Search results for "Figure"
showing 10 items of 239 documents
Computer-Aided Simultaneous Determination of Noise and Gain Parameters of Microwave Transistors
1979
A new method for the determination of noise and gain parameters of microwave linear two-ports (transistors) is presented. The method allows the simultaneous determination of the two parameter sets through a proper computer-aided procedure which processes the experimental data obtained from a measuring system employing noise meters and generators only. Experimental verifications carried-out on a microwave low noise transistor in S-band are reported.
Up to Date Version of a Computer-Driven Noise Figure Measuring System for the Simultaneous Determination of Noise, Gain and Scattering Parameters of …
1995
The complete characterization of microwave transistors in terms of (four) noise, (four) gain and scattering parameters sets ({N), {G) and [SI, respectively) vs. frequency and bias conditions (and also vs. decreasing temperature, if required) is the first and most important step to design low noise amplifiers (LNAs). The characterization of the device under test (DUT) in terms of [SI is friendly by means of commercial Automatic Network Analyzer; then the { G) set may be determined by computation.
On the noise resistance of field-effect transistors at microwave frequencies
2001
This paper presents a survey on the topical aspects of the noise resistance in field-effect transistors (FET) at microwave frequencies. Such noise parameter represents the sensitivity of the device noise figure to the departure from the minimum noise condition and is therefore important in all low-noise applications. The performance of the noise resistance in FETs has been reviewed since the first noise modeling analysis of short-gate devices were presented in the early '70s. The authors also comment and compare their own results on this subject as obtained by extensive experimental activity in the field of noisy device characterization vs. frequency, bias and temperature conditions.
Validating and controlling quantum enhancement against noise by motion of a qubit
2019
Experimental validation and control of quantum traits for an open quantum system are important for any quantum information purpose. We consider a traveling atom qubit as a quantum memory with adjustable velocity inside a leaky cavity, adopting a quantum witness as a figure of merit for quantumness assessment. We show that this model constitutes an inherent physical instance where the quantum witness does not work properly if not suitably optimized. We then supply the optimal intermediate blind measurements which make the quantum witness a faithful tester of quantum coherence. We thus find that larger velocities protect quantumness against noise, leading to lifetime extension of hybrid qubit…
Readout of quantum information spreading using a disordered quantum walk
2021
We design a quantum probing protocol using quantum walks to investigate the quantum information spreading pattern. We employ quantum Fisher information as a figure of merit to quantify extractable information about an unknown parameter encoded within the quantum walk evolution. Although the approach is universal, we focus on the coherent static and dynamic disorder to investigate anomalous and classical transport as well as Anderson localization. We provide a feasible experimental strategy to implement, in principle, the quantum probing protocol based on the quantum Fisher information using a Mach–Zehnder-like interferometric setup. Our results show that a quantum walk can be considered as …
Simulations of Array Configurations for the Square Kilometre Array (SKA)
2010
The Square Kilometre Array (SKA) is a new generation radio telescope for the next decades, working at metre to centimetre wavelengths. The SKA will be operational at the same time than other new optical, X-ray and Gamma-ray telescopes. It is of extreme importance that the SKA becomes competitive and complementary to those instruments. An extensive study of technologies and possible configurations involved is needed to ensure the SKA will reach the design specifications. To compare imaging capabilities between different SKA configurations or between the SKA and other instruments, we have implemented figures of merit based on several characteristics of these instruments. In this work we are p…
Cross-Spectrum PM Noise Measurement, Thermal Energy, and Metamaterial Filters.
2017
International audience; Virtually all commercial instruments for the measurement of the oscillator PM noise make use of the crossspectrum method (arXiv:1004.5539 [physics.ins-det], 2010). High sensitivity is achieved by correlation and averaging on two equal channels, which measure the same input, and reject the background of the instrument.We show that a systematic error is always present if the thermal energy of the input power splitter is not accounted for. Such error can result in noise underestimation up to a few decibels in the lowest-noise quartz oscillators, and in an invalid measurement in the case of cryogenic oscillators. As another alarming fact, the presence of metamaterial com…
A Glimpse over the Rising Walls
2009
The authors focus on societal perceptions of the Polish post-communist transformation as reflected in the rising discourse of gated communities. Guarded, (video-) controlled and/or walled housing estates have been on the sprawl in the Polish metropolises throughout the 1990s and 2000s. However, only recently they have been discursively constructed—under the banner of “gated communities”—as a social and political issue in the country. The authors look at this issue from a vantage point offered by Laclau and Mouffe's theory of discourse, which allows the authors to combine a spatial and a linguistic analytical perspective. The analysis emphasizes the manner in which societal perceptions of b…
An emotional contribution to the Festschrift of the Journal of Biomaterials Science for Teiji Tsuruta
2017
AbstractIt is a honor for me to contribute to the ‘Festschrift for Teiji Tsuruta’! Being old, it is much easier for me to look back than to think ahead. Thus, please allow me to make a few ‘historical remarks’ about Biomaterials and Biotechnology, long before Science stepped in. Remarks about Georg Christoph Lichtenberg, the Gottinger physicist and philosopher, and his relation to Teiji Tsuruta. And talking about him as teacher, one cannot do it without looking at Hermann Staudinger and his dreams.
Saying the Saffu and Beating the Law: The Changing Role of Sacred Sites in the Oromo Politico-Juridical System
2013
This chapter presents a semiotic analysis of the role of sacred sites and other physical features and objects in key political/religious rituals of the Oromo people living in the Horn of Africa. Theoretically, it builds on Jacques Derrida’s deconstruction of the concept of ‘archive’ as an intersection of the topological and the nomological of the place and the law. For Derrida, the place of the archive is not a locatable place, but a topos, the marking of a discourse. In contrast to the European tradition based primarily on archives inscribed in writing and summarised in a codified law, for the traditional Oromo society, laws were part of the oral tradition – a mixture of religion, law and …