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Електромагнітна енергія може змінювати метаболічні і біосинтетичні процеси при певних параметрах імпульсного ЕМП (частота прямування імпульсів, шпаруватість, потужність, експозиція) може уповільнювати і пригнічувати клітинний ріст. Опромінювання в ММ діапазоні РНК і ДНК, що містить вірус приводить до зниження їх інфекційності. Пригнічення роста культур бактерій, зміна фагоцитарної активності, біосинтезу білків, ультраструктурні зміни в клітинах при взаємодії ЕМП КВЧ діапазону. В дослідженнях з мікроорганізмами було встановлено, що біологічний ефект від дії ЕМП на мікроорганізми носив резонансний характер. В якості одного з основних механізмів гнітючої дії КВЧ випромінювання на шкідливі мікроорганізми є роль біологічних мембран в реакціях мікроорганізмів на ЕМВ. Електричні явища, які проходять в біомембранах, відіграють виключно важливу роль. Утворення трансмембранної різниці потенціалів обумовлено виборчої іонною провідністю мембран в цілому, є відмінним діелектриком, так біошари електроізолюючих ліпідних молекул здатні витримувати напруженість ЕП порядку 105 В/см. Величина електричного потенціалу на мембрані вкрай важлива. За сучасною теорією трансмембранного транспорту, а саме ЕП всередині мембрани складає потоки необхідних речовин із навколишнього середовища всередину клітини та з клітини в навколишнє середовище через спеціальні гідрофільні канали, скоріше всього, ліпопротеїнової природи. Швидкість проникнення іонів через мембрану визначається такими властивостями, як товщина, значення ДП, наявність фіксованих електричних зарядів на мембрані, розміри і число пор в мембрані, наявність фіксованих зарядів в порах та деякими іншими.

A unique micro-metamaterial antenna for light and microwave wavelength conversion is proposed, where the antenna has the form of a panda ring which consists of the mu negative metamaterial silver bars embedded at the microring center. The micro-metamaterial antenna characteristics are investigated, where the antenna resonance frequency and frequency range of 1.60 THz and 1–2.2 THz are achieved. The radiation pattern of the micro-metamaterial antenna is plotted, where the obtained gain and directivity of the antenna are − 8.13 dB. The optimum antenna radiation efficiency is 1 when the antenna has dissipative loss is neglected. The micro-metamaterial antenna can be used as a converter between light and microwave, which is useful for a wavelength converter device.

The human body’s absorption of electromagnetic fields from communication enabled devices has consistently been a research topic for both researchers from universities and companies in the mobile communication industry. The absorption of electromagnetic fields could mainly result in two consequences: (a) antenna radiation efficiency of the device could deteriorate dramatically; and (b) a large amount of the radiated power could be dissipated into the human body, such as the hand, ear, scalp and brain, which is defined and described by Specific Absorption Rate (SAR). A comprehensive analysis of electromagnetic field absorption by the human body has been carried out to explain and answer some of the key questions in this area.

This paper proposes a simple and efficient technique to improve the antenna radiation performance in stacked printed circuit boards (PCBs) for Internet-of-Things (IoT) applications. In the ...

In this article, tunable integrated filter/antennas are demonstrated with two coupling configurations that provide design control of the bandwidth performance over the tuning range. The first is a single-layer third-order tunable filter/antenna with an increasing fractional bandwidth (FBW). The measured device has a frequency tuning range from 1.62 to 2.08 GHz, an FBW increasing from 3.0% to 4.8%, and a gain increasing from −7.3 to 3.6 dBi. The second is a double-layer vertically integrated third-order tunable filter/antenna that provides a constant absolute bandwidth over the tuning range. This design accounts for the frequency-dependent behavior of the antenna radiation $Q$ . The constant absolute bandwidth device is tunable from 1.65 to 1.90 GHz, has a maximum bandwidth variation of 45.3 ±7.4 MHz over the tuning range, and exhibits a gain from −6.1 to 4.3 dBi.

Properties of V-shaped metasurface fabricated on flexible substrate polyimide are numerically and experimentally explored at frequency of 4.3 THz. The results verify that anomalous refraction can be produced both for transverse electric and transverse magnetic polarized waves. However, different influences on excited antenna modes and polarization conversion are provided for different polarized incidences. Our results facilitate the application of metasurface in antenna radiation, polarization converter, THz communication, and so on.

This paper presents a design methodology of three-dimensional (3-D) passive metallic waveguide-array lens antenna (MWALA) by implementing the Rotman lens concept (RLC) for collinear multi-beam radiations on the same angular plane. The RLC methodology extends the original concept of two-dimensional (2-D) tri-focal Rotman lens into a 3-D one in free space. Thus, the MWALA has a planar aperture facing to the radiation boresight to resemble a planar phased array of waveguide antennas and also has a curved focal surface profile (CFSP) on the opposite side to receive the illumination by the radiations of feed antennas. The three co-planar focal points are specified to define a circular focal arc (CFA) for multiple feed placement to radiate multi-beams through this MWALA. The boundary formed by the CFSP and CFA resembles the shape of Rotman lens equivalently realized in free space. In addition, the shortage of freedoms in conventional MWALA design limited to dual-focus configurations and resulting in narrow scan angles, is relaxed by adopting the phase velocities inside the waveguides as an additional freedom to realize a tri-focal configuration and broaden the scan angles of multi-beam radiation. Theoretical foundation and design guidelines are summarized with numerical and experimental examples presented to validate the feasibility.

Operation principle of non-coherent radar system (NCRS) is based on antenna radiation of electromagnetic waves into direction of an object of interest and receiving of reflected energy, its processing and information obtaining on parameters of this object, i.e., its coordinates—azimuth, elevation angle and range. NCRS structure is depicted.

In this paper, a multi-band antenna composed of irregular metal plate, input feeders and symmetrical defect ground is designed. The antenna radiation enhancement is improved by placing a rectangular artificial magnetic conductor array with zero phase reflection points corresponding to the multi-band antenna frequencies at a fixed distance below. The three impedance bandwidths of the antenna are 2.13-2.58GHz, 3.43-3.64GHz and 5.7-6.0GHz respectively, which effectively cover the 2.4/5.8GHz WLAN band and 2.5/3.5/3.8GHz WIMAX band. By adding AMC reflector, the performance of the antenna in the working frequency band is significantly improved, and a new frequency band is generated at 7.54-8.63 GHz.

This work presents a metamaterial structure to improve the isolation between two linear slotted waveguide arrays. The proposed decoupling structure consists of two columns of metal pin arrays that can suppress surface wave propagation. Also, the resulting structure only takes up a small space between the radiating slots of the two arrays. Simulated results show a 5 dB improvement in the inter-element isolation without a significant impact on the antenna radiation performance. Moreover, the reflection coefficient bandwidth can be slightly increased.

In this paper, a transmitting antenna fed by rectangular waveguide are intend for the operation at relatively high power levels in practical use, such as mid-range wireless charging. The proposed transmitter is composed of square patches on a 1.5mm thick dielectric substrate. The square patches are connected by main feeder and excited by rectangular feeding patches in the middle of the antenna. Single antenna is fed by a rectangular waveguide and sized for 370×480 mm (14.6×18.9 inch). The transmitting antenna is investigated by simulation and experimentally. The simulated results indicated that this antenna achieves 30dB gain and 150MHz bandwidth from 5.74 to 5.89 GHz. Experimental results are in accordance with those of the simulation results. The electromagnetic field distributions of antenna radiation direction have been characterized both in horizontal and vertical sections. Further analysis of the power density of the improved transmitting antenna is given.

Forthcoming wireless systems are developed to support greater data rate and extra coverage area. This can be achieved with the help of multiple input multiple output and smart antenna techniques. One of the major rapidly emerging areas of communication is the smart antenna system which aids in attaining better coverage by increasing the signal strength only in the chosen direction. With effective optical beamforming techniques, the smart antenna systems demonstrate to be more competent in terms of excellence of signals in wireless communication. In this paper, a succinct outline of the smart antenna, an analysis and the comparison of different architectures of optical signal processing beamforming network (OSPBFN) is presented. The performance of OSPBFN is analyzed and the comparison is done for different architectures with the antenna radiation parameters. This paper can enhance the understanding of the ongoing research work in the area of OSPBFN.

In this Letter, a new polarising grid for a folded reflectarray is proposed to improve the aperture efficiency of the antenna. This polarising grid is designed using a partial grid and a director which can improve the antenna radiation characteristic. Consequently, the measured aperture efficiency of the proposed antenna with the new polarising grid is 60.49% at 77 GHz.

We propose a novel antenna design enabled by 3-D printing technology for future wireless intrachip interconnects aiming at applications of multicore architectures and system-on-chips. In our proposed design we use vertical quarter-wavelength monopoles at 160 GHz on a ground plane to avoid low antenna radiation efficiency caused by the silicon substrate. The monopoles are surrounded by a specially designed dielectric property distribution. This additional degree of freedom in design enabled by 3-D printing technology is used to tailor the electromagnetic wave propagation. As a result, the desired wireless link gain is enhanced and the undesired spatial crosstalk is reduced. Simulation results show that the proposed dielectric loading approach improves the desired link gain by 8–15 dB and reduces the crosstalk by 9–23 dB from 155 to 165 GHz. As a proof-of-concept, a 60 GHz prototype is designed, fabricated, and characterized. Our measurement results match the simulation results and demonstrate 10–18 dB improvement of the desired link gain and 10–30 dB reduction in the crosstalk from 55 to 61 GHz. The demonstrated transmission loss of the desired link at a distance of 17 mm is only 15 dB, which is over 10 dB better than the previously reported work.

A high-gain ridge gap array antenna, consists of an array of 2×8 monopole antennas with inter-element spacing equals to a wavelength, is proposed and investigated as a promising state-of-the-art grating lobe suppressed high-gain array for millimeter-wave frequency-bands. Increasing the inter-element spacing is a technique for enhancing the directivity; however, it would bring the grating lobe into the visible zone and deteriorate the antenna radiation efficiency. The proposed technique using a supplementary sub-array would suppress the grating lobe in the visible zone. On the other hand, the feeding network is designed with ridge gap waveguide technology in which the waveguide width is about a wavelength making the design of an array antenna with lower inter-element spacing more challenging.

A novel dual-band two port Multiple-Input-Multiple-Output (MIMO) antenna at 28/38 GHz bands for the approaching 5G wireless applications is configured and manufactured in this paper. The MIMO antenna takes in identically positioned two rectangular slotted patches with inverted I-shaped slots at the lower border of the mobile substrate. The system has an overall size of 55 x 110 x 0.508 mm3. The antenna works in a 1.0683 (27.58–28.649) GHz bandwidth at 28 GHz and 1.4306 (37.213-38.643) GHz 38 GHz. A defected ground construction (DGS) to raise the isolation among the two ports and magnify the antenna radiation is introduced. The isolation is further desirable than -29.4 dB and -27.3 dB for the higher and lower frequencies, respectively among antenna elements. The MIMO antenna is planned and optimized through CST-MW Studio 2017 simulator as well as by measurement. The results from simulation and measurement are in a good agreement in the meaning of reflection coefficients and mutual coupling of the introduced MIMO antenna.

A novel technique is presented to enhance the gain of a rectangular Dielectric Resonator Antenna (DRA) over a wideband. The antenna structure achieves a 16 GHz bandwidth of relative bandwidth of 27.5 % in the 60 GHz band. The peak realized gain is 12.6 dBi with a total antenna radiation efficiency of 96 %. Printed Electromagnetic Band Gap (EBG) technology has been used to feed the antenna and eliminate any parasitic radiation from the feed line. The antenna is suitable for high data rate short-range personal area networks applications at millimeter wave frequencies.

A 2D periodic leaky wave antenna produces a narrow and highly directive beam at broadside. This structure is optimized and implemented in the microwave regime and also the optical regime. The antenna radiation characteristics as well as the modal properties of the 2D periodic leaky wave structure have been studied. The 2D periodic leaky wave antenna (LWA) for microwave frequencies is then further optimized in the shape of a cross to eliminate grating lobes.

This paper presents the potential of perovskite antenna in the millimeter band. New materials have been developed to obtain suitable chemical characteristics to offer several advantages including simple structure, high operating bandwidth, high gain, compact and low-profile antennas in the millimeter range. The performance of antennas fabricated using these materials is analyzed here. Simulated results of the antenna prototype show a wide bandwidth of 26-33 GHz. Moreover, simulation evaluation of peak gain of the antenna is 1.443 dB at 28.8 GHz. Low efficiency of 45% in the range of operation presents as the main drawback of this design. The analysis is further extended to examine the impact of different flexible substrate materials. The thickness of the patch is also examined to optimize the antenna radiation performance.

The high-speed flying train in vacuum tube is a brand new mode of transportation proposed in recent years. Unlike the traditional high-speed railways, the ultra high speed of high-speed flying train results in severe Doppler effect, exerting an adverse impact on the vehicle-to-ground communication. In this paper, two structures are proposed mainly to solve the Doppler effect problem. The purpose of first structure is to control the angle between movement direction and antenna radiation direction as small as possible by helical distribution of directional antennas so as to keep the Doppler shift vary within narrow range. The second structure aims to keep the angle as close to 90° as possible by the helical distribution of slots based on the leakage waveguide. The simulation result shows that both two proposed structures present good performance of reducing the Doppler shift caused by high speed dramatically.

The radiation efficiency prediction using the Wheeler cap is introduced using a semianalytic approach based on the adaptive fitting quality factor method. The procedure details, highlighting the benefits of using the proposed method, are presented, especially in the presence of cavity modes. Also, a procedure is proposed to eliminate the effect of cavity modes for low-frequency antenna measurements. Several studies over the suitability of the proposed procedure are presented to justify the usage of the quality-factor-based method beyond its previous limited usages. The reproduction of results is ensured by considering sufficient data based on an asymptotic prediction of the cavity modes’ frequency spacing. Moreover, full-wave simulation results are presented to verify the proposed method and its immunity to the effects of arbitrary Wheeler caps’ cavity modes in a controlled environment, anticipating possible sources of errors. Also, the same simulated responses are used through other circuit model-independent radiation efficiency prediction procedures to evaluate the performance of the proposed method. Furthermore, the measurement results are presented for various antennas to verify the proposed method in comparison with the full-wave analysis.

In this letter, we show that a cylindrical, single-layer impedance metasurface enclosing a radiating source is capable of reshaping the electromagnetic field pattern at a predetermined radius outside of the metasurface. We first present the design procedure of a cylindrical impedance metasurface and then proceed to an example demonstrating the achievable pattern accuracy. Simulation results validate the design methodology and show that complete amplitude control can be achieved in the azimuthal direction for a vertically polarized source.

Metamaterial (MTM) anomaly dispersion characteristics have a great interest to be analyzed in the potential for increasing antenna performance. Dispersion material with a simple structure is able to cover the weaknesses of the antenna parameters. Characterization and optimization need to be applied to the MTM antenna design to obtain more effective antenna performance. Antenna operation is performed at 0-9 GHz microwave frequency with four SRR-H MTM structures varying in three radii of 2.5 mm, 2.7 mm, and 2.9 mm. The highest MTM characteristics occurred at four SRR-H radii of 2.9 mm with a refractive index of -8.5 which resulted in antenna parameters RL -48.8 dB, 5.98 dBi, and working frequency of 1.09-9.00 GHz. Antenna radiation occurs precisely in all MTM structures with an isotropic pattern or in all directions of 4.63 dBi at a frequency of 5.976 GHz.

Submarines can navigate underwater and widely used in national defense construction, underwater geological exploration and rescue operations. However, how to achieve effective communication with the submarine has become an urgent problem. According to the development of very low frequency (VLF) communication needs, the electromagnetic theory model of airborne VLF dual trailing antenna system is established. VLF dual trailing antenna radiation characteristics and simulation analysis of near-field characteristics of airborne platform are realized.

This paper presents a compact and highly-efficient inverted-F antenna (IFA) suitable for Internet of Things (IoT) applications. A slotted ground is applied to significantly improve the antenna radiation efficiency. Compared to a conventional IFA on a solid ground plane, the proposed structure enhances radiation efficiency approximately 100%, from 14% to 27%, at 750 MHz. Simulated and measured results are in an excellent agreement, fully validating the IFA response.

A square patch microstrip antenna was initially studied; its frequency and bandwidth characteristics were noted. The frequency selective surface (FSS) was then employed based on the studied characteristics to enhance the impedance bandwidth and antenna gain. With embedded air lacunas and low loss dielectric properties of the substrate integrated suspended line (SISL) technology, an antenna radiation efficiency of 91.6% is seen. The size of the antenna is relatively smaller and can be fabricated on a standard PCB technology at low cost.

Up to now most limits for radiated emission are given as values for the electrical field strength. Battermann, 2007 has shown that the frequency range extension for radiated emission measurements above 1 GHz generates a lot of problems while performing the test on a classical test site as depicted in Fig. 1. This paper will give a motivation to use an other measurand namely the total-radiated-power than electrical field strength by using alternative test sites like reverberation chambers, TEM-waveguides, Fully Anechoic Rooms (FAR) etc. Nevertheless most of the existing standards still specify electrical field strength limits. This paper will show how to set the parameters in the given algorithm to establish a link between measured total radiated power and equivalent electrical field values.

In this communication, the design and implementation of a three-band substrate integrated waveguide (SIW) leaky-wave antenna (LWA) based on the composite right/left-handed (CRLH) structure is presented. CRLH unit cell of the proposed antenna is composed of two adjacent interdigital slots with two vias between them. Two CRLH bands along with a new right-handed (RH) band between them are achieved through this structure. The first CRLH band (7.1–10.75 GHz) is balanced and the second one (15.1–21.75 GHz) is unbalanced with 0.25-GHz stop band. Beam scan angle in the first CRLH band is from $- 78^\circ $ to $+ 78^\circ $ , in the second one from $- 40^\circ $ to $+ 20^\circ $ and in the new RH band (12.6–13.4 GHz) from $+ 22^\circ $ to $+ 54^\circ $ . Antenna radiation efficiency in the first CRLH band is about 90%. Simulated and measured results are compared and there is a good agreement between them.

A double-layer complementary metasurface (MS) with ultra-wideband polarization conversion is presented. Then, we propose two application cases by applying the polarization conversion structures to aperture coupling patch antenna (ACPA). Due to the existence of air-filled gap of ACPA, air substrate and dielectric substrate are used to construct the double-layer MS. The polarization conversion bandwidth is broadened toward low-frequency range. Subsequently, two application cases of antenna are proposed and investigated. The simultaneous improvement of radiation and scattering performance of antenna is normally considered as a contradiction. Gratifyingly, the contradiction is addressed in these two application cases. According to different mechanism of scattering suppression (i.e., polarization conversion and phase cancellation), the polarization conversion structures are utilized to construct uniform and orthogonal arrangement configurations. And then, the configurations are integrated into ACPA and two different kinds of metasurface-based (MS-based) ACPA are formed. Radiation properties of the two MS-based ACPAs are improved by optimizing the uniform and orthogonal arrangement configurations. The measured results suggest that ultra-wideband polarization conversion properties of the MS are achieved and radiation enhancement and scattering suppression of the two MS-based ACPAs are obtained. These results demonstrate that we provide novel approach to design high-performance polarization conversion MS and MS-based devices.

In this paper, we present a wideband implantable antenna operating at ISM band. To obtain directional radiation pattern, five PEC planes are arranged at the bottom layer and on the four sides of the antenna to limit antenna radiation. The proposed antenna has a wide −10 dB bandwidth of 2.18–2.69 GHz covering ISM band and the back-to-front ratio of the antenna is 22 dBi on xoz plane. The directional antenna has a compact size of 11 mm×12 mm×10 mm.

Corrugated horn is often preferred due to having low cross polarization over a very wide bandwidth in C-band satellite communication, but the corrugated horn is challenging to fabricate and weight. Therefore, a novel smooth-walled horn is proposed in this paper. The horn has low cross-polarization (

In this paper, a novel design of Vivaldi antenna worked in the C, X band with lower RCS has been given. Through the perforation of the antenna metal surface and the dielectric plate, the induced current caused by the incident wave can be bounded with these conductive vias. On the condition that the antenna radiation performance is basically the same circumstances, the RCS of the antenna in the working band can be reduced significantly, especially in the higher frequency part of the operation band.

This work is devoted to calculation of constitutive parameters and numerical simulation of anisotropic metamaterial lens via transformation optics concept. The possibility to use this lens as a device for imitation of an antenna radiation out its real location is shown in this work.

Spatially distributed generators on electron-oscillator flows are promising for high-power microwave radiation. In the case of multibeam generator output microwave energy of each beam can be made via antenna assemblies that determine the polarization of the field including a linear polarization in one direction of the coordinate axes. By the method of the non-linear nonstationary theory developed the discrete model of the multibeam microwave generator based on use of the equivalent self-oscillators with slowly varying amplitudes and phases. Formation of an antenna radiation field in three-dimensional approximation on the example of cylindrical ring system of radiators is considered. Each ring consists of a large number dipoles oriented in the longitudinal direction.

International audience; The design of multi-band patch antennas is addressed within the System-by-Design (SbD) paradigm. A fast optimization-driven strategy combining customized tools for the effective exploration of the solution space and the efficient evaluation of the antenna radiation performance is proposed. Toward this aim, an Ordinary Kriging (OK) predictor is used as a surrogate model of the cost function while the Differential Evolution (DE) algorithm is used to effectively minimize it. Some preliminary numerical results are reported to show the potentialities of the proposed design methodology.

In this paper, we present a theoretical investigation on the radiation efficiency of small on-body antennas in the context of Body Area Networks. In particular, we show that operation at frequencies above 20 GHz experiences less human-tissue losses than below 6 GHz, and could therefore be a suitable candidate for more efficient off-body wireless communications.

International audience; In this paper, an antenna with reconfigurable radiation pattern in H-plane at 2.45 GHz for high power applications is presented. It is based on a 3-slot array in E-plane covered partially with two mobile metallic flaps in order to reduce their length, and in consequence, they ensure the mechanical reconfiguration pattern in H-plane. The power distribution of the array is ensured with a power splitter in E-plane, and the uniform and in phase field distribution on the slots is ensured with a sectorial horn placed before the splitter. To reduce cost and weight, the power splitter is realized with metalized wood. © 2017, Electromagnetics Academy. All rights reserved.

Unidirectional waveguide grating antennas for nanophotonic phased arrays are demonstrated with over 90% directionality. Unidirectional emission eliminates the fundamental problem of element factor blind spots due to reflections of the antenna radiation within the substrate.

A compact patch antenna with stacked parasitic strips (SPSs) based on low temperature cofired ceramic (LTCC) technology is presented. By adding three pairs of SPSs above the traditional patch antenna, multiple resonant modes are excited to broaden the bandwidth. At the same time, the SPSs act as directors to guide the antenna radiation toward broadside direction to enhance the gain. The measured results show that the prototype antenna achieves an impedance bandwidth of 16% forS11<-10 dB (32.1–37.9 GHz) and a maximum gain of about 8 dBi at 35 GHz. Furthermore, the radiation patterns and gain are relatively stable within the operating bandwidth. The total volume of the antenna is only 8 × 8 × 1.1 mm3.

With the development of nano-optic technology, the optical nano-antenna has been widely used in the flelds of novel light sources, high-sensitive biological sensors, nanometer lithography, and nano-optical imaging. The relationship between the structural parameters of the antenna and the Purcell factor is very important for engineering applications. The electric near fleld proflle of the antenna was calculated and analyzed by using the flnite-difierence time-domain (FDTD) method, and the in∞uence of the structural parameters on the Purcell factor and the electric fleld was thoroughly investigated. A careful comparison of bowtie antenna radiation characteristics with difierent structural parameters was carried out. The results show that the thickness, the length and the curvature radius have great efiects on the Purcell factor and the optical antenna's electric near fleld. These flndings are promising for improving the performance of the optical bowtie nano-antenna.

In this paper, a partially ferrite-loaded rectangular waveguide is proposed as a periodic transmission line. Based on the modal analysis and the calculated dispersion diagram, this structure has a magnetically tunable composite right/left-handed (CRLH) response. As an application of this CRLH structure, a novel magnetically scannable antenna is presented with fixed and multi frequency beam scanning capability. Compared to the conventional ferrite-based antenna, the efficiency of the proposed antenna is high. In addition, there is not any mechanical switch or electrical tuning chip in the proposed scannable antenna. The simulation results show that the proposed antenna can be scanned from −23 to 40 degrees where the minimum antenna radiation realized gain is 14 dB. This work can be used as a first step in the design of a high performance reconfigurable scannable antenna in future investigations.

Here we present a new detection approach based on microwave technology. The previous works show that the proposed approach gives a hope for human neuronal activities detection and has its own unique advantages and characteristics of non-contact and being nondestructive. In this paper, The novel detection method and its basic principle will be studied and demonstrated first. Then, an anatomically accurate high-fidelity human head model was applied in simulation to study the electric field distribution and brain's influence on the antenna radiation.

International audience; This paper investigates the effect of the radius of a Over-The-Air (OTA) multi-probes ring employing half-wavelength dipoles, on the emulated spatial correlation. The Device Under Test (DUT) is considered randomly oriented in the test zone. Based on the correlation error metric, antenna effect on correlation is evaluated for a Clarke's and single cluster scenarios and OTA two-dimensional rings with up to 32 probes. © 2016 European Association of Antennas and Propagation.

International audience; We propose an approach to increase the operating range and matching stability of in-body ingestible or implantable capsule antennas. It involves using high permittivity biocompatible superstrate on a high-Q narrowband microstrip antenna. In this way, the antenna-body coupling can be significantly reduced, resulting in improved detuning immunity, increased radiation efficiency, and reduced power absorption inside the body. To demonstrate the feasibility of the proposed approach, we designed a mid-ISM band (433 to 434.8) MHz low-profile (85 μm) conformal microstrip antenna loaded with high permittivity ceramic superstrate. We achieved a simulated gain of -20.4 dBi. The radiation efficiency reaches 0.6%, which exceeds the counterparts operating within the same band by at least 3.5 times. The bandwidth is 26 MHz (6%), while the antenna remains matched (S11 < -10 dB) at 434 MHz within a wide range of tissue-equivalent phantoms. To validate the numerical results, we manufactured an antenna prototype and characterized it in terms of reflection coefficient S11. © 2016 European Association of Antennas and Propagation.

In this paper we study the radiation patterns of metallic cylinders by the acousto-optical technique named pulsed Schlieren. The cylinders have diameters of the order of ultrasonic wavelength. The results obtained are compared to the antenna radiation theory. The future application of this work is to study bone tissue by Schlieren techniques to detect diseases early on.

We investigate here the capabilities of a 400-element reconfigurable transmitarray antenna to synthesize monopulse radiation patterns for radar applications in $X$ -band. The generation of the sum ( $\Sigma )$ and difference ( $\Delta $ ) patterns are demonstrated both theoretically and experimentally for broadside as well as tilted beams in different azimuthal planes. Two different feed configurations have been considered, namely, a single focal source and a four-element focal source configuration. The latter enables the simultaneous generation of a $\Sigma $ - and two $\Delta $ -patterns in orthogonal planes, which is an important advantage for tracking applications with stringent requirements in speed and accuracy.

Luneburg lens antenna radiation fields are calculated with Green's functions of spherical and cylindrical layered structures. Electric field components of spherical and cylindrical Luneburg lenses excited by linear and circular polarized incident field are analysed. Dipole, slot and aperture antennas are described by electric and magnetic extraneous currents. Radiation patterns of cylindrical and spherical Luneburg lens are analysed. Co-polarized and cross-polarized field radiation patterns are shown. The proposed method significantly reduces the computing time for multi-layered lenses in comparison with the most commonly used in antenna design. The first step antenna structure optimization may be performed for a shorter time. The results may be used as the first approximation for Ansys HFSS and other software.

Each of us are exposed to the environmental electromagnetic fields, such as the geomagnetic field, electromagnetic field from power line, and antenna radiation etc. all the time, when the biological tissue exposure in the electromagnetic fields may lead some certain effects, and many effects are studied during the past few years, most of these studies concentrated on negative effects of electromagnetic fields. It is necessary to explore effects of these environmental electromagnetic fields on human body comprehensively, some effects of environmental electromagnetic fields are studied theoretically in the following paper, and attenuate characteristics of several environmental electromagnetic fields propagate in human body is discussed. The theoretical results expressed the penetration depth of several environmental electromagnetic fields, and the possible effects of long term effects are analyzed.