Design Method Of Antenna Research Articles

Deterministic Equation of Self-Resonant Structures for Normal-Mode Helical Antennas Implanted in a Human Body

Recently, helical antennas had been used as a very small implantable antenna in a capsule endoscopy system. For a helical antenna, a normal-mode helical antenna (NMHA) is promising because of its small size and the completeness of an antenna design method, which has already been established. However, in the human body, the effects of human tissues on the electrical characteristics of an NMHA were not clarified. The most important aspect is to determine the self-resonant structures. In this letter, a deterministic equation is derived for the self-resonant structures of an NMHA in the human body. By utilizing simulation results of an electromagnetic simulator, a capacitive reactance equation is deduced based on the electric field distributions around an antenna. An inductive reactance equation is obtained by modifying the equation of free space to the condition of inside a dielectric material. Finally, by equating the capacitive and inductive reactance equations, the self-resonant equation is determined. The accuracy of the equation is ensured through the agreements of the antenna structures given by equations and electromagnetic simulations. Moreover, by fabricating an NMHA and a human body phantom, the measured results are obtained. The self-resonant structure is ensured through the measured results.

A Wideband Dual-Polarized Antenna Using Shorted Dipoles

A novel design method of a wideband dual-polarized antenna is presented by using shorted dipoles, integrated baluns, and crossed feed lines. Simulation and equivalent circuit analysis of the antenna are given. To validate the design method, an antenna prototype is designed, optimized, fabricated, and measured. Measured results verify that the proposed antenna has an impedance bandwidth of 74.5% (from 1.69 to 3.7 GHz) for VSWR < 1.5 at both ports, and the isolation between the two ports is over 30 dB. Stable gain of 8–8.7 dBi and half-power beamwidth (HPBW) of 65°–70° are obtained for 2G/3G/4G base station frequency bands (1.7–2.7 GHz). Compared to the other reported dual-polarized dipole antennas, the presented antenna achieves wide impedance bandwidth, high port isolation, stable antenna gain, and HPBW with a simple structure and compact size.

A Nonbalancing End-Fire Microstrip Dipole With Periodic-Offset DSPSL Substrate

A nonbalancing microstrip dipole with end-fire capability is presented. The proposed antenna consists of a simple microstrip-fed dipole with a periodic-offset double-sided parallel-strip line (DSPSL) substrate, which is used to replace the balun of a conventional end-fire antenna. The periodic-offset DSPSL substrate exhibits phase shift characteristics and excites the odd mode of the microstrip dipole. A director and a truncated ground are used to increase the directivity of the antenna. After placing the DSPSL, the bidirectional radiation pattern is converted to a unidirectional one. The measured and simulated results indicate that the antenna operates at 2.4 GHz. End-fire directional radiation patterns are obtained with this novel periodic substrate. When compared with the original design of the microstrip dipoles, the proposed microstrip dipole uses the periodic-offset DSPSL substrate to replace the balun. The front-to-back ratio is about 10 dB. The design method of the end-fire antenna is a new technique and can be easily applied in other antennas.

Radiation Pattern Reconfigurable Graphene Leaky-Wave Antenna at Terahertz Band Based on Dielectric Grating Structure

Based on the dielectric grating structure, the concept and design method of a novel reconfigurable graphene leaky-wave antenna (LWA) working at terahertz band is presented. The leaky-wave mode is excited by using the dielectric grating, while the applied bias voltage is varied to control the surface plasmon polariton in the graphene. Radiation pattern reconfigurability of the LWA can be realized at a fixed frequency or over a wide frequency range at the terahertz band.

Model-Based Optimization of Compressive Antennas for High-Sensing-Capacity Applications

This letter presents a novel, model-based compressive antenna design method for high-sensing-capacity imaging applications. Given a set of design constraints, the method maximizes the capacity of the compressive antenna by varying the constitutive properties of scatterers distributed along the antenna. Preliminary two-dimensional design results demonstrate the new method's ability to produce antenna configurations with enhanced imaging capabilities.

Mobile antenna design based on controlling current distributions

ABSTRACTIn this letter, an antenna design method based on control of current distribution is presented. By adjusting the current distributions using reactive elements, the antenna can couple differently with the ground plane, achieving different performances. When the antenna is located in the ground plane where the electric field is strong, monopole‐type current distributions are preferred to loop‐type current distributions. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2937–2940, 2016

MoM-based topology optimization method for planar metallic antenna design

The metallic antenna design problem can be treated as a problem to find the optimal distribution of conductive material in a certain domain. Although this problem is well suited for topology optimization method, the volumetric distribution of conductive material based on 3D finite element method (FEM) has been known to cause numerical bottlenecks such as the skin depth issue, meshed “air regions” and other numerical problems. In this paper a topology optimization method based on the method of moments (MoM) for configuration design of planar metallic antenna was proposed. The candidate structure of the planar metallic antenna was approximately considered as a resistance sheet with position-dependent impedance. In this way, the electromagnetic property of the antenna can be analyzed easily by using the MoM to solve the radiation problem of the resistance sheet in a finite domain. The topology of the antenna was depicted with the distribution of the impedance related to the design parameters or relative densities. The conductive material (metal) was assumed to have zero impedance, whereas the non-conductive material was simulated as a material with a finite but large enough impedance. The interpolation function of the impedance between conductive material and non-conductive material was taken as a tangential function. The design of planar metallic antenna was optimized for maximizing the efficiency at the target frequency. The results illustrated the effectiveness of the method.

휴대형 RFID 리더용 소형 준-야기 안테나 설계

ABSTRACT In this paper, we considered a design method of a compact quasi-Yagi antenna for portable UHF RFID readers. The antenna consists of a dipole driver and a reflector printed on a dielectric substrate, and it is fed by a microstrip line. In order to reduce the antenna size, the dipole and reflector are bent and the balun between the feeding microstrip line and coplanar strip (CPS) line is integrated within the CPS line. The effects of the geometrical parameters of the proposed antenna on the antenna performance are examined, and the parameters are adjusted to be suitable for the operation in UHF RFID band (902—928 MHz). The size of the fabricated antenna is 70 mm ×75 mm, and the experiment results reveal a frequency band of 892—942 MHz for a voltage standing wave ratio 3.5 dBi, and a front-to-back ratio > 6.6 dB over the frequency band for UHF RFID. 키워드 : 준-야기 안테나, RFID 안테나, 휴대형 RFID 리더, 소형안테나, UHF 안테나 Key word : quasi-Yagi antenna, RFID antenna, portable RFID reader, compact antenna, UHF antennaJournal of the Korea Institute of Information andCommunication Engineering

Design and implementation of dual-band antennas based on a complementary split ring resonators

A simple dual-band antenna design and implementation method is proposed in this work, based on the equivalent media properties inspired by resonant metamaterial elements. The equivalent circuit model of dual-band patch antennas based on a complementary split ring resonator (CSRR) is presented and validated. The dual-band patch antenna is designed etching a CSRR in the patch of a conventional rectangular microstrip patch antenna. The first resonance is governed by the quasi-static resonance of the CSRR while the second resonance is originated by the rectangular patch. The fact of etching a CSRR on a rectangular patch antenna also produces a miniaturization of a conventional patch antenna. The equivalent circuit model proposed in this letter is sound in order to understand the functionality of dual-band patch antennas based on a CSRR. Good agreement between simulation, equivalent circuit model and experimental results is shown and discussed. These results lead the equivalent circuit model to become a simple and straightforward tool for the design of this type of multiband antennas, of low cost and versatile operation for a broad range of wireless communication systems.

A modified coaxial probe-fed Sierpinski fractal wideband and high gain antenna

This paper deals with modified Sierpinski fractal wideband antenna design. As research in the field of antenna design has already established, therefore it is exceptional that a novel approach is used over conventional antenna design methods to optimize the existing Sierpinski fractal antenna. The implemented antenna exhibits the broadband behaviour in the frequency bands of 12.2–13.4GHz and 21–30GHz in which it follows S11≤−10dB all through the frequency bands. The measured peak gains within the specified frequency bands vary from 8 to 22dB. This high gain is achieved by employing the modifications to the initial Sierpinski geometry. The experimental and measured results of the modified coaxial probe fed Sierpinski fractal antenna are also presented. Experimental results are also validated.

Efficiency Improvements of Antenna Optimization Using Orthogonal Fractional Experiments

This paper presents an extremely efficient method for antenna design and optimization. Traditionally, antenna optimization relies on nature-inspired heuristic algorithms, which are time-consuming due to their blind-search nature. In contrast, design of experiments (DOE) uses a completely different framework from heuristic algorithms, reducing the design cycle by formulating the surrogates of a design problem. However, the number of required simulations grows exponentially if a full factorial design is used. In this paper, a much more efficient technique is presented to achieve substantial time savings. By using orthogonal fractional experiments, only a small subset of the full factorial design is required, yet the resultant response surface models are still effective. The capability of orthogonal fractional experiments is demonstrated through three examples, including two tag antennas for radio-frequency identification (RFID) applications and one internal antenna for long-term-evolution (LTE) handheld devices. In these examples, orthogonal fractional experiments greatly improve the efficiency of DOE, thereby facilitating the antenna design with less simulation runs.

CAD Model and Simulation of T-Shaped Microstrip Antenna for LTE 1800MHz Applications

In this paper, the simulation of proposed T-shaped microstrip antenna is presented. The proposed procedure in this research includes frequency-dependent characteristic impedance in GHz frequency range in the standard microstip patch antenna design methods. The proposed antenna in this paper is designed for broadband 1800MHz LTE applications in the E-UTRAN band of 1, 2, 3, 4, 9, 10 and 11. The proposed procedure and designed formulas in this research are used to construct in-house MATLAB program software which is compatible with Computer Aided Design (CAD) with fast and user-friendly implementations.

A noncontact wireless passive radio frequency (RF) resonant pressure sensor with optimized design for applications in high-temperature environments

A noncontact wireless passive pressure sensor based on alumina ceramic for pressure measurement is presented in this paper. A faithful pressure signal in harsh environment is captured through wireless sensing, and a novel antenna design method is developed to increase the measurement distance between the antenna and the sensor. The sensor is fabricated using a novel no-co-fired technology, and the properties of the alumina ceramic and platinum ensure the feasibility of the sensor in high-temperature environments. The experimental results show that the coupled distance between the antenna and the sensor can be up to 5.5 cm, and the designed sensor, featuring improved structural parameters, has a high responsivity (15.5 kHz kPa−1) in a pressure environment at room temperature. The sensor can be coupled with the antenna at 850 °C, which verifies the feasibility in high-temperature environments.

Design and Analysis of Polarization Diversity Antenna for Mobile Terminals

This letter presents an antenna design method for an orthogonally-polarized dual antenna for use in mobile stations (MSs) and includes a verification method for improving the link-level throughput performance of an MS that uses a proposed multiple-input multiple-output antenna. The link-level throughput performance of an MS is strongly related to the correlation between antenna branches, which is determined by the cross polarization discrimination of the second branch antenna, both numerically and experimentally.

Design and Analysis of Polarization Diversity Antenna for Mobile Terminals

This letter presents an antenna design method for an orthogonally-polarized dual antenna for use in mobile stations (MSs) and includes a verification method for improving the link-level throughput performance of an MS that uses a proposed multiple-input multiple-output antenna. The link-level throughput performance of an MS is strongly related to the correlation between antenna branches, which is determined by the cross polarization discrimination of the second branch antenna, both numerically and experimentally.

Research on Ultra-Wideband TEM Horn Antenna and its Miniaturization

TEM horn antenna is one kind of directional Ultra-wideband antenna with simple structure. Based on the design method of TEM horn antenna, satisfied impedance and radiation character are obtained by simulation and experiment research. On this basis, by means of metal ridged loaded, background dielectric material loaded and distributed lossy metal loaded respectively, the miniaturization character is realized. The simulation analysis results show that load of traditional TEM horn antenna can get efficiently improvement in structure and performance which have widely application foreground in pulse radiation communication system and ultra-wideband radar system.

Design of Pattern Reconfigurable Antennas Based on a Two—Element Dipole Array Model

A new method for pattern reconfigurable antenna (PRA) design is introduced on the basis of a two-element dipole array model in this communication. Firstly, a two-element dipole array loaded with varactor diodes is analyzed in detail. The two dipoles of the array are folded to form a square and the reconfigurable pattern characteristics of the array can be still explained by the phased array theory. And then, based on the two-element dipole array model, a patch top-loaded monopole antenna is proposed to design the PRA (denoted as PTMPRA). Applying the field equivalence principle, the antenna radiation can be analyzed with two couples of magnetic dipoles. The phase of the magnetic dipoles may be adjusted by the loaded varactor diodes, and the antenna can reconfigure the patterns in two orthogonal planes. The antenna is fabricated and measured. The studies validate that the new method for designing pattern reconfigurable patch antenna is simple and efficient.

Characterization of Performance of a Mobile MIMO Antenna in Free Space

This letter presents an antenna design method for a dual antenna with high isolation for mobile stations (MSs) and includes a verification method for improving the correlation performance of an MS that uses a proposed multiple-input-multiple-output (MIMO) antenna by using MIMO over-the-air (OTA) channel models. The large-scale parameters for the MIMO OTA channel models are important because they determine the fixed geometrical parameters to be used for channel impulse response realization. The correlation performance of an MS has a strong relation to the cross-polarization discrimination (XPD) of the second branch antenna both numerically and experimentally. This study applies modern technology to implement MIMO antenna switch high isolation by selecting Band 5 to have low-frequency fabricated antenna samples that have several XPD values, thereby comparing their characteristics.

Development of single point feed circularly polarized coplanar antenna

AbstractA single point fed circularly polarized coplanar antenna is proposed. The antenna consists of a rectangular slot loop of 1λ (wavelength) and the earth conductor. The antenna has orthogonal surface currents and appropriate phase differences suitable to generate circularly polarized waves. The antenna design method is studied and the design parameter table is obtained for several applications. Antenna performance was measured and examined with numerical simulation results. Finally, an application for XMSR was examined with a car body model. © 2012 Wiley Periodicals, Inc. Electron Comm Jpn, 96(1): 33–42, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11425

Structure–electronic synthesis design of deployable truss antenna

This paper deals with a kind of deployable truss antenna that consists of tetrahedral modules. The structure–electronic synthesis design method is proposed and mechanical performance and electrical performance of the antenna are researched together. The basic module and structural topology are described. The coordinate of each joint, the joint angles, the length of the struts and the pattern of the joint are formulated on the basis of the topology method. By employing these formulas, numerical models of deployed and folded configuration can be built. According to the feature of the deployable truss antenna, the numerical algorithm for computing the scattered field of the antenna is developed based on geometric optics theory. The radiation integral of reflector is discrete approximated when the projection area of triangular facet onto the caliber plane is meshed by rectangular grid. Combining these two components, the structure–electronic synthesis design method of antenna is presented. A 6-meter deployable truss antenna was designed by the corresponding design procedures. The results indicated that the structure parameter and radiation-patterns of the antenna can be designed and optimized by the synthesis design method. Additionally, a scaled model of the antenna was manufactured to illustrate its feasibility.