Bandwidth Definition and 134 Threads

So I am trying to learning FM from textbooks and it says that the modulation index of FM is given by ##m=\frac{\Delta}{f_{m}}##, where ## f_{m}## is the message signal bandwidth and ##\Delta## is the peak frequency deviation of the FM modulated signal. What I do not understand is that normally...

Hello, I am trying to clearly understand the concept of bandwidth. Let's assume we have two type of cables and a signal ##x(t)## that travels a distance ##L## along each cable. The first cable has bandwidth ##BW1## and the signal has speed ##v1## along it. The other cable has bandwidth ##BW2##...

Can someone give me a better intuition of bandwidth. The way I see it, is that the bandwidth is the range of frequencies which a signal/wave is allowed to have. This doesn't feel complete though. For example, how can I explain that TDMA, FDMA and CDMA are similar in this sense. As far as I know...

Hi everyone I am finishing the last problem for a DSP problem set and just frankly have no idea where to start this one. I'm thinking I could compute the magnitude of each filter and then compare, but again am not sure. Can anyone point me in the right direction? Thanks

I just found this piece in an article: Terahertz waves (THz), which are submillimeter waves sitting between microwave and infrared light on the electromagnetic spectrum, have been used to achieve data rates greater than 100 Gbps. Unfortunately, THz waves share an Achilles’ Heel with the...

A few days ago, I noticed that there is a Linux terminal command 'tc', which can be used for limiting the download and especially upload speeds of your internet connection. When I write sudo tc qdisc add dev eth0 root tbf rate 100kbit latency 10ms burst 1540 in the terminal, the download speed...

Hello, Some trouble came up today with designing a 50 ohm system for a wireless powering project. I'd like to increase the frequency range for which my system impedance is 50 ohms in order to reduce power losses due to mismatch. I've simulated two RLC circuits in OrCAD SPICE to demonstrate my...

I tried solving this problem and got it correctly until the part A of the question. My solution is the same as the one given in the solutions manual until the part I put in the red box. I don't understand what is the logic behind the calculation of the bandwidth and center frequency there...

I am new to photodetectors. I know there are usually two concepts of bandwidths of photodetectors, i.e the spectral and electrical. What I do not understand is the electrical bandwidth. The electrical bandwidth is used to calculate the shot noise of a photodetector. However, the papers usually...

Hi, I'm studying p-i-n photodiode (PD) at the moment and understand that the photodiode's response will depend on the frequency of the light signal going into it. I am struggling however to understand the concept of bandwidth, and why is it that the photocurrent at the PD decreases with higher...

Homework Statement Calculate the expected peak wavelength and spectral bandwidth (in units of wavelength) of the emission for both a GaAs and silicon LED at liquid nitrogen temperature (77 K) and room temperature (300 K). Which of these cases would you expect to result in the best emitter and...

Homework Statement The attempt at a solution Constructing the total impedance of the circuit as follows, $$\frac{1}{Z_T}=\frac{1}{Z_R}+\frac{1}{Z_C}+\frac{1}{Z_L}$$ where $Z_R=R$, $Z_C=-j\frac{1}{\omega C}$ and $Z_L=j\omega L$. $$\frac{1}{Z_T}=\frac{1}{R}+j\omega C+\frac{1}{j\omega L}$$...

What is the connection of relative permittivity and bandwidth of an antenna? Higher relative permittivity resulted in high wider bandwidth?

I had an experiment I was working on where I needed to know the temperature of a circuit element down to 10uS time resolution. I had a thermistor handy, so I thought I would attach it to the element, force a constant current into it, and look at the voltage change on a scope. This would...

Hi everyone! In amatuer radio, when we transmit on a specific frequency, we 'use' that frequency and depending on the power you "use' a slice of bandwidth around that frequency. So if two people transmit on the same frequency there's either a pleasant conversation, interference, or they'll just...

When we use pulse code modulation , it is said that the min bandwidth requirement is half the transmission rate. Transmission rate given in Bits/sec. But why?

Hi everyone :] This is my first time here. I have this Quantum Optics question (though I don't believe there is anything QM about this question, so please let me know if I've incorrectly placed this thread) as part of a (nonmarked) assignment. Here's the question: "What is the maximal...

Homework Statement Find Fourier coefficients of the periodic function whose template is x(t) where the Fourier Transform of x(t) is X(f) = (1-f^2)^2 where \left|f\right|<1 and period T_0= 4. Homework Equations FC=\hat x_T(k,T_0)=\sum_{k=-\infty}^\infty\frac{1}{T_0}X\left(k/T_0\right) The...

I have a baseband signal in IQ form. I have a method to calculate the carrier offset and estimate the carrier bin. I want to center the carrier to the middle of the bandwidth. How do I do so? Do I simply multiply the IQ data by the exponential with the carrier offset, but doesn't that shift the...

Net Neutrality is being overturned as ISP telecoms claim they need to throttle bandwidth and speed as too many customers want to stream HD videos and play HD online games. EM waves are fast and unlimited, so is Tiered Premium Billing absurd? ISP telecom expenses include transmitters...

If we have 300kHz bandwidth and every channel uses 100kHz BW, then theoretically we can have total of 3 channels that won't overlap. Why do we need to assign some of the bandwidth for "safe gap" between channels if they "don’t" overlap?

I have an op-amp with frequency range 20Hz - 20kHz. Is frequency range the same as bandwidth?

Homework Statement The Attempt at a Solution What should the bandwidth be over here? Confused since there is no mention of carrier frequency.

Hello, I am reading a book about simulation, modeling and automatic control. In a chapter about hydraulic transmission line, a pipe's "bandwidth" is mentioned. Contex: "Long pipes are used in large hydraulic installations where pipes of length up to 10 m are not uncommon. Moreover, in offshore...

Homework Statement Consider the frequency-modulated (FM) signa A(t)=A0sin[2πfct+Δfsin(2πfmt)/fm] , where fc = 3.5 kHz, fm = 88.1 MHz. What is the bandwidth of the signal? [Note: You may take sin≅ and cos≅1 for x (in radian) << 1.] Homework Equations A(t)=A0sin[2πfct+Δfsin(2πfmt)/fm] The...

The commercial AM radio channels are separated by 10 kHz. What is the maximum bandwidth of the base-band signal each of these channels can carry?

What is meant by the infinite bandwidth of an ideal amplifier? If some extreme frequency signals were to be input in an amplifier of limited bandwidth and in the ideal amplifier, what will be the difference in their outputs?

In the following text the authors state: "The full width at half maximum (FWHM) we measure is about 2 km/s" and this is in the local standard of rest (LSR), ##v_{LSR}##. I have seen basic doppler shift equations to convert from these velocities to frequency (shown below in link). Although if I...

Hello, I was watching this video 07:37 there is instrument called digital bandwidth finder written on it. what it do? There is standard dish and High definition dish. will coaxial wire used with LNB and feed horn are same for both broadcasting?

My questions is about the conversion of a range of wavelengths in Hz, such as for an optical filter, in a medium different from air. Since the refractive index n is higher than 1, (let's say n=1.5) and than the value of c is almost 2x108 m/s, also the equation in the link below has to be...

Does SNR give a clue to bandwidth limitations? i. e. Would it help to figure out how the signal is distorted due to the limitation of the bandwidth? I think answer is "no" though.

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >[/color] Hi! I am having a bit trouble understanding how to determine the wavelength bandwidth for a monochromator. If anyone could suggest what to look for it'd be really nice. The problem is...

I'm having hard time understand what bandwidth really is? The book I'm using defines it as the width of a signal's spectrum (where spectrum is the range of frequencies in a signal). So, for example, I have a composite, periodic signal s(t) = 4/π[sin(2πft) + (1/3)sin(2π(3f)t)]. Then the...

Homework Statement How and why does quality factor change in a series RLC circuit when the resistance in the circuit increases? I've made a small experiment circuit which looks like one in the picture: The current frequency is 1 kHz and the voltmeter should show 2V throughout the whole...

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 Consider a propagating wavepacket with initial length ## L_{0}##. Use the bandwidth theorem to show that the minimum range of angular frequencies present in the wavepacket is approximately: $$ \Delta{\omega}\approx \frac{v_{g}}{L_{0}} $$ Homework Equations Bandwidth theorem...

Homework Statement Consider a propagating wave packet with initial length L0. Use the bandwidth theorem to show that the minimum range of angular frequencies present in the wave packet is approximately: \begin{equation} \Delta \omega = \frac{v_{g}}{L_{0}} \end{equation} where vg is the group...

Does current flow through the feedback resistor without going through the op-amp at all? After all, the op-amp is supposed to have very high input impedance right, so if the current just flows through the feedback resistor, wouldn't there be nothing going through the op-amp? Also, how does the...

Hi, I am new to world of electronics and to high frequency Domain. But I am working on a design where I have a coax of 30cm length. I have used an external oscillator to generate 7GHz fast falling pulse. I am using a Controller to control the oscillator. Now I have a pulse of about 350ns...

Could some please explain to me how the equation BW=fr/Q is derived? Where BW=bandwidth, fr=resonance freq and Q is Quality factor. I understand this relationship suppose to hold, I just don't understand why. I basically am looking for a proof. thank you all a priori. drforbin

Hi pf, please could someone help explain some concepts relating to bandwidth and radio transmission. As I understand it, radio transmission involves modulating a carrier wave with the signal you wish to send. The bandwidth is the range of frequencies that are contained within the signal. I have...

Hi All I hope that someone can help me. I have this thermal actuator with a resistance of ~1 Ohm that I want to operate at high frequencies, up to 100 kHz. In order to get the right amount of actuation I need to pass 1-2 A through the actuator. Can anyone tell me what kind of circuit would be...

I know they are directly proportional but how? could anyone explain it graphically ? thanks in advance

Some researchers claim that wireless soliton technics offer bandwidth up to 1 THz and they even made some type of such device. I wish to know if that thing is capable to work as an omni-directional antenna or it works rather like point-to-point laser communication? Could there be a such thing as...

Good Morning I loved the idea of four wave mixing in an optical fiber and how by satisfying phase matching condition you get a broad bandwidth but I want to know why am I interested in a large bandwidth why do I want to think about even enlarge it more? Thank you

Hi PF, please could someone help explain how the bandwidth of a telephone line works. I have read that fibre optics uses light which has a high frequency and therefore can offer a high bandwidth versus a standard telephone line. But what I don't understand is the bandwidth of a standard...

I am using the book Electronic Communication Systems by Wayne Tomasi: I had a problem with a certain part of the book: The book gives the formula for the minimum nyquist bandwidth as: " The minimum theoretical bandwidth necessary to propagate a signal is called the minimum Nyquist bandwidth...

Can anyone tell me if Control bandwidth and closed loop bandwidth means the same thing? If not what does control bandwidth mean? Please & Thank you!

Thank you in advance for your help!What is the bandwidth efficiency (R/B) of PSK for a bit error rate of 10^-7 on a channel with an S/N of 12 dB?[/b] From the graph, for BER= 10^-7, Eb/N0 = 11.2 dB./b]I have applied the formulae Eb/N0 = S/N * B/R Where, S/N is Signal power over noise power *...

Homework Statement Consider the PM (phase modulated) signal, s(t) = Acos(wt+x(t)) where x(t) is the information bearing signal. Assume that |x(t)|< y, which is not necessarily small. Using Taylor's series expansion, derive an estimate for the bandwidth of the PM signal s(t). Homework...