Resonant Frequency Of Antenna Research Articles

Electro-Geometrical Analysis of Transversal V-Fold Patch Antenna

This paper investigates an original concept of electro-geometrical analysis of flexible microstrip antenna. The research work is focused on the analysis of the innovative effect of “V”- shape folding on the resonance frequency and input impedance of microstrip patch antenna. The V-folded antenna is assumed to behave as an arm constituted by horizontal and tilted members which are geometrically characterized by the folding angle, a. The folding is characterized by the angle between the horizontal plane and the folded part of the patch antenna printed on a Kapton flexible substrate. The initially flat-configured planar antenna was designed to operate at about 2.45 GHz. The innovative design method of the V-shape folded flexible antenna is explained. Full wave electromagnetic simulations of different geometrical states of the flexible antenna were performed in the frequency range from 1 GHz to 5 GHz. Exceptional results of tilted surface radiating part of flexible patch antenna were found with a positive folding angle from amin=0° to amax=45°. It was understood for the first time in the area of antenna engineering that the resonance frequency is fluctuating according to typical sine damping in the function of the V-folding angle variation. The folded angle effect, which has never been understood before is discussed. In addition to the angle effect, the input resistance and input reactance of the V-folded flexible patch antenna is also plotted.

Analysis and synthesis of L- and T-shaped flexible compact microstrip antennas using regression-based machine learning approaches

Abstract The purpose of this study was to analyze and synthesize L-shaped compact microstrip antennas (LCMA) and T-shaped compact microstrip antennas using regression-based machine learning algorithms (TCMA). This was accomplished by simulating 3808 LCMAs and 900 TCMAs operating at UHF and SHF frequencies with different physical and electrical characteristics. The acquired data was utilized to create a data set containing the antennas’ physical and electrical characteristics, as well as their resonant frequencies in the TM010 mode. Four baseline regression models and seven machine learning models were developed to determine the resonance frequency of antennas and the values of the physical parameters required for a particular frequency. To examine the efficacy of machine learning models, three-dimensional LCMAs and TCMAs were created using polylactic acid (PLA) and felt-based flexible substrates, as well as copper tape. The results illustrate the feasibility of using machine learning models for LCMA and TCMA analysis and synthesis.

A Miniaturized Triple-Band Antenna Based on Square Split Ring for IoT Applications

This article presents a miniaturized triple-band antenna for Internet of Things (IoT) applications. The miniaturization is achieved by using a split square ring resonator and half ring resonator. The antenna is fabricated on an FR4 substrate with dimensions of (33 × 22 × 1.6) mm3. The proposed antenna resonates at the frequencies 2.4 GHz, 3.7 GHz, and 5.8 GHz for WLAN and WiMax applications. The obtained −10 dB bandwidth for the three bands of the proposed antenna are 300 MHz, 360 MHz, and 900 MHz, respectively. The measured reflection coefficient values of the proposed antenna corresponding to each resonant frequency are equal to −14.772 dB, −20.971 dB, and −28.1755 dB, respectively. The measured gain values are 1.43 dBi, 0.89 dBi, and 1 dBi, respectively, at each resonant frequency. There is a good agreement between the measured and simulated results, and both show an omnidirectional radiation pattern at each of the antenna resonant frequencies that is suitable for IoT portable devices.

Design and Simulation of Miniaturization of Triangular Shape Dielectric Resonator Antenna Using AMC Surface for 5G Applications

A Dielectric Resonator Antenna (DRA) is a radio antenna. It is built up of ceramic material into blocks of various forms and is generally suitable at frequencies larger than 1 GHz (microwave frequencies and higher than microwave frequencies). Using this Dielectric Resonator Antenna, the operating frequency is achieved at 4.8GHz for 5G applications like IOT (Internet of Things), AI (Artificial Intelligence). Here, artificial magnetic conductor (AMC) surface is used to miniaturize a triangular shaped Dielectric Resonator Antenna (DRA). There are nine tiny copper patches forms the Artificial Magnetic Conductor (AMC) surface having gap of 1.5mm between the patches. AMC is installed on FR4 substrate which has dielectric constant as 4.4. On the AMC surface, a Dielectric Resonator (DR) of dielectric constant 2.2 is placed. The surface of the Artificial Magnetic Conductor is shorted with ground metal using tiny metallic vias. Antenna characteristics such as antenna gain, resonant frequency, and efficiency will not be affected due to the usage of Dielectric Resonator. As a result, the overall volume of DRA is significantly diminishing. There are three primary aspects in this design: (a) Impedance matching using a Parasitic Metallic Strip (b) Design miniaturisation with an AMC surface (c) Simple microstrip line Feeding. Overall volume of Dielectric Resonator Antenna size reduced by 85%. In addition, when compared to the original Dielectric Resonator Antenna without the surface of Artificial Magnetic Conductor, the ground surface is lowered by 15.5 percent.

Space Diverse and Frequency MIMO Antenna with Defected Ground Structure

A four-port DGS (defective ground structure) MIMO antenna is the subject of an inquiry. The proposed design in this study operates at a range of frequencies (1.8 GHz NB-IoT band, 2.4 GHz ISM band, 3.1 GHz sub 6 GHz, Wi-Max, and 4.8 GHz 5G connectivity band). The antenna is driven by an excited microstrip transmission line. All ports of the recommended MIMO antenna are isolated by less than -15dB, and its tiny (20 cm by 15 cm) footprint. It also takes into account radiation characteristics including s-parameters, radiation pattern, directivity, gain, return loss, and bandwidth. Measurements of MIMO performance such the Envelop correlation coefficient (ECC), diversity gain (DG), total active reflection coefficient (TARC), and mean effective gain (MEG) are also employed to ensure proper diversity performance. Utilizing CST Microwave Studio, the proposed antenna is examined. The resonant frequencies of antennas 1, 2, 3, and 4 are 1.8 GHz, 2.4 GHz, 3.1 GHz, and 4.8 GHz, respectively. The greatest gain it provides is 9.15dB. There is 20 dB isolation between ports.

An off-center fed patch antenna with overlapping sub-patch for simultaneous crack and temperature sensing

This paper presents an off-center fed patch antenna for simultaneous crack and temperature sensing. The antenna sensor consists of an off-center fed underlying patch and an overlapping sub-patch. The bottom copper sheet of the sub-patch is tightly attached to the underlying radiation patch allowing the electric current to flow through the integrated patch. The off-center feeding can activate the resonant modes in both transverse and longitudinal directions. The transverse resonant frequencies of the combined patch are utilized for temperature sensing. Therefore, the crack width sensed by the longitudinal frequency shift can be adjusted, eliminating the temperature effect. In addition, this unstressed structure of the combined patch can avoid the issues of incomplete strain transfer ratio and the insufficient bonding strength of a monolithic antenna. The authors developed theoretical relationships between the antenna resonant frequencies, the temperature, and the crack width. They also developed simulations of the off-center fed patch antenna sensor as well as a series of experimental tests to demonstrate the feasibility of the proposed sensor for simultaneous crack and temperature sensing.

Feasibility study of patch antenna for monitoring moisture content of made tea

This study aims to analyze the patch antenna for moisture content measurement of made tea. The patch antenna-based system uses an air gap between the ground plane and an electrically conductive patch. The tea sample is contained in the air gap. The patch antenna design has a resonance frequency of 5 GHz. The resonance frequency and S11 parameters are measured for tea samples in the moisture range of 2–10%. The resonance frequency of the patch antenna was observed to decrease with an increase in the moisture content of tea. However, the return loss of patch antenna was observed to increase with an increase in the moisture content of made tea. Linear model parameters were calculated for the prediction of the moisture content of tea leaves.

Design and Optimization of Miniaturized Microstrip Patch Antennas Using a Genetic Algorithm

The main objective of this work is to propose an approach for improving the performance of miniaturized microstrip patch antennas (MPAs) that are loaded with a thin film consisting of a high relative permittivity material. The method uses a thin film to decrease the antenna’s resonance frequency while keeping the antenna’s patch dimensions. For the enhancement of the antenna’s performance with a thin film, the dimensions of the patch of the designed antenna are optimized utilizing genetic algorithms (GAs). The resonance frequency of the microstrip patch antenna was changed from 5.8 GHz to 4.0 GHz, and the area of the proposed antenna was minimized by around 60%, especially in comparison to a conventional antenna alone without thin film. Most of the performances of the proposed antenna such as the return loss, bandwidth, and voltage standing wave ratio (VSWR) were improved.

Model for Estimating Time-Varying Properties of an Inductively Coupled Plasma

A developing application of inductively coupled plasmas is in the field of electrodeless (propellant-flexible) electric propulsion. A significant issue facing this application is the need for diagnostic techniques that do not disturb the plasma (are nonintrusive), are propellant-agnostic, can resolve time variance, and are suitable for use in-flight. A new technique meeting these criteria is presented in this work. The technique makes use of the transformer model of inductive coupling to estimate the plasma impedance from the antenna current and resonant frequency, both of which can be measured nonintrusively. Having an estimate of the plasma impedance, it is possible to estimate a variety of plasma properties under the assumption of a uniform tubular plasma volume. Starting with a circuit representation of a high-power inductive plasma source, governing equations are derived and a solution method is described. Experimental data from the plasma source showing transient behavior (fluctuations within 300-Hz cycle) in oxygen plasmas with various input powers and flow rates are analyzed to demonstrate the technique and investigate trends. The technique produces results that are self-consistent and align well with previous theoretical work.

Generalized formulation for resonance frequency of even polygonal microstrip antennas

ABSTRACT A generalized expression has been derived for resonance frequency of polygonal microstrip antennas with even number of edges using modified magnetic wall method. Nature of polygonal resonators is analyzed with their equivalence to corresponding circumcircle resonators. Magnetic wall has been transformed into a dynamic function of vertex angle of polygons. The transformed magnetic wall includes the effect of non-uniform fringing around vertices and edges. A scheme to achieve the complete response of circular antennas from square and other polygonal antennas has also been presented. The proposed general expression accurately gives resonance frequency of even polygonal antennas at the fundamental frequency as well as higher harmonics. The proposed expression and theory agree with simulation and measured results of different polygonal antennas.

Data Processing Mechanism and Algorithm Optimization for Radiated Emission Measurement of Electronic and Electrical Equipment

Radiated emission is one of the most important measurement items in the field of electromagnetic compatibility. The measured value of field strength often deviates from the real value to a certain extent. According to the characteristics of typical log-periodic dipole array antenna, the relation between antenna resonance unit and frequency, as well as the position relation between phase center and calibration reference point, the calculation formula of field strength correction factor is derived. The correction factor of field strength in the 30MHz-1GHz is also calculated precisely. The data processing mechanism of radiated emission measurement is clarified. An optimization algorithm for the measurement of radiated emission is obtained eventually. After the test value is optimized by the correction factor, more accurate field strength can be obtained. The optimization interval is within (-0.348, 2.741) dB. As a data processing mechanism of the radiated disturbance, it can not only improve the accuracy of measurement, but also reduce the uncertainty and error.

Pentagonal-shaped slot two port MIMO antenna for sub 6 GHz 5G wireless applications

In this paper, two-element multiple-input-multiple-output (MIMO) antenna system is presented for future sub-6 GHz 5G applications with improved impedance matching and isolation. In first design, a single rectangular patch antenna of 16.76 mm × 14 mm with pentagonal shaped slot and defected ground structure is proposed with a gain of 2.79 dB for WLAN (5.2 GHz) application. Second design consist of two elements MIMO patch antenna of dimension 16.76 mm × 47 mm × 1.6 mm on front side and defected ground structure on the back side of a FR4 substrate. The resonance frequency of antenna is 5.2 GHz with S11 = S22 = −26.47 db and good isolation between two ports and gain is 6.83db. Simulation has been performed on CST studio suite.

Detection of MDMA using Rectangular Microstrip Patch Antenna

Objective: This study is to design and analyze a rectangular microstrip patch antenna (MPA) for detecting 3,4-Methylenedioxy methamphetamine (MDMA) in the human body. The antenna's performance characteristics including resonant frequency, return loss, gain, VSWR, and radiation pattern are investigated to assess its suitability for drug detection applications. Methods: The rectangular microstrip patch antenna (MPA) is designed using electromagnetic simulation software. The antenna is optimized to resonate at a frequency sensitive to the presence of MDMA. The simulation results are analyzed to determine the resonant frequency, return loss, gain, VSWR, and radiation pattern of the antenna. The antenna's performance is evaluated under various conditions to assess its effectiveness for MDMA detection. Results: The proposed rectangular microstrip patch antenna (MPA) exhibits a resonant frequency of 1.3918 THz with a return loss of 41.136 dB and a VSWR of 1.0177034. The antenna achieves a gain of 7.993 dBi and demonstrates a radiation pattern suitable for MDMA detection. These results indicate that the designed antenna is promising for detecting MDMA in the human body due to its specific resonant characteristics and performance metrics. Conclusion: The designed rectangular microstrip patch antenna (MPA) shows potential for detecting 3,4-Methylenedioxy methamphetamine (MDMA) based on its resonant frequency, return loss, gain, VSWR, and radiation pattern. The antenna's resonant frequency aligns with the presence of MDMA, making it suitable for sensing applications aimed at drug detection in biological environments. Further experimental validation is recommended to verify its performance in real-world scenarios.

Miniaturization of S-band circularly polarized microstrip antenna

A S-band miniaturized circularly polarized microstrip antenna is designed and fabricated. The curved current technique is utilized, and the effective path length of current is increased by loading the U-shaped slot on the radiating patch. Thus the antenna resonant frequency can be tuned and the antenna can be significantly miniaturized. The experimental samples of the antenna are fabricated and tested. The measured results show that the two resonant frequencies of the miniaturized S-band circularly polarized microstrip antenna are 2.17GHz and 2.25GHz, with an impedance bandwidth (S11 <−10 dB) of 152 MHz (from 2.132 GHz to 2.284 GHz). The measured gain is about 0dB. The measured results are basically consistent with the simulation results.

Tunable Filtenna With DGS Loaded Resonators for a Cognitive Radio System Based on an SDR Transceiver

This paper introduces the design of a filtenna for cognitive radio systems. Four varactor diodes, which are inserted in the bandpass filter, are used to achieve the desired tunability. The proposed bandpass filter is integrated with a wideband monopole antenna. The bandpass filter is achieved by using two coupled defected ground structure (DGS) resonators and two coupled microstrip lines ended with two stubs. The monopole antenna is designed to operate in a frequency band from 1.3 GHz to 3 GHz. The four varactor diodes are used to tune the antenna resonance frequency from 2.7 GHz to 2 GHz when the capacitance increases from 1.55 pF to 2.67 pF. The performance of the proposed filtenna is validated by simulation and measurements from a fabricated prototype. Finally, the proposed filtenna is tested using the Software Defined Radio (SDR) platform bladeRF. This transceiver can transmit and receive in a wide frequency range of 0.3 GHz up to 3.8 GHz, which makes it suitable for testing the proposed reconfigurable filtenna.

Regression analysis‐based identification model of key impactful parameters on buried antennas

SummaryThe antenna's bandwidth is strongly dependent on its physical properties and the environment where it is located. Nevertheless, for transmitting devices embedded permanently in the soil, the propagation medium's properties are unstable due to dielectric permittivity's spatial and temporal changes. Relying on soil parameters values, we present three new multivariable regression models allowing a good fit to the dataset curves with antenna's resonant frequency variations prediction of about 98%. Precisely, such models have been obtained with the help of the multiple linear regression analysis method. Additionally, the results revealed that amongst four considered parameters (i.e., volumetric moisture, bulk density, specific density, and temperature), volumetric moisture is the most influencing factor on the antenna operating frequency band with a correlation coefficient of −0.989, whereas it equals 0.04, −0.035, and −0.002 for the temperature, bulk density, and specific density, respectively.

A miniaturized quasi‐Yagi antenna using defected ground structure and double dog‐bone driver

AbstractA miniaturized quasi‐Yagi antenna is presented using a defected ground structure and double dog‐bone driver. The antenna has a simplified feeding structure. With the help of the dog‐bone driver and slotted ground structure antenna's resonance frequency is lowered. Thus, the miniaturization is achieved. Additional angled dog‐bone driver and circular patches in the ground improve impedance matching and bandwidth characteristics. The overall size of the proposed miniaturized quasi‐Yagi antenna is , where is the wavelength at the lowest operating frequency( dB). The antenna achieves dB between and GHz in the simulation, and GHz in the measurement. The antenna has a gain of 3.8–5.4 dBi, over total efficiency, and stable end‐fire radiation characteristics in the frequency range of operation. The proposed antenna is a good candidate for compact portable wireless communication systems.

Comments on “Analysis of Bent Wire Antenna Resonant Frequency for Different Bent Angles”

AbstractThe recent article by Suganya et al. is incomplete and, in some places, unclear, which has resulted in misleading and incorrect conclusions on the performance of their bent wire dipole antenna. These comments serve to address the shortcomings of their paper.

Design and Realization of an UHF Frequency Reconfigurable Antenna for Hybrid Connectivity LPWAN and LEO Satellite Networks.

UHF satellite communication for Internet of Things (IoT) technology is rapidly emerging in monitoring applications as it offers the possibility of lower-costs and global coverage. At the present time, Low Power Wide Area Network (LPWAN) solutions offer low power consumption, but still suffer from white zones. In this paper, the authors propose an UHF frequency reconfigurable Antenna for hybrid connectivity LoRaWAN (at 868 MHz) and UHF satellite communication (Tx at 401 MHz and Rx at 466 MHz) with the Low Earth Orbit (LEO) Kineis constellation. The antenna is based on a meandered line structure loaded with lumped components and a PIN diode to control the antenna resonant frequencies. It resonates at 401 and 868 MHz when the PIN diode is forward-biased (ON state) and 466 MHz in reverse-biased configuration (OFF state). The antenna is designed inside the enclosure with the presence of all the parts of the connected device. The results of EM simulations and parametric studies on the values of the lumped components and the PIN diode equivalent model, which are obtained with HFSS, are presented. The antenna is prototyped and has dimensions of 78 mm × 88 mm × 1.6 mm. The paper proposes a fast and practical method to reduce time development and compensate the frequency shift between measurement and simulation.

Asymmetric coplanar strip‐fed electrically small reconfigurable 5G mid‐band antenna

SummaryThis work aims to provide an electrically small reconfigurable antenna with modification in the radiating strip length to switch between 5G mid‐band and 4G band‐40 application. Initially, the length of the radiating strip is designed to operate at 3.5 GHz for 5G mid‐band applications. Using switch configuration, the length of the radiating strip is modified so that the antenna's resonant frequency shifts from 3.5 GHz to 2.32 GHz, which can be operated at 4G band‐40. The effective radiation remains the same at two resonant modes. In terms of size, the proposed antenna geometry is (16.5 × 10.5 × 1.6) mm3. The designed antenna with an electrical length of 0.7014 mm is electrically small in size in comparison with the works of literature. Antenna structure provides a gain of 0.69 dBi and 1.35 dBi at resonant frequencies 2.32 GHz and 3.5 GHz, respectively. The geometry of the antenna is straightforward, and the prototype is fabricated on a low‐profile FR4 substrate. The simulated results are validated experimentally.