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).
Hello!
If one were to push uncollimated light through a tube of inner radius R and length L, coated with matte black - the maximum incidence angle it will allow through would be ATAN2(R, L). On the other end of the tube, only the "most collimated" fraction of light would exit - a very small...
Homework Statement
Consider a LTI system for which the filter coefficients are ##{\mathrm{h}_k}=\{1,2,1\}##. Find the output when the input is ##\mathrm{x}[n]=3\mathrm{cos}(\frac{\pi}{3}n-\frac{\pi}{2})-3\mathrm{cos}(\frac{7\pi}{8}n)##. Identify two frequencies in this composite signal. Show...
What is the difference between the harmonic resonance tune frequency and the higher order harmonic frequency to be filtered, How do you calculate ths frequency in power system network?
I'm doing some work and don't really know if there is a better way to proceed. I have vendor information of how much premium they bring in, and how much losses they incur. With those 2 figures, I can get a 'loss ratio' of each vendor. My job is to look through the list and Identify any...
Im selecting sunglasses for the holidays. How come brown sunglasses will filter blue light? How about green sunglasses? it's supposed to filter some blue light.. how much and why?
Hi.i am reza from iran.
really i don't know how many membrane have been introduced and what kind of it have being discussed here.but anyway ask my question and hope to get useful answers.
in membrane filter press the filter press producers importing membrane from china. no one and no company...
This is not homework. I am doing old exams so i have the full solution but need help understanding it.
1. Homework Statement
A WSS random signal {X(t)}t∈R with PSD S_X(ω) is transmitted on a noisy channel where it is disturbed by an additive zero-mean WSS random noise {N(t)}t∈R that is...
This may be a dumb question, but maybe someone can help me out:
Consider a pair of entangled photons A and B, fired at respectively Alice and Bob who both let it go through a polarisation filter at different angles. Now Alice establishes that half of the photons get through her filter, and half...
Hi,
as I am in need of Low- and Highpass filters i would like to simulate my circuit using LT-Spice.
I hope that i can get optimal caps and coils values like that.
So i simply started to build my pi-network lowpass filter in LT-Spice and got the simulation results (please check the picture in...
I am working in a group for designing a LED interactive Screen. My part of the project is the design of the music visualization system. I am new in this area, but I know I need to use some op-amps to filter the input signal from the mp3 player.
Could anyone give me any suggestions on how to...
Hi!
Here is my task:
Lowpass filter circuit is given:
Input signal to this circuit is:
L=36.4mH, C=85.4nF.
Calculate and draw output signal.
My idea is to:
1) Represent input signal in term of Fourier series (complex form),
2) Calculate transfer function for given circuit (for n-th...
I am studying "maths III" in my university. And the course has this project you have to do called "Practical differential equations". You are basically supposed to describe some practical system that uses differential equations.
My thought was PID loops, but I'm not sure if they use...
Homework Statement
I'm having trouble understanding part C of this question.
Homework Equations
ΔVo = Vout/2fRC
The Attempt at a Solution
So to get ~12V at the output, the turns ratio should be 14 because 120√2/12 = 14.14.
Using a turns ratio of 14, the output voltage will be 12.12 V.
To...
I am doing an experiment that generates data in three 1-hour-blocks. Each block has a different number and timing for acquisitions. (The first hour is more frequent and numerous, while the last hour is only 6 acquisitions)
The reason for breaking it up into 3 hours is to give the subjects a...
The following circuit is giving me the following response at each resonator, however it's not the correct response. There's supposed to be a time delay for each resonator response, however they're all more or less starting around 0 seconds...when I'm expecting a proper time delay between each...
Good day all,
I have a question:
I built a passive high pass filter in an experiment using a hand wound inductor (toriod) and a resistor. The filter worked great as a high pass at frequencys ranging from 100 Hz - 1,000,000 Hz (rolling off around 10,000 Hz). After creating a bode plot, I...
Hi
I'm using INS with GPS. and I have some question about noise.
After denoising measures from high frequency noise with wavelet. the short frequency will stay on measures.
we generally GM or Auto-regression to model the remain error.
Is this models used only for kalman filter or it can be...
Homework Statement
Converting a 50kHz high pass filter to a 5.3kHz high pass filter.
The circuit:
Homework Equations
Working out the Capacitance, C, and Resistance, R, of the circuit in order to work out the cut-off frequency, Cf, using:
Cf = 1/(2*pi*R*C)[/B]
The Attempt at a Solution...
I'm trying to design a bandpass filter with a BW of 50MHz in LTSpice, however my simulations aren't coming out as I'd like. I'm using the frequency transformation method, with a centre frequency of 2GHz., fractional BW 2.5%. I'd like a wider passband, however I can't seem to get away from the...
I am having some trouble deriving the a posteriori estimate covariance matrix for the linear Kalman filter. Below I have shown my workings for two methods. Method one is fine and gives the expected result. Method two is the way I tried to derive it initially before further expanding out terms to...
Suppose we have a creation point C where two entangled photons A en B are produced. 1m in the direction of A is a vertically polarized filter V. 2m in the direction of B is a horizontal polarized filter H.
Now, I understand that when photon A strikes filter V, it either gets blocked or gets...
Homework Statement
Design a filter that will pass frequencies greater than 20 Hz and set the -3dB point at 10 Hz. Assume zero source impedance and 10k load impedance.
Homework Equations
##f=\frac{1}{2\pi RC}## which is the equation used to determine the 3 dB frequency of an RC filter.
The...
Suppose we have a Kalman filter. We have a position sensor, for example GPS. We use the filter to estimate position. However in all examples I see higher derivatives in the state vector: speed, acceleration and sometimes jerk. There is no sensor that calculates these values directly, so they...
Hello.
I've uploaded similar question before but I think it is time to make this clear.
I've seen the attached one during reading of grounding.
In the picture, the body of the power line filter (or ground of the filter) is connected to inner surface of Faraday cage and signal ground is...
Hey guys,
I am learning about the filter shapes deduced from the poles and zero plots, however a lot of sources are describing it differently with no logical explanation. I want to know what exactly the poles and zeros do between the range Ω = 0 and Ω = π. One source i read explains if the pole...
Hi,
I am new member over here. I wanted to know how to perform discrete wavelet transform, probably using symmlet 8 wavelet with 16 Low/High pass filter coefficients using matrix transformation method when decomposing to a certain level the approximate coefficients i.e. sample size becomes less...
Homework Statement
I would like to define pressure loses through transmission line to the transducer. In transmission line I have a reducing union, filter and L pipe. How I can find this differences?
In case of frequency my reducing union reduce pipe diameter 6 mm to 3 mm how i can determine...
In fluorescence microscopy, dichroic mirrors reflect light under a critical wavelength (used to excite the sample) and transmit light over a critical wavelength (emission light from the sample). Are there mirrors that reflect two different wavelengths of light and transmit the rest? Essentially...
To make a filter out of a bjt where the poles don't shift when you load it, do you need to have a buffer stage that follows the bjt such as a unity gain mosfet and then put the load after that buffer stage?
Homework Statement
Determine the center frequency and bandwidth of the bandpass filter.
Homework Equations
center frequency of bandpass filter = ωc occurs when the magnitude of H = 1
H = V0/Vs
Center frequency occurs when Im(Z) = 0
Zc = 1/(jωC) = 1/s
ZL = jωL
ZR = R
I don't know a formula...
Homework Statement
Draw the circuit diagram of a second-order series High pass filter RLC filter.
Given:
R = 50 ohm
Q_s = .5
f_0 = 30 MHz
determine L and C
Homework Equations
f_0 = 1/(2*pi*sqrt(LC))
Q_s = 2*pi*f_0*L/R = 1/(2*pi*f_0*R)The Attempt at a Solution
I know how to find L and C, given...
I have the values for all the voltages and currents. I'm wondering how I go about it, given that v3 = v30 (cos (Θ3) + isin(Θ3)) and I have a value for v3. Since v3 = i4 * Z where Z is C3 and R2 in parallel, there'd still be 2 unknowns. I feel as though I'm missing something obvious, if anyone...
Homework Statement
I am doing a project on the Elenco AM/FM superheterodyne radio kit. I have been stuck for ages trying to figure out how the two common emitter amplifiers are tuned to filter out anything that is not around 455 kHz. I tried to find a bandpass filter, or a high-pass and a...
I want to replace a dielectric resonator in a satellite LNB to change the frequency of the LO.
Can I use a filter to replace this resonator? a Helical filter maybe.
Homework Statement
See attached image, assignment a)
Homework EquationsThe Attempt at a Solution
Using ordinary trigonometry, I got simply $$\Delta = sin(\theta_i) 2 d tan(\theta_t) n_{air} - 2n_{oxide} d/cos(\theta_t)$$. However, even if I apply Snell's law, it's not the answer I'm supposed to...
I have my state vector containing
$$[X, Y, v_x, v_y, \theta, r, a_x, a_y, b_{\theta}]^T$$
and I have them related by
$$dX = v_x cos \theta - v_y sin \theta\\
dY = v_x sin \theta + v_y cos \theta\\
dv_x = a_x\\
dv_y = a_y\\
d\theta = r\\
dr = 0\\
da_x = 0\\
da_y = 0\\
db_\theta = 0\\
$$
Now...
Homework Statement
Derive an analytical expression for the permeability (k) of the structured porous medium (which is a size selective filter) constituted by a periodic array of cylinders of diamter d separated by a distance h = 1.8d
Homework Equations
Q=k*(μ/A)*(Δp/L)
Q = volumetric flow rate...
Homework Statement
(a) If R1 = 4.7kΩ, what value for C1 will give a cutoff frequency of 50kHz?
(b) If the input voltage is described by the equation Vin = 3cos(2π(4000)t), what will the peak output voltage be?[/B]
Homework Equations
(a) fc = 1/(2πRC)
(b) Vout/Vin = 1/√(1 + (2πfRC)2)
The...
Homework Statement
A simple way to build a bandpass filter is to filter the output of an RC highpass filter with an RC lowpass filter, as shown on the left in the diagram below. The isolation buffer is a circuit element that keeps the two circuits isolated so they behave as they would on their...
I'm having trouble finding cheap (<$100) and effective (90%+ transmission) optical filters for fluorescence, specifically band-passing around 530nm, as narrowly as possible .
Anyone have any suggestions?
1. Homework Statement
''A machineoutputs a 4kHz sine wave signal of amplitude 2 volts peak, plus a 100Hz interference component of amplitude 1 V peak''
Given equation: Vout/Vin = 1/((1+(f0/f^2))^0.5 phase lead = inverse tan (f0/f)
f0 = 1/(2*pi*R*C)I'm given a 4 kilo-ohm resistor and need to...
An optical low pass filter is supposed to blur the image using birefringence. I took out an optical low pass filter from a digital camera where it is used for anti-aliasing purposes. The filter looks just like a piece of glass. I pass a diode laser beam through it and look at the beam spot on...
Hello everybody, nowadays I am working on shaping amlifiers and need guidiance about how to design one and do its simulations before pcb design and manufacturing. When googling about shaping amplifiers i found documents mostly about filters (active and passive), which i know works for rejecting...
Homework Statement
A resonance filter is a specific second-order digital system designed to attenuate all frequencies except at and
around a given center frequency. The transfer function of a resonance filter is:
H(z)=(1 - r)(1 - rz-2) / (1 - 2rcos(ωcT)z-1+r2z-2)
where ωc = 2πfc, where fc is...
i am having trouble finding out all the names given to the components in this circuit. Also i am struggling to find the names to the two different parts of the circuit. can anyone help me please?
In this time I try to search after information about 2 things:
1. the gas flow system in the car and the car exhaust
2. the materials that use in air pollution filters
If you know good website / professor / paper / book / video lecture / other in one of this area so I will glad if you can let me...
I would like to find the distance that a vehicle travels using a Kalman filter. The vehicle is a car that travels the road between two positions. The vehicle has a GPS/barometer/accelerometer device that collects position data, which I converted from a longitude and latitude to a North, East...