Phase shift and amplitude change when put through FIR filter

In summary, the conversation discusses a problem involving a sinusoidal signal, an FIR filter, and finding the factor and phase shift of the input signal. The conversation also mentions a theory involving z and the normalized frequency, which is equal to omega divided by the sampling rate. The solution can be obtained directly from H(z).
  • #1
Jd303
35
0
Hey all,
I am having trouble with this problem:

A sampled sinusoidal signal having a normalized frequency of 0.30π is sent through an FIR filter. The filter impulse response is,

h[n] = 1/3δ[n] + 1/3δ[n-1] + 1/3δ[n-2]

From this I must find out by what factor the input signal is multiplied by and what the phase shift is, (if there is in fact a phase shift).

my current theory is:
Let z = e^(jω) (j = i for those not in an electrical field)

H(z) = 1/3 + 1/3*z^(n-1) + 1/3*z^(n-2)

y[n] = H(z)*z^n

Then I am lost from here assuming my above theory is even correct. Any help would be greatly appreciated as I have been stuck on this one for a while. :)
 
Physics news on Phys.org
  • #2
Do you know what "normalized frequency" means? I sure don't. It must be related to the sample time T. So assuming T = 1 then f = 0.3pi/T?
 
  • #3
Not to worry, figured it out you can obtain phase and magnitude directly from H(z), also normalised frequency is just omega divided by the sampling rate
 

FAQ: Phase shift and amplitude change when put through FIR filter

What is a phase shift?

A phase shift is a change in the timing or position of a signal. In the context of an FIR filter, it refers to the delay or advance of the output signal compared to the input signal.

How does a phase shift affect a signal?

A phase shift can cause changes in the frequency and amplitude of a signal. It can also affect the overall shape and timing of the signal.

What causes a phase shift in an FIR filter?

A phase shift in an FIR filter is caused by the delay elements within the filter, as well as the coefficients used to weight the delayed signals.

What is amplitude change in an FIR filter?

Amplitude change refers to the change in the magnitude or strength of a signal after passing through an FIR filter. It can be affected by the filter coefficients and the characteristics of the input signal.

How can I control the phase shift and amplitude change of an FIR filter?

The phase shift and amplitude change of an FIR filter can be controlled by adjusting the filter coefficients and the filter order. Different filter designs and techniques can also be used to achieve specific phase and amplitude responses.

Similar threads

Engineering Recursive implementation of an FIR Filter
Replies
2
Views
1K
Phase Shift of IGMF Band-Pass Filter at Corner Freq: Solved Problem
Replies
10
Views
3K
Engineering Filter Linear Phase Property for non-integer time delays
Replies
3
Views
1K
FIR Filter and Signal to Noise ratios
Replies
12
Views
10K
Cascaded low-pass filter followed by a buffer amplifier
Replies
11
Views
3K
Engineering Questions about the workings of a phase locked loop
Replies
10
Views
1K
What is the value of the impulse function?
Replies
1
Views
2K
Problem understanding a parameter in a digital filter
Replies
1
Views
1K
Engineering Issue with shift registers — PIPO, PISO, SIPO and SISO
Replies
10
Views
2K
Impulse response of FIR filter given the output is known
Replies
1
Views
1K

Hot Threads

Recent Insights

Back
Top