This paper presents a dual-band power amplifier (PA) covering the 5G n257 to n260 frequency 2 bands (24.25 to 29.5 GHz and 37 to 43.5 GHz), fabricated in the 22 nm fullydepleted silicon-on-insulator (FD-SOI) CMOS technology. Its design is based on a distributed balun at the output that efficiently performs a wideband load impedance transformation. The backgate terminal of each transistor is connected to different pads for detailed back-gate bias variation analysis. Under 5G new radio (NR) modulated signal measurements, we show how the average output power and efficiency can be optimized by varying the back-gate bias, which optimal value depends on (i) the signal bandwidth, (ii) the carrier frequency and (iii) the target error-vector-magnitude (EVM) value. To the best of the authors’ knowledge, the impact of back-gate bias control on the system-level EVM figure of merit is shown for the first time in this work. Overall, with 7.5 dBm and 7.3% mean output power and efficiency, respectively, at 27 GHz, 6 dBm and 5% at 40 GHz, for a 800 MHz bandwidth 5G NR signal, the presented PA shows outstanding performance among wideband/multiband FD-SOI-based PAs covering the 28 and 39 GHz bands, featuring comparable performance to best-in-class narrowband PA designs in FD-SOI technology.

Most nonlinear behavioural models of amplifiers are based on functions that are analytic at the origin and thus can be replaced by their Taylor series development around this point, e.g. polynomials of the input signal. Chebyshev Transforms can be used to compute the harmonic response of the model to a sine input signal. These responses are polynomials of the input signal amplitude. A second application of the Chebyshev transform to the first harmonic response or RF characteristic will lend the carriers and intermodulation (IM) products for a 2-carrier input signal, again polynomials. An important class of non-analytic nonlinear behaviour encountered in practice, such as hard limiters and detectors are either empirically treated or only approximated by an analytic function such as the hyperbolic tangent. This work proposes to generalize the polynomial nonlinearity theory by adding non-analytic at the origin functions that, like polynomials, are invariant elements of the Chebyshev Transform. Devices modelled with these non-analytic at the origin functions exhibit intermodulation behaviour significantly different from that of classical polynomial models, giving theoretical foundation to a number of important unexplained practical measurement observations.

This paper describes existing and new criteria for comparison and optimization of non-linear power amplifiers such as RF or microwave transmitters. In addition to intermodulation, receiver noise, and losses in the transmission system, the proposed new criteria take into account efficiency or consumed power. This results in the global optimization of a combined signal-to-noise-plus-intermodulation ratio as a function of saturated or nominal power but also consumed or dissipated power. Saturated power is limited by available technology. Consumed power and dissipated power are some of the main constraints in telecommunication satellite payloads, mobile phone handsets, and RFID (Radio Frequency IDentification). Another constraint comes from the limited size of antennas, which limits the system equivalent isotropic radiated power and gain-to-temperature ratio. With the proposed criteria the designer will be able to compare different amplifier technologies and to optimize the design and operating point of each stage of a multistage amplifier or a linearizer for a given amplifier. Interference from same or other systems is also introduced in the optimization through the use of signal-to-noise-plus-IM-plus-interference ratio criteria.

This paper presents some theoretical results and measurements of passive intermodulation (PIM) products made on a waveguide flange contact nonlinearity with 2 and 3 carriers at different power levels. The dependence of the passive intermodulation (PIM) products power on the carrier power is the main difference between active and passive intermodulation (IM) products. For easy computation, memoryless active nonlinearities are generally modelled by polynomials or by analytical mathematical functions (e.g. hyperbolic tangent) [1, 2]. These functions are continuous, have continuous derivatives of all orders and can be approximated by their Taylor series developments, at least in “small signal” conditions where the IM power is much less than the fundamental carrier power, mathematically in a domain around the origin. In these conditions, the power of each active IM products depends on the carrier power elevated to an exponent equal to the order of the IM product, e.g. exponent 3 for order 3, exponent 5 for order 5 [1, 2]. On a dB/dB graph, the slopes of IM levels versus carrier level are equal to their order 3, 5, … This is not the case for passive IM products where the level of IM products depends on the carrier level with a slope that is different from the order, generally a non-integer value between 2 and 3 and about the same for all orders on a dB/dB graph [3 - 8]. A model based on a non-analytical power function has been proposed [9]. It has been used to predict the behavior of the passive IM products such as the level of high order of products, the nearly equal slope for all IM orders, and the decrease of a 2-carrier IM product power when a third carrier is added [9, 10]. The experiment is carried out on a nonlinear graphite material introduced between two waveguide flanges in a PIM test bench in Ku band using two low PIM triplexers. Two carriers with power up to 40 watts per carrier or three carriers with power up to 40 watts per carrier can be transmitted on the test bench. The main theoretical and experimental results are presented in this paper and validate the theoretical results: a slope of 2.4 dB/dB is measured on the third order PIM product and the levels of higher order PIM products are correctly obtained in different configurations of carriers and power by using the non-analytical model based on a power law nonlinearity with an exponent of 2.4 for order 3. Measurement with 3 carriers (with the same or different power) are compared with the theory. A particular combination of 3 carrier powers shows that some third order PIM can be nearly eliminated in concordance with the theory.

A novel Digital-Twin technology platform is introduced for enabling system-level IC-Package-PCB-Antenna co-design, co-simulation and co-verification. The platform, based on noise and correlation-aware physics-informed behavioral modeling, integrating VISION (IVCAD) software developed by Dassault Systèmes, hosts an innovative SPICE compatible broadband RLC representation of antenna elements. The ability of the platform to account for dynamic impedance loading of antennas by multi-harmonic (MH) nonlinear RF electronics is demonstrated using energy-efficient hybrid 3D heterogeneous front-end-module technologies integrating adaptive biasing and antenna tuners (load-aware matching). The Digital-Twin technology will enable new generations of tooling (unified EDA & OTA) where classical Electromagnetic (EM) metrics (radiation pattern, noise, auto and cross-correlation functions, power-spectral density) are extended with wireless-circuit metrics (e.g., EVM, SNR, ACPR, NMSE). Unification of EDA and OTA, based on holistic Multiphysics (EM, Thermal, Mechanical) approaches, will foster new standards for joint communication and sensing at any time and from anywhere (remote ubiquitous connectivity).

This paper presents some measurements made on samples of raw materials used for antenna reflectors on communication satellites. Two theoretical results have been experimented: the first one is the power dependence of the passive intermodulation products versus the power of the carriers; the second one is the direction along which intermodulation products are radiated when the incident carriers come from different directions.

CNES is involved in the protection of Radio Astronomy near the far side of the Moon, in a zone defined by ITU as the Shielded Zone of the Moon (SZM). The 2483.5-2500 MHz band has been chosen for lunar in-situ PNT notably since it is the only band recommended by SFCG (Space Frequency Coordination Group) for lunar in situ PNT. This band is also the only GNSS band recommended by SFCG for radiocommunications from Martian orbit to Martian surface. CNES proposed this band for lunar and Martian frequencies to SFCG. Regarding the protection of Radio Astronomy in Shielded Zone of the Moon (SZM), which is more or less the far side of the Moon and above, this 2483.5-2500 MHz band is well adapted, while it is not the case for any part of the other GNSS bands used on Earth: both RNSS L and C bands constitute each an important threat for Radio Astronomy in the SZM. SFCG issued two recommendations concerning the protection of lunar in-situ PNT in its 2483.5-2500 MHz band: Recommendation SFCG 32-2R6, so called “Freqs for lunar region”, and Recommendation SFCG 43-1, so called “Protection of lunar S-band PNT”. Obeying both SFCG RECs 32-2R6 and 43-1simultaneously is mandatory to ensure protection of lunar in-situ PNT from wireless WIFI and 3GPP (like 4G, 5G, …) lunar surface links. Adjacent to the 2483.5-2500 MHz in-situ lunar PNT band recommended by SFCG 32-2R6, the bands 2400-2480 MHz and 2503.5-2655 MHz are among the bands recommended for lunar surface wireless systems. This means that there is a minimum of 3.5 MHz mandatory guard bands on each side of the 2483.5-2500 MHz PNT band in SFCG 32-2R6 for the protection of lunar in-situ PNT. The SFCG REC 43-1 recommends the PNT devices to implement filtering, and that each lunar surface wireless system should not generate an aggregated PFD exceeding -121dBW/m²/MHz at the input of the PNT receiving antenna. The SFCG REC 32-2R6 recommends the Wireless device to implement filtering when necessary to avoid Out Of Band harmfull interference to PNT. The paper details these 2 SFCG recommendations which are fundamental for protection of in-situ lunar PNT. It provides some rules to the implementers to respect both SFCG recommendations. A model of PNT receiver response to interference has been developed by TéSA. Different cases are considered, such as astronauts on the lunar surface in a suit equipped with wireless and PNT devices and related antennas on their backpack, with the wireless transmitters (WIFI and 5G) interfering with the PNT reception. Technical justifications of the PFD limit of SFCG REC 43-1 are also provided. These explanations and rules are valid for in-situ lunar PNT, like the AFS (Augmented Forward Service) of LunaNet, but also for the baseline of the future Chinese insitu lunar PNT service. This paper presents the Wireless to PNT interference simulator developed by TéSA. The interference results from this simulator were used by CNES to participate to the elaboration of REC 32-2R6 and REC 43-1 in order to contribute protecting lunar in-situ PNT and, consequently, Radio Astronomy in the SZM. The SFCG recommendation applicable in the Mars region is REC 22-1R4, “Frequency assignment guidelines for communications in the Mars region” , so called “Freqs for Mars region”. In addition to the 2483.5-2500 MHz orbit to surface band, REC 22-1R4 recommends several surface wireless bands, including 2400-2480 MHz and 2503.5-2620 MHz (likely to be extended up to 2655 MHz in a next version). CNES showed that there would also be Radio Astronomy issues with GNSS L and C bands if one of them were broadcast by a Martian radiocom constellation, since Mars is regularly visible from the Shielded Zone of the Moon. The protection measures for a Martian in-situ PNT in 2483.5-2500 MHz would then be similar to the ones described for lunar in-situ PNT systems. This paper introduces the CCSDS Standard for lunar and Martian 3GPP and WIFI wireless links. This CCSDS Standard specifies to comply with the described SFCG recommendations. The paper finally concludes the systematic need to conduct system studies for each lunar wireless network, combining wireless and PNT, and involving wireless to PNT interference computations.

Nous proposons de partitionner l’architecture d’un réseau ad-hoc mobile en plusieurs groupes, afin de re-distribuer équitablement la charge entre les membres du réseau. Notre étude porte sur un essaim de nanosatellites fonctionnant commue un télélescope spatial distribué, placé en orbite lunaire. Chaque nanosatellite de l’essaim collecte des données d’observation de l’espace, puis les échange avec les autres membres de l’essaim. Les données recueillies sont ensuite combinées localement afin de produire l’image globale observée par l’essaim. Cependant, un système fondé sur ce mode opératoire est particulièrement sensible aux pertes de paquets et aux pannes d’énergie. En effet, la transmission simultanée d’un important volume de données peut entraîner des problèmes de communication, notamment en surchargeant le canal radio ou en augmentant le risque de collisions, menant dans les deux cas à des pertes de paquets. La consommation énergétique totale de l’essaim est également proportionnelle au nombre de paquets transmis : il faut alors trouver une solution pour limiter le nombre de transmissions afin d’économiser l’énergie des nanosatellites. La principale contribution de ce papier est de proposer une approche basée sur la division équitable du réseau en plusieurs groupes de nanosatellites. Nous comparons les performances de trois algorithmes de division de graphe : Random Node Division (RND), Multiple Independent Random Walks (MIRW), et Forest Fire Division (FFD). Nos résultats montrent que MIRW obtient les meilleurs scores en termes d’équité, peu importe le nombre de groupes produit.

Smart Integrated Electromagnetic Skins’, acting as antenna arrays that are conformal to the shape of the object they are mounted on, are introduced. The underlying technological solution offers a replacement for the concept of “elements” in antenna arrays. The radiating current flows over a textured surface (“Metasurface”) that is fed by a limited number of source points (or “ports”), through which the electronics can sense the near-field and far-field electromagnetic environment and adapt to it. The proposed approach of co-design and co-integration of metasurface (MTS) antennas with front-end-modules (FEM) accounts for thermal-dissipation management and accommodates curved and flexible electronic substrates. The resulting requirements call for new functional materials engineering with challenges in relation with processes and circuits EM-Thermal-Mechanical co-design and co-assembly. New designs and realizations of leaky-wave (LW) MTS antennas fed at multiple points are manufactured and experimentally evaluated. This work demonstrates for the first time, co-integration of dual-channel MTS antenna and transceiver FEMs using 3D heterogeneous packaging with the benefits of Multi-Feed (MF) Chip-in-Connector (CiC) technologies. At the system-level, the measured performance of MTS antennas co-integrated with adaptive FEMs is reported for dual-beam applications.

EVM (Error Vector Measurement) is used to measure the end-to-end quality of digital communication links. It comes from noise, linear and non-linear distortion, and interference if any. I propose a method to discriminate between random noise that is independent of the signal and distortion that depends on the signal. Interference is more complex to discriminate as it is not random but can be either synchronous with the signal or not. Echoes such as multipath cause linear distortion if they are static. However, variable echoes, such as those created in a reverberation chamber must be treated specifically.