European Microwave Research Articles

European Microwave Week

European Microwave Week

Welcome to the 27th European Microwave Week in Paris, France [Around the Globe

Welcome to the 27th European Microwave Week in Paris, France [Around the Globe

RF circuit techniques for transition to 5G advanced

Abstract Worldwide adoption of 5G mobile devices has been one of the main driving engines behind semiconductor industry. Since the initial release in 2020, 5G-enabled devices have surpassed the market penetration of 3G/4G smartphones. 5G brings higher data capacity, low latency, and new applications. These are possible due to lower feature nodes such as FinFET 3 nm/5 nm but also due to improvements of the 5G radio frequency (RF)front-end circuitry. This paper presents 5G RF front-end architectures with novel circuits and measurement details which will be part of future 5G advanced and 6G mobile devices and are easier to be controlled using digital circuitry. The paper presents an envelope-controlled power amplifier (PA) principle, along with a novel simplified calibration architecture designed for 5G/5G+ operating under 6 GHz, as well as for frequency range 2 millimeter-wave PAs. An earlier version of this paper was presented at the 2023 53rd European Microwave Conference and was published in the Proceedings [Balteanu F, Thoomu K, Pingale A, Venimadhavan S, Sarkar S, Choi Y, Modi H, Drogi S, Lee J and Agarwal B (2023) Enabling RF circuit techniques for 5G and beyond In 53rd European Microwave Conference (EuMC), Berlin, Germany, 22–25].

The 26th European Microwave Week, in Berlin, Germany [Around the Globe

The 26th European Microwave Week, in Berlin, Germany [Around the Globe

The 26th European Microwave Week in Berlin, Germany [MTT-S Society News

The 26th European Microwave Week in Berlin, Germany [MTT-S Society News

The 25th European Microwave Week (EuMW 2022) [Conference Report

The 25th European Microwave Week (EuMW 2022) took place fully in person in Milan, Italy, on 25–30 September 2022 at the new Milano Convention Center in the City Life District. Luca Perregrini was the general chair, Luciano Tarricone was the general cochair and treasurer, and Maurizio Bozzi was the TPC general chair, who, together with the entire steering committee ( <xref ref-type="fig" rid="fig1" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Figure 1</xref> ), dedicated more than a year putting together a full and engaging Microwave Week. The event was hosted at the Milano Convention Center in the heart of the City Life District, with an amazing view of the area, and it was strongly supported by a fantastic international group of young volunteers ( <xref ref-type="fig" rid="fig2" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Figure 2</xref> ) whose tireless activity and enthusiasm were fundamental for the success of EuMW 2022.

RCS prediction and optimization for anomalous reflection metasurfaces using Floquet analysis

AbstractDue to their periodic nature, metasurfaces used to perform anomalous reflection raise parasitic harmonic reflections. We show a classical synthesis example of such a structure and highlight its limitations. Floquet analysis and its associated simulation environment are exploited to understand the origin of these parasitic reflections and to mitigate them. The proposed method is based on the optimization of the metasurface periodic pattern: the supercell. A predictive method is built to calculate radar cross-section patterns from supercell Floquet simulation, avoiding dealing with heavy simulations. The proposed model, the optimization outputs, and the general results are exposed in details. Different cases are also discussed to prove the repeatability of the proposed method. An earlier version of this paper was presented at the European Microwave Conference and was published in its proceedings.

A 39 GHz spatial division multiplex MU-MIMO using 256 element hybrid AAS for IAB application

AbstractThis paper describes the design and implementation of a 39 GHz 256-element hybrid active phased array antenna system with 16 individual digital transceivers, and its wireless multi-user, multi-input, multi-output verification. An earlier version of this paper was presented at the 2021 51st European Microwave Conference and was published in its Proceedings [1]. Using the prototype device, a single carrier transmission test assuming a mobile backhaul link and a MU-MIMO transmission test using a zero-forced orthogonal multi-beam based on channel reciprocity assuming an access link was performed. As a result, an EIRP of 43 dBm and a data rate of 5.5 Gbps in 1 GHz bandwidth single carrier 128QAM operation and an estimated total throughput of 2.4 Gbps by 3GPP TS38.214 [2] in 100 MHz bandwidth OFDM 8 MU-MIMO operation were achieved, respectively. As far as the author knows, this is the first demonstration for integrated access and backhaul (IAB) application that uses the 39 GHz band.

Compact hand-guided 3D scanning terahertz sensor platforms with 3D-printed aspherical telecentric f-θ lens

AbstractWe report on the development of a handheld three-dimensional (3D) terahertz scanning system with an aspherical telecentric 3D-printed f-θ lens using selective laser sintering. The lens covers a broader scan line of 50 mm with its larger aperture, compared to the 20 mm range in our initial work, which was presented at the European Microwave Week 2021. In order to evaluate the adaptability of the optomechanical components with different sensor units, two different integrated frequency-modulated continuous wave radar modules based on monolithic microwave integrated circuit technology, operating in W- and D-bands are tested within the measurement scheme. The optomechanical part consists of a galvanometer scanner mirror and the f-θ lens. The optical system enables B-scans perpendicular to the manual translational movement of the sensor unit by its user. An integrated guiding wheel system with rotary encoder makes it possible to correlate the measurement points to their respective locations, enabling complete 3D volumetric inspection of the corresponding structures, which is particularly useful for the inspection along cracks and welds.

International Conference on Microwave Acoustics &amp; Mechanics [Conference Reports

After being postponed for two years, the inaugural edition of the IEEE Microwave Theory and Technology Society (MTT-S) International Conference on Microwave Acoustics & Mechanics (IC-MAM) was held from 18 to 20 July 2022 in the Training Center of Rohde & Schwarz in Munich, Germany. It was financially sponsored by the IEEE MTT-S (Figure 1) and technically cosponsored by the European Microwave Association.

The 25th European Microwave Week, in Milan, Italy [Conference Report

Presents information on the 25th European Microwave Week conference.

A Technical Tribute to Peter Clarricoats [Historically Speaking

During European Microwave Week (EuMW2021), held in London in April 2022, there was a special session devoted to the achievements and impact of Prof. Peter J.B. Clarricoats, CBE, FRS, who passed in 2020. I was asked to contribute during the session. Here is my tribute in more detail.

European Microwave Conference

European Microwave Conference

Irrigation and Precipitation Hydrological Consistency with SMOS, SMAP, ESA-CCI, Copernicus SSM1km, and AMSR-2 Remotely Sensed Soil Moisture Products

Numerous Surface Soil Moisture (SSM) products are available from remote sensing, encompassing different spatial, temporal, and radiometric resolutions and retrieval techniques. Notwithstanding this variety, all products should be coherent with water inputs. In this work, we have cross-compared precipitation and irrigation with different SSM products: Soil Moisture Ocean Salinity (SMOS), Soil Moisture Active Passive (SMAP), European Space Agency (ESA) Climate Change Initiative (ESA-CCI) products, Copernicus SSM1km, and Advanced Microwave Scanning Radiometer 2 (AMSR2). The products have been analyzed over two agricultural sites in Italy (Chiese and Capitanata Irrigation Consortia). A Hydrological Consistency Index (HCI) is proposed as a means to measure the coherency between SSM and precipitation/irrigation. Any time SSM is available, a positive or negative consistency is recorded, according to the rainfall registered since the previous measurement and the increase/decrease of SSM. During the irrigation season, some agreements are labeled as “irrigation-driven”. No SSM dataset stands out for a systematic hydrological coherence with the rainfall. Negative consistencies cluster just below 50% in the non-irrigation period and lose 20–30% in the irrigation period. Hybrid datasets perform better (+15–20%) than single-technology measurements, among which active data provide slightly better results (+5–10%) than passive data.

Review of advances in microwave and millimetre-wave NDT&E: principles and applications.

Microwave and millimetre-wave non-destructive testing and evaluation (NDT&E) has a long history dating back to the late 1950s (Bahr 1982 Microwave non-destructive testing methods ; Zoughi 2000 Microwave Non-destructive testing and evaluation principles ; Feinstein 1967 Surface crack detection by microwave methods ; Ash 1973 In 3rd European Microwave Conference ; Auld 1981 Phys. Technol. 12, 149-154; Case 2017 Mater. Eval. 75). However, sustained activities in this field date back to the early 1980s (Zoughi 1995 Res. Nondestr. Eval. 7, 71-74; Zoughi 2018 Mater. Eval. 76, 1051-1057; Kharkovsky 2007 IEEE Instrumentation & Measurement Magazine 10, 26-38). Owing to various limitations associated with using microwaves and millimetre waves for NDT&E, these techniques did not see much utility in the early days. However, with the advent and prevalence of composite materials and structures, in a wide range of applications, and technological advances in high-frequency component design and availability, these techniques are no longer considered as 'emerging techniques' (Zoughi 2018 Mater. Eval. 76, 1051-1057; Schull 2002 Nondestructive evaluation: theory, techniques, and applications ). Currently, microwave and millimetre-wave NDT&E is a rapidly growing field and has been more widely acknowledged and accepted by practitioners over the last 25+ years (Case 2017 Mater. Eval. 75; Bakhtiari 1994 IEEE Trans. Microwave Theory Tech . 42, 389-395; Bakhtiari 1993 Mater. Eval. 51, 740-743; Bakhtiari 1993 IEEE Trans. Instrum. Meas. 42, 19-24; Ganchev 1995 IEEE Trans. Instrum. Meas. 44, 326-328; Bois 1999 IEEE Trans. Instrum. Meas. 48, 1131-1140; Ghasr 2009 IEEE Trans. Instrum. Meas. 58, 1505-1513). Microwave non-destructive testing was recently recognized and designated by the American Society for Nondestructive Testing (ASNT) as a 'Method' on its own (Case 2017 Mater. Eval. 75). These techniques are well suited for materials characterization; layered composite inspection for thickness, disbond, delamination and corrosion under coatings; surface-breaking crack detection and evaluation; and cure-state monitoring in concrete and resin-rich composites, to name a few. This work reviews recent advances in four major areas of microwave and millimetre-wave NDT&E, namely materials characterization, surface crack detection, imaging and sensors. The techniques, principles and some of the applications in each of these areas are discussed. This article is part of the theme issue 'Advanced electromagnetic non-destructive evaluation and smart monitoring'.

Design of a miniature dual-band bandpass filter with interlocked stepped-impedance resonators for 5G new radio access technology

AbstractA miniature dual-band bandpass filter with interlocked stepped-impedance resonators (SIRs) is presented in this paper, which was designed for the student design competition held in European Microwave Week 2019. This bandpass filter is required to have two concurrent passbands, namely, the first passband at 900–1000 MHz and the second passband at 1427–1518 MHz bands, which cover six designated bands in sub-6 GHz range of fifth generation (5G) New Radio Access Technology. Three stopbands are required at 500–850, 1050–1350, and 1600–2000 MHz, respectively. To achieve the best figure of merit, an interlocked configuration of two SIRs is proposed. One advantage is that the impedance ratio of the inter-locked SIR can be controlled to have two passbands at the required frequencies. Second, the coupling section of the interlocked SIR gives three transmission zeros distributed to every stopbands such that the stopband suppression are dramatically enhanced. The measured results show that the passband insertion losses are 2.16 dB at the first passband and 1.33 dB at the second passband, and the return losses are greater than 10 dB. The stopband suppression at the transmission zeros are greater than 38 dB. The circuit is very compact as 41.40 × 19.96 mm2, equivalent to $0.25 \times 0.12\,\lambda _g^2$.

Quasi-elliptic dual-band bandpass filters based on series-cascaded multi-resonant cells

AbstractThis paper reports on quasi-elliptic dual-band bandpass filters (BPFs) that were designed for the Filter Student Design Competition of the 2019 European Microwave Week. The proposed lumped-element (LE) BPF concept is based on two dual-band transversal cells and one multi-resonant cell that allow the realization of symmetric and asymmetric dual-band transfer functions shaped by six poles and five transmission zeros. A compact implementation scheme based on LE series resonators is proposed for size compactness and wide spurious free out-of-band response. For proof-of-concept demonstration purposes, a dual-band LE prototype with two passbands centered 1 and 1.5 GHz was designed, manufactured, and measured. It exhibited the following radio frequency measured performance characteristics. Passbands centered at 1.02 and 1.45 GHz, minimum insertion loss levels of 2.0 and 2.7 dB, and bandwidth of 146 and 105 MHz, respectively, for the first and the second passband, and out-of-band rejection &gt;30 dB between 0 and 894 MHz, 1.17–1.34 GHz, and 1.72–6.9 GHz.

The Impact of Rain on Short ${E}$ -Band Radio Links for 5G Mobile Systems: Experimental Results and Prediction Models

The results from 1 year of data collected during an electromagnetic wave propagation experiment at ${E}$ -band are presented. The research activity originates from the collaboration between Politecnico di Milano, Milan, Italy, and the Huawei European Microwave Centre in Milan, which installed short (325 m) terrestrial links operating at 73 and 83 GHz, connecting two buildings in the university main campus. The received power data are processed, using a novel approach, to identify rain events and to remove the wet antenna effect, with the aim of accurately quantifying the fade induced by precipitation, $A_{R}$ . Moreover, $A_{R}$ is estimated by taking advantage of the ancillary data collected by the laser-based disdrometer collocated with the link transceivers. The results definitely point out the higher prediction accuracy achieved by exploiting the information on the rain drop size. A full year of data are used as reference to test the accuracy of the statistical prediction model for terrestrial links currently recommended by the ITU-R, which reveals a large overestimation. Finally, alternative models providing a higher accuracy are proposed and their accuracy assessed.

Professor Peter Clarricoats CBE FREng FRS FIEEE HonFIET, April 1932 – January 2020

Professor Peter Clarricoats CBE FREng FRS, one of the founding Editors of Electronics Letters, died on Friday 17 January 2020 after a short illness. Peter Clarricoats made major fundamental contributions as a microwave engineer in the fields of applied electromagnetics for microwave and optical waveguides, and microwave antenna feeds. He was appointed a Fellow of the Royal Academy of Engineering in 1983 and was awarded the Sir Frank Whittle medal of the Royal Academy of Engineering in 2015. He was educated at Minchenden Grammar School and Imperial College London, receiving his PhD from the University of London in 1958. He started his academic career in 1959 at Queen's University Belfast and was subsequently appointed as a Professor at the University of Leeds in 1963; in each case starting research groups in microwave engineering which still thrive today. In 1967, he moved to Queen Mary College (now Queen Mary University of London), founding the Electromagnetics and Antenna Group which went on to make significant contributions to antenna and microwave research. Peter was also a pioneer of optical fibres, publishing one of the first monographs on this topic in 1975. He established the theory, which has since been widely used in the context of optical fibres, of electromagnetic propagation on dielectric and ferrite structures. In the course of this, he also discovered that such structures can, under some conditions, support ‘backward waves’ and that guides can propagate complex modes. Over 40 years of his academic career, Professor Clarricoats had numerous notable achievements including pioneering designs for shaped reflectors, reconfigurable reflectors and especially corrugated horns for microwave antennas. The latter are now universally used in satellite ground stations and in spacecraft. Peter was one of the first to recognise the radical improvements which arise from the use of a corrugated horn antenna. He went on to publish what became standard reference texts on Corrugated Horns for Microwave Antennas, Microwave Horns and Feeds. His personal research was recognised through many significant awards from the IEE (now IET) and IEEE where he received the highest honour from the IEEE Antenna Society (APS), The Distinguished Achievement Award in 2001. His contribution to microwaves in Europe was recognised through the European Microwave Association's Microwave Prize in 1989 and the Outstanding Career Award in 2004. Professor Clarricoats was vice-president of the Institution of Electrical Engineers, from 1989 to 1991, and vice-president and treasurer of URSI (the International Union of Radio Science) from 1993 to 1999. He was elected Fellow of the Royal Society, the Royal Academy of Engineering, the Institute of Electrical and Electronics Engineers (IEEE) and the Institution of Engineering and Technology (IET). He was awarded the CBE in 1996. Peter worked with other leading figures to establish new journals and conferences. Perhaps the journal he was most proud of was the internationally renowned Electronic Letters, which remains one of the most successful technical publications of all time. Ian White, current co-Editor-in-Chief of the journal, expressed his sympathy: “Professor Clarricoats’ commitment to Electronics Letters was unparalleled and its success owes greatly to his outstanding expertise, enthusiasm and dynamism to his field. He will be sorely missed.” After he retired from his full-time post in 1997, Professor Clarricoats continued to supervise research and through his personal innovation developed a new compact horn design needed for satellites and spacecraft. In September 2015, he was awarded the Sir Frank Whittle medal of the Royal Academy of Engineering. Peter had sparkle, which together with his great intellect never left him and he will be greatly missed by the many Fellows and colleagues he mentored and encouraged throughout his career.

Modification of the Extended Advanced IEM for Scattering From Randomly Rough Surfaces

In this letter, we modify the extended advanced integral equation model (EAIEM) for electromagnetic backscattering and bistatic scattering from rough surfaces with small to moderate heights. We extend the first-order approximation of the error function as introduced in the EAIEM model to the second order, in a hope to be more suitable for large roughness and high frequency. In addition, a new transition model for the reflection coefficient is proposed to make the dependences explicit on the mean surface curvature, frequency, and dielectric constant, whereas making no use of the complementary term, the effect of inadequate evaluation of this term is mitigated. Comparison with POLARSCAT data for backscattering and with European Microwave Signature Laboratory (EMSL) measurements for bistatic scattering demonstrates the validity of the updated model.