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We report techniques based on cesium dispensers to fill microfabricated vapor cells for miniature atomic clocks applications. Two main types of dispensers are considered, which take the form of pills or paste. Whereas the pill contains a large quantity of Cs, the paste is more compatible with wafer-level fabrication. In both cases, the main advantage is the release of the cesium vapor only once the...
The paper reports on the long-wave infrared HgCdTe detector for short response time operating for unbiased and room temperature condition. The response time was calculated at the level of ∼ 220–520 ps for zero bias condition. It was shown that depending on architecture extra series resistance < 20 Ω related to the processing allows to reach response time within the range ∼ 220 ps. The highest detectivity...
High frequency response is an important capability of infrared detectors in many applications. High-temperature long wavelength infrared HgCdTe heterostructure photodiodes exhibit sub-nanosecond time constants while operating under reverse bias. However, the noise, as well as the high current requirements are severe obstacles to their widespread applications. Thus, the present efforts are focused...
For many navigation scenarios, it is known that the accuracy of navigation state estimates depends on the path traveled, particularly when access to external navigation aids such as the Global Positioning System (GPS) is not available. In this work, we present a path planning method that attempts to minimize the navigation uncertainty of a pair of autonomous vehicles traveling from known initial locations...
Deploying the 1B processor involved installing and retrofitting it in a live, fully operational 4ESS™ switch. The customer requirements for deploying the 1B processor were simple, clear, and stark: “flawless execution with no interruption to service.” To accomplish this, special bus switches were designed to allow peripheral units to be switched from the 1A to the 1B processor as part of the retrofit...
CEA-LETI and CNES have successfully realized a helium-4 isotropic space-qualified magnetometer for the SWARM mission. The present paper reviews the progress made in the miniaturization of this isotropic optically pumped magnetometer. Sensor isotropy is provided by a liquid crystal polarization rotator that sets the pumping beam polarization at 90° with respect to the ambient magnetic field. It allows...
Redevelopment of engineering course from traditional to blended model is a challenging prospect. Some general guidelines are given at first, then Electric Circuit Theory (ECT) case study is discussed. Over the last six years the ECT course, at the Silesian University of Technology (SUT), has been gradually converted into blended e-course, for both the Learning Content and Assessment Program. Some...
In 2005 an integrated blended e-learning service based on Moodle Learning Management System (LMS), was introduced in Silesian University of Technology, Gliwice, Poland. Review of LMS content shows that some courses contain insufficient number of components, and in many cases the quality of resources is poor. The goal of our research was to identify why some teachers are reluctant to utilize LMS. A...
This paper is focused on the diagnosis of analog and mixed electronic circuit in frequency domain. A multi tone signal excites a circuit under test in order to detect and locate a single fault. The input signal consists of a number of frequencies which are selected by Principal Component Analysis (PCA) algorithm. An exemplary circuit has been examined and results have been discussed.
There is a method of global parametric faults location in analogue integrated circuits presented in this paper. Circuit Under Test is diagnosed in the time domain. The method is based on a utilisation of the tested device response and its derivative base features, i.e. following maxima and minima. The set consisted of base features is transformed into an advanced feature. Base features and the advanced...
A new method, using N-terminal network, for analog testing electronic circuits is presented. During test mode the circuit under test is connected to an active N-terminal network. The structure and values of elements of this network are selected to obtain best identification of faults. The proposed N-terminal based test (N-tBT) method consist of 4 stages. This paper is focused on the 2nd stage of this...
This paper describes new method of fault diagnosis in analog electronic circuits (AEC). Fault diagnosis in analog electronic circuits is in general tested along with one dimension: the generator frequency. In this paper, we present a novel approach that uses more than one dimension to test AEC (those new dimensions are: the load resistance & reactance, generator resistance & reactance). Proposed...
A method of a global parametric faults diagnosis in analogue integrated circuits is presented in this paper. The method is based on basic features calculated from a circuit's under test time domain response to a voltage step, i.e. locations of maxima and minima of circuit under test response and its first order derivative. The testing and diagnosis process is executed with the use of an artificial...
This paper presents a novel method to a multiple parametric faults diagnosis (global parametric faults - GPF) in analogue integrated circuits (AIC). The method is based on features of AIC time domain response to voltage step excitation, i.e. AIC response and its first order derivative maxima and minima locations. A circuit states classification is acquired with the use of linear evolutionary classifier...
This paper describes how increasing number of dimension of search space (in analog circuit diagnosis) can influence on identification of states of circuit under test (CUT). The criterion of optimization is the maximum number of identified states of CUT. In order to achieve this goal, first each state S and ambiguity set AS must be find and then optimized using Particle Swarm Optimization (PSO) algorithm...
An evolutionary technique for a linear analog circuit state recognition is presented in this paper. Transfer function zeros, poles and its amplification coefficient are determined by means of differential evolution. Time responses to a unit step stimulus for the circuit under test and for the evaluated phenotype are compared during the fitness calculation. Absolute response error of phenotype is minimized...
The method presented in this paper uses evolutionary computations to analog circuit testing stimulus shape optimization. The proposed testing excitation is a PWL waveform that generates responses of the tested circuit with appropriate relationship between current values of its specifications and the value of the observed parameter. The energy of error signal between nominal and actually obtained responses...
The testing and diagnosis catastrophic faults technique for analog high frequency (HF) circuits (passive filters and impedance matching circuits) is described in this paper. The novel method based on load and frequency as testing pair has been proposed. The impact of load on testing and diagnostic has been investigated. The best pairs of load and frequency have been chosen. The proposed approach of...
This article presents design of specialised aperiodic excitation. Purpose is improvement of fault diagnosis of analog electronic circuits. The goal is enhancement of catastrophic (hard) faults location. Further improvement is achieved after utilising additional feature extraction by means of wavelet transform. Obtained results are compared to fault diagnosis without feature extraction and diagnosis...
This article describes optimization of excitation signal for purpose of fault diagnosis. The goal is to enhance efficiency of faults detection in analog electronic circuits. The method has been verified on cases with single hard (catastrophic) and soft (parametric) faults. Further enhancement of fault detection efficiency has been achieved with additional feature extraction by means of wavelet transform...
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