Keysight Research Articles

Enhancement of electromagnetic interference shielding properties of hemp fiber sandwiched carbon fiber composites using electroless NiP coating

The present study aimed to improve the electromagnetic interference (EMI) shielding effectiveness (SE) of woven hemp fiber (HF) sandwiched carbon fiber (CF) epoxy composites using electroless Nickel-phosphorus coating. Furthermore, the phase composition, functional groups, microstructure, elemental composition, mapping and electrical conductivity of the raw fiber and coated fiber were analyzed in detail. Three different composite samples were prepared and their EMI SE was studied using a key sight 9374A vector network analyzer with 8–12 GHz frequency band (X-band frequency). The EMI SET of the raw HF sandwiched CF composite (S1) was observed as 61.17 dB. But, the addition of 1-layer coated HF between CF (S2) has increased the EMI SET from 61.17 to 83.16 dB. The 2 layer coated HF between CF (S3) had exhibited 92.77 dB which is 51.66 % higher than the S1 composite.

DESIGN OF AMPLITUDE AND PHASE CONTROLLED BUTLER BEAMFORMING NETWORK FOR X/KU-BAND AIRBORNE SYNTHETIC APERTURE RADAR APPLICATIONS

Beamforming networks play an important role in today's communication systems. The Butler matrix network is one of the most useful networks used to feed array antennas and generate multi-beamforming systems. Its complexity increases with an increase in the number of input and output ports. This research work presents simulated results of an unequal amplitude 8 × 8 Butler matrix network, in which the Taylor series synthesis technique was employed to generate unequal amplitudes (-9.626, -9.125, -8.798, -8.636, -8.636, -8.798, -9.125, and -9.626 dB). The design of the Butler matrix beamforming network is based on two frequency bands, i.e., the X-band and Ku-band, with center frequencies of 9.3 and 13.265 GHz, respectively. The design mainly involves 12 hybrid couplers and eight phase shifters that can generate beams in eight different directions (-32.4°, -26.5°, -15.5°, -10.3°, 10.3°, 15.5°, 26.5°, and 32.4°). This design is based on the Taylor series expansion, which has the advantage of sidelobe level reduction of -17 dB. All of the simulations were done using advanced design system software key sight technologies. The simulations results were in line with the theoretical calculations.

Design and analysis of square shape slot cut high gain Sierpinski carpet fractal antenna for wireless applications

AbstractIn this paper, a fractal antenna is proposed for wideband application. It has a resonance frequency of 5 GHz, and has been designed using an FR4 substrate with a width and a length of 40 mm and patch with a width, length of 35.288 mm. The proposed antenna has been made with five iterations, and the result obtained multiband behavior and agrees with the various efficient wireless applications. In the proposed antenna, there are four bands response at frequencies 1.6, 2.9,5.2, and 6 GHz, and bandwidth percentage are 4.56%, 7.89%, 12.13%, and 4.6%. It also covers application in 1.5–1.7, 2.8–3.1, 4.8–5.4, and 5.9–6.2 GHz. The gain and the directivity of the proposed antenna is measured as 15.885 dBi greater than other fractal antennas to date, and 7.422 dBi respectively. The proposed antenna has been implemented successfully using IE3D and the result has been tested successfully using a key sight vector analyzer.

Toward IoT device fingerprinting from proprietary protocol traffic via key-blocks aware approach

IoT Device fingerprinting of network traffic is valuable for many management and security solutions as it provides insights into the devices active on a network. Unfortunately, existing techniques focus on the public (de facto) standard protocol and suffer from low efficiency and high data packet dependence at flow-level granularity. Hence, accurately identifying the types of proprietary-protocol-oriented IoT devices is still a challenge that cannot be ignored. As a solution, we propose DeepFinger, a full-automated, byte-level payload fingerprint generation approach to fill this gap. DeepFinger aims to eliminate the manual intervention required to extract available payload-driven fingerprints, in the absence of priori protocol specification information. The key sight of DeepFinger is that it utilizes deep clustering to automatically cluster similar payloads and infer key-blocks as fingerprints. Through extensive evaluation, we demonstrate that DeepFinger achieves the average TPR with 98.81%, the average FTF with 98.74%, and the average FPR with 0.07% on the dataset containing multiple proprietary protocols. In addition, on three datasets containing public protocols such as MQTT, Modbus, HTTP, and XMPP, DeepFinger also achieved excellent performance by virtue of its extensibility. These results suggest that DeepFinger can be a promising tool for automatizing the payload fingerprint extraction process, based on proprietary protocol assumption.

A(nother) time for nature? Situating non-human nature experiences within the emotional transitions of sight loss

Sight impairment is experienced by approximately 253 million people worldwide, including people of all generations, at all life course stages. Caught between past and present embodiments of the world, people often express feelings of loss with the onset of sight impairment. This paper examines the role of nonhuman nature encounters as a contingent resource amongst individuals navigating these emotional transitions. It responds to recent calls to attend to the life course in both critical disability studies and the growing body of work linking nonhuman nature relations to human wellbeing. The paper draws on findings from a qualitative study that combined in-depth narrative interviews with in situ go-along interviews to explore how 31 people with sight impairment in England describe and experience a sense of wellbeing (or otherwise) with nature across their everyday lives and life trajectories. The data were analysed using inductive narrative thematic analysis. While nonhuman nature encounters were valued by many participants in promoting a sense of freedom, relatedness, pleasurable sensory immersion, opportunities for exploration and 'skilling up', this paper cautions against generalised or overly Romantic tropes of what nonhuman nature can 'do' through key sight loss junctures, and for whom. It highlights the value of providing timely and sensitive social scaffolding and nurturing creativity to open up meaningful opportunities to engage with nonhuman nature and to counter feelings of loss exacerbated by identity-limiting life course narratives and disability stereotypes. Informed by the stories shared by participants to chart and situate their experiences of sight loss, we call for a new identity politics within and beyond the growing movement to 'connect' people to nonhuman nature for wellbeing; a politics that affirms diverse forms of more-than-human embodiment, recognising how and why such relations may weave into - and indeed out of - people's varied, interdependent life course trajectories.

Design of RF Receiver Front end Subsystems with Low Noise Amplifier and Active Mixer for Intelligent Transportation Systems Application

This paper presents the design, simulation, and characterization of a novel low-noise amplifier (LNA) and active mixer for intelligent transportation system applications. A low noise amplifier is the key component of RF receiver systems. Design, simulation, and characterization of LNA have been performed to obtain the optimum value of noise figure, gain and reflection coefficient. Proposed LNA achieves measured voltage gains of ~18 dB, reflection coefficients of -20 dB, and noise figures of ~2 dB at 5.9 GHz, respectively. The active mixer is a better choice for a modern receiver system over a passive mixer. Key sight advanced design system in conjunction with the electromagnetic simulation tool, has been to obtain the optimal conversion gain and noise figure of the active mixer. The lower and upper resonant frequencies of mixer have been obtained at 2.45 GHz and 5.25 GHz, respectively. The measured conversion gains at lower and upper frequencies are 12 dB and 10.2 dB, respectively. The measured noise figures at lower and upper frequencies are 5.8 dB and 6.5 dB, respectively. The measured mixer interception point at lower and upper frequencies are 3.9 dBm and 4.2 dBm.

Implementation of time-window based analog self-interference cancellation for full-duplex radios

Multi-tap delay line circuits are widely used to model the analog self-interference multipath channel in full-duplex wireless communication systems. However, the complexity of these circuits is a considerable problem. To overcome this issue, this paper investigates a simple dual-channel analog self-interference cancellation circuit. Instead of modeling the multi-tap for multipath reflections, the key sight is that the light-of-sight self-interference is estimated by designing a dual-channel with the fixed delay and tunable attenuator circuit. Feasibility of only canceling the light-of-sight self-interference is explored first. Then, according to the distance of transceiver antennas, delays of the dual-channel are calculated which acts as a time-window to let the light-of-sight self-interference pass. Additionally, due to the error caused by the non-light-of-sight self-interference, attenuators of the dual-channel are designed be tuned adaptively based on the minimum residual mean square error. Finally, the experimental results show that the proposed method can provide up to 50 dB cancellation over different transmission signal bandwidths.