless Communications Networks

A type of telecommunication technology called an ultra-wideband (UWB) is used to provide a typical solution for short-range wireless communication due to large bandwidth and low power consumption in transmission and reception. Printed monopole antennas are considered as a preferred platform for implementing this technology because of its alluring characteristics such as light weight, low cost, ease of fabrication, integration capability with other systems, etc. Therefore, a compact-sized ultra-wideband (UWB) printed monopole antenna with improved gain and efficiency is presented in this article. Computer simulation technology microwave studio (CSTMWS) software is used to build and analyze the proposed antenna design technique. This broadband printed monopole antenna contains a jug-shaped radiator fed by a coplanar waveguide (CPW) technique. The designed UWB antenna is fabricated on a low-cost FR-4 substrate with relative permittivity of 4.3, loss tangent of 0.025, and a standard height of 1.6 mm, sized at 25 mm × 22 mm × 1.6 mm, suitable for wireless communication system. The designed UWB antenna works with maximum gain (peak gain of 4.1 dB) across the whole UWB spectrum of 3–11 GHz. The results are simulated, measured, and debated in detail. Different parametric studies based on numerical simulations are involved to arrive at the optimal design through monitoring the effects of adding cuts on the performance of the proposed antennas. Therefore, these parametric studies are optimized to achieve maximum antenna bandwidth with relatively best gain. The proposed patch antenna shape is like a jug with a handle that offers greater bandwidth, good gain, higher efficiency, and compact size.

Design and Analysis of a 35 GHz Rectenna System for Wireless Power Transfer to an Unmanned Air Vehicle

In this article, the concept of a 22-kW microwave-powered unmanned aerial vehicle is presented. Its system architecture is analyzed and modeled for wirelessly transferring microwave power to the flying UAVs. The microwave system transmitting power at a 35 GHz frequency was found to be suitable for low-cost and compact architectures. The size of the transmitting and receiving systems are optimized to 108 m2 and 90 m2, respectively. A linearly polarized 4 × 2 rectangular microstrip patch antenna array has been designed and simulated to obtain a high gain, high directivity, and high efficiency in order to satisfy the power transfer requirements. The numerically simulated gain, directivity, and efficiency of the proposed patch antenna array are 13.4 dBi, 14 dBi, and 85%, respectively. Finally, a rectifying system (rectenna) is optimized using the Agilent advanced design system (ADS) software as a microwave power receiving system. The proposed rectenna at the core of the system has an efficiency profile of more than 80% for an RF input power range of 9 to 18 dBm. Moreover, the RF-to-DC conversion efficiency and DC output voltage of the proposed rectenna are 80% and 3.5 V, respectively, for a 10 dBm input power at 35 GHz with a load of 1500 Ω.