Antenna Dimensions Research Articles

Channel Impulse Response at 60 GHz and Impact of Electrical Parameters Properties on Ray Tracing Validations

This paper outlines a study of the effect of changing the electrical properties of materials when applied in the Wireless InSite (WI) ray-tracing software. The study was performed at 60 GHz in an indoor propagation environment and supported by Line of Sight (LoS) and Non-LoS measurements data. The study also investigates other factors that may affect the WI sensitivity, including antenna dimensions, antenna pattern, and accuracy of the environment design. In the experiment, single and double reflections from concrete walls and wooden doors are analysed. Experimental results were compared to those obtained from simulation using the WI. It was found that materials selected from the literature should be similar to those of the environment under study in order to have accurate results. WI was found to have an acceptable performance provided certain conditions are met.

UWB-Printed Rectangular-Based Monopole Antenna for Biological Tissue Analysis

This paper presents the design of a printed step-type monopole antenna for biological tissue analysis and medical imaging applications in the microwave frequency range. The design starts from a very simple and widely known rectangular monopole antenna, and different modifications to the antenna geometry are made in order to increase the bandwidth. The antenna dimensions are optimized by means of a parametric analysis of each dimension using a 3-D electromagnetic simulator based on the finite element method. The optimized antenna, with final dimensions of 40 × 36 mm2, is manufactured onto a low-cost FR4 (fiber glass epoxy) substrate. The characteristics of the antenna have been measured inside an anechoic chamber, obtaining an omnidirectional radiation pattern and a working frequency range between 2.7 GHz and 11.4 GHz, which covers the UWB frequencies and enables the use of the antenna in medical imaging applications. Finally, the behaviour of four of these antennas located around a realistic breast model, made with biocompatible materials, has been analysed with the electromagnetic simulator, obtaining good results and demonstrating the usefulness of the designed antenna in the proposed application.

Liquid-Based Reconfigurable Antenna Technology: Recent Developments, Challenges and Future.

Advances in reconfigurable liquid-based reconfigurable antennas are enabling new possibilities to fulfil the requirements of more advanced wireless communication systems. In this review, a comparative analysis of various state-of-the-art concepts and techniques for designing reconfigurable antennas using liquid is presented. First, the electrical properties of different liquids at room temperature commonly used in reconfigurable antennas are identified. This is followed by a discussion of various liquid actuation techniques in enabling high frequency reconfigurability. Next, the liquid-based reconfigurable antennas in literature used to achieve the different types of reconfiguration will be critically reviewed. These include frequency-, polarization-, radiation pattern-, and compound reconfigurability. The current concepts of liquid-based reconfigurable antennas can be classified broadly into three basic approaches: altering the physical (and electrical) dimensions of antennas using liquid; applying liquid-based sections as reactive loads; implementation of liquids as dielectric resonators. Each concept and their design approaches will be examined, outlining their benefits, limitations, and possible future improvements.

Dual-polarized nanocrescent antenna designed using efficient optimization techniques.

A novel nanocrescent antenna with polarization diversity is introduced. It is formed from a crescent-shaped patch fed with a coupled strip transmission line. The antenna is located on top of a SiO2 thin film with a shielding ground layer underneath. The structure is supported by an arbitrary substrate. Polarization of the radiated field can be adjusted to be along either one of the two orthogonal polarizations based on which one of the two crescent patch modes is going to be excited. The excitation of either one of these two modes of the patch is achieved by switching between the two propagating modes of the feeding coupled strip transmission line. Using a dual-polarized antenna allows doubling the optical communication system's capacity via frequency reuse. The new crescent antenna dimensions are optimized to satisfy several goals, such as minimizing the losses, the deviation of the main beam direction away from broadside, and maximizing the radiation efficiency and axial ratio. Through the optimization process, simple surrogate kriging models replace the detailed electromagnetic simulation. The optimal response is achieved by applying two different optimizers. The first optimizer employs the design-centering technique using normed distances. The multiobjective particle swarm with the preference ranking organization method for enrichment evaluations is used by the second optimizer. In order to identify the critical dimensions to which the nanoantenna is most sensitive, a sensitivity analysis is used. The optimized antenna is capable of switching its radiation between two orthogonal pure linear polarizations with maximum radiation along the broadside direction. The size of the proposed antenna is about 500nm×500nm. Its impedance-matching bandwidth is higher than 30 THz centered around 193 THz (1550 nm). Its gain and radiation efficiency are higher than 5.2 dBi and 85%, respectively, all over the working frequency band.

A Dual-Band Modified Franklin mm-Wave Antenna for 5G Wireless Applications

Franklin array antennas are considered as one of the most competitive candidates for millimeter-wave (mmW) 5G applications due to their compact size, simple geometry and high gain. This paper describes a microstrip Franklin antenna array for fifth generation (5G) wireless applications. The proposed modified Franklin array is based on a collinear array structure with the objective of achieving broad bandwidth, high directivity, and dual-band operation at 22.7 and 34.9 GHz. The designed antenna consists of a 3 × 3 array patch element as the radiating part and a 3 × 3 slotted ground plane operating at a multiband resonance in the mmW range. The dimensions of the patch antennas are designed based on λ/2 of the second resonant frequency. The designed antenna shows dual band operation with a total impedance bandwidth ranging from 21.5 to 24.3 GHz (fractional bandwidth of 12.2%) at the first band and from 33.9 to 36 GHz (fractional bandwidth of 6%) at the second band in simulation. In measurement, the impedance bandwidth ranges from 21.5 to 24.5 GHz (fractional bandwidth of 13%) at the first band and from 34.3 to 36.2 GHz (fractional bandwidth of 5.3%) at the second band, respectively. The performance of the antenna is analyzed by parametric analysis by modifying various parameters of the antenna. All the necessary simulations are carried out using HFSS v.14.0.

Investigation of energy stealth of radar stations with band antennas from the radio monitoring complex

Using spectral representation of non-harmonic processes and partial characteristics of antennas, energy equations of transmissionreception of broadband signals in the radio channel with scattering on the object and the direct radio channel between the radar and the radio monitoring (RM) complex have been obtained. Energy of received signals is determined by value of product of spectral density of radiation power and partial moment of transmission-reception averaged in the range of cyclic frequencies. The signal-to-noise ratio at the receiver input reaches the highest value when the partial moment of transmission-reception of signals in the radio channel changes according to a linear law. At fixed average radar power, energy of information signals at incoherent accumulation can be increased due to selection of antennas with partial directive gain amplifying wave processes in areas of their spectra concentration. The range of the radar is proportional to the linear dimensions and significantly depends on the shape of the object. The rules of antenna characteristics selection are justified to ensure radar stealth from RM systems while maintaining the required range of target detection and recognition. When using an antenna with a partial directive gain constant in the range of working cyclic frequencies in the radar, and in the RM complex of an antenna system with a frequency-independent effective area, the partial moment of transmission-reception of signals in the forward radio channel is constant. Its value is determined by the product of partial directive gain at the central frequency of the range. Forms of pulses supplied to input of transmitting antenna and radiated into space coincide, and shape of signal at output of receiving antenna has the form of their derivative. Due to application of frequency-independent antennas in radar and RM complex, energy of probing signals increases compared to levels typical for antenna systems with partial directivity indices varying in proportion to current value of cyclic frequency in the first or second degree. This pattern is due to the significant effective area of the receiving antenna in the lower part of the frequency range, which parries the low efficiency of radiation of low-frequency components of the radar signal spectrum. In radio channels with partial moments of transmission-reception of signals varying with frequency increase according to linear law, energy supplied to receiver input increases in comparison with levels achievable at quadratic and cubic dependencies of partial moments on cyclic frequency due to the same type dependencies of partial directive gain antenna of radar and effective area of antenna of RM complex. Stealth of probing radiation increases as dimensions of radar antennas increase due to increase of partial directive gain and decreases as dimensions of antenna systems of RM complexes increase due to increase of their effective areas. The duty cycle of pulses forming regular sequences, established due to the condition of accumulation of energy of reflected signals due to irradiation of the object, which is required to complete the functional tasks of the radar, decreases in proportion to the increase of the partial directive gain antenna at the central cyclic frequency. Energy of information signals increases in proportion to coefficients depending on relative half-width of their spectra, and decreases with increase of central cyclic frequency to the second degree. As pulse repetition frequency increases at maximum permissible average density of radiation power limited by radar stealth requirements, energy density of probing signals decreases proportionally. The average power of the radar at a fixed level of spectral density varies in proportion to the bandwidth occupied by the probing signals due to a reduction in the following period.

Reduction of Mutual Coupling between Radiating Elements of an Array Antenna Using EBG Electromagnetic Band Structures

In this paper, a new array antenna configuration based on Electromagnetic Band Gap (EBG) structures has been proposed for 3.5GHz wireless communication systems. The proposed slotted EBG structure, high impedance surface (SHI), consists of three squares and a square ring deposited on a substrate (Rogers RO4350) which has a relative permittivity of 10.2 and a thickness of 1.27mm. Initially a matrix of 3×7 unit cells of EBG structures is introduced between two patches of an array and then a matrix of 3×14 unit cell of EBG structures is integrated between eight patches, which resonate around 3.5GHz (Wi MAX). The insertion of these structures between the radiating elements of an array antenna reduces the mutual coupling and antenna dimensions by approximately (8dB, 11%) and (12 dB, 5%) respectively for two, eight elements array antenna. In addition, the directivity has been slightly improved in the presence of EBG structures, from 4.52dB to 6.09dB for a two-element array antenna, and from 8.18dB to 8.4dB for an eight-element antenna.

Design of Miniature Planar Antennas for 5G Systems

The objective of this work is the design and simulation of an antenna based on metamaterials in order to miniaturize the dimensions of planar antennas. Metamaterials have been on the rise in recent years. The new properties make it possible to envisage the realization of new electronic components with new functions. Metamaterials are artificial materials designed for different telecommunications applications in order to improve the performance of antennas in terms of efficiency, compactness and miniaturization of structures. The use of these materials offers advantages such as reduction in weight and bulk, which is beneficial for their integration into 5G telecommunications and telephony systems. The fifth generation 5G mobile network is a set of emerging global telecommunications standards, typically using high frequency spectrum, to provide network connectivity with reduced latency and higher speed and capacity than the forerunners. It is argued that the recurring communication infrastructure is very inefficient in energy and that 5G should be designed to solve this problem, increasing energy efficiency by several orders of magnitude. To meet the demands of 5G, we need radically new network architectures and technologies, such as heterogeneous ultra-dense network, massive multi-output MIMO, and millimeter wave communications. Our goal is to achieve a planar antenna based on metamaterials which must operate at the resonance frequency of 5G which is f=3.5GHz by the CST Studio Suit electromagnetic design and simulation software and Matlab calculation.

Simulation study of microstrip antenna for 2.45 GHz applications based on octagon shaped

In late years, microstrip patch antennas have been widely used in various communication systems due to their lightness in weight, smallness in size, low manufacturing cost and, reasonable gain. Therefore, various figures and dimensions of microstrip patch antennas are available. This paper presents an octagonal ring-shaped multi-slot patch antenna with a single resonant frequency at 2.45 GHz of the Industrial Scientific and Medical (ISM) band with an omnidirectional pattern based on the Tikrit university logo. The unique structure of the octagon figure is demonstrated by adding trigonal patches on the sides and top of the rectangular microstrip patch antenna to achieve the eight-pointed star figure. The Octagon ring shape is achieved by inserting a single octagon slot and multi slots of a rectangular, square, triangle to maintain the operating frequency. The reduction in the size of the antenna is carried out by adding an octagon/rectangular patch to the partial ground plane. The suggested antenna is plotted and simulated on a substrate board FR-4 of dimensions 60 × 46 × 1.6 mm3 using CST Microwave Studio 2017. The results show compact size, 2.9 dBi gain, improved S11 response of −23.18 dB at 2.45 GHz, size reduction of 10.44%, and omnidirectional radiation pattern that can be utilized to harvest radio frequency (RF) energy from Wi-Fi and bluetooth (2.4–2.5 GHz).

Co-Designed 3+3 Port Dual-Band Broadside Tri-Modal Patch Antenna

A co-designed (3+3)-port antenna for dual-band operation that requires no feeding or decoupling network is proposed and verified. The antenna consists of six ports which are divided into two groups that resonate in two different frequency ranges. The basic radiating element is a tri-modal patch in a folded snowflake-shaped structure with the largest antenna dimension of 0.48λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> or 0.68λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> , where λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> and λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> are the wavelengths in air at the center frequencies of the lower and upper operating bands, respectively. Measurement results show that the 10 dB impedance bandwidths of the two respective bands are 19.7% and 14.4%. The proposed antenna exhibits compact, multiport, multiband and broadside radiation characteristics which are not only suitable for dual-band MIMO applications, but also for energy harvesting systems with spatial and frequency diversities, or dual-function wireless systems with simultaneous information and power transfer.

Predicting Rectangular Patch Microstrip Antenna Dimension Using Machine Learning

When designing a microstrip antenna, the designers determined the desired parameters. However, the simulation software can only give the parameters result based on the given dimension. Therefore, optimization is required to meet the desired parameters. The designers usually do the optimization by the trial-error process. This research conducts machine learning implementation to predict the microstrip antenna dimension. The study focused on rectangular patch microstrip antenna with resonant frequency ranged from 1-8 GHz. The dataset used to make the prediction is obtained from simulation with antenna width ranged from 19-63 mm and length 10-54 mm. There are four algorithms employed: decision tree, random forest, Support Vector Regression (SVR), and Artificial Neural Network (ANN). Among all algorithms, random forest with estimator 15 gives the best result with Mean Square Error (MSE) value is 3.45. From the obtained result, the researchers can estimate the rectangular patch microstrip antenna dimension based on the desired parameters, which can’t be done by the antenna simulation software before.

A triple band modified F-shaped monopole antenna for RFID application

Radio frequency identification (RFID) is a very prominent technology and is used in object-attached identification and tracking tags. In this paper a triple band monopole antenna is designed to work at 2.2-2.6 GHz (lower RFID band), 5.3-6.8 GHz and 8.7-9.5 GHz (upper RFID band) frequency ranges. The antenna design resembles a modified F-shaped radiator and is built on a low cost easily available FR4 dielectric substrate. Initially an F-shaped radiator with partial ground plane is studied which exhibits the operation at 2.6 and 6.5 GHz. Further, modifying this F-shaped radiator exhibits an additional resonance at 9.2 GHz. Fundamental characteristics such as reflection coefficient (S11), radiation pattern and 3D gain have been analyzed and good results have been obtained. Parametric analysis is carried out to fix the optimized antenna dimensions. All the simulations are carried out using the high frequency structure simulator software (HFSS). The antenna structure is easy to design and produce, and ideal for use in RFID applications.document quickly and accurately, to determine its relevance to their interests, and thus to decide whether to read the document in its entirety.

A novel reconfigurable G shaped patch antenna for wireless IoT applications using BAR64-02W PIN diode

In this paper, a novel reconfigurable antenna for wireless IoT operations is proposed.The antenna dimensions of 27.5 x 8 x 0.8 mm3 and fabricated on the FR-4 dielectric substrate with a hlaf ground plane. The desined antenna works in the frequency range of WiMAX, I.S.M. and X band (3.2-3.8 GHz, 5.2-6.9 GHz, and 7.1-10 GHz). The frequencies can be reconfigured by one P.I.N. diode BAR64-03W, and antenna attained the gain ranging of 2.84-3.26 dBi. The proposed antenna has bidirectional radiation at higher-frequency bands and unidirectional at lower frequency bands. The suggested frequency reconfigurable antenna has a radiation efficiency of 96.12% at 3.5 GHz and 94.34% at 5.9 GHz,92.02% at 8.4 GHz in ON state. Antenna giving the best agreement between the measured and simulated results (C.S.T. Microwave Studio)

Design of a Compact Dual-Band Antenna for On-/Off Body Communication

In this paper, a compact, dual-band, patch antenna structure for body-centric relay node communication is presented. The antenna is designed to operate at Industrial, Scientific and Medical (ISM) bands at 2.45 GHz for receiving data from intra-body sensor nodes and 5.0 GHz for transmitting signal to external monitoring device. The antenna is designed by using coplanar waveguide feed and etching two open-end slots on radiating patch. Overall antenna dimensions are 15 mm × 28 mm × 1.57 mm. Effective dielectric constant for the multiple dielectric layers, due to its heterogeneous tissue structure, has been calculated. Antenna performance is measured both in free space and on tissue model. On body, a wide bandwidth of 250 and 370 MHz is obtained that enhances antenna robustness to operate on different types of body tissues. Radiation pattern toward the surface of body at 2.45 GHz and directional pattern normal to the surface of body at 5.0 GHz are achieved. High directivity of 7.18 dBi at 5.0 GHz is obtained which is good to maintain robust communication link with the external control unit. Small size, good radiation characteristics and low SAR value make the antenna a good choice for operating in close proximity to human body.

SEMI-AUTOMATED DESIGN OF MICROSTRIP DUAL BAND COAXIAL FEED ANTENNA USING DIFFERENTIAL EVOLUTION ALGORITHM FOR WLAN APPLICATIONS

Traditional antenna design uses discrete steps manually to create and optimize the antenna structure. This approach costs both time and effort, especially when a complex antenna structure is on demand. The evolutionary algorithm emerges as a potential alternative method to formulate the antenna model as well as to optimize the structure so as to comply with the design requirements. In this paper, we propose a method for determining the surrogate model and dimensions of an ultra-wideband patch antenna using a differential evolution algorithm. This antenna is desired to work at the frequency range of 2.45GHz to 5.8GHz for WLAN applications. Through the evaluation of reflectivity and investigation of the algorithm,the surrogate model is obtained faster with optimized dimensions. The algorithm is investigated with different strategies to detect the best strategy when an object is a differential evolution applied.

On the Uplink Transmission of Extra-Large Scale Massive MIMO Systems

With the inherent benefits, such as, better cell coverage and higher area throughput, extra-large scale massive multiple-input multiple-output (MIMO) has great potential to be one of the key technologies for the next generation wireless communication systems. However, in practice, when the antenna dimensions grow large, spatial non-stationarities occur and users will only see a portion of the base station antenna array, which we call visibility region (VR). To assess the impact of spatial non-stationarities, in this paper, we investigate the uplink transmission of extra-large scale massive MIMO systems by considering VRs. In particular, we first propose a subarray-based system architecture for extra-large scale massive MIMO systems. Then, tight closed-form uplink spectral efficiency (SE) approximations with linear receivers are derived. With the objective of maximizing the achievable SE, we also propose schemes for the subarray phase coefficient design. In addition, based on the obtained ergodic achievable SE approximations, two statistical channel state information (CSI)-based greedy user scheduling algorithms are developed. Our results indicate that the statistical CSI-based greedy joint user and subarray scheduling algorithm collaborating with the on-off switch-based subarray architecture is a promising practical solution for extra-large scale massive MIMO systems.

FMCW radar antenna using a half parabolic reflector with microstrip-patch-array offset feed and tuning strip

In this paper, we propose a reflector antenna with a microstrip-patch-array offset feed. The proposed antenna offers several advantages in design flexibility, especially to determine the horizontal and vertical beam patterns by the modular feed and the reflector curvature design, respectively. Moreover, it provides an internal tuning mechanism in the form of a tuning strip which is relatively simple to apply. The paper describes the steps in a parametric study carried out to minimize the antenna dimensions. The resulting optimized design is found to be around 50% smaller in dimension than the initial design of the proposed antenna. A demonstrator for experimental analysis, consisting of a transmit and a receive antenna, has been constructed, and the isolation between the antennas is found to be better than 70 dB. The antenna demonstrator has been integrated with an FMCW radar transceiver and satisfactorily tested to operate as a coastal surveillance radar.

Optimizing Dimensions of Cassegrain Antenna System with Large Magnification Factor

In this paper, computer-aided design methods are used to optimize Cassegrain antenna dimensions in the case that the feed antenna is placed exactly behind the main reflector. Conical corrugated horn antenna is utilized as the feed antenna. Parabolic reflector antenna dimensions are calculated considering link budget initially. Then to reduce blockage effect due to the presence of subreflector in front of the main reflector a mathematical equation is extracted. Considering the complexity and nonlinearity of this equation, we used a numerical method to solve it, and optimum edge angle of the rays emerging from the feed antenna toward the subreflector is obtained. The other geometric parameters of the structure are then specified using the relations governing the structure. A design example is presented that clarifies the method more obviously. In this example, the slant ratio of the horn is chosen arbitrarily equal to 0.2. This example is simulated using FEKO software to verify the theory. Then to investigate the effects of choosing different slant ratio values on the Cassegrain antenna specification, the extracted mathematical equation is solved for different slant ratio values for the design example. Magnification factor, subreflector diameter, and the slant radius of the feed antenna are then calculated in optimum for distinctive slant ratio values, and the results are presented.

Omega-Shaped Tag Antenna with Inductively-Coupled Feeding Using U-Shaped Stepped-Impedance Resonators for RFID Applications

This study proposes a new omega-shaped tag antenna with inductively-coupled feeding (ICF) using U-shaped stepped- impedance resonators (SIRs). It aims at improving the performance of the tag antennas for Radio Frequency Identification (RFID) applications. The radiating body of the antenna is fed using two mirroring symmetrical U-shaped SIRs. This antenna is a simpler alternative for the existing antennas that match the impedance of the antenna to the chip impedance effectively applying varied reinforcement of the equivalent inductance of the radiating structure. In addition to the use of an omega-shaped structure, the proposed feeding technique boosts performance of the antenna impedance, dimensions, and peak gain. The measured size of the antenna was 50×55.55×1.6 mm3. It attains a peak gain of 1.8 dBi and radiation efficiency higher than 85% at its operating frequency. The experimental results revealed that this tag antenna has the characteristic of good impedance matching within the frequency range of 900-940 MHz, corresponding to a better power reflection coefficient of -3 dB. Comparison between the measured and simulated results verified that the proposed feeding method is capable to improve overall performance of RFID tag antennas.

Evaluation of SAR sensor design parameters on remote sensing missions

PurposeThe purpose of this study is to investigate the design parameters of an optimal SAR satellite sensor on remote sensing missions. Synthetic aperture radar (SAR) satellite missions, with the advantages of using all weather conditions, repetition of a pass, high spatial resolution and adequate balance, can not only provide timely coverage in disaster areas but also environmental monitoring and accident assessment. It also provides resources. The product of images depicts the needs of government organizations not only before and after the crisis but also during the crisis. Therefore, low-cost SAR satellite loading efforts have begun with SAR satellites and key technologies.Design/methodology/approachInformation about the basic parameters of SAR satellites such as antenna dimensions, image resolution, pulse and relationship repetition, as well as the tradeoff between required parameters and design needs’ evaluation was achieved. In this paper, the tradeoff methods between some technical requirements are presented, and the limitations in the design of a SAR prototype sensor in the X band are examined. Diagrams can provide a complete overview of the predicted fluctuations and tradeoffs between them for a designer.FindingsAnalysis of findings reveals that data transmission rate with PRFmin is independent of antenna incidence angle, but in contrast, it is dependent on PRFmax, and afterward its relationship was analyzed. Drawn diagrams approved presented design and calculations. Other important parameters in the design of the SAR sensor such as antenna dimensions, tilt angle, amplitude and resolution of azimuth can be achieved as significant elements in systematic design according to the results of this paper. Regarding the displayed diagrams, it can be understood that the angle of the antenna should not be from 15 to 60 degrees.Originality/valueThis paper provides an overview of the new observational capability offered by the second generation of SAR sensors, especially in the field of remote sensing applications. The built-in antenna is built for the small SAR sensor. This array antenna is designed with a parallel screen to work in X-frequency with vertical polarity.