SUPPRESSING PHASE LOCKED LOOP GAIN FLUCTUATIONS IN WIDEBAND LINEARLY FREQUENCY MODULATED WAVEFORM SYNTHESIZERS

2012 ◽  
Vol 11 (02) ◽  
pp. 1250011
Author(s):  
WEN-QIN WANG
Keyword(s):  
Frequency Band ◽  
System Performance ◽  
Phase Locked Loop ◽  
Experimental Results ◽  
Limiting Factor ◽  
Voltage Controlled Oscillator ◽  
Effective Solution ◽  
Loop Gain ◽  
Compensation Algorithm

Wideband linearly frequency modulated (LFM) signals are required for many communication navigation applications; however, a limiting factor is the presence of frequency nonlinearity which degrades the system performance significantly. The fluctuations of phase locked loop (PLL) loop gain and voltage controlled oscillator (VCO) gain will results in inconsistent frequency nonlinearity performance in the whole frequency band. In this letter, we propose an effective solution by real-timely tuning the phase/frequency detecting current, along with the iterative compensation algorithm. In this way, the frequency nonlinearity is compensated and a wideband LFM waveform synthesizer can be designed. This approach is validated by experimental results.

scholarly journals An Effective Solution to Eliminate DC-Offset for Extracting the Phase and Frequency of Grid Voltage

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Fehmi Sevilmiş ◽  
Hulusi Karaca
Keyword(s):  
Dynamic Performance ◽  
Phase Locked Loop ◽  
Experimental Results ◽  
Effective Solution ◽  
Control Loop ◽  
Slow Dynamic ◽  
Grid Voltage ◽  
Dc Offset

Recently, several approaches with the ability to reject the DC-offset in phase locked loop (PLL) methods have been developed. These approaches include different filtering structures which can be classified into two categories: prefiltering before the PLL input and in-loop filtering in the PLL control loop. As highlighted in the literature, the DC-offset rejection methods based on in-loop filtering have received less attention due to their slow dynamic performance. Therefore, this paper proposes an alternative DC-offset rejection technique as in-loop filtering of the PLL. The effectiveness of the proposed PLL is confirmed by simulation and experimental results.

Design and analysis of a low noise CMOS charge pump phase locked loop circuit

2021 ◽  
pp. 2140002
Author(s):  
Yanbo Chen ◽  
Shubin Zhang
Keyword(s):  
Phase Noise ◽  
Supply Voltage ◽  
Charge Pump ◽  
Phase Locked Loop ◽  
Low Noise ◽  
Cmos Process ◽  
Voltage Controlled Oscillator ◽  
Output Frequency ◽  
Power Supply Voltage ◽  
Supply Noise

Phase Locked Loop (PLL) circuit plays an important part in electronic communication system in providing high-frequency clock, recovering the clock from data signal and so on. The performance of PLL affects the whole system. As the frequency of PLL increases, designing a PLL circuit with lower jitter and phase noise becomes a big challenge. To suppress the phase noise, the optimization of Voltage Controlled Oscillator (VCO) is very important. As the power supply voltage degrades, the VCO becomes more sensitive to supply noise. In this work, a three-stage feedforward ring VCO (FRVCO) is designed and analyzed to increase the output frequency. A novel supply-noise sensing (SNS) circuit is proposed to suppress the supply noise’s influence on output frequency. Based on these, a 1.2 V 2 GHz PLL circuit is implemented in 110 nm CMOS process. The phase noise of this CMOS charge pump (CP) PLL is 117 dBc/Hz@1 MHz from test results which proves it works successfully in suppressing phase noise.

scholarly journals Modeling PLL Loop with Nonlinearity

Telecom IT ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 9-14
Author(s):  
Y. Nikitin ◽  
G. Tsygankov
Keyword(s):  
Nonlinear Model ◽  
Negative Feedback ◽  
Phase Locked Loop ◽  
Phase Detector ◽  
Stationary Mode ◽  
Voltage Controlled Oscillator ◽  
Feedback Circuit ◽  
Pulse Counter ◽  
Pulse Phase ◽  
Negative Feedback Circuit

A model of a pulse phase-locked loop multiplying ring in a MicroCap11 medium is considered. The analysis uses a nonlinear model of a voltage-controlled oscillator with a user-defined control characteristic. An RS-trigger is used as a pulse-phase detector, a pulse counter in the negative feedback circuit is implemented on JK-triggers. Transient processes in the ring, as well as the spectrum of the output oscillations in the steady (stationary) mode are considered.

scholarly journals Design and Implementation of Charge Pump Phase-Locked Loop Frequency Source Based on GaAs pHEMT Process

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 504
Author(s):  
Ranran Zhao ◽  
Yuming Zhang ◽  
Hongliang Lv ◽  
Yue Wu
Keyword(s):  
Maximum Output Power ◽  
Charge Pump ◽  
Phase Locked Loop ◽  
Low Noise ◽  
Signal Frequency ◽  
Maximum Output ◽  
Voltage Controlled Oscillator ◽  
Chip Area ◽  
Frequency Source ◽  
A Charge

This paper realized a charge pump phase locked loop (CPPLL) frequency source circuit based on 0.15 μm Win GaAs pHEMT process. In this paper, an improved fully differential edge-triggered frequency discriminator (PFD) and an improved differential structure charge pump (CP) are proposed respectively. In addition, a low noise voltage-controlled oscillator (VCO) and a static 64:1 frequency divider is realized. Finally, the phase locked loop (PLL) is realized by cascading each module. Measurement results show that the output signal frequency of the proposed CPPLL is 3.584 GHz–4.021 GHz, the phase noise at the frequency offset of 1 MHz is −117.82 dBc/Hz, and the maximum output power is 4.34 dBm. The chip area is 2701 μm × 3381 μm, and the power consumption is 181 mw.

scholarly journals Pengenalan Ras Berdasarkan Hidung Dan Mulut Menggunakan Gray Level Co-Occurrence Matrix

2021 ◽  
Vol 8 (4) ◽  
pp. 729
Author(s):  
Ema Rachmawati ◽  
Nur Azizah Agustina ◽  
Febryanti Sthevanie
Keyword(s):  
Random Forest ◽  
System Performance ◽  
Experimental Results ◽  
Gray Level ◽  
The Face ◽  
Combined Features ◽  
Occurrence Matrix ◽  
Large Groups ◽  
Performance Of Race

<p class="Abstract">Ras dapat digunakan untuk mengkategorikan manusia dalam populasi atau kelompok besar. Oleh karena itu, pengenalan ras dapat berguna untuk mempermudah dalam mengidentifikasi seseorang dan membantu dalam mempersempit lingkup pencarian. Penggunaan wajah sebagai dasar pengenalan ras mengarahkan penelitian pada identifikasi penggunaan bagian wajah yang berpengaruh signifikan terhadap kinerja pengenalan ras. Pada penelitian ini bagian wajah berupa hidung dan mulut diidentifikasi untuk digunakan sebagai dasar pengenalan ras Mongoloid, Kaukasoid, dan Negroid. Ciri <em>Gray Level Co-occurrence Matrix</em> (GLCM) diekstrak dari bagian hidung dan mulut untuk selanjutnya diklasifikasi menggunakan Random Forest. Hasil eksperimen menunjukkan bahwa penggunaan ciri gabungan dari hidung dan mulut mampu menghasilkan kinerja sistem yang paling baik jika dibandingkan penggunaan hidung atau mulut saja.</p><p class="Abstract"> </p><p class="Abstract"><strong><em>Abst</em></strong><strong><em>r</em></strong><strong><em>act</em></strong></p><p align="center"><em>Race can be used to categorize humans in populations or large groups. Therefore, racial recognition can be useful to make it easier to identify a person and help narrow the scope of the search. The use of faces as a basis for race recognition directs research on identifying the use of facial parts that significantly influence the performance of race recognition. In this study, the face parts of the nose and mouth were identified to be used as a basis for the recognition of the Mongoloid, Caucasoid, and Negroid races. The Gray Level Co-occurrence Matrix (GLCM) feature is extracted from the nose and mouth to be classified using Random Forest. The experimental results show that the use of combined features of the nose and mouth is able to produce the best system performance compared to the use of the nose or mouth only.</em></p><p class="Abstract"> </p>

scholarly journals Optimizing the Spectral Characterisation of a CMYK Printer with Embedded CMY Printer Modelling

2019 ◽  
Vol 9 (24) ◽  
pp. 5308
Author(s):  
Qiang Liu ◽  
Zheng Huang ◽  
Michael R. Pointer ◽  
M. Ronnier Luo
Keyword(s):  
Cellular Structure ◽  
Experimental Results ◽  
Digital Printing ◽  
Input Device ◽  
Effective Solution ◽  
Spectral Accuracy ◽  
Printing Process ◽  
Dark Tone ◽  
Spectral Characterisation

In the digital printing process, reliable colour reproduction is commonly achieved by printer characterisation, which defines the correspondence between the input device control values and the output colour information. The cellular Yule–Nielsen spectral Neugebauer model, together with its variants, is widely adopted in this topic because of its superb colorimetric and spectral accuracy. However, it seems that current studies have neglected an inconspicuous defect in such models when characterising printers equipped with black ink. That is, the cellular structure of these models overemphasises the sampling for dark-tone colours, and thus leads to relatively large errors in light tones. In this paper, taking a CMYK printer as an example, a simple and effective solution is proposed with no need of extra sampling. With the aid of a newly built cellular spectral Neugebauer model for the embedded CMY printer, this approach optimises the printer characterisation for light tones, slightly improves the precision for middle tones while it maintains the accuracy for dark tones. The performance of the proposed method was evaluated with regard to three different kinds of substrates and the experimental results validated its improvement in spectral printer characterisation.

scholarly journals Experimental Investigation of the Propagation and Attenuation Rule of Blasting Vibration Wave Parameters Based on the Damage Accumulation Effect

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Huaibao Chu ◽  
Xiaolin Yang ◽  
Shuanjie Li ◽  
Weimin Liang
Keyword(s):  
Frequency Band ◽  
Damage Accumulation ◽  
Low Frequency ◽  
Experimental Results ◽  
Vibration Velocity ◽  
Blasting Vibration ◽  
Main Frequency ◽  
Wave Parameters ◽  
Accumulation Effect ◽  
Vibration Wave

The propagation and attenuation rule of blasting vibration wave parameters is the most important foundation of blasting vibration prediction and control. In this work, we pay more attention to the influence of the damage accumulation effect on the propagation and attenuation rule of vibration wave parameters. A blasting damage accumulation experiment was carried out, the ultrasonic wave velocity of the specimens was measured, and the damage value was calculated during the experiment. The blasting vibration wave was monitored on the surface of the specimens, and its energy was calculated by using the sym8 wavelet basis function. The experimental results showed that with the increase in the number of blasts, the damage continues to increase; however, the vibration velocity and the main frequency decrease continuously, the unfocused vibration wave energy in the zone near to the blasting source is rapidly concentrated in the low-frequency band (frequency bands 1 to 3), and the energy is further concentrated in the low-frequency band in the intermediate zone and zone far from the blasting source. There is a distortion process in which the vibration velocity and the main frequency increase slightly and the energy of the blasting vibration wave converges to the high-frequency band (the 5th band) before the sudden unstable fracture failure of the specimens. The experimental results indicate that the prediction and evaluation of blasting vibration should consider the variation rule of blasting vibration wave parameters synthetically based on the cumulative damage effect, and it is not safe to use only one fixed vibration control standard for the whole blasting operation.

Study on Method of Recognizing Characteristics of Pipeline Leakage Acoustic Signals

2006 ◽  
Author(s):  
Likun Wang ◽  
Dongjie Tan ◽  
Yongjun Cai ◽  
SongGuang Fu ◽  
Jian Li ◽  
...  
Keyword(s):  
Neural Network ◽  
Field Experiment ◽  
Frequency Band ◽  
Bp Neural Network ◽  
Acoustic Signals ◽  
Pressure Variation ◽  
Experimental Results ◽  
Acoustic Sensors ◽  
Experiment Data

Wavelet package and neural network are used to recognize the characteristics of pipeline leakage acoustic signals. Acoustic signals produced by pressure variation of pipelines can be detected by the acoustic sensors installed on the pipelines. The detecting accuracy can be increased with recognizing the acoustic signals correctly. The method to detect acoustic signals by combining the wavelet package and neural network is introduced in this paper. The signal is decomposed with wavelet package firstly, then the decomposed coefficients in each frequency band are obtained through reconstruction. As a result, the parameters of the new sequences reconstructed on every decomposed node are acquired, and then these parameters are input to BP neural network to recognize the fault reason intelligently. At the end of the paper, field experiment data and their analyzed results are studied. The experimental results are provided to show that the proposed method can increase the accuracy efficiently.

A Study of Biomass Material Pretreatment by Microwave-Based Heating

2011 ◽  
Vol 347-353 ◽  
pp. 2991-2995
Author(s):  
Kuo Hsiung Tseng ◽  
Yong Fong Shiao ◽  
Yu Ting Yeh
Keyword(s):  
Taguchi Method ◽  
System Performance ◽  
Experimental Results ◽  
Dynamic Responses ◽  
Pennisetum Purpureum ◽  
Actual System ◽  
Arx Model ◽  
Parameter Combination ◽  
Plan Optimization ◽  
Auto Regressive

This study discussed the application of microwave-based heating for the pretreatment of biomass material, and selected Pennisetum purpureum for pretreatment. The Taguchi method was used to plan optimization experiments for pretreatment parameter levels, and measured the dynamic responses. With lower frequency of experiments, this study analyzed and determined a parameter combination in which Pennisetum purpureum can be rapidly heated to 190°C. The experimental results indicate an eight-order ARX model (Auto-Regressive eXogeneous) was representative of actual system performance, and the fit was 99.13%.

A Fast Intra Prediction Algorithm Based on WMSE for 360-Degree Video

2020 ◽  
Vol 34 (13) ◽  
pp. 2054032
Author(s):  
Fuqi Mao ◽  
Renbo Su ◽  
Zhi Liu ◽  
Mengmeng Zhang ◽  
Wen Yue
Keyword(s):  
Virtual Reality ◽  
Video Coding ◽  
Rate Increase ◽  
Intra Prediction ◽  
Experimental Results ◽  
Prediction Algorithm ◽  
Effective Solution ◽  
Fast Intra Prediction ◽  
Time Reduction

With the increased demand for virtual reality, 360-degree video coding becomes challenging. A 360-degree video should be projected as a planar video before encoding, but this process causes distortion whose degree depends on the latitude. Traditional coding algorithms cannot effectively adapt to this feature. In this study, a fast intra prediction algorithm based on WMSE for 360-degree video is proposed. The similarity between the mother block and child blocks can reflect whether the mother block needs to be divided. Spherical weights are introduced in WMSE, and the similarity expressed by WMSE can distinguish the video of different latitude, which is consistent with the weight characteristics of ERP projection. Experimental results show that the proposed algorithm achieves 32% time reduction, with only 0.29% luma Bjontegaard delta rate (BD-rate) increase on average. The proposed algorithm provides a more effective solution to reduce the coding complexity of 360-degree video.

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