Kind Of Antenna Research Articles

Q Factor-Based Electrically Small Antenna Radiation Efficiency Measurement Using the Wheeler Cap

In this letter, a small antenna radiation efficiency measurement method is presented. The method utilizes the antenna quality factor, where it is a modification of the original Q factor method, amended by the loss Q factor of the antenna instead of the radiation Q factor. The method is verified for two kinds of antennas: the first is designed to operate at 868 MHz having a series resonance input impedance, and a second at 433 MHz having a parallel resonance input impedance. The method shows very high accuracy and prevent errors that may occur when using the conventional Wheeler cap method if the stored energy is not treated explicitly, which is considering the same imaginary part of the input impedance or input admittance for series resonance or parallel resonance, respectively.

Design and Implementation of Microstrip Array Antenna 2x4 Circular Patch with Defected Ground Structure Dumbbell Hexagonal Head 2.4 GHz Frequency for Wi-Fi Application

Wireless technology is a wireless communication technology that is currently widely used by the public to exchange information. The current information exchange is growing as communication requirements rise. The antenna design needs to be improved in order to boost bandwidth. Microstrip antennas are one kind of antenna that can be used for wireless communication. Meanwhile, to improve the bandwidth value of the antenna can be done using the Defected ground structure or DGS technique. The results of testing the microstrip array circular patch antenna with DGS at 2462 MHz frequency show that it has a maximum gain of 15.7 dBi at a frequency of 2530 MHz and a return loss value of -19.3 dB with a VSWR value of 1,242. There is a type of directional radiation pattern in the antenna of the Microstrip Array with DGS. This study's findings indicate that the Circular Array Microstrip antenna with DGS has a bandwidth of 73 MHz while the Circular Microstrip Array without DGS has a lesser bandwidth of 28 MHz.

Characterization parameters for antennas generating orbital angular momentum waves

As one of the pivotal candidate technologies of 6G, orbital angular momentum (OAM) carrying radio waves have attracted much attention in wireless communication and sensing technology fields owing to the particular twisted phase fronts. Various kinds of antennas have been proposed to generate this kind of wave; however, the antenna performance has not been well analyzed in terms of the OAM carrying wave’s characteristics. In this paper, some dedicated characterization parameters termed as conjugated receiving pattern, purity related bandwidth, and mode phase linearity based on well-known properties of OAM carrying electromagnetic waves are proposed for the first time. These parameters can be used to characterize the performance of OAM antennas. As an example, the performance of a fabricated helical OAM antenna with a wide bandwidth is characterized by the proposed parameters, which proves the reasonableness and necessity of the proposed characterization parameters.

Directivity Analysis for Dual-Band Monopole Antenna for RFID Applications

Design of radio-frequency identification tag with proper signal receiving and transmitting capability is now a challenging task. For that many kinds of antennas are proposed. This paper provides one such kind of design, incorporating the design of monopole antenna and micro-strip antenna. The operating frequency ranges are designed for 2.2–2.6 GHz and 5.3–6.8 GHz, which is suitable for RFID operation bands. Monopole antenna is fabricated in ‘F’ shape. FR-4 dielectric material has been used with 38 x 45 x 1.6 mm3 size. Return loss, VSWR, directivity and gain parameters are analysed using ANSYS HFSS software. The structure of ‘F’ pattern makes the antenna suitable for RFID applications.

Hybrid TM/TE Cylindrical Leaky Waves: Electromagnetic Radiation at Broadside From Radially Periodic Structures

The nature of broadside radiation from planar, radially periodic structures excited at the center is investigated in this article by considering an annular microstrip antenna operating in the microwave range. This kind of antenna, capable of radiating either a scanned conical pattern or a broadside pencil beam, is typically designed by enforcing that its linearized version supports a single TM leaky mode. However, a single TM cylindrical leaky wave is known to be incapable of radiating a directive broadside beam. To solve the conundrum, a generalized pencil-of-function analysis of the exciting field is performed. It is found that a nonnegligible TE component is present, which exhibits a radial decay different from the TM component but the same complex radial wavenumber. Based on the geometrical symmetries of the structure, an electromagnetic model for the surface currents excited on the annular microstrips is developed and validated by full-wave results for both the currents and the associated radiation patterns. The generality of the adopted approach sheds new light on the nature of the electromagnetic field radiated at broadside by the general class of annular, radially periodic structures, including novel terahertz antennas and plasmonic structures used for achieving extraordinary transmission at optical frequencies.

A compact and miniaturized implantable antenna for ISM band in wireless cardiac pacemaker system

A tiny and compact implantable antenna for wireless cardiac pacemaker systems is designed. The antenna works in the Industrial Scientific Medical (ISM) frequency band (2.4–2.48 GHz). The size of the antenna is greatly reduced with the adoption of a high dielectric constant medium and a folded meander structure. The volume of the antenna is 4.5 mm3, and the size is only 3 mm × 3 mm × 0.5 mm. Based on the literature research, it was found that the design was the smallest among the same type of implanted antenna. The antenna is optimized and loaded with a defective slotted structure, which improves the efficiency of the overall performance of the antenna and thus the gain thereof. The antenna maintains good impedance matching in the ISM frequency band, covering the entire ISM frequency band. The actual bandwidth of the antenna is 22%, with the peak gain of − 24.9 dBi. The antenna is processed and manufactured in such a manner that the simulation keeps consistent with the actual measurement. In addition, the specific absorption rate of the antenna is also evaluated and analyzed. The result shows that this kind of antenna is the best choice to realize the wireless biological telemetry communication in the extremely compact space of the wireless cardiac pacemaker system.

Wave Height and Wave Period Measurements Using Small-Aperture HF Radar

A small-aperture receiving array occupying a small area provides convenience for the layout of HF radars. However, this kind of antennas has a wide beam, which adversely affects wave measurements. To solve this problem, a method for extracting wave parameters from wide-beam radar echoes, that models current variations across the beam, is proposed in this article. The nondirectional wave spectrum is extracted from the echoes of a small-aperture HF radar and wave parameters such as the significant wave height, the peak and mean wave period are then calculated from it. Simulation is carried out to assess the performance of the method for different current velocities, radar frequencies and wind conditions. The proposed method is then applied to a 9-day data set collected by an MHF-C radar for further validation via comparisons between the radar-estimated and the buoy-measured wave parameters. Some factors that may affect the performance of wave height measurements are analyzed, such as the signal-to-noise ratio and radial current velocity. The correlation coefficient (CC) between the radar-estimated and the buoy-measured significant wave height is 0.90, and the root mean square difference (RMSD) is 0.51 m. For the mean wave period, the CC is 0.61 and the RMSD is 0.67 s. The results demonstrate that the significant wave height and the mean wave period extracted by the proposed method are consistent with the buoy-measured values and the proposed method can overcome the broadening influence of the Doppler spectrum caused by ocean currents.

Energy Harvesting of Ambient E.M Waves by Employing Different Types of R.F. Antenna

Used to operate small electronic devices, such as the cell phones. This work will deal with the electromagnetic signals as a renewable energy sources. An analog circuit will prepare using diodes and a charged capacitance and antenna to convert the energy of ambient E.M. waves (Radio Frequencies RF) to a D.C. voltage. The measurements will be demonstrated using different kinds of antenna. In addition, the ambient RF frequency according to Iraq/Babylon/Hilla city will be collected from the communications tower and measured using a receiver circuit.in this paper used three kinds of antenna, wire antenna, air antenna, dish antenna, Measuring the DC Power. the amount of the DC Power that obtained using a dish antenna is approximate the energy that collected using an air antenna. The amount of the DC. Power could be controlled by the charging time (RC) of the capacities.

Design and Study of a Wide-Band Printed Circuit Board Near-Field Probe

Magnetic near-field probes (NFP) represent a suitable tool to measure the magnetic field level from a small electromagnetic interference (EMI) source. This kind of antenna is useful as a magnetic field probe for pre-compliance EMC measurements or debugging tasks since the user can scan a printed circuit board (PCB) looking for locations with strong magnetic fields. When a strong H-field point is found, the designer should check the PCB layout and components placement in that area to detect if this could result in an EMI source. This contribution focuses on analyzing the performance of an easy to build and low-cost H-field NFP designed and manufactured using a standard PCB stack-up. Thereby, the frequency range and sensitivity of the NFP-PCB are analyzed through a Finite Element Method (FEM) simulation model that makes it possible to evaluate its sensibility and effective frequency range. The numerical results obtained with the FEM models are validated against measurements to verify the design and performance of our NFP. The FEM model reproduces the experimental procedure, which is used to evaluate the performance of the NFP in terms of sensitivity by means of the simulated near-field distribution. The NFP-PCB has almost a flat response from 180 MHz to 6 GHz, with an almost perfect concordance between numerical and experimental S21 results. The numerical results show an average transmission loss of −27.9 dB by considering the flat response bandwidth, whereas the experimental one is −29.7 dB. Finally, the designed NFP is compared to two high-quality commercial probes in order to analyze its performance.

Micro-nanoscale Loop-shaped Mircowave Antenna for Exciting Spin Waves on Magnetic Materials

In this paper, loop-shaped microwave antenna in the scale of micro- and nanometer loop-shapedis designed to excite and detect spin waves. We consider that spin waves propagate in the yttrium iron garnet (YIG) films grown on gadolinium gallium garnet (GGG) substrate with lowest damping. Loop-shaped microwave antenna is made of loop-shaped gold, which is used to excite the Co disks grown on YIG film and spin waves propagating in YIG film. Firstly, the high-frequency structure simulator (HFSS) is used to simulate the current, magnetic field distributon and input resistance of the loop-shaped antenna. In addition, the k distribution of the antenna is obtained by using the fast Fourier transform (FFT). The influence of different matching degrees of the antenna on k distribution is analyzed. The kind of antenna can be used to produce different modes of spin waves.

Roger 3450 Vs RF4 Martials - Based Frequency And Pattern Reconfigurable Rectangular Patch Slot Antennas For RFID Applications

Rectangular Patch Slot Antennas RPSA are getting becoming more likable and popular for practice in wireless implementations such as RFID applications especially in the UHF band thanks to its low-profile structure. This kind of antenna is able to deliver large communication distances but this antenna coverage is very weak which is part of the main drawbacks of these antennas. In this paper, Rectangular Patch Slot Antenna RPSA with different slots has been designed and simulated to be suitable for RFID applications. Circular polarized CP antenna that has been designed to use feed structure with vertical ground encircling a radiating component. The feeding method to feed this antenna is coaxial probe. The paper will concentration on both substrate materials Roger 4350 and FR4 Glass-Epoxy material to model and simulate the designs. The other factor of the design is the patch antenna will cut at the four truncated corners to enhance the antenna gain which will affect considerably the operating frequency. This paper aims to show and find the best feed point area that has an exceptional antenna return loss (S11) and high gain. S11 describe the power reflected from the antenna, which is known as the reflection coefficient S11 must be ≤ -10dB. The design and simulation results of RPSA has been done by high frequency simulation system (HFSS 13.0).

Planar Annular Leaky-Wave Antenna Array With Conical Beam

In this article, a novel planar annular leaky-wave antenna (LWA) based on substrate integrated waveguide (SIW) for generating conical beam is proposed, which exhibits properties of beam angle designable in the elevation plane, low profile, and small size. It contains two layers, i.e., radiating layer and feeding layer. Propagation properties of wave in the radiating layer are analyzed, which provide theoretical basis for design procedure. In the feeding layer, a coupled feeding network is utilized for improving impedance bandwidth. Three types of the proposed LWA with different sizes are fabricated and measured to validate the design. The measurement results agree well with the simulation results. This kind of antenna can be a suitable candidate for mobile communication.

Comparative Analysis of Directional Antenna of 2-Meter Amateur Band for Ham Radio Applications

VHF Directional Antenna is not easily found in the Philippine market. Supplies of this kind of antenna are expensive that can only be purchased directly from the manufacturers. Ham Radio operators usually build, modify, and perform experimentation on the directional antenna to achieve higher dB gain for DXing activities. In this study, we use the 3- effective directional antenna for comparability analysis. Its performance is needed in long-range communication of 2-meter amateur band application. The 4NEC2 software was used to simulate the radiating pattern and other properties of each directional antenna. Simulation of the antenna with 3, 7, and 13 elements resulted in substantial proof, describing the better usage of the loop feed-in directional antenna system. It would result in a higher dB gain with longer antenna boom length. However, the MOX-GI design is comparable to a Yagi-Uda directional antenna in both boom length, and dB gain. MOX-GI antenna exhibits good impedance and lowers SWR reading which is desirable for easy home brewing directional antenna.

A Conformal antenna with Proper Shape and Good Electrical Properties

A conformal antenna based on Teflon with proper shape to get more space is presented. It is accomplished by using three-dimensional simulation design software HFSS to achieve the best method. A special kind of Teflon has been chosen to meet the requirement for light weight and ease of installation. A series of antennas is designed and optimized and the best result shows that the conformal antenna could achieve 80% relative impedance bandwidth and peak gain>3dBi at 4GHz. The far-field patterns of antenna are also analyzed and have an acceptable performance. All the results show that this kind of antenna can work well for engineering applications with high cost.

Eight-Port Metamaterial Loaded UWB-MIMO Antenna System for 3D System-in-Package Applications

In this article, an eight-element ultra-wideband (UWB) Multiple-Input-Multiple Output (MIMO) antenna system is proposed for 3D non-planar applications. The proposed UWB-MIMO antenna is installed around a polystyrene block in the 3D-octagonal arrangement. The eight radiating elements are placed on the sides of the octagonal polystyrene block with top and bottom surfaces left open. The single antenna element consists of a modified Y-shaped radiating patch, epsilon-negative (ENG) metamaterial, and a partial ground plane. A modified pie-shaped decoupling structure is deployed at the back-side of the radiating patch to improve the isolation among array elements. Each antenna element is printed on a low-cost FR-4 substrate with dimensions of 28 mm $\times23$ mm with coverage of the whole UWB spectrum from 3.1 to 10.6 GHz frequency band. The eight-port UWB-MIMO antenna system consists of symmetric and non-symmetric array configurations. Simulated and measured MIMO performance parameters i.e. Channel Capacity Loss (CCL) < 0.35, Envelope Correlation Coefficient (ECC) < 0.0025 and Total Active Reflection Coefficient (TARC) < −11 dB are in acceptable limits for both symmetric and non-symmetric configurations. The proposed MIMO antenna system is suitable for 3D system-in-package, indoor localization systems, and wireless personal area network applications in industries where multiple machines are connected to a central server wirelessly through such kinds of antennas in a rich scattering environment.

Compact MMW-band Planar Diffraction Type Antennas for Various Applications

The principles of formation of antennas of diffraction radiation with flat surface in the millimeter wave radio band are considered. Such kinds of antennas are based on the effect of the conversion of volumetric electromagnetic waves into surface waves of a dielectric waveguide in an open electrodynamic structure. A brief description of the theoretical basis for the calculations and examples of the technical implementation of flat (2D) antennas of diffraction radiation in the W-band and Ka-band are presented; their parameters and areas of possible use are discussed. In the <i>E</i>-plane angle-to-frequency dependence of beam position is realized with coefficient near 0,9/1% of frequency change. That makes it possible effective control of beam position in space (beam scanning along 1, or even along 2 axes). There was estimated that total active loss in such kind antennas is related to dielectric losses in the material of planar dielectric waveguide and to active losses at the elements of internal waveguide transitions in the ratio near (2: 1). Losses of first kind may be reduced due to implementation of novel dielectric materials providing the smallest dielectric loss (near as for the PTFE material) and appropriate mechanical rigidity at the same time. Active losses of the second kind may be reduced due to implementation of transitions on the base of super-size waveguides.

Wearable Textile Patch Antenna for Medical Applications

In recent years of electronics industrialization, antennas are more popular components; wearable antennas play an important role due to their properties such as wireless communication and miniaturization. The design of wearable antennas have distinction in the area of antenna design and development, in this paper a thorough study had been carried out wearable antennas blended with textile, which has significant dielectric constant. This work describes the design a textile antenna, namely, a rectangular microstrip patch antenna and then rectangular with U-slot antenna with slits. After designing two kinds of antennas, a comparison will be made between their results. Conductive textile, a copper-plated polyester fabric, will be used for fabricating antenna radiators and grounds. An insulating denim fabric with dielectric constant 1.7 with a thickness of 0.7 is used for preparing the substrates. The proposed antenna is designed and all the results will calculated using Ansoft HFSS Software. After evaluating the results of a rectangular microstrip antenna and U-slot Antenna on textile substrate, the rectangular patch resonate at 2.5 GHz with the return loss of -16.86dB and the U-slot Antenna resonated at 2.2 GHz with return loss of -41.68dB and 3.9 GHz return loss of -16.16dB.

Design and Development of Dipole Antenna for NOAA Satellite Image Acquisition System and Processing

The National Oceanic Atmospheric and Administration (NOAA) satellite is the 3rd Series of American meteorological for take information about the physical state of ocean and atmosphere. This research will describes the design of Satellite Image Acquisition System using two kinds of antenna, double cross dipole and Double V Double Dipole antenna as receiver of NOAA satellite and about performance of receiver system. The designed antenna works at frequency 137 Mhz with omnidirectional radiation pattern. The analysis process with analyzing the data receiving process with return loss parameter, signal to noise ratio (SNR), noise floor and image. The process of receiving data is by connecting antenna with RTL-SDR, SDRSharp software, WxtoImg, and Gpredict that has installed on laptop. Both antenna can receive data from NOAA satellite well, the data received are return loss value, noise floor, and image of Indonesian island that can be used for remote sensing. The antenna parameter for Double V Double Dipole are return loss -30.421 dB, VSWR 1.063, input impedance 51.642 Ohm and Gain 5.2 dB. For double cross dipole are return loss -29.315 dB, VSWR 1.071, input impedance 46.946 Ohm and Gain 4.47 dB. Both antenna have omnidirectional radiation pattern.

Multi-Function Adjustable Antenna using Plasma Radiation for Weather Monitoring

Plasma is the fourth state of matter. It is a common state of matter where almost of the universe in a plasma state and it can be found on earth naturally or artificially. The advantages of using plasma antenna are it is invisible to radar, no ringing effect, more efficient, dynamically reconfigurable and has fast transmission. The aim for this study is to investigate the effect of winds and humidity on radio signal using plasma antenna as an alternative to the conventional metal antenna. This research used two different type of commercial fluorescent lamps which are tubular (cylinder) and 2U-shape as plasma antenna. Thus, this kind of antenna can be considered as multi-function as it is originally a light source. The plasma antenna parameters such as return loss, gain and radiation pattern were characterized. In order to realize that, plasma parameters i.e., plasma and collision frequencies need to be obtained. The electrical properties measurement need to be done to record the values of current and voltage, then were used in GLOMAC programming to calculate the plasma parameters. The next stage was the simulation of plasma antenna using CST software. The last stage is signal strength experiment to get the value for radio signal strength received by plasma antenna. Then, the value of radio signal strength in against time was recorded. From the results, as the wind speed over time decreases, the power level decreases and vice versa. From the simulation results, the radiation pattern for tubular and 2U can be categorized as omni-directional pattern. Generally, good correlation was accomplished to prove the wind speed and humidity effect on radio signal using plasma antenna.

Mutual Coupling Reduction in 4×1 Array Antennas Using Mushroom-Like Structures

Microstrip patch antennas are widely used in Telecommunication systems, because of their low manufacturing cost and low weight, but they have some disadvantages such as, low gain. For a long distance communication, antennas with very high gain are suitable. An easier way to improve the gain is a conception with array configuration, but the disadvantage of this design is the appearance of strong mutual coupling, which is a major drawback of this kind of antennas. The use of Electromagnetic Band Gap structures can reduce or suppress surface waves, then reducing the mutual coupling. This paper describes the use of Mushroom-like structures 4×1 to reduce mutual coupling between radiating elements. The effect of these structures is studied and demonstrated by plotting variations of return loss and transmission coefficient versus frequency, surface current and E-field distributions of the proposed array antennas are also investigated. Simulation results are performed with High Frequency Structural Simulator.