A low-pass filter is a filter that passes signals with a frequency lower than a selected cutoff frequency and attenuates signals with frequencies higher than the cutoff frequency. The exact frequency response of the filter depends on the filter design. The filter is sometimes called a high-cut filter, or treble-cut filter in audio applications. A low-pass filter is the complement of a high-pass filter.
In optics, high-pass and low-pass may have different meanings, depending on whether referring to frequency or wavelength of light, since these variables are inversely related. High-pass frequency filters would act as low-pass wavelength filters, and vice versa. For this reason it is a good practice to refer to wavelength filters as short-pass and long-pass to avoid confusion, which would correspond to high-pass and low-pass frequencies.Low-pass filters exist in many different forms, including electronic circuits such as a hiss filter used in audio, anti-aliasing filters for conditioning signals prior to analog-to-digital conversion, digital filters for smoothing sets of data, acoustic barriers, blurring of images, and so on. The moving average operation used in fields such as finance is a particular kind of low-pass filter, and can be analyzed with the same signal processing techniques as are used for other low-pass filters. Low-pass filters provide a smoother form of a signal, removing the short-term fluctuations and leaving the longer-term trend.
Filter designers will often use the low-pass form as a prototype filter. That is, a filter with unity bandwidth and impedance. The desired filter is obtained from the prototype by scaling for the desired bandwidth and impedance and transforming into the desired bandform (that is low-pass, high-pass, band-pass or band-stop).
can someone do a design of a FIR filter using the Window design method by hand as an example and post it? Please do not use mat lab. I would like to learn how to do it myself by hand. I have been have use Google but no luck .
all the pages I have seen use mat lab in their example.
So I...
"][/URL]Hi to all,
i have a SISO system with microwaves devices. The 16-QAM information is about 20KHz , upconverted at 30 MHz and then at 2462MHz.At the receiver the same procedure, downconverting. After the first LNA i have a BPF fc=2430MHz which has large Bandwidth so it does not protect...
Homework Statement
Write an IIR (or ARMA) model in state space representation:
Homework Equations
y(k) = b_1 y(k-1) + \cdots + b_p y(k-p) + a_0 u(k) + \cdots + a_r u(k-r)
The Attempt at a Solution
I found much info how to write it in space state representation but no explanation...
I am using a extended Kalman filter for the state estimation of a nonlinear system. The real system has accelerometers, so I need to include the acceleration of the system as part of my measurements with noise added (position and angular rates are other measurements).
All of the Kalman...
Homework Statement
An expression for Zin (impedance seen fromthe input) and Zout (impedance seen from the output) of the high-pass filter circuit with respect to frequency is: ?
The Attempt at a Solution
i have, bythe way, equation for transfer function already. Vout/Vin= R/(R+1/jwC). i am...
I want to learn do aberrations and compensation actions used as unsharp filter for final image ?
I read a Leica paper. There was symmetrical lens Summicron as a subject. I found that at the exit of the lens there were no aberrations without corrected. But when you look inside , some lens...
Hi, I've gotten a little confused and would like some guidance and confirmation,
I've designed an H-Bridge inverter which should output 100A at 20Vrms onto a 200mΩ load. The current target output peak voltage (with max duty cycle of 98% considered) is 28.86V. The LC filter is made up of a...
Homework Statement
Due to its bandwidth and power efficiency, SSBSC is commonly used in Frequency Division Multiplexing (FDM) systems. FDM systems are used to combine a number of separate information channels into a single transmission. Each channel uses a separate carrier frequency and the...
I am attempting to come up with a systematic way to design Multiple Feedback bandpass filters with certain specifications.
• Frequency is some given number
• Bandwidth varies with Frequency by
f0*2^13/12
• The Q should therefore be .4719
• The gain should be 1
I am at an understanding of how...
Hi All,
I am looking to design LPF with Inductor and Capacitor that can reject 60Hz frequency.
I tried on google about the same but did not get an idea.
Basically, I am trying to do is this, Incoming mains (AC Signal) has 60Hz frequency and I wanted to make it like a DC (close to DC) which...
There are a lot of really tacky oil filters on the market. Get a filter that costs at least $8. The $3.27 filter that my daughter in law got with her $19.95 Walmart oil changed failed in three days.
I use the top of the line Purolator or Mobile 1 filters. There are other good brands, but...
Now, assume I have a white noise, n(t)\tilde \ N(0,1), i.e gaussian with zero mean and variance 1, and it goes through a Hilbert filter, i.e we get:
$$ \hat{n}(t) = \int_{-\infty}^{\infty} \frac{1}{t-\tau} n(\tau) d\tau $$
I read that \hat{n} should be also a gaussian, because this is an...
Exams are coming up and I've been doing some revision from past papers. Having issues with working out part c of the attached problem. I've already calculated part a and b, possibly correct. Basically I simplified resistances and capacitance. And to have a constant frequency I let Z equal the...
I am designing a 5-pole low-pass butterworth filter to have a cutoff frequency of ~50 Hz. It has a source impedance of ~1 Ohm, and a load impedance of ~50 Ohm (The load impedance can be changed around if that will help later). Because of these, I am using the "T" configuration. I used the table...
1. How do we find the normalized value of the pass-band and stop-band frequencies to be used in a butterworth filter?I am using the following code in MATLAB to design a butterworth filter. Can someone please tell me what is the pass-band/stop-band frequency of the filter in this code? 4000 is...
Got excel spreadsheet.
in my excel worksheet "4" i plot bode plot for low and high pass.
Our lab experiement aim was measure two set of data and identify which one is low pass and which one is highpass filter.
But as soon as I am trying to put lograitham graph it is not allow me ?
I...
Homework Statement
F(w) = a / [1 - be^(-jwT)]
where a and b are constants
Find the magnitude of this filter response
Homework Equations
e^(-jX) = cos(X) - isin(X)
The Attempt at a Solution
the answer is a/ √[1-2bcos(wT) + b^2*cos^2(2wT)]
but I can't seem to get rid of...
Homework Statement
A digital filter is defined by yn = xn - n-2 - 0.81*yn-2.
At what frequency, in terms of fNyquist, is the filter response zero and maximum?
Homework Equations
H(z) = Y(z)/X(z)
The Attempt at a Solution
I figured out that H(z) = [z2-1] /[z2 +0.81]
and...
hi:
i designed an active low-pass filter,but i don't know if it correct method or not
i want fc=200 Hz and n(order)=4. i use this method:
by let C=100 nF and use this equation "fc=1/(2*pi*C*R1)"
i get R1= 8 Kohm,R2=R1
this is for one stage
to get filter of 4 order,i repeat that...
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...
Good day,
i read a lot about the kalman filter and the extended kalman filter, but some things are still not clear to me. E.g. I have one question concerning the jacobian matrix of the measurement matrix h. I want to point out my problem with a concrete example:
A vehicle is represented by...
If an object of mass M falls under the influence of gravity and a drag force Fdrag, we may write Newton’s Second Law as
Ma = Mg - Fdrag
Where a is the acceleration of the object and Mg is the weight of the object. The drag force has the general form:
Fdrag = bv^n
Where the drag...
Hi all,
I am faced with this question, I am stumped as it is presented in a different way to what I am used to:
The output from a FIR filter for a unit step input u[n] is
y[n] = δ[n] + 3 δ[n - 1] + 6 δ[n - 2] + 10 δ[n - 3] + 15 u[n]
What is the impulse response of the FIR filter?
A...
Hi all,
I have a question relating to sample rates and data filtering.
I have a (relatively) high sampling rate of 100Hz, there is some high frequency "noise" present that acts over the range of 1-15Hz.
My question is, given that I am interested in much lower frequencies (slow movement...
Reconstructing a signal using an equilizer "filter" function
Homework Statement
A low pass signal g(t) is sampled at a rate of ##f_{s} > 2B## needs to be reconstructed. Sampling interval is ##T_s=\frac{1}{f_s}##
The reconstruction pulse to be used is
$$p(t)=∏(\frac{t}{T_s}-\frac{1}{2})$$...
I have a PDE that can be interpreted as basically an exit time problem for a certain stochastic process. I would like to use this to verify an analytical solution I've found. If I start the stochastic process at (x,y), then the average exit time from a certain region will be equal to the value...
After getting an oil change yesterday, the people there said my air filter was pretty dirty and it needed to be changed soon. They didn't have a replacement, but said the one I need is like 50$.
I was wondering if you really need to replace the air filter, or if you can just clean it.
If you...
Homework Statement Q3. Sampling and reconstruction
A) It is common practice to use low order low pass filters instead of a Sinc filter, at the expense
of a higher sampling rate. Here we investigate how to do this.
Compare:
a) the ideal reconstruction of a low pass sampled signal, which can be...
Hi All,
I would like to know how can I call or express the following process!
I use a (3x3) 2D FIR Filter for imaging processing with DC = 0, like this:
0 1 1
2 O 2 /8
1 1 0
My filter is such that I can decompose it into finite sates, as my image (medical)
can take 9...
Homework Statement
Consider one bit time of Manchester code of duration T where a positive pulse of amplitude A/2 and length T/2 is followed by a negative pulse of amplitude –A/2 and length T/2.
a) Determine the impulse response of a filter matched to this signal and sketch it as a...
I am designing an eeg circuit and planning to do an adc for it. Since the eeg requires a band pass filter I am planning to use a second order low pass bessel filter in it.
Suppose I want to reduce the noise ( as I am working with low frequencies ) and increase the efficiency of the circuit...
Dear people,
I want to implement the Extended Kalman Filter for identification. I have a model of the system and I want to estimate the states. My question is, how can give the Q Matrix, I mean, how can I calculate the elements of the covariance matrix related to the dispersion of the system...
Hello everyone!
What materials are used for making optical filter glasses?
I bought this:
http://www.alibaba.com/product-gs/495852853/Digital_Camera_lens_43mm_950nm_IR.html
and took its transmission spectrum. So, it reminds me a transmission spectrum of CdTe.
But a-CdTe is more...
Homework Statement
hey there..
I really hope u guys can help me extracting the important element from the question below;
A signal is sampled at the sampling rate of 10kHz. The signal has useful signal content
between 1kHz and 2.4kHz, and distortion of not more than 1dB is required for...
Hi,
On section 2.4.2. of the "Probabilistic robotics" book, there is an example to demonstrate the way a Bayes filter works. I only can't understand one point in the example, I hope you help to get it.
This is the whole example:
The point I can't get to, is the formula (2.42). I think...
Homework Statement
Need to design a second order notch filter whose transfer function is given by:
H_a (s) = \frac{(s^2 + Ω_z^2)}{(s^2 + \frac{Ω_0}{2}s + Ω_0^2)}
For part a (which is what I need help with) it says to assume suitable values for Ω_0 and Ω_z with Q = 2.
The Attempt at a...
Hello,
I am designing an op-amp to be used as a low-pass filter and am using a TLC271. I have attached an image of the topology of the circuit. I found the transfer function to be G(s) = Y(s)/X(s) = 1/(10^-4s + 1).
I plotted the bode plot in MATLAB and have attached the result in the...
Homework Statement
When calculating the overall gain of a two-stage pass-band filter, can one simply add the gain from the high-pass filter (R1/C1) to the gain from the low-pass filter (R2/C2)?
Homework Equations
N/A.
The Attempt at a Solution
For example, if the gain from the high-pass...
Homework Statement
Here is the problem with the solution:
The Attempt at a Solution
I don't understand why the filter is low pass. How I solve this usually is I plug in ω=0 and ω=∞. When I plug in 0 I get the gain of a non inverting op amp. When I plug in ∞ I get that the transfer...
Say you have a dichroic filter with a bandwidth of 10nm centered at 500nm, so it will pass 495nm - 505nm light through.
In an optical system the light is generally focused as a cone through the filter, which means that most of the light, if not all, is entering the filter at an oblique angle...
Homework Statement
Select component values to design for corner frequencies at 500 rad/s and 1500 rad/s.
Homework Equations
KCL, transfer function
The Attempt at a Solution
Gain:
[1] G = 1 + \frac{R_{A}}{R_{B}}
Voltage division:
[2] V2 = V1\frac{R_{2}}{R_{2}+1/sC_{2}}...
Homework Statement
I want to find the overall transfer function of Instrumentation amplifier with a DC-Suppression filter. I know how to calculate the TF of a normal Instrumentation amplifier. But when feedback is given from the Filter to the IA, I couldn't find it.
Homework Equations...
I am working on designing a music visualization system using LEDs. I would like to create an analog design that uses op amps to filter, amplify, and add DC bias to an audio signal so it can be read into the A/D of a 5V microprocessor. The input signal is a +/- 1.5V volt audio signal coming from...
Homework Statement
when I'm trying to calculate and show the graphic of the phase characteristic i don't understand why the domain range of the arctan function is [0,90] :
Homework Equations
The Attempt at a Solution
shouldn't be the domain of arctan function between...
I'm trying to use a second order passive RC filter to attenuate noise in a thermocouple signal. I've heard that using two passive RC filters in series can generate "loading" effects. I'm not sure exactly what this means, except for the output response is different from the theoretical...
I am attempting to build an Op-Amp circuit in which a sinusoidal input is used. Below is the description:
An active, op-amp bandpass filter circuit for audio frequency inputs. The
implemented filter circuit must provide a maximum gain of 14 dB inside the pass-band and less than 9 dB of...
Homework Statement
Find the digital filter equivalence of the
circuit in a difference equation formHomework Equations
Is this the difference equation form?The Attempt at a Solution
If that is the proper form.. I think this is how to solve it? I got this example from my textbook I'm just not...
hi guys:
if i have signal(YT) consist of two frequencies(30 and 300 Hz),as the following:
t=0:1/1000:1;
Y30=sin(2*pi*t*30);
Y300=sin(2*pi*t*300);
YT=Y30+Y300;
i want remove the frequency of 300 Hz from(YT) by using low pass filter
so how can i do that(by using MATLAB command)?