A 216–256 GHz fully differential frequency multiplier-by-8 chain with 0 dBm output power

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.This work presents a fully differential wideband and low power 240 GHz multiplier-by-8 chain, manufactured in IHP's 130 nm SiGe:C BiCMOS technology with fT/fmax = 300/500 GHz. A single ended 30 GHz input signal is multiplied by 8 using Gilbert cell-based quadrupler and doubler, and then amplified with a wideband differential 3-stage cascode amplifier. To achieve wide bandwidth and optimize for power consumption, the power budget has been designed in order to operate the frequency multipliers and the output amplifier in saturation. With this architecture the presented circuit achieves a 3 dB bandwidth of 40 GHz, meaning a relative 3 dB bandwidth of 17%, and a peak saturated output power of 0 dBm. Harmonic rejections better than 25 dB were measured for the 5th, 6th, and 7th harmonics. It dissipates 255 mW from 3 V supply which results in drain efficiency of 0.4%, while occupying 1.2 mm2. With these characteristics the presented circuit suits very well as a frequency multiplier chain for driving balanced mixers in 240 GHz transceivers for radar, communication, and sensing applications.DFG, 255715243, SPP 1857: Elektromagnetische Sensoren für Life Sciences (ESSENCE

Nonverbal Social Behavior Generation for Social Robots Using End-to-End Learning

To provide effective and enjoyable human-robot interaction, it is important for social robots to exhibit nonverbal behaviors, such as a handshake or a hug. However, the traditional approach of reproducing pre-coded motions allows users to easily predict the reaction of the robot, giving the impression that the robot is a machine rather than a real agent. Therefore, we propose a neural network architecture based on the Seq2Seq model that learns social behaviors from human-human interactions in an end-to-end manner. We adopted a generative adversarial network to prevent invalid pose sequences from occurring when generating long-term behavior. To verify the proposed method, experiments were performed using the humanoid robot Pepper in a simulated environment. Because it is difficult to determine success or failure in social behavior generation, we propose new metrics to calculate the difference between the generated behavior and the ground-truth behavior. We used these metrics to show how different network architectural choices affect the performance of behavior generation, and we compared the performance of learning multiple behaviors and that of learning a single behavior. We expect that our proposed method can be used not only with home service robots, but also for guide robots, delivery robots, educational robots, and virtual robots, enabling the users to enjoy and effectively interact with the robots.Comment: 10 pages, 7 figures, 3 tables, submitted to the International Journal of Robotics Research (IJRR

Expanding Scanning Frequency Range of Josephson Parametric Amplifier Axion Haloscope Readout with Schottky Diode Bias Circuit

The axion search experiments in the microwave frequency range require high sensitive detectors with intrinsic noise close to quantum noise limit. Josephson parametric amplifiers (JPAs) are the most valuable candidates for the role of the first stage amplifier in the measurement circuit of the microwave frequency range, as they are well-known in superconducting quantum circuits readout. To increase the frequency range, a challenging scientific task involves implementing an assembly with parallel connection of several single JPAs, which requires matching the complex RF circuit at microwaves and ensuring proper DC flux bias. In this publication, we present a new DC flux bias setup based on a Schottky diode circuit for a JPA assembly consisting of two JPAs. We provide a detailed characterization of the diodes at cryogenic temperatures lower than 4 K. Specifically, we selected two RF Schottky diodes with desirable characteristics for the DC flux bias setup, and our results demonstrate that the Schottky diode circuit is a promising method for achieving proper DC flux bias in JPA assemblies.Comment: 7 pages, 6 image

Undulatory topographical waves for flow-induced foulant sweeping

Diverse bioinspired antifouling strategies have demonstrated effective fouling-resistant properties with good biocompatibility, sustainability, and long-term activity. However, previous studies on bioinspired antifouling materials have mainly focused on material aspects or static architectures of nature without serious consideration of kinetic topographies or dynamic motion. Here, we propose a magnetically responsive multilayered composite that can generate coordinated, undulatory topographical waves with controlled length and time scales as a new class of dynamic antifouling materials. The undulatory surface waves of the dynamic composite induce local and global vortices near the material surface and thereby sweep away foulants from the surface, fundamentally inhibiting their initial attachment. As a result, the dynamic composite material with undulating topographical waves provides an effective means for efficient suppression of biofilm formation without surface modification with chemical moieties or nanoscale architectures

Integration of 150 Gbps/fiber optical engines based on multicore fibers and 6-channel VCSELs and PDs

Multicore fiber enables a parallel optic data link with a single optical fiber, thus providing an attractive way to increase the total throughput and the integration density of the interconnections. We study and present photonics integration technologies and optical coupling approaches for multicore transmitter and receiver subassemblies. Such optical engines are implemented and characterized using multimode 6-core fibers and multicore-optimized active devices: 850-nm VCSEL and PD arrays with circular layout and multi-channel driver and receiver ICs. They are developed for bit-rates of 25 Gbps/channel and beyond, i.e. <150 Gbps per fiber, and also optimized for ruggedized transceivers with extended operation temperature range, for harsh environment applications, including space

Group I Self-Splicing Intron in the recA Gene of Bacillus anthracis

Self-splicing introns are rarely found in bacteria and bacteriophages. They are classified into group I and II according to their structural features and splicing mechanisms. While the group I introns are occasionally found in protein-coding regions of phage genomes and in several tRNA genes of cyanobacteria and proteobacteria, they had not been found in protein-coding regions of bacterial genomes. Here we report a group I intron in the recA gene of Bacillus anthracis which was initially found by DNA sequencing as an intervening sequence (IVS). By using reverse transcriptase PCR, the IVS was shown to be removable from the recA precursor mRNA for RecA that was being translated in E. coli. The splicing was visualized in vitro with labeled free GTP, indicating that it is a group I intron, which is also implied by its predicted secondary structure. The RecA protein of B. anthracis expressed in E. coli was functional in its ability to complement a recA defect. When recA-negative E. coli cells were irradiated with UV, the Bacillus RecA reduced the UV susceptibility of the recA mutant, regardless of the presence of intron

Fabrication of magnetic field-responsive flexible pillar arrays and its application to droplet manipulation

The manipulation of droplets is of significant interest for a broad range of applications. To manipulate a droplet, patterned surfaces, chemical gradients or electrowetting have been suggested as a passive approach. Due to inherent limitations of existing techniques, magnetically actuatable structures became considerable for the active droplet manipulation due to their reversible structural tunability in response to a remote magnetic field. To this end, we report a novel technique that enables dynamic control over the position and motion of a pure droplet by utilizing a magnetically responsive flexible film. comprising reversibly actuating hierarchical pillars on the surface (Fig. 1). The droplet can be rapidly manipulated to arbitrary targets with only the use of a permanent magnet. This surface exhibits reliable actuating capabilities with immediate field responses and maximum tilting angles of ~90?? with superhydrophobicity