frequency spectrum


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frequency spectrum

[′frē·kwən·sē ‚spek·trəm]
(physics)
A plot of the distribution of the intensity of some type of electromagnetic or acoustic radiation as a function of frequency.
(systems engineering)
In the analysis of a random function of time, such as the amplitude of noise in a system, the limit as T approaches infinity of 1/(2π T) times the ensemble average of the squared magnitude of the amplitude of the Fourier transform of the function from -T to T. Also known as power-density spectrum; power spectrum; spectral density.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
Shittu urged Ministries, Departments and Agencies, as well as private individuals and organisations that use the frequency spectrum to enhance communication and transmission of data within their organisation.
Thus, extracting interference fringes from a hologram would suppress the zero-order term and enhance the real-image term in the frequency spectrum. Therefore, with the enhanced O*R(x, 7), phase noises would be reduced.
Additionally, Figures 18(a) and 18(b) show the time-domain waveforms and frequency spectrum of pressure fluctuation signals under the wear of floating tile.
Frequency spectrum of the CHB output voltage with PD-PWM or R-PD-PWM ([f.sub.m]=50Hz, [m.sub.f]=40, [m.sub.a]=0.9)
The natural frequency spectrum of the rod under consideration for B-spline cubic approximation polynomials and equidistant node distribution is presented in Figure 9, while corresponding relative error [[epsilon].sub.n] is presented in Figure 10.
Keywords: harmonics, inter-harmonics, UPS, total harmonics distortion (THD), frequency spectrum.
Unlike roadways, power lines, water pipes or other physical infrastructure, which can be expanded to meet increasing demand, the frequency spectrum is a finite resource.
ISLAMABAD -- In an interesting twist at a time when Aqeel Karim Dhedhi (AKD) has been put on the Exit Control List in the OGRA scandal for inside trading and stock market manipulation, AKD has managed to sell his frequency spectrum in DV Com Ltd.
The FBA has exclusive authority to allocate and assign portions of the radio frequency spectrum to the government, providers of telecommunication services and telecommunication systems, radio and television broadcasting operations, public and private wireless operators and others.
T-Mobile announced an important deal with Verizon Wireless to swap T-Mobile's higher frequency spectrum for lower frequency spectrum owned by Verizon Wireless, it added.
By unfolding the Doppler frequency, the stationary phase point expansion coefficients are obtained, which makes it easy to get the 2D frequency spectrum of the target echo signal.
The meeting also discussed the topic of providing frequency spectrum in a bid to enhance the electronic radiocommunication systems inside the aircraft with the aim of replacing the current aircraft wired equipment with wireless equipment and thus reducing the weight of the aircraft and which in turn will lead to lower costs and reduce the fuel consumption of the aircraft.

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