ABSTRACT. In many areas, the identification and monitoring of objects have become a necessary requirement for people to facilitate their tasks and minimise their intervention, and for this reason, the Internet of Things (IoT) makes it possible to connect physical objects to the internet. One of the important technologies applied in IoT is a radio-frequency identification (RFID), and its deployment has created an RFID network planning problem that can be seen as a non-linear combinatorial NP-hard optimization problem that needs to identify the location of a minimum number of antennas to satisfy full coverage and zero interference. The ultimate goal of this paper is to solve the RNP problem under perturbation by introducing a probabilistic power-based coverage model and by presenting a hybrid approach based on artificial neural networks and the redundant antenna elimination algorithm RAE. The results obtained by our approach, applied to the most commonly used benchmarks by several researchers, show the effectiveness of the proposed approach in dealing with the existence of simulated perturbations in real cases and, furthermore, in generating a perfect deployment of an RFID system.

ABSTRACT. Internet of things (IoT) has transformed numerous fields while providing better connectivity. In such scenario, the integration of various IoT devices have to be satisfied. The downside of commuting between cross platform IoT devices are difficult to achieve, because low power high range communication front end is mandatory. This paper proposes to utilize the Modulated Scattering Technique (MST) to integrate with IoT devices and to achieve the radio frequency communication capabilities. An MST system works similarly to an RFID, is highly miniaturized and exhibits good performances at microwave frequency bands without the necessity of radio frequency front-end. MST communication systems provide an high operative range with respect to standard RFID systems, and a very low consumption with respect to standard wireless radio frequency front ends, such as WiFi modules. This work proposes the integration of MST communication paradigms with an IoT system, in particular a prototype of air quality IoT sensor is presented and assessed

ABSTRACT. Over the past 30 years, the consumption of fresh fruits and vegetables in industrialized countries has increased, along with the circulation of goods on a world-wide scale. This implies the risk of outbreaks of food poisoning and food infections related to consumption of fresh fruits, as well as a huge increase in the risk of wasting impressive amounts of products. To reduce this waste, Radio Frequency Identification (RFID) systems can be beneficial, enabling early detection via low-cost tagging of contaminated vegetables and fruit, which can help reduce these losses and stop the spread of disease. An inexpensive sensor antenna has been designed using a sensitive substrate in this paper. In order to estimate the freshness of mangoes, this design optimizes the matching of input impedance based on the surface permittivity changes of the substrate The analysis of the dielectric characteristics of Tommy Atkins Mango data is used so to investigate the maturation, ripping and freshness of mangos. Using the proposed approach, it was demonstrated that a smaller sum of dielectric constants, leads to greater contribution of the substrate and the performance of the antenna is as follows: resonant frequency and S-parameter amplitude tend towards 1 GHz and –33.37 dB, respectively.

ABSTRACT. In this work, a flexible narrowband fully passive printable multi-resonator is proposed for UHF RFID chipless tags working within the UHF band. The multi-resonator structure is flexible, has a compact size, a low cost of fabrication, and a very compact frequency bandwidth for each of the resonators, which unambiguously correspond to one stored data bit. The data can be encoded using spectral signatures, providing a unique ID for every tagged object. The multi-resonator has been designed using a general-purpose 3D CAD, CST Microwave Studio.

ABSTRACT. A novel encoding strategy for near-field chipless-RFID systems based on sequential bit reading is proposed in this paper. The tags consist in a chain of C-shaped resonators (inclusions) etched (or printed) at predefined positions in the tag substrate. However, contrary to previous near-field chipless-RFID systems, encoding is not achieved by the presence or absence of functional inclusion at their positions, but through the dimensions of the inclusions. Thus, the C-shaped resonators can exhibit four different dimensions in the direction transverse to the chain axis, corresponding to four different states, or two bits, per inclusion. By this means, the number of bits of the whole system is twice the number of bits of the tags based on absence/presence of functional inclusions. For tag reading, the chain should be displaced at short distance on top of the reader, a transmission line with a gap feed by four harmonic signals tuned to the resonance frequencies of the four different C-shaped inclusions. Thus, in this system, the data is encoded in frequency, but the bits are read sequentially, by means of a time-division multiplexing scheme. This justifies the designation of this novel approach as hybrid time/frequency domain chipless-RFID. The paper reports a first proof-of-concept demonstrator, where the tags are based on four inclusions, providing 8 bits.

ABSTRACT. The impact of precipitation on future next generation large NGSO satellite constellations is investigated in this contribution. To this aim, an advanced tool is used, which combines a model to generate realistic space-time correlated rain fields on a Global basis and a satellite orbit propagator for large constellations. The impact of rain attenuation on Q-/V-band links is investigated: the results indicate the need of Fade Mitigation Techniques for the correct operation of the system. Specifically, the benefits provided by the implementation of orbital and site diversity are assessed in terms of increased system availability for a given atmospheric fade margin.

ABSTRACT. A low-profile antenna for satellite communications (SatCom) applications is presented here. The antenna covers the entire K/Ka frequency bands from 19 GHz to 31 GHz with a reflection coefficient better than -10 dB, corresponding to a relative bandwidth of more than 50%. A continuous transverse stub (CTS) antenna array is chosen as a radiating aperture for its very wideband performance. The radiating aperture is fed by a pillbox quasi-optical beamformer. The full antenna is realized in printed circuit board (PCB) technology by stacking several dielectric layers without any buried or blind vias in the full stack-up. Multiple horns are placed along the focal plane of the pillbox coupler to achieve beam-scanning in elevation. ± 25°. The peak value of the realized gain is 19 dBi and radiation efficiency equals 50%.

ABSTRACT. A high-gain, broadband, and low-profile Continuous Transverse Stub (CTS) antenna array is presented at Ka-band for SatCom applications. This antenna is designed to cover the downlink (17.7-20.2 GHz) and the uplink (27.5-30 GHz) bands. This array comprises 16 long slots fed in parallel by a corrugated parallel plate waveguide beam forming network. The design and simulations results are summarized, together with a simple design methodology for different network components. The dual-linear polarization is achieved by using two orthogonal modes namely: the quasi- transverse electric magnetic mode (QTEM) and the 1st order transverse electric mode (QTE1). The antenna array is well matched (S11 <−10 dB). The maximum realized gain (in one plane) is around 15 dB at 29 GHz and around 12 dB at 19 GHz for both polarizations.

ABSTRACT. Ground stations for space communications are often requires to operate at different frequency bands, normally spanning from L band to Ka band. In some cases, especially when they are realized according to a beam-waveguide architecture, dichroic mirrors can be used to insert/extract different bandwidths along the propagation of the beam. As these antennas generally operate high-power transmitting channels, all-metal high-pass dichroic mirrors are usually preferred. This paper presents a quantitative comparison between two possible manufacturing technique for such mirrors, milling and wire erosion, in terms of manufacturing possibilities, accuracy and surface roughness. To this aim, a test case for dichroic mirrors, aimed at installation in the deep space antennas of the European Space Agency to support future missions to the Moon and designed to be as transparent as possible for the K band, is discussed.

ABSTRACT. This work presents an overview of the current state-of-the-art Power Amplifiers and Low-Noise amplifiers in the 40-75 GHz frequency band (i.e., V-band). These RF blocks are critical for the development of future LEO constellations that have recently begun to target these frequencies. Special attention is brought to GaAs, GaN, SiGe, FDSOI and classical CMOS technologies. The aim of the paper is to give a clear overview of the attainable performances with each technology as well as their relative trade-offs.

ABSTRACT. BACKGROUND: RFID or Radio Frequency Identification is a technology for identifying objects or people. It is based on the use of radio waves to remotely read the data written on RFID transponder, commonly called an RFID tag. This technology has become one of the most promising research areas and has attracted growing interest, hence the need for a scoping review of this research field. OBJECTIVE: We intend to carry out a systematic map as part of a scoping review to clarify and show the current state of existing studies in the RFID area. METHOD: We followed the scoping review process defined by Petersen et al. [1][2], based on a well-established research methodology from the medical and software engineering scientific communities. 219 primary studies were selected rigorously, subsequently a classification framework was applied to extract key information for further analysis. We synthesized the resulting data and produced a clear state-of-the-art. RESULTS: We outline the process of a Scoping Review applied to the field of RFID technology from a software engineering perspective. On this basis, this work contributes with (1) a general framework for classifying information on published studies in this disciplinary field, (2) a presentation of current research in the RFID field in a systematic map form, (3) a discussion of emerging results and their implications for future research. CONCLUSIONS: This scoping review provides an overview of the RFID field and, more importantly, identifies research gaps and future research directions for researchers, practitioners interested in RFID technology, reviewers and universities, and journal editors. One of the findings is that, although there is a lot of research being conducted in this area, a limited amount of work is focused on the problem of RFID data acquisition and processing, or in other words, on the "middleware" component of RFID systems.

ABSTRACT. This work focuses on a comparative study between the artificial neural networks (ANNs) and the Lorentzian fitting method, which are applied for modeling of the resonant characteristics of a humidity sensor. The device under test (DUT) is a microwave microstrip resonator, developed on FR4 substrate, with a Ag@α-Fe2O3 nanostructured layer deposited on the gap, aimed at humidity sensing applications. To determine the frequency-dependent behavior of the tested device, the reflection coefficient (G) is measured from 3.4 GHz up to 5.6 GHz. It is achieved that each analyzed approach has pros and cons, depending on the given application requirements.

ABSTRACT. Radio frequency identification and sensing can benefit from the degrees of freedom offered by additive manufacturing processes, both bi-dimensional as well as three-dimensional ones. Moreover, the characterization of the electromagnetic properties of the involved materials plays an important role in the concept as well as the design of innovative devices, too. The envisioned applications span from tags embedded in items to wearable sensors and metasurfaces adopted for enhancing probing signals into the human body

ABSTRACT. A miniature PIFA RFID tag antenna for metal surface applications is presented in this article. The RFID tag antenna has a compact size (45mm × 45mm × 5.162mm) UHF, with a high gain of 4.2dB and a long maximum read range of 24m. The designed antenna is a two-substrate PIFA whose radiating plane, made of copper, is printed on Rogers RT / duroid 5880 (ε_r = 2.2, tan σ= 0.0009), the artificial magnetic conductor (AMC) and the ground plane are printed on top and bottom of FR4 epoxy substrate (ε_r = 4.4, tan σ= 0.02) respectively. The antenna is connected to the Monza R6 chip of impedance Z = 13.6 - j 127 at 866 MHz. It covers a bandwidth of 780 MHz (570 MHz-1.35 GHz) and therefore it covers the entire UHF RFID band. To test its robustness, this tag antenna is placed on different metal plates but these do not affect the performance of the tag.

ABSTRACT. The Generalized Reflect Thru Line (GTRL) calibration technique is used for the measurement of a waveguide devices operating in a multioctave band region. In this contribution some preliminary results are shown concerning measurements done up to the third harmonic, where up to four modes are above cutoff.

ABSTRACT. This work reports the design of two key building blocks of a K/Ka-band SatCom phased-array transceiver. The circuits are developed by using 130-nm SiGe BiCMOS technology. A Ka-band single-ended Power Amplifier (PA) and a K-band single-ended Low-Noise Amplifier (LNA) have been designed. Simulation results have shown that the PA achieves 30.5 dB peak small-signal gain, 27.6% peak power added efficiency (PAE), and an OIP3 better than 25 dBm within the entire operating frequency band. The maximum power consumption is 76 mW with a 2 V supply voltage, and it occupies an area of 1234 μm × 758 μm, pads included. The simulations results of the LNA have shown 32 dB peak power gain, 2 dB minimum noise figure, and –18 dBm IIP3 at 20 GHz. The NF, in the entire frequency band of interest, is less than 2.3 dB. The LNA exhibits a power consumption of 20.7 mW with a supply voltage of 2.4 V and it occupies an area of 1000 μm × 800 μm, pads included. It is worth noting that, a set of test structures that includes all the HBTs used for PA and LNA development have been designed and measured in order to evaluate both the accuracy of the models provided by the foundry and the impact of the extrinsic elements due to base, collector, and emitter interconnections.

ABSTRACT. Multipactor is nowadays crucial when analyzing the final performance of satellite communication systems, as the critical components of these systems must meet demanding high-power specifications. Therefore, having access to fast and reliable multipactor simulations is of paramount importance for the radio frequency (RF) design process. This paper describes the Coarse method as a technique enabling faster predictions for time-varying signals, but also highlights the limitations of the method when analyzing long signals. In this work, the capabilities of the Coarse method are expanded by introducing the Kadane's search algorithm, which allows to identify the multipactor critical sequence of long signals with a limited CPU effort.

ABSTRACT. In this communication, some preliminary results on the design of an isoflux reflectarray, suitable for being mounted on board a satellite or even a CubeSat, carried on with a global optimization technique, are presented. The obtained radiation patterns, relative to a small-medium size configuration, are good and confirm the effectiveness of the proposed procedure.

ABSTRACT. One of the biggest challenges in the research and innovation world is to address and push technology maturity by reducing time to market for the benefit of science and industry.

A goal also taken up by the European Space Strategy as a priority for a more competitive and innovative sector to push technology maturity for subsystems, equipment and technologies, including in-orbit demonstration and validation activities.

Containing and optimizing the launch and deployment costs of a space mission have pushed the upstream world to design satellites of reduced mass and size using smaller and less expensive launchers.

These new mini-satellites can be carried into orbit as Secondary Payload on ordinary launchers or as cargo, and then put into orbit by deployment.

D-Orbit is a service provider for the traditional and new space sectors, founded in 2011, with spaceflight heritage since 2013 – over 60 payloads in space today. Our ION Satellite Carrier is a family of end-to-end solutions for CubeSats and microsatellites, a satellite platform that can both carry satellites to be deployed in orbit and carry third-party experiments to be tested in space.

The platform is able to modify its own attitude, altitude, and local time of ascending node (LTAN) to quickly deploy CubeSats and microsatellites into precise and independent orbital slots, allowing customers to start their missions faster and in optimal operational conditions.

ION can host sensors and scientific instruments integrated within CubeSat-like structures to be operated in orbit, but it can acts also like a “service module” providing resources such as power, communications, and control.

ION features:

Faster Time-To-Revenues and positioning in target orbit; Launch Cost Reduction: deploy a constellation in multiple orbits on a single mission; Faster Time-To-Space: ride on the first available launcher; Reduction In Number Of Satellites: ION replenishes constellations faster so there is less need for spare satellites; Lower Manufacturing Cost: reduced need for propulsion decreases costs. ION advanced services:

Backup Satellite for an existing constellation; Integrating Satellite Services via Payloads Hosted on ION; Satellite Communication Hub Services. In-Orbit Validation and Demonstration (IOD/IOV); In-Orbit Demonstration/Validation (IOD/IOV) enables the space research community to develop space technologies and test them in real-world conditions, accelerating TRL and technology maturation.

“In-Orbit demonstration/Validation (IOD/IOV) is a unique tool to boost industry’s competitiveness by eliminating the famous “valley of death” and accelerating the deployment of innovative technology. “This maturity level is crucial to enable the competitiveness, non-dependence and innovation of the European space sector” (European Commission).

Speakers: Ms Elena Giglio is “Institutional Relations Manager” at D-Orbit since Jan.2021. She graduated at University of Calabria on the 2009 and she holds a PhD at the Politecnico of Torino with a thesis on “Geopolitics on Rare Earth elements. Focus on Lithium”. Her professional career has been a mix of national and international experiences in different areas (both in the public and private sectors). While working in APRE from 2011 to 2018, she was appointed by the Ministry of Research and Education (MIUR) in Italy as National Contact Point for Horizon 2020 on SMEs and SPACE where she has been heavily involved in EU-related matters and acquired a profound familiarity with the processes of the European Commission and of other EU Institutions. She also managed and coordinated projects in three main areas: (1) “Technology Transfer and Internationalization”; (2) International/extra EU cooperation on R&I (eg such as the “Bilat projects” with Mexico, Argentina and Canada); (3) “Coordination and Support Action projects” to raising awareness about the R&I international opportunities.

Mr. Matteo Bartolini is a launch manager in D-Orbit. He joined the company in 2019. Matteo was mission manager on the first three ION Satellite Carrier launch campaigns, he is also in charge of the mission management, the ION payload integration and the ESA ITT application. Before joining D-Orbit, he held several positions in the field of GNC and flight safety for launch vehicles, including several years at Rocket Lab, where he was in charge of the definition and verification of the system and subsystems requirements for the new Rocket Lab Launch Complex One in the Mahia peninsula (New Zealand). He was also responsible for the flight safety milestones documentation for FAA and NASA, and of the AFTS (Autonomous Flight Termination System) development and testing. Matteo holds a Bachelor’s degree in aerospace engineering and a Master’s degree in aeronautical engineering from the Università La Sapienza, in Rome. He also completed a postgraduate Master course in civil aviation management from the same institution. Matteo is a an archer, a passionate scuba diver and certified drone pilot.

ABSTRACT. A. Massa, A. Benoni, P. Da Rù, G. Oliveri, P. Rocca, M. Salucci, F. Zardi

Abstract - The next generation of wireless cellular systems will be required to comply withunprecedented requirements in terms of data transfer speed, flexibility, coverage,reliability, and quality of service. The request to meet such ambitious expectations,jointly with the need of relying on cost‐effective and efficient technologies, ismotivating a deep re‐visitation of the general guidelines so far considered for thedesign of wireless communication systems and their deployment. Indeed, the main actorsof the technological evolution from one to the subsequent mobile communication generationhave been the user terminals and the base stations and network. On the contrary, thepropagation environment has been considered as an uncontrollable element, given a‐priori.This viewpoint is being completely overrun by the emerging paradigm of the SmartElectromagnetic Environment (SEE). The SEE vision originates from the key idea that thepropagation of the electromagnetic waves/signals can be tailored by properly controllingthe reflection by buildings and urban structures. In the SEE scenario, the environmentis no longer seen as an uncontrollable part, but rather it can cooperatively support thepropagation to improve the coverage, the data rate, and the network reliability withoutthe need to install additional base stations.This talk will review some on‐going activities at the ELEDIA Research Center towards theimplementation of the SEE ranging from the capacity‐driven design of wireless infrastructures,the synthesis of the ‘smart skin’ for field manipulation and their installation planning,to the compressive‐processing of sensing and communication signals.

ABSTRACT. The role of Electromagnetic (EM) fields in our lives has been increasing. Communication, remote sensing, integrated command/ control/surveillance systems, intelligent transportation systems, medicine, environment, education, marketing, defense are only a few areas where EM fields have critical importance. We have witnessed the transformation from Engineering Electromagnetics to Electromagnetic Engineering for the last few decades after being surrounded by EM waves everywhere. Among many others, EM engineering deals with broad range of problems from antenna design to EM scattering, indoor–outdoor radiowave propagation to wireless communication, radar systems to integrated surveillance, subsurface imaging to novel materials, EM compatibility to nano-systems, electroacoustic devices to electro-optical systems, etc. The range of the devices we use in our daily life has extended from DC up to Terahertz frequencies. We have had both large-scale (kilometers-wide) and small-scale (nanometers) EM systems. Large portion of these systems are broadband and digital, and have to operate in close proximity that results in severe EM interference problems. Engineers have to take EM issues into account from the earliest possible design stages. This necessitates establishing an intelligent balance between strong mathematical background (theory), engineering experience (practice), and modeling and numerical computations (simulation).

This keynote lecture aims at a broad-brush look at certain teaching / training challenges that confront wave-oriented EM engineering in the 21st century, in a complex computer and technology-driven world with rapidly shifting societal and technical priorities.

The lecture also discusses modeling and simulation strategies pertaining to complex EM problems and supplies several user-friendly virtual tools, most of which have been presented in the IEEE AP Magazine and which are very effective in teaching and training in lectures such as EM Wave Theory, Antennas and Radiowave Propagation, EM Scattering and Diffraction, Guided Wave Theory, Microstrip Circuit Design, Radar Cross Section Prediction, Transmission Lines, Metamaterials, etc.

References

L. Sevgi, Electromagnetic Modeling and Simulation, IEEE Press – John Wiley (EM Wave Series), NJ, Apr 2014. L. Sevgi, Complex Electromagnetic Problems and Numerical Simulation Approaches, IEEE Press – John Wiley & Sons, May 2003. L. Sevgi, A Practical Guide to EMC Engineering, ARTECH House, Norwood, MA, March 2017. G. Apaydın, L. Sevgi, Radiowave Propagation and Parabolic Equation Modeling, IEEE Press – John Wiley, NJ, Sep 2017. G. Apaydın, L. Sevgi, Electromagnetic Diffraction modeling and simulation with MATLAB, ARTECH House, Norwood, MA, Feb 2021.

ABSTRACT. To build the future of autonomous driving, we shall enable cars to see the targets in their environment in any condition; radar is the most dependable sensing technology, providing the highest reliability across all weather and environmental conditions and capable of detecting obstacles at the longest range.

The biggest challenge is, e.g., to be able to reliably identify a child (vs. a manhole and close to a car) up to 100 m! To accomplish tasks like this one, we have minimum resolution requirements of 1° azimuth, 1° elevation, 0.1 m range, and 0.1 m/s speed.

The enabling technologies that will be discussed to fulfill these requirements at reasonable costs are millimeter waves, advanced MIMO techniques, new modulation schemes, and Silicon CMOS technology.

ABSTRACT. This paper reports on the design of a Doherty power amplifier (DPA) for 5G mm-wave applications. Conversely to standard DPAs, this design presents a delay at the input of the carrier amplifier, which enhances the isolation of the peaking amplifier while the DPA is in its low power regime. Moreover, the circuit leverages a novel power divider (PD) to reduce both size and number of passive components. Moreover, the PD transforms the input impedance of the carrier and the peaking amplifiers to 50 Ω avoiding lossy matching networks. Performance consists of a peak gain without pre-driver amplifiers of more than 7 dB at 26.5 GHz, a back-off efficiency plateau of 5 dB, and a saturation power of more than 14 dBm. The circuit has been fabricated in the IHP 130-nm SiGe technology and occupies an effective area of 660x360 μm2, which makes it suitable to be integrated into a beamformer chip.

ABSTRACT. A reconfigurable waveguide antenna array design for the MIMO beamforming system is demonstrated in this article, which is fed by the multilayer substrate integrated coaxial line (SICL) feeding network. According to the design purposes, the reconfigurable waveguide transitions and waveguide linearized-polarized/circular-polarized antenna arrays have high flexibility to meet different requirements in beamforming applications. The multilayer SICL feeding network could achieve wideband performance for both the MIMO beamforming transmission and receiving system for K/Ka-band. Both simulated results and some preliminary experimental results are presented for the demonstration.

ABSTRACT. In this paper, a novel microstrip-fed filter-antenna (filtenna) exhibiting dual-wideband response is introduced. In this direction, a dual-wideband bandpass filter is designed first and then it is integrated into the feed line of a wideband monopole microstrip antenna. The dual-wideband bandpass filter is constructed by stub loaded multi-mode resonators. Two types of stub-loaded multi-mode resonators are coupled to the feeding lines from the filter's input and output ports. The proposed topology allows controlling both bandwidths independently. The designed filtenna was fabricated for the experimental verification. Measurements of the fabricated filtenna show a good agreement with the simulated results. Center frequencies of the proposed filtenna are 3.23 and 5.65 GHz with the fractional bandwidths (FBWs) of 46 % and 21.6 %.

ABSTRACT. Design and characterization of both a single-stage and a 2-stage Variable Gain Amplifier operating at E-Band is presented. Characterization issues of differential RF amplifiers are discussed, and integrated input and output baluns seem to be an easy solution for on-chip or on-board preliminary characterization by standard 2-port Network Analyzer. Amplifiers have been prototyped in a SiGe BiCMOS commercial technology, and exhibit about 22 dB of gain control range. After balun de-embedding, more than 10 dB of maximum gain has been also demonstrated for both amplifiers.

ABSTRACT. In the recent years, thanks to possibilities opened up by the advancement of space technology, novel satellite architectures have been defined to shift the system complexity from the ground segment to on-board the satellite. One of the equipment that enables a high flexibility in the satellite enhancing its ability to be reconfigured is the beamforming function. A specific type of beamformer is the True-Time Delay (TTD) whose characteristic allows increasing the instantaneous bandwidth and FoV of the equipment allowing to support high data rate or high resolution applications. Within the RETINA program, the team lead by DAS Photonics with Airbus Italia, AMO, UPV and UKRI developed a reconfigurable multibeam photonic beamformer with centralised processing supporting a very innovative SAR approach based on photonic technologies. The BFN is based on an optimized PIC in silicon-nitride technology implementing designs of TTD beamforming network, suitable to be used in broadband applications without beam-squint degradation and compatible with large antennas requirements. The flat Array Antenna is based on PCB technology with sub-array BFN integrated in the PCB. A breadboard of the Antenna System was developed and tested and resulting performances show the ability of the system to fully support future EO SAR and Telecom systems.

ABSTRACT. Autotrack systems for space applications are typically based on monopulse. These systems require a specific test before being operative, typically through calibration towers, leading to expensive operating costs and antenna downtime. This work aims to present a technique to test in-lab these systems by the generation of high order modes as if they would be coupled using a calibration tower as well-known target. The theoretical working principle and a proof-of-concept design will be presented in Ku-band to confirm the reliability of the model.

ABSTRACT. This manuscript presents a technique to perform the initial design of a transmitting phased array in order to provide a given EIRP within a prescribed scan angle while limiting the overall power consumption. Such constraints are typically found in commercial Earth-observation satellite missions. The paper discusses a closed-form approach yielding the optimum number of elements and power capabilities of each transmitting element, from which the antenna elements and the overall array size can be then obtained. A numerical simulated example is provided to support this simple technique.

ABSTRACT. Abstract—In this article, we present the proof of concept of techniques exploring ambient signals for low power and secure backscatter communications. This real-time system operates by scavenging a crowded electromagnetic spectrum and recycling active incoming signals for secure quasi-passive wireless communications. This is achieved through a low power and efficient spectrum sensing approach to identify prominent communication channels and using this energy and spectrum, to backscatter a superimposed frequency shifted signal for secure communication, utilizing a semi-passive adaptive modulation approach. No new spectral energy is added to the system in this approach, demonstrating a net zero spectral crowding or a quasi-passive opportunistic communication.

ABSTRACT. While millimeter-wave (mmWave) technologies are often associated with costly implementations using large arrays, several inexpensive approaches promise mmWave connectivity closer to the user in Body Area Networks (BANs) applications. Here, we evaluate the potential for multi-mode mmWave links for information and power transfer applications. The co-existence of off-body radiative and on-body wave-guiding mechanisms is experimentally investigated based on state-of-the-art transmission lines and antennas. First, a body-to-body link with at least -50 dB channel gain is demonstrated based on wide-beam microstrip and reflector-backed broadband antennas. Co-existence is then studied experimentally by measuring the coupling between the off-body communication/power transfer antenna and a wearable Single Wire Transmission Line (SWTL), with an ultra-low on-body attenuation under -0.8 dB/cm around 28 GHz. Under -40 dB coupling is demonstrated for clearances as low as 1 cm between the antenna and SWTL. The measured results indicate that co-located textile-based antennas and transmission lines can enable multi-mode high-performance body-centric mmWave networks, and highlight the need for interference-countering mechanisms in future high-density BANs.

ABSTRACT. This paper presents the first symbol-level modulation technology for ZigBee backscatter communication. The developed backscatter tag, leveraging ambient ZigBee transmissions as radio frequency (RF) carrier excitation, conveys data by translating an excitation signal into a new ZigBee signal in neighboring ZigBee channels. This avoids the strong interference from the ambient excitation signals. The key enabling technique is a symbol-level codeword translation, which exploits square waves based on the difference between the excitation and tag data. A working prototype was successfully demonstrated to validate the modulation technology, which consists of two parts: an RF front-end circuit and an FPGA-based control circuit. Through extensive experiments and field studies, the evaluation shows that the bit error rates (BERs) can be controlled to be less than 0.1 when the communication distance is within 2 meters.

ABSTRACT. According to the "Smart Electromagnetic Environment" (SEME) paradigm, the propagation scenario will become a key actor in the design of future wireless systems. As a matter of fact, the exploitation and arbitrary manipulation of the complex electromagnetic (EM) phenomena arising in multi-path and non-line-of-sight (NLOS) environments will represent a fundamental asset to fulfill the ever-growing needs and requirements of the forthcoming communications standards. An overview of some of the most promising SEME-enabling technologies is given, along with a discussion of the current and future trends within such an emerging framework.

ABSTRACT. In this work a sub-array hybrid cluster is proposed for phased array applications. The sub-array cluster is based on a driven element surrounded by parasitically coupled radiators which can be controlled in phase through a reactive element such as a varactor diode. By varying the capacitance of the varactor diode, the phase of the field radiated by the parasitic patch can be controlled thus resulting in a reconfigurable cluster where only the central element is connected to the array beam forming network. Preliminary simulations were performed taking as a reference an elementary cluster composed by a single parasitic element. The proposed configuration, designed at 6 GHz, shows beam steering range between -30 and 12.5 degrees with a gain higher than 7 dBi over the entire scanning range.