Purchase Solution

Examining frequency to time domain signals

Not what you're looking for?

Ask Custom Question

A spectrum analyzer is connected to an unknown signal. The spectrum analyzer displays the power level of signals in dBm vertically and frequency horizontally. The spectrum of the unknown signal creates the following display:
A continuous spectrum that is completely filled so no lines are visible.
The spectrum has a sin X / X (sinc X) shape. The spectrum has maximum power spectral density at 0 Hz and falls to zero at 2 kHz, 4 kHz, 6 kHz and other even kHz frequencies.

a. What is the input waveform?
b. Is the input signal periodic or non-periodic?
c. What is the pulse width?
d. If the spectrum suddenly changes to have zeroes at 5 kHz, 10 kHz, 15 kHz, etc, what is the new pulse width?

Purchase this Solution
Solution Summary

In this solution from a description of a Sinc function we back engineer the signal to its tiime domain representation to answerthe following

A spectrum analyzer is connected to an unknown signal. The spectrum analyzer displays the power level of signals in dBm vertically and frequency horizontally. The spectrum of the unknown signal creates the following display:
A continuous spectrum that is completely filled so no lines are visible.
The spectrum has a sin X / X (sinc X) shape. The spectrum has maximum power spectral density at 0 Hz and falls to zero at 2 kHz, 4 kHz, 6 kHz and other even kHz frequencies.

a. What is the input waveform?
b. Is the input signal periodic or non-periodic?
c. What is the pulse width?
d. If the spectrum suddenly changes to have zeroes at 5 kHz, 10 kHz, 15 kHz, etc, what is the new pulse width?

Solution Preview

(a)

The Sin(x)/x type waveform (also known as Sinc(x) function) in the frequency domain is charactristic of a stream of pulses. The zero crossing points (nulls) in the Sinc(x) = Sin(x)/x waveform occur at points denoted by

1/t, 2/t, 3/t.......n/t (n an integer ranging from 1 to infincity) where t represents the pulse width (time duration) of the pulses. In addition with the Sinc(x) function if there is any periodicity in the pulse stream (ie repeated data patterns) then this ...

Purchase this Solution
Free BrainMass Quizzes
Air Pollution Control - Environmental Science

Working principle of ESP

Architectural History

This quiz is intended to test the basics of History of Architecture- foundation for all architectural courses.

View More Free Quizzes
Related BrainMass Solutions

  • Interpreting frequency domain signal spectrum to time domain

    424279 Interpreting frequency domain signal spectrum to time domain A spectrum analyzer is connected to an unknown signal. The spectrum analyzer displays the voltage level of signals in volts vertically and frequency horizontally.

  • Decompsotion of time domain signals into frequency component

    359849 Decompsotion of Time Domain Signals into Frequency Component Please provide necessary explanations leading to the answer. a.

  • Using Laplace transforms to analyse diff circuits responses

    345396 Using Laplace transforms to analyse diff circuits responses Laplace transforms enable interpretation and manipulation of different signals by viewing these signals as either time domain signals/pulse or else frequency domain representations.

  • Fourier transform and convolution

    As T increases, the sinc function's peak becomes sharper and sharper but is still centered at f=100Hz The solution shows how the convolution of two signals on the time domain translate to the frequency domain

  • Fourier Analysis of system in MatLab

    Plot x versus t and y versus t, and compare the two signals in terms of frequency content. (In the time domain, we characterize high-frequency content qualitatively by sharp transitions or quick motion of the signal.) (c).

  • Analysing spectrum anlyser output

    These are all ODD harmonic terms so would suggest that the waveform in the time domain would be an ODD function with no symmetry about the y axis when viewed in the time domain.

  • Time Division Multiplexing and Frequency Division Multiplexing

    14794 Time division multiplexing and Frequency division multiplexing What's the difference between Time division multiplexing and Frequency division multiplexing TDM: Time division multiplexing.

  • Impulse response using inverse discrete-time Fourier transform.

    Step-by-step: Let hd[n] be the time-domain impulse response and Hd(ejw) be its discrete-time fourier transform.: Time domainfrequency domain To solve this problem, we can use two basic discrete-time fourier transform pair between the time domain

  • Digital Signal Processing and maintainability engineering

    The two signals are linearly related in this frequency band B. The signal-to-noise ratios of both signals are high in this frequency band C. The signal-to-noise ratios of both signals are low in this frequency band D. A and B E.

View More Related Solutions