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Frequencies from 100 GHz to 3 THz are promising bands for the next generation of wireless communication systems because of the wide swaths of unused and unexplored spectrum. These frequencies also offer the potential for revolutionary applications that will be made possible by new thinking, and advances in devices, circuits, software, signal processing, and systems. This paper describes many of the technical challenges and opportunities for wireless communication and sensing applications above 100 GHz, and presents a number of promising discoveries, novel approaches, and recent results that will aid in the development and implementation of the sixth generation (6G) of wireless networks, and beyond. This paper shows recent regulatory and standard body rulings that are anticipating wireless products and services above 100 GHz and illustrates the viability of wireless cognition, hyper-accurate position location, sensing, and imaging. This paper also presents approaches and results that show how long distance mobile communications will be supported to above 800 GHz since the antenna gains are able to overcome air-induced attenuation, and present methods that reduce the computational complexity and simplify the signal processing used in adaptive antenna arrays, by exploiting the Special Theory of Relativity to create a cone of silence in over-sampled antenna arrays that improve performance for digital phased array antennas. Also, new results that give insights into power efficient beam steering algorithms, and new propagation and partition loss models above 100 GHz are given, and promising imaging, array processing, and position location results are presented. The implementation of spatial consistency at THz frequencies, an important component of channel modeling that considers minute changes and correlations over space, is also discussed. This paper offers the first in-depth look at the vast applications of THz wireless products and applications and provides approaches for how to reduce power and increase performance across several problem domains, giving early evidence that THz techniques are compelling and available for future wireless communications.

In multi-user beamforming systems, the inter-user interference are controlled by spatial filtering. Since the implementation of digital beamforming is difficult due to high hardware cost of large array system, the analog beamforming system with one phase shifter at each antenna element is considered with antenna selection scheme. However, the beamwidth is not sufficiently narrow to perfectly remove the interference due to limited size of antenna arrays. To mitigate the interference, we propose the random antenna selection system in millimeter wave channel. The random antenna selection expands the effective array size so that the beamwidth becomes narrow. We compare the beamwidth of conventional fixed antenna selection with random antenna selection and analyze the amount of interference for each selection scheme. Theoretical analysis and bit error rate simulation results indicate that the beamforming with random antenna selection can take advantage of large array.

A novel antenna design for implantable pacemakers is proposed. The housing of a pacemaker is utilized as an antenna to cover both the 402–405 MHz Medical Implant Communication Service band and the 433-MHz Industrial, Scientific and Medical band. This is achieved by exploiting radiating characteristic current modes of the housing case. These modes are excited using a capacitive coupling element with the help of a matching circuit. The radiation pattern of this antenna is optimized to be in a desirable direction away from the body (off-body direction). The ability of the proposed antenna for communications is demonstrated using a transceiver and a base station at 433 MHz. A communication range of 1 m is established when a transmitter with the proposed antenna is implanted in a rabbit and the power fed by the transceiver to the antenna is $25~\mu \text{W}$ . A longer range of up to 19 m can be established with the maximum allowable transmit power within the safety limits. Furthermore, the far field wireless power transfer through the proposed antenna is investigated by experiment. A received power of up to $22.38~\mu \text{W}$ by the proposed antenna is demonstrated when an equivalent isotropically radiated power of 140 mW is transmitted 1 m away from a transmitting antenna. From the same transmitting antenna in the same distance, a power of 4 mW can be received when the transmit power is within safety limits. This power can be used to recharge a small battery or a capacitor, which can potentially cover the communication power consumption of the pacemaker and hence extend the life span of the primary battery.

A planar Vivaldi antenna was reconstructed and assessed as a candidate for a short range, high range resolution railway cutting monitoring radar. The initial flare section of the Vivaldi antenna was found to control the return loss of this type of antenna at lower frequencies, and a compact antenna for 120% fractional bandwidth was demonstrated experimentally. Group delay was used as a UWB antenna assessment method, and the prototype antenna gave reasonable performance across the lower half of the band considered.

In the scope of broadband radiators, the biconical antenna, or its monopole conical counterpart, is long known to be a proper choice. One common form of such radiator, the spherically capped conical antenna (SCCA), has closed-form solution to its input impedance, from which the broadband performance potential is easily verified. Nonetheless, from the design perspective, apart from a few clues inferred from existing solutions, little is found to accurately guide the choice of the main geometrical parameters of the antenna that will enable it to comply with a set of imposed bandwidth requirements. This paper proposes a simple 10-step sequence to derive conical or biconical antenna design charts. These charts provide straightforward information on the geometrical limits within which the required antenna impedance matching broadband performance is achieved. The method is assessed for the SCCA and the open conical antenna (OCA) using theoretical and simulated estimates of the input impedance. A discussion on the impact of the cap and the feed gap is included.

In this paper, we present the antenna design for a nano-satellite mission launched in September, the GOMX-3 mission. Some of the key design challengesare discussed and the chosen solutions are presented. In an effort to minimize development and manufacturing costs for future missions, this study showshow to modify off the shelf components in order to tailor them to the specifications of the mission at hand. The performance of the antenna is increased by up to 1.4 dB with a simple modification to adjust the resonance frequency. The antenna system’s performance is investigated through simulation and measurement and the results indicate that the design meets specification requirements.

International audience; This paper presents and investigates a broadband sounding rocket antenna developed for dual-band data transmission of telemetric and payload systems. This single-element antenna permits the use of both the well-established 869.4-869.65 MHz and 2.4-2.4835 GHz frequency bands available in Europe to implement a redundant transmission of telemetric and tracking data desired for reliability. Furthermore, the available spectrum in the upper band offers a high-speed wireless link for transmitting payload data. To preserve the mechanical integrity and aerodynamics of rocket, the antenna is integrated in its nose cone. The proposed low-cost and low-weight structure is based on PCB (Printed Circuit Board) pieces assembled in a LEGO-like manner to form a broadband 3-Dimentional (3-D) bi-conical antenna, which is fed by a diplexer integrated in its base. A prototype has been fabricated, and validated using a reduced-length fuselage in a near-field measurement system.

This paper shows the design of a radial line slot antenna for Space Debris Radar Applications. The monopulse antenna has two beams, sum and difference, and requires an amplitude and phase receiver for detection of the azimuth and elevation direction of arrival. The antenna is circular polarized, and this paper focus on the design of the receiver antenna. The paper shows the optimization process of the position and length of slots in the central frequency of 94 GHz and a first analysis of the feeding network. This design will be tested with the fabrication of a prototype.

The characteristics of a novel antipodal Vivaldi antenna array mounted on a dielectric cone are presented. By employing antipodal Vivaldi antenna element, the antenna array shows ultrawide bandwidth and end-fire radiation characteristics. Our simulations show that the cone curvature has an obvious influence on the performance of the conformal antenna, in terms of both the bandwidth and the radiation patterns. The thickness and permittivity of the dielectric cone have an effect on the bandwidth of the conformal antenna. Measurement results of both single antenna and conformal antenna array show a good agreement with the simulated results. The measured conformal antenna can achieve a −10 dBS11with bandwidth of 2.2–12 GHz and demonstrate a typical end-fire radiation beam. These findings provide useful guidelines and insights for the design of wideband end-fire antennas mounted on a dielectric cone.

This paper deals with the electromagnetic modeling of a dipole antenna mounted on a micro Unmanned Aerial Vehicle (UAV). Such a setup has been recently used as a test source to characterize the radiation pattern of fairly large VHF and UHF antennas in their installation conditions i.e. on the ground, with adjacent elements. In this framework, an accurate modeling of the test source is fundamental to distinguish properly its radiation characteristics from those of the antenna under test. The computed results are verified with both reflection coefficient and pattern measurements showing a very good agreement.

The concept of a local phase center is discussed. At the test example, the computation algorithm has been validated by an analytical one. A technique overwhelming some calculus difficulty is presented. An indefiniteness of a local phase center is proved to be not greater than that of a widely used notion of an antenna phase center.

A novel low profile two elements array of circular patch antenna is designed, analyzed and simulated for wireless sensor applications in extremly harsh environments like jet engines. The designed antenna is simulated using 'Ansys Designer 2014'. Due to the environmental constraints, the antenna is designed to be extremly thin and flexible. The size of the antenna is small enough to have a reliable radiation pattern. The simulated characteristics of the antenna is really promising for the future fabrication and implementation inside jet engines. 2015 IEEE. Scopus 2-s2.0-84953719802

A novel antenna measurement strategy has been developed to characterize both the embedded-element and the array patterns in the real installation conditions at low frequencies (50 MHz - 650 MHz) [1]. It exploits a micro Unmanned Aerial Vehicle (UAV) as a far-field test source. The system demonstrated good performance on the copolarization radiation pattern of VHF and UHF antennas. Several results with reference antennas have been published [2, 3]. Further experiments have been performed on the Aperture Array Verification System (AAVS0) array and the Medicina Array Demonstrator (MAD), which also focus on the calibration of a small array and the beam forming. This paper presents two recent experiments performed on a log-periodic antenna at 250 MHz and 350 MHz. Significant results have been achieved for both co- and cross-polarization patterns. Moreover, the symmetry of the test-source pattern has also been demonstrated.

This paper presents an S-band AESA antenna with inexpensive T/R-modules and a novel RF feeding network operation technique. The antenna ports of the front-end's feeding network have no isolation mechanisms, which can be problematic in case of not well matched T/R-modules. However, a novel operation is proposed, and the issue is overcome. A system demonstrator is presented, proving: the novel feeding network operation, the low-cost T/R-module approach and the electronic scanning capabilities of the front-end. This low-cost architecture can enable the use of phased-array technology for civil applications like maritime navigation radar.

This paper describes the development of a dualband slotted waveguide antenna for communication, navigation and surveillance radar applications. Two different slot sizes on opposite faces are designed for enabling antenna operation over two different frequency bands. In this way, it becomes possible to perform diverse sorts of tracking using a unique structure. Numerical results, obtained using ANSYS HFSS, demonstrate the proposed antenna provides two bandwidths of approximately 15% and 6.5% for S-band and C-band, respectively. The antenna gain varies from 12.7dBi at 2.2 GHz to 16.37dBi at 4.6GHz.

International audience; A wideband antenna is developed for the mine detection application in the desert via on-board radar. The wideband matching is achieved with resistively loaded Vivaldi antenna. The final 128 elements antenna is split into 16 sub-arrays of 8 elements each driven by electronic switches for SAR imaging purpose. In a first step a sub-array has been made and measured. Then the influence of the overall mechanical structure supporting the antenna is studied in simulation.

Trabajo presentado a 2014 International Radar Conference, 13-17 de octubre de 2014, Lille (Francia) In this work, a metaradome based on a fakir’s bed of nails is designed and tested in order to suppress the blind directions of a 100-element antenna array. The antenna is a microstrip array designed to operate in X-band. The fakir’s bed metamaterial-like was first approximated using analytical formulas before a full-wave numerical optimization. Experimental results are exposed and confronted to numerical results. They show a significant reduction of the blind spot subsequent to the metaradome addition. This work was supported by the METALESA project A- 1089-RT-GC that is coordinated by the European Defence Agency (EDA) and funded by 11 contributing Members (Cyprus, France, Germany, Greece, Hungary, Italy, Norway, Poland, Slovakia, Slovenia and Spain) in the framework of the Joint Investment Programme on Innovative Concepts and Emerging Technologies (JIP-ICET).

In real urban deployments, base station antennas are typically not placed in free space conditions. Therefore, the radiation pattern can be affected by mounting structures and nearby obstacles located in the proximity of the antenna (near-field), which are often not taken into consideration. Also the intrinsic propagation mechanisms of the urban environment (far-field) can contribute to the distortion of the radiation pattern observed in a practical deployment scenario, especially when comparing it to the antenna pattern provided by the manufacturer and typically measured in free space. This paper presents a combination of near-field and far-field simulations aimed to provide an overview of the distortion experienced by the base station antenna pattern in two different urban deployment scenarios: rooftop and telecommunications tower. The study illustrates how, in comparison with the near-field effects, the urban propagation becomes the main contributor to the total distortion experienced. For the considered scenarios, the simulation results show a front-to-back-ratio reduction of approximately 10-15 dB in the effective antenna pattern compared to the free space reference. The near-field distortion has been evaluated by means of finite integration technique (FIT) simulations, while the far-field effects have been analyzed through intelligent ray tracing (IRT).

A general design of the coplanar waveguide excited IIFA, traditionally excited by a Microstrip or coaxial excitation is presented. This coplanar excitation permits the bandwidth improvement (from around 10% to 50%) by the creation of a new resonance on the ground plane. It makes also the antenna more suitable to body area network (BAN) context by facilitating the integration on textile fabric or clothes, and the limitation of body effect at the operation frequency. The antenna principle is analyzed and general designs are presented. As application; a solution of a meandered IIFA integrated on Denim substrate is realized. All results are validated through comparative simulations and measurements.

International audience; In this work we study the impact of antenna radiation patterns disturbed by urban furniture on propagation characteristics. The propagation in urban scenario is modeled with a ray-based deterministic tool. Different base station scenarios are discussed: antenna in proximity of a wall, antenna mounted on a lamp-post and antenna on a bus-stop shelter. The statistical influence of the support is evaluated comparing the results in terms of pathloss with the ones obtained when the isolated antenna radiation patterns are considered.

Any antenna mounted on complex platforms such as ships or planes significantly contributes to the radar signature of an object and increases its detectability as a potential target. Therefore it is important to find solutions which allow mitigating this drawback without compromising the radiative properties of the system. In this work an analysis of the possible improvements able to reduce the Radar Cross Section (RCS) of an antenna array is addressed both in the monostatic and bistatic case at normal and oblique incidence. Different superstrates comprising hybrids FSS configurations are investigated for decreasing the RCS of a slot antenna array although the presented strategy can be successfully adopted for any other planar array.

Accurate evaluation of the Antenna Phase Center (APC) position is a key issue in radar applications. In this work we propose an approach for the APC position measurement in anechoic chamber. The presented method allows overcoming some limitations of the classical algorithm known as Two Point Approach, and it has been tested on two X-band antennas: a standard horn antenna and the three-horn array antenna mounted onboard the TELAER airborne Synthetic Aperture Radar system.

A ray tracing method was proposed to analyze arbitrarily shaped dielectric lens antenna. The lens, made of ABS resin had its flat inner surface and convex outer surface rotationally symmetric with respect to z-axis. The radiation patterns of the dielectric lens antenna fed by conical horn antenna were also presented. The analysis suggested that the lens antenna had suitable characteristics for application in collision warning radar., text, IEEE Antennas & Propagation Society, International Symposium : 2001 , July 8-13, 2001, Boston, Massachusetts, held in conjunction with USNC/URSI National Radio Science Meeting, Proc. of 2001 IEEE Antennas and Propagation Society International Symposium, Vol. 2, pp. 769-772, July 2001.

Civil and military applications increasingly require agile antenna devices which respond to wireless telecommunications, radars and electronic warfare requirements. The objective in this paper is to present the design of a new agile antenna system called EBG Matrix antenna which must be controlled by a synthesis algorithm; this algorithm uses in its loop an analysis procedure which evaluates the radiation patterns. The principle of the antenna is explained and constitutes the subject of an accepted CNRS patent, numbered FR 11 62141. The results obtained by this antenna are good and interesting for many important applications. In order to optimize these results and to respond to several radiation targets, an analysis procedure and synthesis algorithms are indispensable. The aim of this paper is to design a new antenna system which will be used for beam forming, beam steering and geographical coverage applications.

A previous study of a novel technique to design a band-reject UWB monopole antenna by using patch loading is extended. Frequency-domain measurements have confirmed that the antenna designed using this technique rejects the interfering signal at the two intended narrowband frequency ranges. Moreover, the antenna radiation pattern distortion is negligible except at the notched bands. A study of time-domain characteristics based on the antenna pulse response and system fidelity factor is presented. The time performance has been extracted from frequency-domain measurements using a standard method. The obtained time-domain results promise the suitability of the proposed technique to design band-reject antennas useful for future UWB system applications.

The small carrier wavelength at millimeter-wave (mm-Wave) frequencies enables the implementation/nof a large number of co-located antennas. This paper exploits the potential of large antenna arrays at these/nfrequencies to develop a low-complexity directional modulation technique: Antenna Subset Modulation/n(ASM) for point-to-point secure wireless communication. The main idea in ASM is to communicate/ninformation by modulating the far-field radiation pattern at the symbol rate by driving only a subset/nof antennas in the array. Two techniques for implementing antenna subset selection are proposed. The/nfirst technique is simple where the antenna subset to be used is selected at random for every symbol/ntransmission. While randomly switching antenna subsets does not affect the symbol modulation for a/ndesired receiver along the main lobe direction, it effectively randomizes the amplitude and phase of the/nreceived symbol for an eavesdropper along a sidelobe. Using a simplified statistical model for random/nantenna subset selection, an expression for the average uncoded symbol error rate (SER) is derived/nas a function of observation angle for linear arrays. To overcome the problem of large peak sidelobe/nlevel in random antenna subset switching, an optimized antenna subset selection procedure based on/nsimulated annealing is then discussed. Finally, numerical results comparing the SER performance and/nsecrecy capacity of the proposed techniques against conventional array transmission are presented. While/nboth methods produce a narrower information beam-width in the desired direction, the optimized antenna/nsubset selection technique is shown to offer better security and array performance.

International audience; A compact dual pattern diversity antenna combining a slot loop and a dielectric resonator antenna (DRA) is presented for body area network (BAN) applications at 2.4 GHz. A common bandwidth of 1.5% is obtained with an isolation of -12dB. The slot loop provides slightly asymmetric broadside radiation patterns while purely symmetric end-fire type radiation patterns are obtained with the DRA. The diversity gain performance of the antenna has been tested in receiving mode for three different on-body communication channels.

International audience; This paper proposes two studies on a Shark antenna array, working in the frequency band [800MHz - 8GHz], in a configuration including N generators and N antennas. The first study deals with the evaluation of the performances of the array from the analyze of the transient performances of the elementary system "generator + antenna". The second study concerns the comparison of two arrays having the same surface area, but a different number of antennas thanks to a scaling method on the dimensions of the elementary antenna.

A wide-slot UWB antenna is presented for intended use in the detection scheme being developed at the University of Bristol, based on the principle of synthetically focused UWB radar using a fully populated static array. The antenna's measured and simulated, input and radiation characteristics are presented and compared to an existing, stacked patch antenna that has been designed for the same purpose. The results of this study show that the wide-slot antenna has excellent performance across the required frequency range. Compared to the stacked-patch antenna used in our previous array, the wide-slot antenna can be 3 times smaller (in terms of front surface). The compact nature of the slot antenna means that the detection array can be densely populated. Additionally, this new antenna offers better radiation coverage of the breast. For angles up to 60° away from bore-sight radiated pulses are almost identical (fidelity >95%), whereas for the patch antenna fidelity falls to 58% at the angular extremes. This uniform radiation into the breast should result in focused images with low levels of clutter. A wide-slot UWB antenna is presented for intended use in the detection scheme being developed at the University of Bristol, based on the principle of synthetically focused UWB radar using a fully populated static array. The antenna's measured and simulated, input and radiation characteristics are presented and compared to an existing, stacked patch antenna that has been designed for the same purpose. The results of this study show that the wide-slot antenna has excellent performance across the required frequency range. Compared to the stacked-patch antenna used in our previous array, the wide-slot antenna can be 3 times smaller (in terms of front surface). The compact nature of the slot antenna means that the detection array can be densely populated. Additionally, this new antenna offers better radiation coverage of the breast. For angles up to 60° away from bore-sight radiated pulses are almost identical (fidelity >95%), whereas for the patch antenna fidelity falls to 58% at the angular extremes. This uniform radiation into the breast should result in focused images with low levels of clutter.

This letter describes a novel compact solution for integrating a Global Positioning System (GPS) and a Satellite Digital Audio Radio Service (SDARS) antenna in a very small volume to satisfy the requirements of the automotive market. The GPS antenna is a classic small commercial ceramic patch, and the SDARS antenna is designed in order to fit in the reduced space without affecting radiation and band performance of the GPS antenna. The SDARS basic geometry is a square-ring microstrip antenna operating in the frequency range 2.320-2.345 GHz with left-hand circular polarization (LHCP), and it is wrapped around the GPS patch, which receives a right-hand circular polarization (RHCP) signal at 1.575 GHz. The overall volume of the presented integrated antenna solution is only 30 x 30 x 7.6 mm3, rendering it attractive for the automotive market.

This paper presents an overview of radiating devices for various wireless applications, using the "monopolar wire patch antenna", and the "coplanar wire patch antenna" concepts, developed by Xlim Laboratory. (5 pages)

Although GPS antennas are commonly used for vehicle applications, their on-vehicle gain patterns are not known well. Especially, when the antenna is mounted at locations other than the roof center, the antenna gain becomes directional at mid-to-low elevation angles. The goal of this letter is to investigate the GPS passive antenna performance at its actual, on-vehicle mounting locations. For four different antenna locations on a sedan vehicle with sunroof, the antenna gain is measured in a quasi-far-field antenna range. The results are also compared to those of finite ground plane, anechoic chamber measurements. © 2007 IEEE.

UWB antenna design must be carried out in accordance with the global radiation system architecture. Different applications and inherent antenna design constraints are envisaged in the paper. (6 pages)

The paper deals with the panel antenna modeling using NEC Win PRO v. 1.1 package. Base of antenna modeling would be wire construction. To achieve better performance and characteristics, several solutions for reflector and dipole will be proposed. Antenna with best results and attributes will be compared with technical data of APX907016 RFS antenna given by producer. The challenge in the design of a suitable antenna is overcoming the inherent relationships between gain, pattern beam width, the presence of pattern side and back lobes, and also the size of the antenna.

A method to perform antenna far-field measurements in semi-anechoic chamber is presented. The method requires the measurement of the amplitude and phase of the pattern of the antenna under test in different spatial positions. The data are elaborated to estimate the direction of arrival of the reflected signals and to synthesize a receiving pattern with nulls in these directions. Experimental results confirm the effectiveness of the technique.

The paper presents a microwave metal disk antenna with axis-symmetric excitation operating in the TM/sub 010/ mode. Experimental investigations of the input characteristics of the antenna, and of the near-fields and the radiation pattern, have been performed. It was shown that the antenna forms a conical radiation pattern, oriented 36/spl deg/ to the zenith, and has a bandwidth of 18% that can be evaluated as a record for antennas of this kind. The antenna also has a level of side radiation as well as a cross-component level less than -25 dB. Within the working frequency band, the radiation pattern width and the direction of maximum radiation change by 17% and 40%, respectively. The experimental results agree well with theoretical predictions.

Air defense radars using reflector antennas for area surveying were not found suitable for operating new targets. Antennas with great aperture surface and electrical beam moving were required. Antenna complexes of "Dunay-3" and "Dunay-3U" radars are presented in this paper. It operates in the decimeter wave band and consists of two antenna systems located in two sites - the transmitting one and the receiving one. The antenna is also an active array with linear radiators. The "Dunay-3" radar antenna uses 200 radiators while the "Dunay-3U" consists of 100 linear radiators. The main radar element is an antenna made as a phased antenna array on relatable system for the upper semi-sphere observation. The antenna array is divided at sub arrays with an analogue beam forming way and the full antenna pattern is formed with an adaptive digital way. Another antenna complex presented in this paper is the "Volga" radar. The "Volga" radar is the new generation of distant detection stations operating in continuous radiation regimen: the radar illuminates a target and receives reflected signals simultaneously.

European Space Agency is developing EMS (European Mobile System) land mobile system for voice and data communications. Two different antenna concepts have been realised for a mobile terminal The first one is a rotating antenna consisting of two radiating elements. The second one is an electronic array antenna in which 12 radiating elements locate on the facets of a truncated pyramid. Several field trials have been performed in order to optimise the tracking software and to evaluate the behaviour of the antenna in different environmental conditions. The results show that the developed antenna is feasible from the cost and performance point of view for this application. >

Novel design of Psi-shaped printed monopole antenna consisting of modified feeding structure is proposed. A detailed parametric study for various antenna parameters that forms the Psi shaped patch is presented. The pair of vertical slots in Psi shaped patch optimizes the antenna bandwidth till 4 GHz of frequency range whereas position of horizontal slots that constitutes modified feeding structure optimizes the antenna bandwidth till 6GHz. Further optimization for bandwidth beyond 7 GHz is obtained by suitably selecting the feed line position along patch base edge which optimizes the input impedance at higher order patch resonant mode. The proposed Psi shaped patch antenna yields BW from 1.5 GHz to more than 10GHz. The proposed configuration shows broadside radiation pattern over most of the bandwidth with peak broadside gain of nearly 2 dBi. Due to the realized antenna characteristics Psi shaped antenna can find applications in Bluetooth, Wi-Fi and personal communication systems for frequencies above 1GHz.