Research of output signal spectrum of active running-wave interferometer

2016 ◽  
Author(s):  
A. G. Lazarenko ◽  
A. N. Andreev ◽  
O. N. Andreeva ◽  
A. V. Kanaev
Keyword(s):  
Output Signal ◽  
Signal Spectrum ◽  
Running Wave

Research of Methods for Suppression of Parasitic Components in RF Quadrature Modulator Output Signal Spectrum

2021 ◽  
Vol 26 (1) ◽  
pp. 54-63
Author(s):  
T.Yu. Krupkina ◽  
◽  
V.V. Losev ◽  
L.V. Nedashkovskiy ◽  
Yu.A. Chaplygin ◽  
...  
Keyword(s):  
Output Signal ◽  
Communication Systems ◽  
Point Of View ◽  
Phase Shifting ◽  
Signal Spectrum ◽  
Polyphase Filter ◽  
Digital To Analog Converters ◽  
Quadrature Modulator ◽  
Phase Amplitude ◽  
Parasitic Components

The quadrature modulators and demodulators are widely used to create modern wireless communication systems. It is important to ensure high quality of the transmitted signals in order to have the exchange of information without loss or failure. From the point of view of the spectral decomposition of the signal (Fourier series decomposition), the useful component of the spectrum must be much larger than all other components. The carrier (LO frequency and spurious sideband are the most critical and undesirable quadrature modulator output signal spectral components. In the work, in the course of the research using the methods of suppressing the parasitic components, based on minimizing phase, amplitude and current imbalances in various nodes of the quadrature modulator circuit, have been revealed. In order to realize suppression, the special digital-to-analog converters are used in conjunction with a polyphase filter on varicaps, a phase-shifting block and current sources. The effectiveness of these methods is confirmed by the achievement of suppression of parasitic components in prototypes of 50 dB or more. It has been stated that the phase unbalance minimization is more effective than the amplitude unbalance minimization to sideband suppression. It has been revealed that the use of a phase-shifting block is a more suitable architecture to control the phase unbalance. The obtained results can be useful in the design of high-precision radio frequency units for various purposes.

scholarly journals Research on the output bit error rate of 2DPSK signal based on stochastic resonance theory

2017 ◽  
Vol 31 (35) ◽  
pp. 1850069 ◽  
Author(s):  
Daqin Yan ◽  
Fuzhong Wang ◽  
Shuo Wang
Keyword(s):  
Stochastic Resonance ◽  
Bit Error Rate ◽  
Error Rate ◽  
Output Signal ◽  
High Speed ◽  
Digital Signal ◽  
Signal Spectrum ◽  
Resonance Theory ◽  
Conventional Model ◽  
Differential Phase Shift

Binary differential phase-shift keying (2DPSK) signal is mainly used for high speed data transmission. However, the bit error rate of digital signal receiver is high in the case of wicked channel environment. In view of this situation, a novel method based on stochastic resonance (SR) is proposed, which is aimed to reduce the bit error rate of 2DPSK signal by coherent demodulation receiving. According to the theory of SR, a nonlinear receiver model is established, which is used to receive 2DPSK signal under small signal-to-noise ratio (SNR) circumstances (between −15 dB and 5 dB), and compared with the conventional demodulation method. The experimental results demonstrate that when the input SNR is in the range of −15 dB to 5 dB, the output bit error rate of nonlinear system model based on SR has a significant decline compared to the conventional model. It could reduce 86.15% when the input SNR equals −7 dB. Meanwhile, the peak value of the output signal spectrum is 4.25 times as that of the conventional model. Consequently, the output signal of the system is more likely to be detected and the accuracy can be greatly improved.

Investigation of Gap Dependency of Distortion in Output Signal from Scale Slit of Optical Encoder

2010 ◽  
Vol 130 (12) ◽  
pp. 1356-1362
Author(s):  
Hajime Nakajima ◽  
Kazuhiko Sumi ◽  
Hiroshi Inujima
Keyword(s):  
Output Signal ◽  
Optical Encoder
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