Radiation Diagram Research Articles

Digital twin modeling of open category UAV radio communications: A case study

The modeling of radio links plays a crucial role in achieving mission success of unmanned aerial vehicles (UAVs). By simulating and analyzing communication performance, operators can anticipate and address potential challenges. In this paper, we propose a full-featured UAV software-in-the-loop digital twin (SITL-DT) for a heavy-lifting hexacopter that integrates a radio link module based on an experimental path loss model for ‘Open’ category Visual Line of Sight (VLOS) conditions and drone-antenna radiation diagrams obtained via electromagnetic simulation. The main purpose of integrating and simulating a radio link is to characterize when the communication link can be conflicting due to distance, the attitude of the aircraft relative to the pilot, and other phenomena. The system architecture, including the communications module, is implemented and validated based upon experimental flight data.

Design And Simulation of a Hexagonal High-Gain MIMO Patch Antenna For 5G Applications

View of the technological evolution and the problems encountered by the world, researchers are obliged to find solutions, particularly researchers in the field of antennas. This article has been devoted to the design and study of a hexagonal dual-band MIMO patch antenna for Satellite and 5G applications. Several parameters have been studied, we can quote among other things the gain, the bandwidth, the radiation diagram, the directivity, and the distribution of the electric field E. To achieve these studies and find optimal solutions, several designs have been made like the design of a simple hexagonal patch antenna, and, in the end, the proposed antenna is a MIMO with a hexagonal shape and 2 feeding ports. The proposed antenna operates at 25 GHz as the central frequency. The obtained ECC (envelope correlation coefficient) value is less than 0.006 for the entire operating bandwidth, which satisfies the standard value criteria of less than 0.5 and indicates minimal isolation between the antenna arrays. The values of the gain and the maximum directivity of the antenna obtained are respectively 8.12 dB and 8.37 dB, which gives us an efficiency of the antenna at 97.01% with high isolation > 25 dB. The results are found to be sufficient for the device to be used for mm-wave 5G MIMO applications. Additional MIMO performance metrics, such as the channel capacity loss (CCL), diversity gain (DG), and total active reflection coefficient (TARC), are evaluated. All this work has been done using HFSS 15 as software.

ЗНИЖЕННЯ ЗОВНІШНЬОГО ШУМУ БРОНЕАВТОМОБІЛЯ «НОВАТОР» ЗАСТОСУВАННЯМ ВИСОКОЕФЕКТИВНОГО ГЛУШНИКА ШУМУ

Armored vehicles are widely used for combat operations, for which it is extremely important to be as inconspicuous as possible. There are different types of masking, one of which is reducing the level of external noise. For the Novator armored car, a highly effective muffler of the exhaust gases of the internal combustion engine was devel-oped. The Novator armored car has a pickup-type body, a gross weight of 9,000 kg and a Ford F8 turbodiesel engine with a power of 300 hp. The uniqueness of the developed muffler is that it seeks to return all the sound waves that entered it back to the intake pipe. This effect is achieved due to the specific structure of the silencer housing. The case is an ellipsoid of rotation.At the same time, the section of the intake pipe (the pipe that goes into the muffler) is placed in the first focus of the ellipsoid of rotation, and the sound waves propagate to the inner wall of the elliptical body, reflect from it, con-verge at the second focus, and then continue to move to the opposite wall, reflect from it, converge in the first focus and spread further back into the intake pipe. In the intake pipe, there is partial interference of the reflected sound waves when they meet the incoming waves, and the final absorption by the sound-absorbing material. At the same time, exhaust gas-es, bouncing off the walls of the muffler, leave the latter through the exhaust pipe. At the same time, the exhaust pipe exits the ellipsoid of rotation coaxially with the intake pipe, which enters the pipe tel-escopically with a gap. Taking into account the directional diagram of sound energy radiation at the exit from the ex-haust pipe, a proposal was made to create a muffler not as a full ellipsoid of rotation, but in the form of a half ellipsoid of rotation. Such a solution will make the muffler significantly cheaper and much more compact, which is essential for a military vehicle. Keywords: armored car, “novator”, masking, camouflage, silencer, ellipsoid of rotation, directional diagram, acoustic efficiency, sound waves, sound absorbing material.

Design of Wide‐Beam Leaky‐Wave Antenna Arrays Based on the Bilinear Transformation of IIR Digital Filters and the Z Transform

Abstract In the pioneering work, the radiation diagrams of leaky wave antenna arrays can achieve attenuation nulls and gains at specific angles by manually placing the zeros and the poles in the Z domain of the corresponding discrete linear time‐invariant (LTI) system. This handcrafted design procedure does not allow radiation diagrams with wide beams since the interaction between poles involved in the wide beam and their corresponding leaky modes cannot be easily handled. To overcome this limitation, this paper describes a novel method for designing radiation diagrams of leaky‐wave antenna arrays based on the theory of IIR discrete filters. The proposed method relies on the design of discrete filters with the prototypes of analog low‐pass filters defined by Butterworth and Chebyshev type I polynomials, whose roots along with the bilinear transformation provide the location of the poles and the zeros of the discrete LTI system and, therefore, the parameters of the leaky‐wave antenna array. Results with different designs and a comparison with other approaches show the utility and effectiveness of this novel method to design wide‐beam leaky‐wave antenna arrays.

Investigation into energy performance of a multi-building complex in a hot and humid climate: efficacy of energy saving measures

PurposeCommercial buildings, which include office buildings, are one of the three major energy-consuming sectors, alongside industrial and transportation sectors. The vast increase in the number of buildings is a positive sign of the rapid development of Malaysia. However, most Malaysian government office buildings tend to consume energy inefficiently due to lack of energy optimization. Most of the previous studies focused on the performance of green buildings in fulfilling the green development guidelines. As such, it is essential to study the energy performance of existing government office buildings that were constructed before most energy-efficient standards were implemented to mitigate energy wastage due to the lack of energy optimization. This study aims to analyse the energy performance of existing non-green Malaysian government office buildings and the factors that influence building energy consumption, as well as to evaluate the efficacy of the existing energy conservation measures.Design/methodology/approachThis study was conducted by a literature review and case study. The chosen buildings are six government office building blocks located in Kuala Lumpur, the capital city of Malaysia. In this study, a literature review has been conducted on the common factors affecting energy consumption in office buildings. The energy consumption data of the buildings were collected to calculate the building energy intensity (BEI). The BEI was compared to the MS1525:2019 and GBI benchmarks to evaluate energy performance. SketchUp software was utilized to illustrate the solar radiation and sun path diagram of the case study buildings. Finally, recommendations were derived for retrofit strategies based on non-design factors and passive design factors.FindingsIn typical government office buildings, the air-conditioning system consumed the most energy at 65.5%, followed by lighting system at 22.6%, and the remaining 11.9% was contributed by office appliances. The energy performance of the case study buildings is considered as satisfactory as the BEI did not exceed the MS1525:2019 benchmark of 200 kWh/m2/year. The E Block recorded the highest BEI of 183.12 kWh/m2/year in 2020 due to its north-east orientation which is exposed to the most solar radiation. Besides, E Block consists of rooms that can accommodate large number of occupants. As such, non-design factors which include higher occupancy rate and higher cooling demand due to high outdoor temperature leads to higher energy consumption. By considering passive design features such as building orientation and building envelope thermal properties, energy consumption can be reduced significantly.Originality/valueThis study provided a comprehensive insight into the energy performance of Malaysian government office buildings, which were constructed before the energy-efficient standards being introduced. By calculating the BEI of six government office buildings, it is found that the energy performance of the case study buildings fulfils the MS1525 benchmark, and that all their BEIs are below 200 kWh/m2/year. Malaysia's hot and humid climate significantly affects a building's cooling load, and it is found the air-conditioning system is the major energy consumer of Malaysian government office buildings. This study discusses the efficacy of the energy-saving measures implemented in the case study buildings to optimize energy consumption. Recommendations were derived based on the non-design factors and passive design factors that affected the energy consumption of the case study building. It is envisioned that this study can provide practical strategies for retrofit interventions to reduce energy consumption in Malaysian office buildings as well as for office buildings that are in a similar climate.

Reddening-Free Q Parameters to Classify B-Type Stars with Emission Lines

The emission-line B-type stars constitute a heterogeneous group. Many of these stars show similar optical spectroscopic features and color indices, making it difficult to classify them adequately by means of photometric and spectroscopic techniques. Thus, it is relevant to deal with appropriate classification criteria to avoid as many selection effects as possible. For this purpose, we analyzed different reddening-free Q parameters, taking advantage of the Gaia and 2MASS photometric surveys, for both main sequence and emission-line B-type stars. Along with this work, we provided various criteria to search for normal and emission-line B-type stars, using different color–color, Q–color, and Q–Q diagrams. It was also possible to identify stars in different transition phases (i.e., (Rp−J) vs. (J−Ks) diagrams) and to classify them according to their NIR radiation excesses (i.e., the (Bp−Rp) vs. (H−Ks) diagram). Other diagrams, such as the QJKHK vs. (H−Ks) or QBpJHK vs. (Bp−Ks), were very useful to search for and classify different classes of B-type stars with emission lines. These diagrams highlighted the presence of several stars, classified as CBe, with large color excesses that seemed to be caused by the presence of dust in their envelopes. Therefore, these stars would be misclassified. Three groups of HAeBe stars with different intrinsic dust properties were also distinguished. The amount of intrinsic dust emission in the diverse groups of emission-line stars was well-recognized via the QJHK vs. QBpRpHK diagram. The different selection criteria are very important tools for automated designs of machine learning and optimal search algorithms.

Counterpropagating radiation emitted by an electron in the field of a Gaussian laser pulse

The transition from the nonlinear Thomson scattering (electron initially at rest) to the classical limit of Compton scattering (electron moving towards the laser pulse) is considered. The radiation emitted by an electron in the form of plane waves in the far zone is analyzed, and the intensity distribution over the solid angle is obtained. By constructing radiation diagrams, we find numerically the dependences of the intensity and power of radiation on the initial energy of the electron The backscattering intensity as is find analytically is proportional to six power in initial energy and to the peak power of the laser pulse. It is shown that as the initial energy of the electron increases, the effective solid angle of the scattered radiation decreases monotonically and becomes constant.

Smart Fractal Antennas in Transition Projects to 5G

This paper proposes the combined use of two promising techniques in the design of 5G systems: fractal antennas and smart antennas. This new arrangement is capable to operating efficiently in multiband while directing the beam to the region of interest, promoting a better use of the spectrum and therefore allowing multiplesbeamforming to share resources in the time and frequency domain, an essential requirement for the fifth generation. In addition, the proposed array can be availed in projects that still use the previous generation technology, 4G, which would allow a more economically viable transition to 5G, especially for Latin American countries.A new type of smart fractal antenna is simulatedfor a wide range of frequencies.The parameters chosen for measuring the performance of the structure are the return loss, the radiation diagram and the 3D polar diagram, the most used in the literature. The proposed antenna achieved a return loss of -36 dB for 20.6 GHz and a notable gain of 15 dB, operating in multiband. These values are compared with other works already carried out by other researchers, which allows us to conclude that the proposed antenna is suitable for modern 5G communications.

Directional diagrams of acoustic radiation from unmanned aerial vehicles

When solving the urgent task of detecting small unmanned aerial vehicles (UAVs) by their acoustic radiation (AR), there is a need to study the AR characteristics of UAVs. Therefore, considerable attention is paid in the literature to theoretical and experimental studies of the structure and parameters of the sound field created by UAVs.
 This article is devoted to the experimental study of the directional diagrams of the acoustic radiation from the DJI Phantom 3 unmanned aerial vehicle. The UAV AR recording experiment was conducted in a "silenced" chamber, the walls of which are covered with sound-absorbing panels with a surface of a special geometric shape. The experimental setup includes the UAV mounted on a boom, a microphone for sound recording, and a boom for the microphone.
 Studies of the structure and parameters of the sound field of the quadcopter have shown that the spectra of the emitted signal have pronounced harmonic components with frequencies multiples of the propeller rotation frequency. The spectral components have the greatest power in the frequency range up to 500 Hz, where the first harmonic has the largest amplitude, and then the spectrum components decrease to the ambient noise level.
 Obtained two-dimensional and three-dimensional directional diagrams of the UAV AR with and without propellers when only the aircraft engine is operating. It is shown that in the absence of screws, the acoustic radiation is much weaker in level. The experimental data was also presented in the form of three-dimensional AR diagrams for the four harmonics of the acoustic signal, and it was analyzed what changes in the spatial orientation of the UAV AR are observed based on changes in the three-dimensional figure for each of the radiation harmonics.
 It is shown that the spatial distribution of both the total energy (over the entire frequency range) of the acoustic signal and the energy of its individual spectral (harmonic) components is significantly anisotropic. It follows from this conclusion that the range of UAV detection and observation in real conditions is a statistical value that depends on the angle of its observation.

Fluorescence of anisotropic primary X-ray radiation

In the X-ray spectral fluorescence analysis, the anisotropy of primary radiation results in an uneven radiation of a sample’s surface, strengthening the role of some sections and weakening the role of others. The goal of the current work was to determine the minimal distance from the window of the X-ray tube with a cone-shaped anode at which the intensity of the sample’s radiation becomes homogeneous. The research method was the computer modeling of the X-ray fluorescence experiment. The working model was built on the basis of two equations for the densities of the fluxes of braking and characteristic radiations of the massive anode, which took into account the absorption of primary radiation by the anode’s material and the back-scattering of electrons. The ring source was represented in the model as the sum of infinitely small linear elements of equal power, and the sample was disc-shaped and coaxial with the source. The calculation diagram was very well consistent with the experimental diagram of radiation’s direction described in the research literature. Two spatial distributions were calculated. The first one described the distribution of primary radiation’s intensity on the surface of the sample, while the second one described the distribution of the fluorescent radiation, which was more valuable for the X-ray spectrometry. The calculations showed that although the second distribution, unlike the first one, considered the absorption of the primary radiation and secondary radiation in the sample, the shapes of both radiations were close. It was demonstrated that the area of the sample, which carried the most information on the composition of the irradiated material, was ring-shaped, and the width of this ring depended on the distance to the X-ray tube’s window. As the distance increased, the diagram of the spatial distribution of the radiation’s intensity became smoother, and, when the distance exceeded two diameters of the anode, the radiation became homogeneous. The constructed model, which considered the anisotropy of the primary analysis, could be applied in the method of fundamental parameters of X-ray fluorescence analysis for a spectrometer with compressed geometry.

TRANSITION RADIATION OF A RELATIVISTIC ELECTRON BUNCH ON A SEMI-INFINITE METAL CYLINDER

Transition radiation of a relativistic electron bunch, which arises when it collides with the end face of a semi-infinite ideally conducting cylinder, is considered. An electron bunch moves along the axis of a semi-infinite cylin-der. Expressions for the field strength of electromagnetic radiation in the wave zone are obtained. The influence of the guiding properties of an ideally conducting cylinder on the directional diagram of the transition radiation is investigated.

Акустический сенсор для оценки состояния производственного оборудования

An important trend in the development of industry is the development of digital models of industrial facilities, the work of which is based on information coming from sensors. This allows you to optimize functionality, predict the technical condition of objects, which is especially important, for example, in the field of metallurgical production, where forced stops are accompanied by huge losses. The sensors themselves are also modeling objects, because they need to adapt to rigid production conditions in which their own shortcomings are manifested, while the correct introduction of corrections for environmental conditions, diagnostics and self-diagnostics, which are impossible without building various types of sensor models, is important. The purpose of the work is to deve¬lop a universal discrete model of an acoustic sensor suitable for receiving and emitting acoustic signals. Methods. The work used methods of classical mechanics and mathematics, vibration theory, generalized functions, distributed systems, and mathematical programming methods were used to provide calculations. Results. The main result is a universal discrete model of a sensor with a working element in the form of a round plate, which by choosing parameters can be transformed into a model of a unidirectional dynamic microphone with a flat membrane or a radiator with a focusing spherical element. It is shown that on the basis of the model it is possible to synthesize narrow-directional radiation diagrams and thereby obtain the necessary spatial selectivity and noise immunity of measurements. Conclusion. Calculations made using the proposed model correspond to the known results of acoustics. Verification of the discrete model using a natural sample showed a high accuracy in determining the resonant frequencies and forms of oscillation of the sensor.

Rapid Prototyping of Bio-Inspired Dielectric Resonator Antennas for Sub-6 GHz Applications.

Bio-inspired Dielectric Resonator Antennas (DRAs) are engaging more and more attention from the scientific community due to their exceptional wideband characteristic, which is especially desirable for the implementation of 5G communications. Nonetheless, since these antennas exhibit peculiar geometries in their micro-features, high dimensional accuracy must be accomplished via the selection of the most suitable fabrication process. In this study, the challenges to the manufacturing process presented by the wideband Spiral shell Dielectric Resonator Antenna (SsDRA), based on the Gielis superformula, are addressed. Three prototypes, made of three different photopolymer resins, were manufactured by bottom-up micro-Stereolithography (SLA). This process allows to cope with SsDRA’s fabrication criticalities, especially concerning the wavy features characterizing the thin spiral surface and the micro-features located in close proximity to the spiral origin. The assembly of the SsDRAs with a ground plane and feed probe was also accurately managed in order to guarantee reliable and repeatable measurements. The scattering parameter S11 trends were then measured by means of a Vector Network Analyzer, while the realized gains and 3D radiation diagrams were measured in the anechoic chamber. The experimental results show that all SsDRAs display relevant wideband behavior of 2 GHz at −10 dB in the sub-6 GHz range.

On frequency-independent horn antenna design for plasma positioning reflectometers, from simulation to prototype testing

Using a new framework for horn antenna optimization, a first frequency-independent horn antenna for a plasma positioning reflectometer (PPR) is designed.This hardware optimization is a new approach aiming on lowering the computational complexity of PPR interpretative models able to extract profiles and fluctuations of electron density and temperature from reflectometry measurements. PPR measurements are a strong candidate to provide real-time feedback for plasma position control in long-discharge fusion tokamaks such as ITER and DEMO, which requires fast interpretative models. Reducing the computational complexity of these models is therefore critical.In this paper, ray tracing simulations in the poloidal plane are used to compare different radiation patterns and evaluate them on multiple performance criteria. An antenna shape leading to a frequency-independent far-field radiation diagram is found with the PROFUSION optimizer and a prototype of this antenna is tested against an unoptimized conical reference antenna.The ray tracing performance criteria indicate that fundamental Gaussian frequency-independent antennas perform well, albeit in general worse than same-sized frequency-dependent antennas. Furthermore, it is seen that the pyramidal ITER gap 6 antenna performs well given the spatial constraints and that more performant antennas could be used, when more space was available.The prototype testing reveals challenges in obtaining frequency-independent characteristics within a tokamak blanket environment, which is additionally complicated by misalignment risks.

Invention a Paradigm to Discovery the Network Navigation Using Poisson Distribution

Due to increasing the act of Applied science College in Tamil Nadu, the level of competition for admission price is also increased. By implementing some dynamic strategies only the academic introduction s can meet their own competition. One survey clearly commonwealth that more than 75% of the Engineering Colleges their forcefulness is less than thirty % of their actual intake. Hence the surveillance is the job for the insane asylum s. One more survey shows that every year 10% of the applied science college’ windup their affiliation and blessing due to lack of admittance, and 5% of the engineering college have decided to sell due to lack of strength. With the strong effort and dynamic strategy framed by the institution, the nominee finds admission in an institution only when their own orientation matches exactly, otherwise the candidate continues to go by the next alternate in the list of preference [1]. This paper clearly emphasis some factors influenced to identify the pattern for getting the potency of the bookman to meet at least the breakeven point. In plus to the above, the Populace Wide Web in cyberspace plays an important role to store, part and distribute data about the academic innovation. A social survey states that more than 65% of the admissions gained by their effective network pages. The exponential ontogeny of the World Wide Web has provided an excessive prospect to study the potency student and their deportment by using www accession logs. If the institution’s web sphere clearly contains the information required for the potential educate, surely they can attract the above by which they can get more number of admissions even beyond our jurisdiction.[2] Some of the attractions from the potential students while accessing the web site for getting the admission are: get the required information by clicking minimum act of hits from the vane Page, no network traffic occurred while accessing and navigating the college World Wide Web website. Search interrogation will be rectified within a short period of answer time by implementing the practice of search railway locomotive optimization, search engine spiders. Always use fastest and latest browsers and operating systems in their WWW and not to display much more web server erroneousness while navigating the college web site. For attracting the counseling class and other state students, this network Thomas Nelson Page swordplay an important part. World Wide Web usage Mine lying is the practical application of data excavation techniques to very large data deposit to selection pattern radiation diagram. In general every World Wide Web server keeps a record book of all Synonyms/Hyponyms (Ordered by Estimated Frequency) of noun transaction needed for the potential students and act as a bridge between the potential students and introduction. The record contains full phase of the moon contingent about every user click to the entanglement documents of the entanglement site. The useful record 5 senses of detail needs to be scrutinized and inferred to gather knowledge about actual potential student and their parent preferences in accessing www pages. In recent years several method acting s have been proposed for mining web logarithm data. This theme its main intention is to use the statistical method of Poisson statistical distribution analysis to breakthrough out the higher probability session episode and also comparability the efficiency of our developed algorithm with Poisson value. The subject field of large volumes of click stream data demands the employment of data mining method. Conducting data mining on records of web host contains the determination of frequently occurring access sequences. A statistical method of toxicant distribution clearly shows the probability of oftenest of specific consequence when the norm probability of a single natural event is known. Here the probability of poison value is compared with the efficiency of our developed algorithm. For more bit of transactions, our developed algorithm its performance is better than poison value[3].Because our algorithms excerpt the authority tier as dependent rather independent. The Poisson distribution is used in this paper to find out the probability frequency of particular page is visited by the user as independent, but the result of the developed algorithm is dependent

A compact inexpensive UWB-modified elliptic antenna including a slotted ground plane for an indoor positioning system

Within the present article, an original inexpensive UWB-modified elliptic antenna including slots in its ground plane is presented. This antenna with the FR4-epoxy substrate has a very modest size of 21 × 24 × 1.6mm3. The measured results confirm that the suggested antenna has an impedance bandwidth (|S11|< − 10 dB) of 134.13%, which expands from 3.1 to 15.72 GHz, covering the entire UWB frequency range and reaching a maximum gain of approximately 9.5 dBi at 14 GHz with an average value equal to 3.3 dBi throughout the functional frequency band and a maximum radiation efficiency of 97% obtained for the frequency 8.3 GHz with an average value equal to 94% over the whole frequency band. Excellent accordance between the simulation and measurement is observed. This antenna presents an approximately omni-directional radiation diagram in some directions, a dipole-like radiation pattern at lower frequencies and a quasi-stable group delay through the operating band, making the antenna relevant for most useful UWB applications, especially for indoor localization. Impedance matching is performed by employing two ellipses with diverse semi-major axes ″a″ as radiating patches and by optimizing the size, number, and position of the inserted slots in the downsized ground plane. Detailed information on the simulation and experimental results is provided and discussed.

Uncooled Antenna-Coupled Microbolometer for Detection of Terahertz Radiation

In this contribution, we describe the design, technology, and physical parameters of antenna-coupled microbolometer, used for broadband detection of terahertz electromagnetic spectrum. This microbolometer features an application of La0.67Sr0.33MnO3 layer grown on multilayered material stack ensuring lattice matching of the sensing LSMO layer to silicon. By virtue of bulk micromachining of silicon-on-insulator substrates, the sensing structure is built on thin suspended membrane to provide weak thermal link, increasing thermal response, thus sensitivity. Additionally, it helps suppressing excitation of in-plane guided surface modes that will otherwise deteriorate the antenna radiation diagram and affect the spectral responsivity of the sensor. Finally, the operation of sensor is demonstrated using a molecular laser setup at 762 GHz (and also 1.4 THz) emission line. The parameters of the said microbolometers are analyzed in terms of response and time constant. Optimal working temperature of the detectors is about 65 °C.

A Switchable Polarization Slotted WLAN Antenna with DGS for IOT and Medical Applications

This work a 20 X 35 X 0.8 mm3 rectangular polarization reconfigurable antenna with four slots made at the corners of the patch. These four slots give the appropriate extra modes for circular polarization. Switching between LP and CP can be achieved using a PIN diode which is inserted across an L-shaped slit in the plane of the ground. The designed antenna is optimized and analyzed through simulations. The axial ratio (< 3 dB) bandwidth and impedance bandwidth (< -10 dB) are overlapped from 5.15 to 6.25 GHz (19.3%). The prototype antenna is tested for both states of the diode (forward and reverse bias). The working band covers the wireless local area network (IEEE 802.11a) band (5150 – 5350 MHz, 5725 – 5825 MHz) and HIPERLAN band (5450 – 5725 MHz) and a favorable compromise between simulated and tested outcomes. The omnidirectional radiation diagrams of the antenna are suitable for wireless portable medical devices.

Electromagnetic band gap based in Peano fractal geometry for harmonic suppression

AbstractIn this paper, an electromagnetic band gap structure with fractal geometry based on Peano curves is proposed to suppression of degenerated modes. The geometry is characterized by the inclusion of air slots into the substrate, under the feed line, of a rectangular microstrip patch antenna. The parameters analyzed are the input impedance using the Smith chart, the reflection coefficient (S11), radiation diagram and the electric field distribution of the propagation modes. The simulated results were compared with the measured results, obtained from manufactured prototypes and show that the proposed structure can be used to attenuate and suppress higher‐order modes.

Design of Compact MIMO Antenna for 5G Mobile Terminal

This report gives the research work carried out for design and analysis of MIMO antenna using two identical Microstrip slot radiators having enhanced isolation. The slot radiators offer compact size in order to accommodate other electronic components for reduction of volume of the wireless communication system. The defected ground structure is formed on the ground plane in between the antenna elements and feed lines to improve the isolation between them. The substrate used for constructing the antenna is FR-4 having the measurements of 26mm x 22mm x 0.8mm and it has the relative permittivity of 4.4. The printed microfilm strip etched on the opposite side of the substratum is used to couple the signal to each antenna. The HFSS software is used in this paper for designing the antenna and for checking the performance of the antenna. The -10dB bandwidth is 1.1GHz in the frequency range of 3.1 GHZ to 4.2GHz. The maximum isolation obtained after simulation is -23.1dB at 3.13GHz. The maximum gain of 2.26dB is obtained. Simulated radiation diagram of the designed antenna indicates that it is a good radiator for 5G applications in the sub 6GHz frequency band.