Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
In this paper, prototypes of SC-cut resonators with 5 MHz resonant frequency are presented. The resulting short-term stability of some resonators has been measured lower than 8·10−-14 in terms of Allan standard deviation. The results are compared according to the overtone behavior on different vibrating modes to find a correlation with the intrinsic noise of the resonators. The comparison of these...
In this paper, after explaining the reasons why some players asked to standardize also the 3–150 kHz EMC maximum acceptable range, we describe the type of disturbances depending on the frequency range and on the type of equipment that can generate such disturbances. Furthermore, we illustrate the different methods to reduce them. In particular, we explain a method to design a suitable passive filter...
A new microstrip sensor using the transmission interferometric measurement principle for scanning near-field microwave microscopy is presented. The structure originates from a Wilkinson power divider but has a resistor removed. The wideband design was verified by simulation using AWR Microwave Office and experimentally in frequency band of 45 MHz to 20 GHz. Ten times suppression of measurement uncertainties...
The application of the proposed mathematical tools, that can be used for signal processing self-generating transducers of physical quantities, are considered. Its operating mechanism is based on frequency modulation, when the frequency deviation depends on the intensity of exposure measurement parameter. It is shown that the action for leveling additive errors in the channel the signal generator is...
Partial discharge (PD) can be used to predict insulation failures in power transformers. Accurate detection of particular PD types has a significant role in anticipating forthcoming outages. However, the noise encountered with PD measurements negatively affects the detection accuracy. In this paper, we propose a robust PD detection technique that is immune to noise through efficient frequency domain-based...
This contribution aims at studying the input impedance of household appliances in the frequency range from 9 kHz to 500 kHz (FCC band). The method using the network analyzer is chosen as it provides a very good trade-off between required accuracy and ease of use. Some of the most common household appliances present in customer installations are characterized in terms of impedance in their respective...
As part of ONR's Integrated Topside (InTop) Program, in 2014 Northrop Grumman delivered a bi-static, active, electronic scanned array (AESA) system, capable of multifunction, simultaneous transmit and receive operation. The system is wide band, transmits high power and has high receive sensitivity. Further, there are simultaneous transmit and receive modes required, in which the transmit AESA radiates...
Hospital is a place that should be free of acoustic problems. According to previous researches, these acoustic problems are responsible for 20.9% – 26.2% of the ICU patient's recovery process. A research based on soundscape of a hospital was done through objective, subjective and simulation methods. The result has shown that the most perceived loud sound is from the ventilator at 4000 Hz with loudness...
A likelihood function for a multi-sensor, passive sonar Bayesian tracker may use data directly from the array elements or, alternatively, from the output of a conventional beamformer (CBF). Here, we compare the performance of a Bayesian tracker when using element- versus CBF-level data. We observed that, provided the CBF's beams are sufficiently closely spaced, the tracker's performance with CBF-level...
In this paper, a permanent magnet biased inductor has been analysed and designed for a frequency converter. Line current harmonic and conducted emission tests have been carried out to compare the performance of the hybrid inductor. The analysis shows that the hybrid inductor can have volume reduction in comparison with a traditional inductor.
Recent experimental results for the sensitivity of aperture arrays at room temperature show 40 K array noise temperatures over the frequency range from 1000 MHz to 1500 MHz. Further reduction of array noise temperature is important to comply with the SKA sensitivity requirements at affordable cost. Furthermore the frequency range should be extended to a lowest frequency of 500 MHz, in order to meet...
Noise parameter measurements of six candidate transistors for a Square Kilometer Array (SKA) low-noise amplifier (LNA) are presented. They provide reliable data in the frequency range where some low-noise transistors are inadequately characterized. The results of these measurements inform the design of an LNA for SKA1-Survey Band 2 with measured minimum noise temperature of 21 K.
We show timing jitter spectrum measurement of free-running mode-locked lasers from 1-mHz to 40-MHz Fourier frequency. The demonstrated method can resolve different noise mechanisms that cause specific jitter characteristics from <100-ns to >1000-s time scales.
We demonstrate a Brillouin microcavity laser based on a microrod resonator exhibiting a frequency noise of 140 Ηζ/√Hz at 10 Hz offset. The corresponding laser linewidth is measured to be below 400 Hz.
The noise properties of two multi-heterodyne spectrometers based on multi-mode semiconductor lasers (QCLs and ICLs) are investigated to determine their detection performance limitations. Both laser technologies provide well-defined multi-heterodyne beat-note structures suitable for spectroscopic measurements.
An octave-spanning frequency comb is generated using electro-optic modulation of a 1550 nm laser and nonlinear broadening. With this comb we demonstrate offset frequency detection, precise metrology, and ultrastable synthesis of 10 GHz microwaves.
This paper proposes an efficient envelope delta-sigma based transmitter architecture with gate bias modulation for modern wireless communication systems. Using this architecture, envelope varying signals are converted to constant envelope signals. The constant envelope phase signal is up-converted and amplified utilizing high efficiency power amplifier, while the two level delta-sigma modulated envelope...
Electric vehicles are complex systems in which EMC must be approached in a significantly different way to the one in conventional cars. The presence of high power supplies assembled in a very small room together with signalling, control and communications devices brings about new issues related to EM disturbances and noise coupling that must be addressed in order to ensure a good performance of the...
Track-density scaling is projected to be the key driver for increasing the areal density and cartridge capacity in future tape storage systems. To achieve very high track densities, positioning control down to the nanometer scale will be essential. In this paper, the positioning accuracy of the tape track-following control system is investigated and advances in several elements of the system are presented...
We propose a two-degree-of-freedom washout control structure for tracking of sinusoidal references in lightly damped structures subject to sensor drift and measurement noise. An algorithm is derived, assigning stable parameter intervals to a second-order washout damping compensator for a resonant plant with a single dominant mode. Simulation results demonstrate quality drift and noise rejection performance...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.