VSWR Research Articles

Design of a high power combiner in HF band

Power combiners are commonly used in power amplifiers to achieve high power, especially in long-range and medium-range wireless communication device transmission systems. This paper proposes designing and implementing a high-power two-way power combiner operating in the HF (High Frequency) band, aiming to achieve an output power of over 1 kW. The power combiner is designed, implemented, and tested in the laboratory with the following achieved parameters: insertion loss between output and input better than 3.4 dB and isolation between inputs better than 26 dB. The experimental results showed that the proposed power combiner had better performance than existing combiners on the market. Mainly, power combining efficiency is over 88%, the standing wave ratio at ports is less than 1.25, and the operating temperature of the power combiner is less than 50 °C, meeting the set requirements.

Gain enhancement of compact CPW‐Fed ultra‐wideband antenna using an FSS reflector

AbstractIn this paper, an enhancement gain of compact CPW‐Fed antenna using a single layer frequency selective surfaces (FSSs) reflector for ultra‐wideband (UWB) applications is presented. A hexagonal CPW‐Fed antenna with a size of 30 × 30 mm2 is realized to provide a UWB bandwidth operation. In this study, a novel design of an FSS unit cell with reduction and a small size of 8 × 8 mm2 is proposed. It allows one to achieve a UWB band‐stop response between 3 and 11.5 GHz. The FSS reflector has 7 × 7 units with a total size of 56 × 56 mm2. This reflector is placed below the antenna at a distance of 20 mm. The main objective of this contribution is to improve the gain level of the antenna, where the proposed antenna achieves an improvement of realized gain of 6.2 dBi with increasing from 2.2 to 8.4 dBi. The antenna became more directive after the integration of the FSS reflector with a directional radiation pattern. The numerical and experimental results are in good concordance with the simulated one. This study is performed in terms of voltage standing wave ratio, radiation pattern, realized gain, and radiation efficiency.

Investigating the impact of graphene patch width on performance and bandwidth enhancement in nano-patch antennas

This study investigates how varying the width of a graphene patch affects the performance and bandwidth of a nano-patch antenna. High-Frequency Structural Simulator (HFSS) software was employed for simulation, evaluating parameters such as voltage standing wave ratio (VSWR), gain, and return loss. The graphene patch of 0.690nm thick was placed on a silicon dioxide substrate with a thickness of 10 µm, while the patch width was systematically varied at 30 µm, 32 µm, 34 µm, 38 µm, and 42 µm. Surprisingly, the resonating frequency remained unaffected by changes in patch width. The results revealed that the patch widths of 32 µm, 34 µm, and 38 µm produced the highest return losses of -24.5482, -24.4774, and -24.4001, respectively. Additionally, these configurations exhibited impeccable VSWR values of 1.0302, 1.0387, and 1.0480. Notably, a substantial bandwidth improvement exceeding 500 GHz was achieved for these patch widths. This finding underscores the significant relationship between gain, directivity, and patch width in graphene nano-patch antennas. Furthermore, both 32 µm and 34 µm patch widths demonstrated gain and directivity exceeding 7 dB.

Microstrip Patch Antenna Design for 5G and Beyond Wireless Communication Systems

This paper gives a theoretical evaluation on how feeder lengths are appropriate for distinct conductor materials using rectangular microstrip patch antenna shape with the help of finite integration techniques (FIT). In this study, the ground surface width is 5.6mm and the ground surface length is 4.65 mm for the rectangular microstrip patch antenna. The length of the patch is 3.44 mm while the patch width is 4.40 mm. The substrate thickness is at 0.20 mm, the patch thickness is 0.035 mm the additional inner feed length is 1.05 mm and the microstrip line feed width is 0.6 mm. Antenna of rectangular microstrip patch type has been designed to work in the 20 – 36 frequency band and working frequency of the proposed antenna is 28 GHz. Compared to the use of a single conductor on the surface of the designed patch antenna, three different conductor materials-copper, gold, and aluminum-were applied to the patch surface of the antenna. The return loss (S11), voltage standing wave ratio (VSWR), bandwidth (BW), directivity and gain of the microstrip antenna parameters are studied using finite integration method Computer Simulation Technology (CST) based on nine different feed lengths in microstrip antenna design. When analyzing the feature of the simulation, the optimal S11 can be observed at the 28 resonant frequencies in the copper conductor. According to the analysis results, for copper conductor the best S11 was obtained at a resonant frequency of 28.03 GHz. The value of S11 is -31.19 dB and the BW value is 968 MHz. For the gold conductor the high return loss is achieved using the at the resonated frequency of 28.01 GHz. S11 value is -32 dB and the BW value is 972 MHz Aluminum conductor has the highest value of S11 with a resonant frequency of 28.01 GHz as shown in -33.29 dB and BW value is 976 MHz. Unsurprisingly, the characterization of the conductor deposition on each structure shows that aluminum conductor yielded the best S11 among all the conductor types. The VSWR is equal to 1.05 for copper conductor at resonant frequency of 28.03 GHz, 1.05 at gold conductor at a resonant frequency of 28.01 and 1.04 for aluminum conductor at a resonant frequency of 28.01 GHz. The maximum directivity values that have been attained in the three-dimensional (3D) representation of the copper conductor, gold and aluminum conductor antennas are nearly 6.99 dBi, respectively. The maximum values of the gain are obtained for the 3D representation of copper, gold and aluminum conductor antennas are 6.61, 6.60 and 6.58 dBi, respectively.

Synthesis and characterization of (Ba2Zn2Fe12O22)1−x(NiFe2O4)x ferrite composites for antenna applications

A series of (Ba2Zn2Fe12O22)1−x(NiFe2O4)x ferrites (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) were successfully synthesized by one-pot coprecipitation route. XRD analysis reveals the formation of Ba2Zn2Fe12O22 and NiFe2O4 composite after sintering calcined precursor powder at 1200 °C/4 h. Densification behaviour was evaluated by Archimedes’ principle. Field emission scanning electron microscopy was used to study morphological characteristics. Room temperature magnetization behaviour was evaluated using a vibrating sample magnetometer. In composite, it was observed that the saturation magnetization (Ms) and coercivity (Hc) increased with increasing NiF content. With the increase of NiF in the composite, the permittivity (ε) decreased from 28.6 (for x = 0.2) to 13.6 (for x = 0.8) with the corresponding decrease in dielectric loss (tanδε) at 100 MHz. The permeability (μ) also decreased from 21.3 (x = 0.2) to 17.9 (x = 0.8) with the associated decrease of the magnetic losses (tanδμ) at 100 MHz. Miniaturization factor (n) of 19.2 and characteristic impedance of 1.1 were obtained for x = 0.4 composition at 100 MHz along with low dielectric loss factor (tan δε/ε) and magnetic loss factor (tan δµ/µ). The ferrite resonator antenna was fabricated using FR4 as substrate and ferrite pellet as magneto-dielectric resonator material. The antenna characteristics parameters reflection loss S (1,1) and voltage standing wave ratio (VSWR) were measured by vector network analyser (VNA).

6 GHz lamb wave acoustic filters based on A1-mode lithium niobate thin film resonators with checker-shaped electrodes

The first-order antisymmetric (A1) mode lamb wave resonator (LWR) based on Z-cut LiNbO3 thin films has attracted significant attention and is widely believed to be a candidate for next-generation reconfigurable filters with high frequency and large bandwidth (BW). However, it is challenging for traditional interdigitated electrodes (IDTs) based LWR filters to meet the requirement of a clean frequency spectrum response and enough out-of-band (OoB) rejection. To solve the problem, we propose LWRs with checker-shaped IDTs for the design of filters that meet the Wi-Fi 6E standard. By taking advantage of checker-shaped IDTs with unparalleled boundaries, the fabricated 6-GHz resonators successfully suppress higher-order A1 spurious modes, demonstrating a spurious-free impedance response and a high figure-of-merit (FOM) up to 104. Based on the demonstrated checker-shaped electrode design, the filter features a center frequency (f0) of more than 6 GHz, a 3 dB BW exceeding 620 MHz, and an excellent OoB rejection >25 dB, consistent with the acoustic-electric-electromagnetic (EM) multi-physics simulations. Furthermore, through the capacitance-inductance matching network technology, the filter’s voltage standing wave ratio (VSWR) is successfully reduced below 2, showing an excellent 50 Ω impedance matching. This study lays a foundation for ultra-high-frequency and ultra-wideband filters for the Wi-Fi 6/6E application.

A Circular Ring Patch Antenna for Breast Cancer Detection Based on Return Loss and VSWR

Breast cancer is a serious condition that affects women and requires timely identification. Various methods such as magnetic resonance imaging, mammography, digital mammography, and computer-aided detection are used for this purpose. However, these techniques have their drawbacks. To address this issue, a new approach is proposed and detailed in this paper. In this novel method, a circular patch antenna is employed to detect tumors in a breast phantom. The analysis of return loss and voltage standing wave ratio (VSWR) helps in identifying the presence of tumors. High-frequency structure simulator (HFSS) software is employed to design and simulate the antenna for an ultra-wideband (3.1 – 10.6 GHz) frequency of 5.2 GHz, along with a breast phantom with and without a tumor. The antenna is independently simulated on both the breast phantoms with and without tumors. Rogers RT/duroid 5880 (tm) dielectric material is employed to design the antenna, with overall dimensions of 30 × 20 × 0.8 mm3. It possesses a dielectric constant of 2.2, a tangent loss of 0.02, and a thickness of 0.8 mm. The ring slot and partial ground plane techniques are employed to increase the overall effectiveness of the antenna. The properties of the antenna, such as return loss and VSWR, change when simulated with and without a tumor. The presence of a tumor within the breast is clearly indicated by the alterations in return loss and VSWR. The antenna proposed exhibits remarkable efficacy in the detection of tumors owing to its inconspicuous features, straightforward design, petite dimensions, and ideal impedance matching.

Influence of Substrate Materials on the Performance of a Triple-Band Notched Frequency UWB Antenna

In this paper, the influence of different substrate materials on the performance of a triple-band notched frequency of ultra-wide band (UWB) antenna is presented. The antenna has a rectangular shape with dimension 31 by 24 mm and operates at UWB frequency band of 3.1GHz to 10.6GHz. The antenna was simulated using HFSS software. The effect of eight different substrate materials with different dielectric constant was examined on the antenna. Under each substrate, the performance of the antenna was investigated based on the antenna gain, directivity, radiation pattern, voltage standing wave ratio (VSWR), impedance bandwidth and S-parameter. Through thorough analysis, the results gave strong indication that UWB antenna performance is greatly affected by the type of dielectric substrate material chosen for design. The paper demonstrates the effect dielectric substrate material has on the antenna performance measurement like radiation pattern, gain, directivity and VSWR.

Design of Broadband Phased Array Feed Using Stereolithographic Additive Manufacturing Heterogeneous Integrating Technology for Fast Radio Burst Observation

Herein, a stereolithography appearance 3‐D printed phased array feed (PAF) on radio telescopes based on broadband Vivaldi antenna elements covering 4–10 GHz, which meets the requirements of low cost, lightweight, and compact volume, is designed and proposed. The prototype is integrated with two orthogonal linear polarized 4 × 5 arrays, each of which is composed of 20 Vivaldi antenna elements. The distance between adjacent antenna elements is 1/2 λ in both E‐plane and H‐plane. By increasing thickness of the slice elements compared with traditional end‐fire arrays on printed circuit board, the wide‐band impedance matching is realized. The mutual impedance matrix of the dual‐polarization array is calculated and the equivalent circuit of the active and parasitic elements is demonstrated. Due to the orthogonal parasitic elements inserted between the adjacent active antennas, equivalent capacitance is introduced in the tightly coupled array. The measured active voltage standing wave ratio of the manufactured PAF exhibits 4–10 GHz operating bandwidth for both broadside radiation and 45° scan in both E‐ and H‐plane polarization. The proposed wideband PAF has a promising potential application prospect in fast radio burst and other astronomic observation.

A Novel 5G Multi-mode Resonator and Filter with Symmetric Transmission Zeros

5G construction is becoming increasingly important. This paper introduces the theoretical basis of multi-mode filter, and on the basis of theoretical calculation and analysis, a novel 5G cavity multi-mode resonator and filter is designed by using ads/HFSS simulation software. The electric field characteristic of resonator is analyzed, and the mutual coupling between modes is realized by the way of screw perturbation. The electric field distributions of the mode is changed by adding tuning screws, two coupled degenerate modes act as two coupled resonators, so that the numbers of resonator can be reduced while keeping the resonance loop unchanged. For example, the characteristics of 3N section filter can be realized in the physical space of a traditional n-section filter by using three modes of a resonator, thus greatly reducing the volume of the filter. The results show that in the pass-band (3.5 GHz ~ 3.6 GHz): return loss > 17.9 dB, standing wave ratio < 1.29, insertion loss < 0.31 dB, a transmission zero point is introduced at 4 GHz on the right side of the pass-band, which makes the right side out of band attenuation rapidly. The filter has the advantages of small insertion loss, small size and good rejection of out of band, which can be applied to 5G band wireless communication system for better reliability.

Circular Microstrip Patch Antenna : Design, Simulation, and Analysis For 5G Applications

Microstrip Patch Antennas (MPA) have emerged as a remarkable discovery in the period of miniaturization, despite the fact that advancements in antenna engineering have resulted in the fast growth of communication networks. This work encompasses the design, modelling, and analysis of circular microstrip patch antennas. The resonant frequency of the recommended patch antennas is 9 GHz, which is within the X band range. Ansys HFSS software was used to create them using Rogers RT/duroid 5880 material, which has a dielectric constant of 2.2. Five performance measures were utilized to examine the recommended MPAs: return loss, bandwidth, VSWR, gain, and HPBW. The required information refers to the measurements of return loss, voltage standing wave ratio (VSWR), and half power beamwidth (HPBW). The recommended antennas are ideal for use in radar, wireless, and satellite applications.

A wideband flexible antenna utilizing PMMA/PVDF‐HFP/PZT polymer composite film and silver‐based conductive ink for wearable applications

AbstractThe relentless drive towards miniaturization and seamless integration of electronic components in wireless communications and wearable devices has significantly increased the demand for flexible, cost‐effective composites with high dielectric constants and low losses. This study presents a wideband, low‐profile, and flexible antenna with excellent on body radiation performance for wearable applications. The antenna is designed using a low‐loss composite film based on PMMA‐PVDF‐HFP‐PZT and silver‐based ink. The proposed flexible antenna exhibits a wide bandwidth of 132.16% with a voltage standing wave ratio (VSWR) of less than two. It achieves a peak gain of 2.76 dBi at 2.92 GHz and maintains a maximum radiation efficiency of 80% across the 1.26–6.17 GHz frequency range. These characteristics demonstrate that the antenna is an effective solution for achieving high data rates and reliable communication links. The antenna's suitability for wearable applications is assessed by testing it on a simulated human body and analyzing its behavior under physical deformation. The results under bending showed only a minimal frequency detuning, which is negligible given the antenna's wide operational bandwidth. The specific absorption rate (SAR) analysis shows values of approximately 1.88 W/kg at 3.5 GHz with an input power of 0.5 W, and 0.279 W/kg at 5.8 GHz with an input power of 0.45 W, which complies with established safety limits for exposure. Overall, these results suggest that the proposed antenna is a viable solution for integration into wearable medical devices, such as a doctor's chest badge, enabling noncontact interactions and reducing the risk of bacterial contamination.

Design of high flexible multi-band conformal printed patch antenna for sub 6 GHz 5G-based vehicular communication

ABSTRACT Vehicular communications (VCs) play a major role in intelligent transportation systems (ITS). In addition to preventing unintentional collisions and traffic jams, this system can lower fuel and energy usage in the transportation system. The Internet of Vehicles emerges by integrating the IoT with vehicles for smooth communication. In IoV, vehicular communications may be from vehicle to infrastructure (V2I), vehicle to vehicle (V2V), vehicle to pedestrian (V2P), and vehicle to network (V2N) or vehicle to roadside unit (V2R). The antenna used in vehicular communication has some problems, such as less efficiency and high return loss. The frequency response in the existing methods should not give sufficient data for selecting a better band. To avoid this kind of issue and improve the performance by selecting a better frequency band, this work presents a highly flexible multi-band conformal printed patch antenna for sub-6 GHz 5 G-based vehicular communication application. The substrate used to design the antenna is polyimide, and the microstrip patch antenna is designed with cross-shaped slots. The multi-band circularly polarised antenna is designed to operate in vehicular communication bands such as 2.4 GHz, 4.7 GHz, 5.3 GHz, and 5.9 GHz. The proposed work is simulated in HFSS, and the results of directivity, gain, reflection coefficient, Voltage Standing Wave Ratio (VSWR), radiation pattern, axial ratio, Left-Hand Circular Polarisation (LHCP), Right-Hand Circular Polarization (RHCP) and surface current distribution are evaluated for the conformal antenna.

High Broadband Optical Absorption and Bandstop Filter Characteristics of Pb/Nb2O5 Interfaces

AbstractIn this study, semitransparent lead films serve as substrates for depositing niobium pentoxide thin films, forming versatile electro‐optical devices. Using vacuum evaporation and ion sputtering techniques at ≈10−5 mbar, stacked layers of crystalline Pb and amorphous Nb2O5 are created. This process reduces free carrier absorption in Nb2O5 and forms Urbach tail states with a width of 0.91 eV. Pb/Nb2O5 thin films exhibit remarkable broadband absorption, exceeding 440% in the visible and 98% in the infrared. Moreover, Pb substrates induce a redshift in Nb2O5’s energy bandgap. Electrical analysis using impedance spectroscopy on Pb/Nb2O5/Ag structures reveals their series/parallel resonance and bandstop filter properties. Notably, the bandstop filters exhibit reflection coefficient minima at a notch frequency of 1.66 GHz, with a bandwidth of 280 MHz, return loss of 26 dB, and voltage standing wave ratio of 1.13. These findings underscore the device's potential for wide‐ranging electro‐optical applications across the electromagnetic spectrum.

A review on microstrip patch antenna for wireless communication systems at 3.5 GHz

This article presents a review of several microstrip patch antennas for 3.5 GHz wireless applications. Different substrate materials, FR-4 (loss), FR-4 Epoxy, Rogers RT/droid 5880, TLC-30, and Rogers RT/droid 5880 LZ, are used. In recent years, wireless antenna applications have increased, including biomedical appliances, internet of things (IoT) terminals, edge devices, radars, mobile phones, and many more. In this work, several articles were reviewed and investigated, and several microstrip patch antennas with a resonance frequency of 3.5 GHz were designed using different substrate materials and shapes. This article also discussed the geometric shapes of antennas, antenna properties, sizes of substrate materials, loss tangent, thickness, return loss, bandwidth, voltage standing wave ratio (VSWR), gain, efficiency, and directivity. Several software is used for design and simulation, including computer simulation technology (CST), high-frequency simulation frequency (HFSS), and advanced design system (ADS), FEKO, and MATLAB. The main goal of this paper is to talk about different wireless application papers that work in the S-band at a frequency of 3.5 GHz and have been published in various international journals and conferences.

Design of an All-Metal Vivaldi Array Antenna with Dual-Slant Polarization for High-Power Jammer Systems

In this paper, we propose an all-metal Vivaldi array antenna with dual-slant polarization for high-power jammer systems. The single Vivaldi element of the proposed array consists of radiating flares and an inner cavity to achieve high directivity and wide-frequency band impedance-matching characteristics. We expanded the proposed Vivaldi element to a 4 × 4 array antenna with dual-slant polarization considering the occurrence of grating lobes. The fabricated array antenna produced measured active voltage standing wave ratios below 2.74:1 (Port 1) and 2.85:1 (Port 6) in the frequency range of 2.5–5.5 GHz for all steering angles. In addition, the measured array gain is above 9.5 dBi in the frequency range from 2 GHz to 6 GHz. These results confirm that the proposed array antenna consisting of metallic components for high durability is suitable for application to high-power jammers.

Frequency reconfigurable microstrip patch antenna for multiband applications

Wireless communication technology is well-established, and several antennas have been developed and produced specifically for this purpose. However, antenna performance and communication system development need to be enhanced in order to adapt to the present era. The performance of the antenna is significantly influenced by its design. Thus, this work produced a novel wideband antenna design via the use of a frequency reconfigurable approach. In the recommended study, microstrip patch antennas (MPAs) were used in wideband applications to switch frequencies using shunt-series microelectromechanical systems (MEMS). The suggested antenna, which has two switches built into it, is tested in ON-ON, OFF-ON, and OFF-OFF switching scenarios. Radiation pattern, voltage standing wave ratio (VSWR), gain, bandwidth, and return loss are among the antenna performance metrics used to assess the suggested antenna's performance in each switching situation. The simulation findings suggest that the optimal antenna design for usage in wireless communication systems is one that works well with a shunt-series MEMS switch.

IMPLEMENTATION OF MAGNETRON SPUTTERING METHOD IN OBTAINING A RADIO-ABSORBING THIN FILM BASED ON CoC

This paper describes the main results of the study of obtaining samples of radio-absorbing CoC films by magnetron sputtering and evaluates the data of experimental and computational studies on the relationship between the structure and properties of CoC films. To eliminate the ferromagnetic effect of cobalt, a composite target was used. The use of the composite target during magnetron sputtering ensures the production of films of a given and necessary composition. Structural-phase state of the obtained films was studied using XRD, SEM and TEM methods. A distinctive feature of the synthesized coating is the absence of a crystalline structure in some areas due to the amorphizing properties of cobalt and its tendency to form metallic glasses. Results obtained by the experiments are in good agreement with computational modeling results. The radio-absorbing properties of the obtained films were confirmed by the results of measuring the reflection loss, standing wave ratio, reflectance, and impedance. Results presented in the article can serve as a baseline for perspective studies in this field.

Development of nano ferrite coated miniaturised jute antenna for wireless applications

In this work, a microstrip patch antenna is designed using a novel Ytterbium doped Cu-Mn Nano ferrite coated jute substrate for S band (2-4 GHz) applications. The prepared material is characterised by structural and electromagnetic properties to examine and analyse the effect of material factors on antenna substrate suitability. The antenna is designed and simulated using Computer Simulation Technology (CST) software. The antenna parameters such as gain are improved by employing super formula and meander line techniques. The fabricated antenna also shows better performance with return loss, Voltage Standing Wave Ratio (VSWR) and gain values.

Design and Analysis of a Dual-Band Microstrip Patch Antenna for Sub-6 GHz Applications

This paper explores the design, simulation, and analysis of a dual-band Microstrip patch antenna designed to operate efficiently at frequency ranges of 3.32 GHz - 3.62 GHz and 4.72 GHz - 6.83 GHz, utilizing Ansys High-Frequency Structure Simulator (HFSS) software. The primary objective is to enhance performance metrics such as bandwidth, gain, and radiation efficiency to meet the requirements of applications necessitating concurrent operation at both frequency bands. The study involves a comprehensive design, iterative simulation, and detailed analysis using Ansys HFSS, with customized design considerations aimed at optimizing performance for modern wireless communication systems. The research was conducted in a simulated environment over a period that included iterative design processes, multiple simulation runs, and thorough analysis phases. Methodologically, the study focused on iterative design refinement to improve key performance parameters such as reflection coefficient, gain, radiation efficiency, Voltage Standing Wave Ratio (VSWR), and relative permittivity at the specified frequency bands. Results indicate that at 3.32 GHz - 3.62 GHz, the antenna achieves a reflection coefficient of -5 dB, a gain of 2.77 dB, a radiation efficiency of 0.7429, and a VSWR of 1.9299. At the higher frequency range of 4.72 GHz - 6.83 GHz, the antenna exhibits a reflection coefficient of -20.5213 dB, a gain of 3.34 dB, a radiation efficiency of 0.7, and a VSWR of 1.2203. These findings underscore the antenna's capability to deliver improved performance metrics across both frequency bands. In conclusion, the dual-band Microstrip patch antenna designed and analyzed through Ansys HFSS demonstrates significant potential for use in contemporary wireless communication systems, offering enhanced bandwidth, gain, and radiation efficiency suitable for multi-frequency applications.