scholarly journals A PAPR Reduction Technique for Fast Touch Sensors Adopting a Multiple Frequency Driving Method on Large Display Panels

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 429
Author(s):  
Piljoong Kim ◽  
Sanghyun Han ◽  
Yunho Jung ◽  
Seongjoo Lee
Keyword(s):  
High Speed ◽  
Signal To Noise Ratio ◽  
Average Power ◽  
High Signal ◽  
Multiple Frequency ◽  
Signal To Noise ◽  
Large Display ◽  
System Method ◽  
Touch Sensitivity ◽  
Noise Ratio

The multiple frequency driving method (MFDM) capacitive touch system (CTS), which drives transmit (TX) electrodes in parallel, has been developed to improve the touch-sensitivity of large touch screens at high speed. However, when driving multiple TX electrodes at the same time, TX signals are merged through the touch panel, which results in increasing the peak-to-average power ratio (PAPR) of combined signals. Due to the high PAPR, the signal is distorted out of the power amplifier’s linear range, causing a touch malfunction. The MFDM CTS can avoid this problem by reducing the drive voltage or partially driving the TX electrodes in parallel. However, these methods cause a significant performance drop with respect to signal-to-noise ratio (SNR) in the MFDM systems. This paper proposes a stack method which reduces PAPR effectively without the performance degradation of MFDM and achieves real-time touch sensitivity in large display panels. The proposed method allocates a suitable phase for each TX electrode to reduce the peak power of combined signals. Instead of investigating all of the phases for the total number of TX electrodes, the optimal phase is estimated from the highest frequency to the lowest one and fixed one by one, which can reduce the required time to find a suitable phase considerably. As a result, it enables high-speed sensing of multi-touch on a large touch screen and effectively reduces PAPR to secure high signal-to-noise-ratio (SNR). Through experiments, it was verified that the proposed method in this paper has an SNR of 39.36 dB, achieving a gain of 19.35 and 5.98 dB compared to the existing touch system method and the algorithm used in the communication system, respectively.

Non-Resonance Acousto-Optics Signal Analysis from Photonics Microphone Using 1 mW Laser

2016 ◽  
Vol 846 ◽  
pp. 740-747
Author(s):  
Muhammad Adib Akram Mohdami Norashid ◽  
M. Kamil Abd-Rahman
Keyword(s):  
Laser Beam ◽  
Acoustic Waves ◽  
High Speed ◽  
Continuous Wave ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Free Space Optical ◽  
Signal To Noise ◽  
Optical Signals ◽  
Noise Ratio

This paper presents an acousto-optics analysis on free space optical signals modulated by two distinguishable non-resonant acoustic waves. The acoustic waves were directed at two different directions and locations along a laser beam and created non-interference modulated optical signals. The photonics microphone deploys low-powered eye-safe continuous-wave 633-nm laser; high-speed photodiode and a series of Fourier lenses. Two transducers generating 20 Hz to 20 kHz acoustic waves were directed across the laser beam. The receiving modulated signal was filtered and amplified electronically by two sets of passive bandpass filter separated by a transimpedance amplifier and connected to a computer for analysis. The signal was further digitally filtered and amplified to enhance the signal-to-noise ratio via MATLAB software. These signals were analyzed in time and frequency domains using Fast Fourier Transform (FFT) and Spectrogram. It was found that the recorded signals demonstrated higher signal intensities for lower acoustic frequencies with digital signal-to-noise ratio (SNR) ranging from 10.77 to 71.92 for frequency of 1 kHz to 20 kHz and 20 Hz to 1 kHz respectively. The frequencies of both transducers were simultaneously swept through from 20 Hz and 20 kHz respectively. These scanning frequencies approached one another and crossover with no resonant frequency was observed. This illustrates that it is able to detect multiple acoustic signals for any given frequencies along the laser beam and found its applications in stealth sound detection and long range sound sensor. Though low-powered 1-mW laser was used, a relatively high signal-to-noise ratio with clear-recorded playback was achieved.

Narrow-frequency sharp-angular filters using all-dielectric cascaded meta-gratings

Nanophotonics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 3443-3450 ◽  
Author(s):  
Wei-Nan Liu ◽  
Rui Chen ◽  
Wei-Yi Shi ◽  
Ke-Bo Zeng ◽  
Fu-Li Zhao ◽  
...  
Keyword(s):  
Thin Film ◽  
Signal To Noise Ratio ◽  
Incident Angle ◽  
Design Strategy ◽  
Transmission Peak ◽  
High Signal ◽  
Waveguide Array ◽  
Signal To Noise ◽  
Center Wavelength ◽  
Noise Ratio

AbstractSelective transmission or filtering always responds to either frequency or incident angle, so as hardly to maximize signal-to-noise ratio in communication, detection and sensing. Here, we propose compact meta-filters of narrow-frequency sharp-angular transmission peak along with broad omnidirectional reflection sidebands, in all-dielectric cascaded subwavelength meta-gratings. The inherent collective resonance of waveguide-array modes and thin film approximation of meta-grating are employed as the design strategy. A unity transmission peak, locating at the incident angle of 44.4° and the center wavelength of 1550 nm, is demonstrated in a silicon meta-filter consisting of two-layer silicon rectangular meta-grating. These findings provide possibilities in cascaded meta-gratings spectroscopic design and alternative utilities for high signal-to-noise ratio applications in focus-free spatial filtering and anti-noise systems in telecommunications.

scholarly journals Low-dose, phase-contrast mammography with high signal-to-noise ratio

2016 ◽  
Vol 7 (2) ◽  
pp. 381 ◽  
Author(s):  
Lukas B. Gromann ◽  
Dirk Bequé ◽  
Kai Scherer ◽  
Konstantin Willer ◽  
Lorenz Birnbacher ◽  
...  
Keyword(s):  
Phase Contrast ◽  
Low Dose ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Signal To Noise ◽  
Noise Ratio

Research on LIFT Technology for 3D Seismic Denoising in Coalfield

2014 ◽  
Vol 556-562 ◽  
pp. 6328-6331
Author(s):  
Su Zhen Shi ◽  
Yi Chen Zhao ◽  
Li Biao Yang ◽  
Yao Tang ◽  
Juan Li
Keyword(s):  
Signal To Noise Ratio ◽  
High Signal ◽  
3D Seismic ◽  
Signal To Noise ◽  
Denoising Method ◽  
Seismic Processing ◽  
Work Area ◽  
Noise Data ◽  
Noise Ratio ◽  
Effective Signal

The LIFT technology has applied in process of denoising to ensure the imaging precision of minor faults and structure in 3D coalfield seismic processing. The paper focused on the denoising process in two study areas where the LIFT technology is used. The separation of signal and noise is done firstly. Then denoising would be done in the noise data. The Data of weak effective signal that is from the noise data could be blended with the original effective signal to reconstruct the denoising data, so the result which has high signal-to-noise ratio and preserved amplitude is acquired. Thus the fact shows that LIFT is an effective denoising method for 3D seismic in coalfield and could be used widely in other work area.

High signal-to-noise ratio quantum well bolometer materials

2006 ◽  
Author(s):  
Stanley Wissmar ◽  
Linda Höglund ◽  
Jan Andersson ◽  
Christian Vieider ◽  
Susan Savage ◽  
...  
Keyword(s):  
Quantum Well ◽  
Signal To Noise Ratio ◽  
High Signal ◽  
Signal To Noise ◽  
Noise Ratio
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