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Modulation Systems and Characteristics
Published in Jerry C. Whitaker, Power Vacuum Tubes, 2017
The radio carrier wave signal onto which the analog amplitude variations are to be impressed is expressed as e(t)=AEccos(ωct) where e(t) is the instantaneous amplitude of the carrier wave as a function of time (t)A is a factor of amplitude modulation of the carrier waveωc is the angular frequency of the carrier wave (rad/s)Ec is the peak amplitude of the carrier wave
Networking
Published in Richard A. Panke, Energy Management Systems and Direct Digital Control, 2020
There are two basic modulation classifications—baseband and broadband. Baseband MODEMs convert data into binary form using differential current impulses for transmission. However, baseband is not true modulation because a carrier wave is not modulated. At any point in time, data transmission along an individual communication link is limited to a single signal and one direction. Baseband MODEMs are also known as line drivers, local MODEMs, short-distance MODEMs short-haul MODEMs, or digital line adapters. They are 50 to 90% less costly than broadband and are ideal for short-range work. In addition, they can operate at higher speeds, have fewer internal parts, and are not subject to errors common in true modulation techniques.
C
Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
cross luminance NTSC video artifact that causes chrominance information present in the decoded luma signal (chrominance crossed into luminance). Cross luminance has the appearance similar to a zipper caused by the color subcarrier. Television receivers that use a line comb filter to separate luma and chroma signals have crossluminance components appearing on sharp horizontal edges. Television receivers that use a bandpass filter for luma-chroma separation have crosschrominance components appearing on sharp vertical edges. cross modulation an undesired intermodulation of an electromagnetic carrier wave by another electromagnetic carrier wave that is either
Analysis of Cascaded Multilevel Inverter with a Reduced Number of Switches for Reduction of Total Harmonic Distortion
Published in IETE Journal of Research, 2023
Kola Muralikumar, P Ponnambalam
Modulation index, m is defined as a parameter, which determines the amount of modulation. For Amplitude Modulation ma, it is defined as an amount of the extent by which carrier voltage differs as a result of modulating the signal [27,28]. In AM, the ratio among the message wave and carrier wave of amplitude is recognized as modulation index and is given by Modulation index insists on the quantity of energy in carrier wave used in modulation. The original amplitude of carrier wave (AC) and message wave Am, respectively, then, Maximum amplitude modulated wave is Minimum amplitude modulated wave is It can be derived as some results by noticing the above two equations. In AM, amplitude carrier wave must be higher than the amplitude of message wave. To attain ideal results of amplitude message wave, it must be half of the amplitude of the carrier wave.
Common mode voltage reduction of cascaded multilevel inverters using carrier frequency modulation
Published in International Journal of Electronics, 2022
Vinh-Quan Nguyen, Quang-Tho Tran
In addition, an ARSC is also presented in a general way for any n-level inverters to decrease harmonics and the number of switching commutations. This helps improve the inverter power quality and decrease the switching loss. The simulation and experiment results based on the cascaded 5-level three-phase inverter and the load of induction motor have also validated the effectiveness of the proposed method compared with that of the PD and POD methods using unmodulated carriers. Moreover, this paper has also presented an algorithm of general carrier wave frequency modulation for n-level inverters.
Fuzzy Distribution Static Compensator based control strategy to enhance low voltage ride through capability of hybrid renewable energy system
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2021
Ashwani Kumar, Vishnu Mohan Mishra, Rakesh Ranjan
The reference value for active current is obtained from the DC voltage regulator and supplied as step command. Current of d-q-axis are compared with their reference values and errors of these currents are applied to fuzzy controllers. To perform decoupled regulation of d-q current, cross-coupling terms and disturbance voltage are added to outputs of current controllers. Then, obtained Vid and Viq are converted to modulation signals and gate pulses are generated by comparing modulation signals with a carrier wave.