scholarly journals Investigation of Ways of Dynamic Range Expansion for Broadband Receiver Microwave Devices in Multi-Signal Mode

2018 ◽  
pp. 85-90
Author(s):  
S. A. Bogdanov ◽  
P. V. Kupriyanov ◽  
S. V. Nikolaev ◽  
S. A. Petrov
Keyword(s):  
Output Power ◽  
Dynamic Range ◽  
Experimental Studies ◽  
Technical Solution ◽  
Third Order ◽  
Measurement Results ◽  
Signal Mode ◽  
Output Amplifier ◽  
Intermodulation Distortions ◽  
Upper Boundary

 The article investigates ways to expand the dynamic range of broadband microwave receiving devices. The task is to lim-it the output signals while increasing the upper boundary of the dynamic range by the criterion of the thirdorder inter-modulation component suppression. The main relations  determining the dynamic range boundary conditions are pre-sented. Experimental studies of three variants of constructing the broadband microwave receiver output path in two-ton mode of operation are carried out for:– an output amplifier with a point of 1 dB of output power compression at the level corresponding to safe output power;– a powerful output amplifier with a passive diode limiter on the output;– a powerful output amplifier with an automatic attenuation adjustment circuit connected to its input.The measurement results of the magnitude of intermodulation distortions suppression and output power are presented as a function of the input signal level for various nonlinear elements. Based on the analysis of the measured characteristics, an optimal technical solution is found for constructing an output path. The dynamic range is extended by more than 20 dB. Suppression of intermodulation components of the third order exceeds 60 dB. Effective functioning of the broadband receiver in multisign mode is ensured.

Mitigating the Effects of Non-Linear Distortion Using Polarizers in Microwave Photonic Link

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Sarika Singh ◽  
Sandeep K. Arya ◽  
Shelly Singla
Keyword(s):  
Dynamic Range ◽  
Extinction Ratio ◽  
Polarization Angle ◽  
Third Order ◽  
Microwave Photonic ◽  
Linear Behavior ◽  
Spurious Free Dynamic Range ◽  
Non Linear ◽  
Intermodulation Distortions ◽  
Insertion Losses

AbstractA scheme to suppress nonlinear intermodulation distortion in microwave photonic (MWP) link is proposed by using polarizers to compensate inherent non-linear behavior of dual-electrode Mach-Zehnder modulator (DE-MZM). Insertion losses and extinction ratio have also been considered. Simulation results depict that spurious free dynamic range (SFDR) of proposed link reaches to 130.743 dB.Hz2/3. A suppression of 41 dB in third order intermodulation distortions and an improvement of 15.3 dB is reported when compared with the conventional link. In addition, an electrical spectrum at different polarization angles is extracted and 79^\circ is found to be optimum value of polarization angle.

A dual parallel Mach–Zehnder modulator linearization scheme based on 90° phase shifters

Frequenz ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sarika Singh ◽  
Sandeep K. Arya ◽  
Shelly Singla ◽  
Pulkit Berwal
Keyword(s):  
Dynamic Range ◽  
Phase Shifters ◽  
Complete Suppression ◽  
Third Order ◽  
Two Phase ◽  
Spurious Free Dynamic Range ◽  
Non Linear ◽  
Transmission Link ◽  
Mach Zehnder Modulator ◽  
Intermodulation Distortions

Abstract In this paper, a dual-drive dual-parallel Mach–Zehnder Modulator based linearization scheme is implemented by utilizing only two phase shifters and comprehensively demonstrated for a photonic transmission link. Third order intermodulation distortion is suppressed by adjusting angles of electrical phase shifters i.e. π/2 and−π/2 and a non-linear distortion immune system can be proposed for microwave photonic link. A complete suppression in intermodulation terms and 20.8 dB enhancements are found in spurious free dynamic range (SFDR). SFDR reaches 135.6 dB Hz4/5 by suppressing major spurious contributors of third order intermodulation distortions in optical domain only which ensures the improvement in performance of link against non-linear terms.

Wideband high-efficiency linearized PA design with reduction in memory effects and IMD3

2018 ◽  
Vol 10 (4) ◽  
pp. 391-400 ◽  
Author(s):  
Xuekun Du ◽  
Chang Jiang You ◽  
Yulong Zhao ◽  
Xiang Li ◽  
Mohamed Helaoui ◽  
...  
Keyword(s):  
Output Power ◽  
Average Output Power ◽  
High Efficiency ◽  
Second Harmonic ◽  
Memory Effects ◽  
Third Order ◽  
Average Output ◽  
Power Added Efficiency ◽  
Low Pass ◽  
Intermodulation Distortions

ABSTRACTAn analytical method is proposed to reduce the memory effects and third-order intermodulation distortions for improving the linearity of wideband power amplifier (PA). An excellent linearity can be obtained by reducing the second-harmonic output power levels and reducing the envelope voltage components in the megahertz range. An improved wideband Chebyshev low-pass matching network including the bias network is analyzed and designed to validate the proposed method. The measured results indicate that a wideband high-efficiency linearized PA is realized from 1.35 to 2.45 GHz (fractional bandwidth = 58%) with power added efficiency of 60–78%, power gain of 10.8–12.3 dB, and output power of 40.0–41.2 dBm. For a 20 MHz LTE modulated signal, the adjacent channel leakage ratios (ACLRs) of the proposed PA with digital pre-distortion (DPD) linearization are −55.7 ~ −53.9 dBc across 1.5–2.4 GHz at an average output power of 32.4–33.6 dBm. For a 40 MHz two-carrier LTE modulated signal, the ACLRs of the proposed PA with DPD linearization are −51.1 ~ −48.2 dBc at an average output power of ~30.5 dBm in the frequency range from 1.5 GHz to 2.4 GHz.

An Improved Doppler Shift Simulation Method Based on Third-Order DDS

2014 ◽  
Vol 614 ◽  
pp. 356-362 ◽  
Author(s):  
Rui Li ◽  
Yuan Long Cai ◽  
Xin Bei Bai ◽  
Ming Quan Lu
Keyword(s):  
Doppler Shift ◽  
Dynamic Range ◽  
Doppler Frequency ◽  
Simulation Method ◽  
Global Navigation Satellite Systems ◽  
Direct Digital Synthesis ◽  
Third Order ◽  
Satellite Systems ◽  
Digital Synthesis ◽  
Global Navigation Satellite

A method to simulate the Doppler frequency shift of high dynamic signals of Global Navigation Satellite Systems (GNSS) is provided in this paper. The methodology of the method based on third-order Direct Digital Synthesis (DDS) is introduced and the efficient implementation architecture is proposed. The design criteria of the DDS are investigated according to the precision and dynamic range of the Doppler shift. The simulation results are also demonstrated, which indicate that the method is available for the high precision Doppler shift simulation of GNSS signals.

Effect of Speech Processor Program Modifications on Cochlear Implant Recipients’ Threshold and Maximum Acceptable Loudness Levels

1999 ◽  
Vol 8 (2) ◽  
pp. 128-136 ◽  
Author(s):  
John C. Sun ◽  
Margarate W. Skinner ◽  
S. Y. Liu ◽  
T. S. Huang
Keyword(s):  
Electrical Stimulation ◽  
Cochlear Implant ◽  
Everyday Life ◽  
Dynamic Range ◽  
Active Electrode ◽  
Speech Processor ◽  
Significant Change ◽  
Upper Boundary

This study’s purpose was to determine whether or not modifications in speech processor electrical stimulation levels were associated with changes in five Nucleus 22 cochlear implant recipients’ thresholds or maximum acceptable loudness levels (MALs). These modifications in minimum and maximum stimulation levels were made to optimize hearing in everyday life. One threshold and one MAL were obtained on each active electrode during six, weekly test sessions, three before and three after program modification. Only one participant had a significant change in threshold after program modification; this participant and four others had significant changes in MAL. Participants’ threshold variability was the same, but MAL variability was higher than that observed in other studies. Because these participants had no experience making MAL judgments prior to this study, this result suggests that implant recipients should be given sufficient practice in making MAL judgments to provide a stable clinical estimate of the upper boundary of the electrical dynamic range.

Theoretical and Experimental Studies of Third-Order Nonlinear Optical Susceptibilities of New p-N,N'-Diamethylaniline Tetrathiafulvalene Derivatives

2000 ◽  
Vol 660 ◽  
Author(s):  
B. Sahraoui ◽  
K.J. Pluciński ◽  
M. Makowaska-Janusik ◽  
I. V. Kityk ◽  
M. Salle ◽  
...  
Keyword(s):  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Nonlinear Optical ◽  
Experimental Studies ◽  
Physical Nature ◽  
Four Wave Mixing ◽  
Wave Mixing ◽  
Electronic Contribution ◽  
Optical Nonlinearities ◽  
Third Order

ABSTRACTA study was made of third-order nonlinear optical susceptibilities of new tetrathiafulvalene (TTF) derivatives, using the degenerate four wave mixing (DFWM) method, as well as complex quantum chemical calculations. To understand the physical nature of the optical nonlinearities, we separated their electronic and nuclear contributions. We found that the electronic contribution to these nonlinearities predominated. Our investigations suggest that TTF may be a highly promising material for nonlinear optics (NLO).

A 12-BIT 400-MS/s CURRENT-STEERING DAC WITH DEGLITCHING TECHNIQUE

2014 ◽  
Vol 23 (01) ◽  
pp. 1450004 ◽  
Author(s):  
XIAOBO XUE ◽  
XIAOLEI ZHU ◽  
QIFENG SHI ◽  
LENIAN HE
Keyword(s):  
Dynamic Range ◽  
Supply Voltage ◽  
Cmos Technology ◽  
Signal Frequency ◽  
Current Steering ◽  
Digital To Analog Converter ◽  
Measurement Results ◽  
Voltage Swing ◽  
Current Steering Dac ◽  
Low Supply Voltage

In this paper, a 12-bit current-steering digital-to-analog converter (DAC) employing a deglitching technique is proposed. The deglitching technique is realized by lowering the voltage swing of the control signal as well as by using a method of glitch counteraction (GC). A new switch–driver structure is designed to enable the effectiveness of the GC and provide sufficient driving capability under a low supply voltage. Moreover, the control signal's rise/fall asymmetry which increases the glitch error can be suppressed by using the proposed switch–driver structure. The 12-bit DAC is implemented in 180 nm CMOS technology. The measurement results show that the spurious free dynamic range (SFDR) at low signal frequency is 78.8 dB, and it is higher than 70 dB up to 60 MHz signal frequency at 400 MS/s. The measured INL and DNL are both less than ±0.6 LSB.

scholarly journals APPLICATION OF A SCINTILLATION GAMMA-SPECTROMETER FOR DETERMINATION OF RADON CONTENT IN WATER

2021 ◽  
pp. 187-190
Author(s):  
D.А. Hakimov ◽  
I.V. Zhuk ◽  
M.K. Kievets
Keyword(s):  
Water Samples ◽  
Mineral Water ◽  
Experimental Studies ◽  
Gamma Spectrometer ◽  
Scintillation Gamma ◽  
Measurement Results ◽  
Measurable Activity ◽  
Measurement Geometry ◽  
Radon Content

Experimental studies have been carried out to determine the sensitivity of a mobile scintillation gamma-spectrometer to radon-222 in mineral water samples for the selected measurement geometry and the minimum measurable activity of radon-222 in such samples. The measurement results of radon content in mineral water samples obtained using such gamma-spectrometer are presented too.

scholarly journals Dual-band impedance transformation networks for integrated power amplifiers

2014 ◽  
Vol 8 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Robert Wolf ◽  
Niko Joram ◽  
Stefan Schumann ◽  
Frank Ellinger
Keyword(s):  
Output Power ◽  
Power Amplifiers ◽  
Design Procedure ◽  
Dual Band ◽  
Analysis Method ◽  
Large Signal ◽  
Fully Integrated ◽  
Power Added Efficiency ◽  
Relative Bandwidth ◽  
Measurement Results

This paper shows that the two most common impedance transformation networks for power amplifiers (PAs) can be designed to achieve optimum transformation at two frequencies. Hence, a larger bandwidth for the required impedance transformation ratio is achieved. A design procedure is proposed, which takes imperfections like losses into account. Furthermore, an analysis method is presented to estimate the maximum uncompressed output power of a PA with respect to frequency. Based on these results, a fully integrated PA with a dual-band impedance transformation network is designed and its functionality is proven by large signal measurement results. The amplifier covers the frequency band from 450 MHz to 1.2 GHz (3 dB bandwidth of the output power and efficiency), corresponding to a relative bandwidth of more than 100%. It delivers 23.7 dBm output power in the 1 dB compression point, having a power-added efficiency of 33%.

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