Localization of directional noise sources from high-performance military aircraft through subarray beamforming analysis

2018 ◽  
Vol 144 (3) ◽  
pp. 1671-1671 ◽  
Author(s):  
David F. Van Komen ◽  
Tracianne B. Neilsen ◽  
Blaine M. Harker ◽  
Kent L. Gee ◽  
S. Hales Swift ◽  
...  
Electronics ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 29 ◽  
Author(s):  
Marijan Jurgo ◽  
Romualdas Navickas

In recent years number of Internet of Things (IoT) services and devices is growing and Internet of Vehicles (IoV) technologies are emerging. Multiband transceiver with high performance frequency synthesisers should be used to support a multitude of existing and developing wireless standards. In this paper noise sources of an all-digital frequency synthesiser are discussed through s-domain model of frequency synthesisers, and the impact of noise induced by main blocks of synthesisers to the overall phase noise of frequency synthesisers is analysed. Requirements for time to digital converter (TDC), digitally controlled oscillator (DCO) and digital filter suitable for all-digital frequency synthesiser for IoT and IoV applications are defined. The structure of frequency synthesisers, which allows us to meet defined requirements, is presented. Its main parts are 2D Vernier TDC based on gated ring oscillators, which can achieve resolution close to 1 ps; multi core LC-tank DCO, whose tuning range is 4.3–5.4 GHz when two cores are used and phase noise is −116.4 dBc/Hz at 1 MHz offset from 5.44 GHz carrier; digital filter made of proportional and integral gain stages and additional infinite impulse response filter stages. Such a structure allows us to achieve a synthesiser’s in-band phase noise lower than −100 dBc/Hz, out-of-band phase noise equal to −134.0 dBc/Hz and allows us to set a synthesiser to type-I or type-II and change its order from first to sixth.


2013 ◽  
Vol 2013 ◽  
pp. 1-5
Author(s):  
Bing Yang ◽  
Yan Liu

A ring-plate-type cycloid speed reducer is one of the most important reducers owing to its low volume, compactness, smooth and high performance, and high reliability. The vibration and noise tests of the reducer prototype are completed using the HEAD acoustics multichannel noise test and analysis system. The characteristics of the vibration and noise are obtained based on coherence analysis and the noise sources are identified. The conclusions provide the bases for further noise research and control of the ring-plate-type cycloid reducer.


Author(s):  
Brent O. Reichman ◽  
Kent L. Gee ◽  
Tracianne B. Neilsen ◽  
S Hales Swift ◽  
Alan T. Wall ◽  
...  

2014 ◽  
Vol 135 (4) ◽  
pp. 2382-2382
Author(s):  
Tracianne B. Neilsen ◽  
Kent L. Gee ◽  
Michael M. James

2017 ◽  
Vol 142 (4) ◽  
pp. 2514-2514 ◽  
Author(s):  
Kevin M. Leete ◽  
Alan T. Wall ◽  
Kent L. Gee ◽  
Tracianne B. Neilsen ◽  
Micah Downing ◽  
...  

AIAA Journal ◽  
2019 ◽  
Vol 57 (8) ◽  
pp. 3467-3479 ◽  
Author(s):  
Tracianne B. Neilsen ◽  
Aaron B. Vaughn ◽  
Kent L. Gee ◽  
S. Hales Swift ◽  
Alan T. Wall ◽  
...  

Author(s):  
H. A. Cordourier-Maruri ◽  
F. Orduña-Bustamante

An active control system intended for the reduction of strictly periodic noise components in computer cooling fans is described, which is based on high‐performance digital sound device architectures found in some personal computers. The system overcomes causality and synchronization constrains imposed by delayed buffering, as usually found in computer audio processing. Performance of the system is demonstrated and evaluated through measurements in a physical implementation of active noise control of synthetic tones combined with laptop fan noise, carried out under anechoic and slightly everberant conditions. Tests on other types of tonal noise sources, like an electrical transformer, were also carried out. However, its wider applicability to the cancellation of tonal noise has been proved compromised by weak periodicity issues found and reported in this work. Also, a study of noise spectral width requirements for successful operation is presented.


2021 ◽  
Vol 149 (4) ◽  
pp. 2403-2414
Author(s):  
Aaron B. Vaughn ◽  
Kevin M. Leete ◽  
Kent L. Gee ◽  
Bradley R. Adams ◽  
J. Micah Downing

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