Demonstration of a switchless Class E/Fodd dual-band power amplifier

A 250 W dual-band power amplifier belonging to the Class E/F switching amplifier family is presented. The amplifier operates in the 7 MHz and 10 MHz HAM bands, achieving 16 dB and 15 d B gain with power added efficiencies (PAE) of 92% and 87% in those bands, respectively. It utilizes dual-resonant passive input and output networks to achieve high-efficiency Class E/Fodd operation at both frequencies of operation, allowing the same passive networks to be used for both frequency bands without the use of band-select switches

Fully Integrated Frequency and Phase Generation for a 6-18GHz Tunable Multi-Band Phased-Array Receiver in CMOS

Fully integrated frequency-phase generators for a 6-18GHz wide-band phased-array receiver element are presented that generate 5-7GHz and 9-12GHz first LO signals with less than -95dBc/Hz phase noise at 100kHz offset. Second LO signals with digitally controllable fourquadrant phase- and amplitude spread with better than 3° resolution are generated and allow removal of systematic reference clock skew as well as accurate selection of the received signal phase. This frequency- and phase generation scheme was successfully demonstrated in a 6-18GHz receiver system configured as an electrical 4-element array

Abschätzung des faunistischen Potenzials der Revitalisierung der Wiese zwischen Lörrach - Basel anhand des Makrozoobenthos dreier Seitengewässer

Viele Ökosysteme sind aufgrund von menschlichen Eingriffen stark beeinträchtigt oder komplett zerstört. Dies hat schwerwiegende Folgen für den Menschen und seine Umwelt, auch bei den Fliessgewässern. Über Jahrhunderte hat der Mensch bauliche Massnahmen an Fliessgewässern vorgenommen. Diese sollten vor allem einer besseren Nutzung oder dem Hochwasserschutz dienen. Beim vermeintlichen Hochwasserschutz wurde jedoch meistens das Gegenteil bewirkt: Die Fliessgewässer verloren durch Begradigungen ihr natürliches Retentionsvermögen, was bei starken Niederschlägen zu Überschwemmungen führt. Diese können oft auch nicht mittels künstlich geschaffenen Auffangbecken verhindert werden. In den letzten 30 Jahren hat ein Umdenken eingesetzt: Viele Fliessgewässer sollen mittels Revitalisierungsmassnahmen zu ihren ursprünglichen Strukturen zurückfinden. Im Rahmen des Vorprojektes für die Revitalisierung des Flusses Wiese auf Schweizer Boden wurden ausgewählte Seitengewässer bei Riehen BS auf ihr Makrozoobenthos-Vorkommen und auf Struktureigenschaften untersucht. Damit kann einerseits die Vielfalt des Makrozoobenthos dieser Gewässer verglichen werden. Andererseits gibt die Zusammenstellung einen Überblick über das Makrozoobenthos des gesamten Gewässernetzes der Wiese und zeigt so das Besiedlungspotenzial für die zu renaturierende Strecke der Wiese. Mit diesen Erkenntnissen können Aussagen gemacht werden, welche Art von Massnahmen und Strukturverbesserungen bei der Revitalisierung der Wiese umgesetzt werden sollten. Somit kann künftig ein funktionierendes und wertvolles Ökosystem entstehen, von dem sowohl der Mensch als auch die Natur einen Nutzen haben. Die Untersuchungen stellten fest, dass grössere Unterschiede zwischen den einzelnen Seitengewässern sowie im Vergleich mit der Wiese bestehen. Diese betreffen zum einen die Anzahl Individuen und Taxa, zum anderen die Habitatsvielfalt und Wasserqualität. Zusätzlich zeigte sich, dass Fliessgeschwindigkeiten einen direkten Einfluss auf die Anzahl Individuen und Taxa der Gewässer haben. Der Vergleich der Seitengewässer mit der Wiese zeigte überdies, dass trotz der Revitalisierung des untersuchten Gewässerabschnitts, nicht die höchsten möglichen Werte erreicht werden. Dies ist vermutlich auf den immer noch sehr gradlinigen Verlauf des Gewässers zurückzuführen. Many ecosystems are severely impaired or completely destroyed due to human intervention. This has serious consequences for humans and their environment, including watercourses. For centuries, man has carried out structural measures on watercourses. These were primarily intended to improve utilization or flood protection. In the case of supposed flood protection, however, the opposite effect was usually achieved: As a result of straightening, watercourses lost their natural retention capacity, which leads to flooding during heavy rainfall. This can mostly not be prevented even by artificially created catchment basins. In the last 30 years, a rethinking process has begun, and many watercourses are to be restored to their original structures by means of revitalisation measures. Within the framework of the preliminary project for the revitalization of the Wiese river on Swiss land, selected side waters were examined for their macrozoobenthos occurrence and structural properties. On the one hand, the diversity of the macrozoobenthos in these waters can be compared. On the other hand, the compilation provides an overview of the macrozoobenthos of the entire watercourse network of the meadow and thus corresponds to the settlement potential for the section of the meadow to be renatured. With these findings, statements can be made as to what measures and structural improvements should be implemented in the revitalization of the Wiese. Thus, a functioning and valuable ecosystem can be created for the future, from which man and nature can benefit. The investigations proved major differences between the individual side waters and in comparison, with the Wiese. These differences include the number of individuals and taxa, but also habitat diversity and water quality. In addition, flow velocities have a direct influence on the number of individuals and taxa in the water bodies. By comparing side waters with the Wiese, it was also found that despite the revitalization of the investigated watercourse section, the highest possible values are not reached. This is probably due to th

A Scalable 6-to-18 GHz Concurrent Dual-Band Quad-Beam Phased-Array Receiver in CMOS

This paper reports a 6-to-18 GHz integrated phased- array receiver implemented in 130-nm CMOS. The receiver is easily scalable to build a very large-scale phased-array system. It concurrently forms four independent beams at two different frequencies from 6 to 18 GHz. The nominal conversion gain of the receiver ranges from 16 to 24 dB over the entire band while the worst-case cross-band and cross-polarization rejections are achieved 48 dB and 63 dB, respectively. Phase shifting is performed in the LO path by a digital phase rotator with the worst-case RMS phase error and amplitude variation of 0.5° and 0.4 dB, respectively, over the entire band. A four-element phased-array receiver system is implemented based on four receiver chips. The measured array patterns agree well with the theoretical ones with a peak-to-null ratio of over 21.5 dB

A Fully-Integrated Quad-Band GSM/GPRS CMOS Power Amplifier

Concentric distributed active transformers (DAT) are used to implement a fully-integrated quad-band power amplifier (PA) in a standard 130 nm CMOS process. The DAT enables the power amplifier to integrate the input and output matching networks on the same silicon die. The PA integrates on-chip closed-loop power control and operates under supply voltages from 2.9 V to 5.5 V in a standard micro-lead-frame package. It shows no oscillations, degradation, or failures for over 2000 hours of operation with a supply of 6 V at 135° under a VSWR of 15:1 at all phase angles and has also been tested for more than 2 million device-hours (with ongoing reliability monitoring) without a single failure under nominal operation conditions. It produces up to +35 dBm of RF power with power-added efficiency of 51%

Dynamic Focusing of Large Arrays for Wireless Power Transfer and Beyond

We present architectures, circuits, and algorithms for dynamic 3-D lensing and focusing of electromagnetic power in radiative near- and far-field regions by arrays that can be arbitrary and nonuniform. They can benefit applications such as wireless power transfer at a distance (WPT-AD), volumetric sensing and imaging, high-throughput communications, and optical phased arrays. Theoretical limits on system performance are calculated. An adaptive algorithm focuses the power at the receiver(s) without prior knowledge of its location(s). It uses orthogonal bases to change the phases of multiple elements simultaneously to enhance the dynamic range. One class of such 2-D orthogonal and pseudo-orthogonal masks is constructed using the Hadamard and pseudo-Hadamard matrices. Generation and recovery units (GU and RU) work collaboratively to focus energy quickly and reliably with no need for factory calibration. Orthogonality enables batch processing in high-latency and low-rate communication settings. Secondary vector-based calculations allow instantaneous refocusing at different locations using element-wise calculations. An emulator enables further evaluation of the system. We demonstrate modular WPT-AD GUs of up to 400 elements utilizing arrays of 65-nm CMOS ICs to focus power on RUs that convert the RF power to dc. Each RFIC synthesizes 16 independently phase-controlled RF outputs around 10 GHz from a common single low-frequency reference. Detailed measurements demonstrate the feasibility and effectiveness of RF lensing techniques presented in this article. More than 2 W of dc power can be recovered through a wireless transfer at distances greater than 1 m. The system can dynamically project power at various angles and at distances greater than 10 m. These developments are another step toward unified wireless power, sensing, and communication solutions in the future

Distribution of hydrogen peroxide over Europe during the BLUESKY aircraft campaign

In this work we present airborne in situ trace gas observations of hydrogen peroxide (H$_2$O$_2$) and the sum of organic hydroperoxides over Europe during the Chemistry of the Atmosphere – Field Experiments in Europe (CAFE-EU, also known as BLUESKY) aircraft campaign using a wet chemical monitoring system, the HYdrogen Peroxide and Higher Organic Peroxide (HYPHOP) monitor. The campaign took place in May–June 2020 over central and southern Europe with two additional flights dedicated to the North Atlantic flight corridor. Airborne measurements were performed on the High Altitude and LOng-range (HALO) research operating out of Oberpfaffenhofen (southern Germany). We report average mixing ratios for H$_2$O$_2$ of 0.32 ± 0.25, 0.39 ± 0.23 and 0.38 ± 0.21 ppbv in the upper and middle troposphere and the boundary layer over Europe, respectively. Vertical profiles of measured H$_2$O$_2$ reveal a significant decrease, in particular above the boundary layer, contrary to previous observations, most likely due to cloud scavenging and subsequent rainout of soluble species. In general, the expected inverted C-shaped vertical trend with maximum hydrogen peroxide mixing ratios at 3–7 km was not found during BLUESKY. This deviates from observations during previous airborne studies over Europe, i.e., 1.64 ± 0.83 ppb$_v$ during the HOOVER campaign and 1.67 ± 0.97 ppbv during UTOPIHAN-ACT II/III. Simulations with the global chemistry–transport model EMAC partly reproduce the strong effect of rainout loss on the vertical profile of H$_2$O$_2$. A sensitivity study without H$_2$O$_2$ scavenging performed using EMAC confirms the strong influence of clouds and precipitation scavenging on hydrogen peroxide concentrations. Differences between model simulations and observations are most likely due to difficulties in the simulation of wet scavenging processes due to the limited model resolution

A tunable concurrent 6-to-18 GHz phased-array system in CMOS

This paper presents a scalable phased-array receiver system that covers a tritave bandwidth of 6-to-18 GHz implemented in a 130nm CMOS process. The single receiver element with a 10-bit phase shifting resolution achieves a maximum phase error of 2.5° within a baseband amplitude variation of 1.5dB for an arbitrary target angle. This dense interpolation provides excellent phase error/offset calibration capability in the array. A 4-element electrical array pattern is measured at 6 GHz, 13.5 GHz and 18 GHz, showing a worst case peak-to-null ratio of 21.5dB. The EVM and phase noise improvements of the array compared with the single receiver element are also shown